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001package org.hl7.fhir.r5.renderers.utils;
002
003import org.hl7.fhir.r5.model.Bundle;
004import org.hl7.fhir.r5.model.Bundle.BundleEntryComponent;
005import org.hl7.fhir.r5.model.DomainResource;
006import org.hl7.fhir.r5.model.Parameters;
007import org.hl7.fhir.r5.model.Parameters.ParametersParameterComponent;
008import org.hl7.fhir.r5.model.Resource;
009import org.hl7.fhir.r5.renderers.utils.BaseWrappers.ResourceWrapper;
010import org.w3c.dom.Element;
011
012public class Resolver {
013
014 public interface IReferenceResolver {
015 ResourceWithReference resolve(RenderingContext context, String url);
016
017 // returns null if contained resource is inlined
018 String urlForContained(RenderingContext context, String containingType, String containingId, String containedType, String containedId);
019 }
020
021 public static class ResourceContext {
022 private ResourceContext container;
023
024 Resource resource;
025 org.hl7.fhir.r5.elementmodel.Element element;
026
027 public ResourceContext(ResourceContext container, Resource dr) {
028 super();
029 this.container = container;
030 this.resource = dr;
031 }
032
033 public ResourceContext(ResourceContext container, org.hl7.fhir.r5.elementmodel.Element dr) {
034 super();
035 this.container = container;
036 this.element = dr;
037 }
038
039
040// public ResourceContext(Object bundle, Element doc) {
041// // TODO Auto-generated constructor stub
042// }
043
044// public Bundle getBundleResource() {
045// return containerResource;
046// }
047
048
049 public ResourceContext(ResourceContext container, ResourceWrapper rw) {
050 super();
051 this.container = container;
052 // todo: howto do this better?
053
054 if (rw instanceof DirectWrappers.ResourceWrapperDirect) {
055 this.resource = ((DirectWrappers.ResourceWrapperDirect) rw).getResource();
056 } else if (rw instanceof ElementWrappers.ResourceWrapperMetaElement) {
057 this.element = ((ElementWrappers.ResourceWrapperMetaElement) rw).getElement();
058 } else {
059 // this is not supported for now... throw new Error("Not supported yet");
060 }
061 }
062
063 public ResourceContext getContainer() {
064 return container;
065 }
066
067 public void setContainer(ResourceContext container) {
068 this.container = container;
069 }
070
071 // public org.hl7.fhir.r5.elementmodel.Element getBundleElement() {
072// return containerElement;
073// }
074//
075 public Resource getResource() {
076 return resource;
077 }
078
079 public org.hl7.fhir.r5.elementmodel.Element getElement() {
080 return element;
081 }
082
083 public BundleEntryComponent resolve(String value) {
084 if (value.startsWith("#")) {
085 if (resource instanceof DomainResource) {
086 DomainResource dr = (DomainResource) resource;
087 for (Resource r : dr.getContained()) {
088 if (r.getId().equals(value.substring(1))) {
089 BundleEntryComponent be = new BundleEntryComponent();
090 be.setResource(r);
091 return be;
092 }
093 }
094 }
095 return null;
096 }
097
098 if (resource instanceof Bundle) {
099 Bundle b = (Bundle) resource;
100 for (BundleEntryComponent be : b.getEntry()) {
101 if (be.hasFullUrl() && be.getFullUrl().equals(value))
102 return be;
103 if (value.equals(be.getResource().fhirType()+"/"+be.getResource().getId()))
104 return be;
105 }
106 }
107
108 if (resource instanceof Parameters) {
109 Parameters pp = (Parameters) resource;
110 for (ParametersParameterComponent p : pp.getParameter()) {
111 if (p.getResource() != null && value.equals(p.getResource().fhirType()+"/"+p.getResource().getId())) {
112 BundleEntryComponent be = new BundleEntryComponent();
113 be.setResource(p.getResource());
114 return be;
115
116 }
117 }
118 }
119
120 return container != null ? container.resolve(value) : null;
121 }
122
123 public org.hl7.fhir.r5.elementmodel.Element resolveElement(String value, String version) {
124 if (value.startsWith("#")) {
125 if (element != null) {
126 for (org.hl7.fhir.r5.elementmodel.Element r : element.getChildrenByName("contained")) {
127 if (r.getChildValue("id").equals(value.substring(1)))
128 return r;
129 }
130 }
131 return null;
132 }
133 if (element != null) {
134 if (element.fhirType().equals("Bundle")) {
135 for (org.hl7.fhir.r5.elementmodel.Element be : element.getChildren("entry")) {
136 org.hl7.fhir.r5.elementmodel.Element res = be.getNamedChild("resource");
137 if (res != null) {
138 if (value.equals(be.getChildValue("fullUrl"))) {
139 if (checkVersion(version, res)) {
140 return be;
141 }
142 }
143 if (value.equals(res.fhirType()+"/"+res.getChildValue("id"))) {
144 if (checkVersion(version, res)) {
145 return be;
146 }
147 }
148 }
149 }
150 }
151 if (element.fhirType().equals("Parameters")) {
152 for (org.hl7.fhir.r5.elementmodel.Element p : element.getChildren("parameter")) {
153 org.hl7.fhir.r5.elementmodel.Element res = p.getNamedChild("resource");
154 if (res != null && value.equals(res.fhirType()+"/"+res.getChildValue("id"))) {
155 if (checkVersion(version, res)) {
156 return p;
157 }
158 }
159 }
160 }
161 }
162 return container != null ? container.resolveElement(value, version) : null;
163 }
164
165 private boolean checkVersion(String version, org.hl7.fhir.r5.elementmodel.Element res) {
166 if (version == null) {
167 return true;
168 } else if (!res.hasChild("meta")) {
169 return false;
170 } else {
171 org.hl7.fhir.r5.elementmodel.Element meta = res.getNamedChild("meta");
172 return version.equals(meta.getChildValue("version"));
173 }
174 }
175 }
176
177 public static class ResourceWithReference {
178
179 private String reference;
180 private ResourceWrapper resource;
181
182 public ResourceWithReference(String reference, ResourceWrapper resource) {
183 this.reference = reference;
184 this.resource = resource;
185 }
186
187 public String getReference() {
188 return reference;
189 }
190
191 public ResourceWrapper getResource() {
192 return resource;
193 }
194 }
195
196
197
198}
|
__label__pos
| 0.999821 |
HTTrack Website Copier
Free software offline browser - FORUM
Subject: Why the priority mode "just scan" so slow ?
Author: BattosaiHttrackFan
Date: 11/10/2009 15:40
Hi all,
I would like to get the list of links from a given domain in a website.
I am scanning the webiste to get the list of links.
I noticed the expert command "just scan " (-p0) is very slow.
It does not download anything but still its as slow as if i was downloading
the website why is that ?
For example I tried to scan this website :
httrack -p0 -r2 <http://www.bbc.co.uk/>
It takes few minutes to end.
Can you tell me why ?
Thanks,
Reply
All articles
Subject Author Date
Why the priority mode "just scan" so slow ?
11/10/2009 15:40
Re: Why the priority mode "just scan" so slow ?
11/10/2009 16:29
Re: Why the priority mode "just scan" so slow ?
11/10/2009 18:39
Re: Why the priority mode "just scan" so slow ?
11/11/2009 00:19
7
Created with FORUM 2.0.11
|
__label__pos
| 0.992929 |
Blockchain: Past, Present and Future
Developments in technology have long disrupted our everyday lives. Looking back to where the world is at now, it’s hard to believe how we ever managed without the technology we have access to right in the palm of our hands. The introduction of Blockchain is no exception. Though its accumulated some criticism, it’s also had a lot of backing from many companies and investors. Here’s a look into the past, present and future of blockchain and consequently, bitcoin:
Humble Beginnings
The creator of blockchain, Satoshi Nakamoto, was perhaps unaware of how much it would take off in the years to come. Satoshi (a pseudonym) wrote a paper titled ‘Bitcoin: A Peer-to-Peer Electronic Cash System’. This is where the ground-breaking discovery was first conceived. The potential impact of this incredible revelation is still unfolding. Form what we currently understand blockchain has the capabilities of disrupting industries, managing the supply chain and positively changing cybersecurity. Shortly after Satoshi Nakamoto published the paper, Bitcoin was introduced. Bitcoin is a cryptocurrency which operates independently of a central bank system. That’s just the beginning.
Blockchain allows you to transact freely, without the use of a middleman. It offers the opportunity to transfer value across the internet, with no need for third party interference. This will have a tremendous impact on banking and payments. The most important aspect of blockchain is that it’s a real-time transaction with reduced costs. Because of the nature of blockchain, these kind of transactions also carry with them less risk.
Where Does Blockchain Stand Now?
As it stands, bitcoin is a very instable currency, with its value peaking and falling by the day. However, new discoveries are being made about the way in blockchain can be utilised to reach its potential. Developers have understood that blockchain can do so much more than just transfer currency or documents.
Blockchain is used by bitcoin to monitor transactions and activity. The traceability of each transaction is what makes blockchain so important. It can record each communication chronologically and publicly. Even with these monumental developments, blockchain is still a long way from becoming the norm. The business model needs to be refined, outlining how this technology is going to help people save money and whether or not it can be proven.
Bitcoin is being used right now. Bizarrely, a bar in Japan invested in a bitcoin machine. This changes their currency into bitcoin. This can then be used right away at the bar. Though this niche Japanese restaurant is clearly an early adopter of bitcoin, it sets a precedent for what is possibly to come.
The financial services industry was disrupted by bitcoin even in its infancy. However, it’s not only the banking and financial sector blockchain has shaken up; industries such as healthcare, music and energy all stand to benefit from it. For example, in the music industry there is still a growing problem with royalties. Often, many artists don’t claim their royalties or there are disputes over who owns which part of the song. Blockchain could potentially eliminate this problem with complete traceability down to the person. You would effectively have a global database of who wrote the song, the producers and the songwriters and who stand to get the royalties from it. It could change the music industry as we know it.
The Future of Blockchain
Blockchain has received a lot of good press, with many choosing to make significant investments in the platform. The blockchain revolution is set to gradually infiltrate the relevant industries. One of the major concerns when it comes to blockchain is its scalability. With more tokens, users, investors and exchanges taking place there is more room for error. With every single blockchain purchase, a block is added to blockchains ladder of transactions. Each block will increase the data as it carries the history of previous blocks with it. Therefore, as more networks and institutions opt into blockchain, there is the danger that it will not be able to withstand the information. Of course, no one knows whether it can because it’s not happened yet.
“Blockchain needs to adapt and evolve, including its response time” is the common thought in the mobile app development industry. Every peer-to-peer transaction requires verification, so naturally this can slow the system down – considering Bitcoin is verifying at a rate of one block every ten minutes. As the users increase, the more transactions that will be taking place. For now, bitcoin can handle around 60 transactions per second. For future development, it needs to focus on how it can turn that into 47,000 per second (what Visa can currently overturn).
Overall, the future of blockchain is exciting. It’s a safe, reliable, cost-effective and transparent way of connecting online. The rise is set to be gradual, with certain discrepancies needing to be ironed out before it can start to make a real impact.
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|
__label__pos
| 0.520177 |
The tag has no wiki summary.
learn more… | top users | synonyms
10
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0answers
197 views
Bar construction vs. twisted tensor product
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votes
2answers
172 views
Koszul (Exterior/Symmetric) duality for a 1-dim vector space
The simplest example of Koszul duality (see introduction of http://www.ams.org/journals/jams/1996-9-02/S0894-0347-96-00192-0/) Let $V = \mathbb{C}x$ be a $1$ dimensional vector space. Then the ...
3
votes
1answer
356 views
“as close to being semisimple as it can possibly be.”
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5
votes
1answer
241 views
Computing Ext in Exterior algebra (related to Koszul duality)
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1answer
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0answers
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Koszul duality, and coherent sheaves on $pt/G \times_{\mathfrak{g}/G} pt/G$
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Koszulness of the cohomology ring of moduli of stable genus zero curves
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How is this observation related to Koszul duality?
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Koszul duality between Weyl and Clifford algebras?
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What extra conditions are necessary for the following version of Koszul duality?
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|
__label__pos
| 0.969714 |
Parallelise saída de função de entrada em Snakemake
votos
0
comunidade Olá Snakemake,
Estou tendo bastante alguns problemas para definir corretamente uma função em Snakemake e chamá-lo no params seção. A saída da função é uma lista e meu objetivo é usar cada item da lista como um parâmetro de um comando shell. Em outras palavras, eu gostaria de executar várias tarefas em paralelo do mesmo comando shell com um parâmetro diferente.
Esta é a função:
import os, glob
def get_scontigs_names(wildcards):
scontigs = glob.glob(os.path.join(reference, Supercontig*))
files = [os.path.basename(s) for s in scontigs]
return name
A saída é uma lista que parece:
['Supercontig0', 'Supercontig100', 'Supercontig2', ...]
As regras Snakemake são:
rule all:
input:
updated/all_supercontigs.sorted.vcf.gz
rule update_vcf:
input:
len=genome/genome_contigs_len_cumsum.txt,
vcf=filtered/all.vcf.gz
output:
cat=updated/all_supercontigs.updated.list
params:
scaf=get_scontigs_names
shell:
python 3.7 scripts/update_genomic_reg.py -len {input.len} -vcf {input.vcf} -scaf {params.scaf}
ls updated/*.updated.vcf.gz > {output.cat}
Este código é incorreta porque todos os itens da lista são carregados para o comando shell quando eu chamo {params.scaf}. Os comandos shell atual se parece com:
python 3.7 scripts/update_genomic_reg.py -len genome/genome_contigs_len_cumsum.txt -vcf filtered/all.vcf.gz -scaf Supercontig0 Supercontig100 Supercontig2 ...
O que eu gostaria de ter é: *
python 3.7 scripts/update_genomic_reg.py -len genome/genome_contigs_len_cumsum.txt -vcf filtered/all.vcf.gz -scaf Supercontig0
python 3.7 scripts/update_genomic_reg.py -len genome/genome_contigs_len_cumsum.txt -vcf filtered/all.vcf.gz -scaf Supercontig100
e assim por diante.
Eu tentei usar wildcardsdentro da função, mas eu estou deixando de dar-lhe o atributo correto.
Existem vários posts sobre funções de entrada e curingas mais os docs snakemake mas eu não poderia realmente aplicá-los para o meu caso. Alguém pode me ajudar com isso, por favor?
Publicado 19/12/2018 em 14:21
fonte usuário
Em outras línguas...
2 respostas
votos
0
Eu encontrei a solução para a minha pergunta inspirado por @dariober.
rule all:
input:
"updated/all_supercontigs.updated.list"
import os, glob
def get_scontigs_names(wildcards):
scontigs = glob.glob(os.path.join("reference", "Supercontig*"))
files = [os.path.basename(s) for s in scontigs]
name = [i.split('_')[0] for i in files]
return name
rule update_vcf:
input:
len="genome/genome_contigs_len_cumsum.txt",
vcf="filtered/all.vcf.gz"
output:
vcf="updated/all_{supercontig}.updated.vcf.gz"
params:
py3=config["modules"]["py3"],
scaf=get_scontigs_names
shell:
"""
{params.py3} scripts/update_genomic_reg.py -len {input.len} -vcf
{input.vcf} -scaf {wildcards.supercontig}
"""
rule list_updated:
input:
expand("updated/all_{supercontig}.updated.vcf.gz", supercontig =
supercontigs)
output:
"updated/all_supercontigs.updated.list"
shell:
"""
ls {input} > {output}
"""
Respondeu 21/12/2018 em 14:27
fonte usuário
votos
0
E sobre isso abaixo? Note-se que o seu get_scontigs_namesnão faz uso de curingas.
import os, glob
def get_scontigs_names():
scontigs = glob.glob(os.path.join("reference", "Supercontig*"))
files = [os.path.basename(s) for s in scontigs]
name = [i.split('_')[0] for i in files]
return name
supercontigs= get_scontigs_names()
rule all:
input:
"updated/all_supercontigs.sorted.vcf.gz"
rule update_vcf:
input:
len="genome/genome_contigs_len_cumsum.txt",
vcf="filtered/all.vcf.gz",
output:
upd= "updated/{supercontig}.updated.vcf.gz",
shell:
r"""
python 3.7 scripts/update_genomic_reg.py -len {input.len} \
-vcf {input.vcf} -scaf {wildcards.supercontig}
"""
rule list_updated:
input:
expand("updated/{supercontig}.updated.vcf.gz", supercontig= supercontigs),
output:
"updated/all_supercontigs.sorted.vcf.gz",
shell:
r"""
ls {input} > {output}
"""
Respondeu 21/12/2018 em 10:20
fonte usuário
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__label__pos
| 0.927787 |
Unlimited Plugins, WordPress themes, videos & courses! Unlimited asset downloads! From $16.50/m
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1. Code
2. Android SDK
Code
Android SDK: App Resources
by
Difficulty:BeginnerLength:MediumLanguages:
This post is part of a series called Learn Android SDK From Scratch.
Android SDK: Java Application Programming
Android SDK: Project Manifest
We are learning how to develop Android apps in this series. So far, we've looked at the structure of an Android app and explored user interfaces. In this tutorial, we will learn to work with the project resources.
Introduction
In this part of the series, we will examine the resource types you will most likely use in your first projects. Project resources include the layouts, images, and data values used within the app. When you create a new project, a few folders for common resource types are included in your project directory automatically. You can add folders for additional types should you need them.
You can find the resources for the project we created earlier in the series by browsing to the "res" folder in the Package Explorer. Expand the folder to see its contents. You can add new folders to the resources directory and can add new files to each one, as well as work with the existing files (as we did with the layout and strings values files earlier in this series).
1. Alternative Resources
Before we start with the specifics, it's worth noting that you can place your Android resources into two categories: resources that can be used across devices and resources that are tailored to a subset of devices. You can see an example of this in the existing project structure. In the Eclipse Package Explorer, look at the "res" directory. Remember that the different drawable folders are tailored to specific device screen densities. We will add one in this tutorial for drawable files that are not targeted (ones that can be used across devices).
You can add alternative directories for each resource type using qualifiers to target categories, as Eclipse has done with "drawable-hdpi", "drawable-xhdpi", and so on. The Android platform supports such qualifiers for various aspects of the user device, including screen size, density, API level, language, region, and more. Any resource type folder that does not include a qualifier in the name is for resources that can be used across devices. You will not always need qualified folders for all of your resource types, but when you test your apps on different devices you may find that some aspects need tweaking to remain usable across configurations.
2. Drawables
Step 1
As we know, Eclipse creates multiple drawable folders, each targeted at a particular density bucket. The drawable folders contain any images you use in your app. You can include images prepared outside of Eclipse in digital formats, such as JPEG, PNG, and GIF. You can also define drawables in XML code. Let's do this and add one to the main layout.
Although you should generally try to tailor your drawables to each target density, for the purposes of this tutorial we will use a single drawable for all devices. With the "res" folder selected in the Eclipse Package Explorer, create a new folder by choosing "File" or right-clicking the folder, then select "New" and "Folder". Give the folder the name "drawable" and click "Finish" to create it.
New Folder
This is the process to follow any time you need to create a new folder in your project.
Step 2
Your new drawable folder should now appear in the Packager Explorer alongside the existing drawable folders. As we explored above, if a folder is not targeted to a particular subset of devices, e.g. defined using density categories or API levels (such as the values folders), you can place resources within in it that can be used on any user device. So whatever we place in the new drawable folder is displayed on all user devices. For most drawables you should prepare specific versions for different densities, but for simplicity we will use the new folder in this tutorial.
Create a new file in your new drawable folder by selecting it in the Package Explorer, right-clicking or choosing "File", then choosing "New" and "Android XML File". You will see a wizard to create the new file. Android supports a few different types of drawable files. We are going to create a shape drawable in which we define an image using markup to represent the different aspects of its shape and appearance. See the Developer Guide for an overview of the other drawable types.
New Shape File
In the top drop-down list you can choose the type of resource, which is automatically selected for drawable since we are creating the file in that folder. Next is the project drop-down list, which should also be automatically populated with the project you selected. Next is a text-field for the file-name - enter "nice_shape.xml". Below that is a list of root elements you can choose. Scroll down and choose "shape" since we are going to define a shape drawable. Click "Finish". Eclipse will create the new file and open it for editing.
Step 3
With a shape drawable, you can choose from a range of generic shape types, including rectangle, oval, line, and ring. Once you choose a shape type, you can then define properties of the shape including solid or gradient colors, corners, padding, dimensions, and strokes. Edit your root shape element to choose a rectangle:
You can then define the shape properties by adding other elements inside the root shape element. Start by defining a gradient:
We define the gradient type, angle, and start, end, and center colors. After the gradient element, let's add some rounded corners:
Next add a stroke:
When you type in the editor, you will see the available element and attribute types in the Eclipse prompts, so take some time to experiment with them after you complete this tutorial. We will use the shape in our UI in the next step. Save your drawable file for the moment.
Tip: To use digital image files you prepare outside Eclipse in your apps, simply copy them to the relevant drawable folders in your workspace directory. After copying files into the resource folders, you may have to refresh the Eclipse views. Do this in the Package Explorer by selecting the project, right-clicking or choosing "File", then selecting "Refresh". You will then be able to refer to the files in your application code.
3. Layouts
Step 1
We started looking at layouts earlier in the series, when we designed the app user interface. Let's see how the layout file and drawables interact. We can display a drawable in the layout as the background of a View or within a dedicated View. Start by listing the shape drawable we created as background for an existing View. Open your app's main layout file. Let's set the shape drawable as background for the button we added. Add the following attribute to your Button element:
We use the resource type and name (the file-name we gave the drawable) to refer to it in the layout. Notice that this is the same syntax pattern we used when referring to string values. Save and switch to the Graphical Layout tab to see the shape as button background. You may notice that the button needs a little padding, so switch back to XML editing and add a padding attribute to the Button element:
Switch back to the Graphical Layout to see the effect.
Background Layout
Step 2
Now let's use the shape drawable in a dedicated View. Add the following after the Button element in your layout:
We set the ImageView to fill the available space minus a margin. You can optionally set it to use a fixed width and height. Notice that Eclipse displays a warning because you have not added a content description attribute, this helps accessibility so let's add one. Open your "res/values" strings XML file and add the following:
Now you can add the string to the ImageView in your layout file:
As you can see, working with resources involves switching back and forth between various files in the project and using standard syntax patterns to make references between the resource items. Toggle again to view the graphical preview.
Image View
You can use the controls to zoom in and out.
4. Other Resource Types
So far we used three resource types in the app: layout, drawable, and values. There's more you can use in your apps, using the same process we used above to reference them. As we saw earlier in the series, you can also reference resources in your Java files using the following syntax:
Let's briefly summarize some of the other resource types you may find useful in future apps. We used drawable and layout resources above and in previous tutorials, and used string values in the layout file. Expand the "values" folder in the Package Explorer. Alongside the strings file, Eclipse typically adds one for dimensions and one for styles. In the styles file you can define coherent appearance properties for your app UIs. In the "dimens" file you can define dimension values you wish to use in your apps.
As we mentioned above, you can create alternative resource type folders using qualifiers for particular device properties. As you can see Eclipse creates values folders targeted at particular API levels, but you can target devices using many other qualifiers. For example, you may want to use fixed width and height for the ImageView we added, tailoring the displayed size to device screen size. To achieve this, you could add values folders for each size or density bucket ("-small", "-large", "-hdpi", "-mdpi", etc), with a dimensions file in each. By including a dimensions value in each of these files, giving the value the same name but a different number, Android automatically picks the correct one for the user device.
Other resource types you may find useful include those for numbers, menus, animation, and color values. Eclipse normally creates a menu folder when you create an app, so have a look in it now. To define XML animations, you can add an "anim" or "animator" folder to "res", or add your animation files to the drawable folders depending on the type you use.
If you want to use a set of colors across your app UI, you can define them in a file saved in the values directory, using the color element. Each color element can contain a HEX value and a name attribute, so that you can refer to the color in your other files. XML resources that do not fall under one of the defined categories on Android can be saved in an "xml" directory in "res".
For an overview of all of the resource types on Android, see the Developer Guide sections on Resource Types and More Resource Types. Although your needs will be fairly straightforward at first, it's worth looking through the list now so that you have an idea of what's possible later on.
Tip: When you look at Android examples or the Developer Guide, you will often see the same standard filenames being used for resources. However, the filenames are typically arbitrary - as long as you use the correct folder names and elements, your application code will access all of your resources using the identification system. That aside, sticking to conventional filenames can make your apps easier to work with, particularly in the values folders.
Conclusion
In this tutorial, we looked at the basics of app resources on Android. But as you have seen, there is much more to explore. For your first few apps you can keep things relatively simple as you get accustomed to the practice of using resources. But as your apps develop, you should try to think about the variety of user devices your apps may run on, providing additional resources as necessary. In the next part of the series, we will look at the project Manifest file.
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Date
From
SubjectRe: [RFC 1/9] tty: replace BKL with a new tty_lock
On Tue, Mar 30, 2010 at 10:56:12PM +0200, Arnd Bergmann wrote:
> +/* functions for preparation of BKL removal */
> +
> +/*
> + * tty_lock_nested get the tty_lock while potentially holding it
> + *
> + * The Big TTY Mutex is a recursive lock, meaning you can take it
> + * from a thread that is already holding it.
> + * This is bad for a number of reasons, so tty_lock_nested should
> + * really be used as rarely as possible. If a code location can
> + * be shown to never get called with this held already, it should
> + * use tty_lock() instead.
> + */
> +static inline void __lockfunc tty_lock_nested(void) __acquires(kernel_lock)
> +{
> + lock_kernel();
> +}
> +static inline void tty_lock(void) __acquires(kernel_lock)
> +{
> + WARN_ON(kernel_locked());
> + lock_kernel();
> +}
> +static inline void tty_unlock(void) __releases(kernel_lock)
> +{
> + unlock_kernel();
> +}
> +#define tty_locked() (kernel_locked())
> +static inline int __reacquire_tty_lock(void)
> +{
> + return 0;
> +}
> +static inline void __release_tty_lock(void)
> +{
> +}
> +
> +#define release_tty_lock(tsk) do { } while (0)
> +#define reacquire_tty_lock(tsk) do { } while (0)
> +
> +/*
> + * mutex_lock_tty - lock a mutex without holding the BTM
> + *
> + * These three functions replace calls to mutex_lock
> + * in the tty layer, when locking on of the following
> + * mutexes:
> + * tty->ldisc_mutex
> + * tty->termios_mutex
> + * tty->atomic_write_lock
> + * port->mutex
> + * pn->all_ppp_mutex
> + *
> + * The reason we need these is to avoid an AB-BA deadlock
> + * with tty_lock(). When it can be shown that one of the
> + * above mutexes is either never acquired with the tty_lock()
> + * held, or is never held when tty_lock() is acquired, that
> + * mutex should be converted back to the regular mutex_lock
> + * function.
> + *
> + * In order to annotate the lock order, the mutex_lock_tty_on
> + * and mutex_lock_tty_off versions should be used whereever
> + * possible, to show if the mutex is used with or without
> + * tty_lock already held.
> + */
> +#define mutex_lock_tty(mutex) \
> +({ \
> + if (!mutex_trylock(mutex)) { \
> + if (tty_locked()) { \
> + __release_tty_lock(); \
> + mutex_lock(mutex); \
> + __reacquire_tty_lock(); \
> + } else \
> + mutex_lock(mutex); \
> + } \
> +})
> +
> +#define mutex_lock_tty_on(mutex) \
> +({ \
> + if (!mutex_trylock(mutex)) { \
> + if (!WARN_ON(!tty_locked())) { \
> + __release_tty_lock(); \
> + mutex_lock(mutex); \
> + __reacquire_tty_lock(); \
> + } else \
> + mutex_lock(mutex); \
> + } \
> +})
> +
> +#define mutex_lock_tty_off(mutex) \
> +({ \
> + if (!mutex_trylock(mutex)) { \
> + if (WARN_ON(tty_locked())) { \
> + __release_tty_lock(); \
> + mutex_lock(mutex); \
> + __reacquire_tty_lock(); \
> + } else \
> + mutex_lock(mutex); \
> + } \
> +})
> +
> +#define mutex_lock_interruptible_tty(mutex) \
> +({ \
> + int __ret = 0; \
> + if (!mutex_trylock(mutex)) { \
> + if (tty_locked()) { \
> + __release_tty_lock(); \
> + __ret = mutex_lock_interruptible(mutex); \
> + __reacquire_tty_lock(); \
> + } else \
> + __ret = mutex_lock_interruptible(mutex); \
> + } \
> + __ret; \
> +})
> +
> +/*
> + * wait_event*_tty -- wait for a condition with the tty lock held
> + *
> + * similar to the mutex_lock_tty family, these should be used when
> + * waiting for an event in a code location that may get called
> + * while tty_lock is held.
> + *
> + * The problem is that the condition we are waiting for might
> + * only become true if another thread runs that needs the tty_lock
> + * in order to get there.
> + *
> + * None of these should be needed and all callers should be removed
> + * when either the caller or the condition it waits for can be show
> + * to not rely on the tty_lock.
> + */
> +#define wait_event_tty(wq, condition) \
> +do { \
> + if (condition) \
> + break; \
> + release_tty_lock(current); \
> + __wait_event(wq, condition); \
> + reacquire_tty_lock(current); \
> +} while (0)
> +
> +#define wait_event_timeout_tty(wq, condition, timeout) \
> +({ \
> + long __ret = timeout; \
> + if (!(condition)) { \
> + release_tty_lock(current); \
> + __wait_event_timeout(wq, condition, __ret); \
> + reacquire_tty_lock(current); \
> + } \
> + __ret; \
> +})
> +
> +#define wait_event_interruptible_tty(wq, condition) \
> +({ \
> + int __ret = 0; \
> + if (!(condition)) { \
> + release_tty_lock(current); \
> + __wait_event_interruptible(wq, condition, __ret); \
> + reacquire_tty_lock(current); \
> + } \
> + __ret; \
> +})
> +
> +#define wait_event_interruptible_timeout_tty(wq, condition, timeout) \
> +({ \
> + long __ret = timeout; \
> + if (!(condition)) { \
> + release_tty_lock(current); \
> + __wait_event_interruptible_timeout(wq, condition, __ret); \
> + reacquire_tty_lock(current); \
> + } \
> + __ret; \
> +})
Ouch, these helpers make me living again all the insane things I had to
do in reiserfs :-)
I first had doubts about this Big Tty Mutex (or whatever german meaning :-)
Because I thought this only carries the problem forward, or even
worst: now that it's not the bkl anymore, fewer people will even care about
removing this new big lock.
But now I actually think this is a good thing as every single tricky points
is underlined explicitly with these wait_event_tty, mutex_lock_tty, and so...
It's not anymore something released under us on schedule, it's not something
that might or might not be acquired recursively.
Removing this big lock later will then be easier as we can do it with more
granularity and visibility.
This is at least the experience I had with reiserfs. Its code _looks_
crappier than ever since 2.6.33, but it's a wrong appearance.
Now it shows which points require the reiserfs lock to be released because
there is an event dependency and it shows what are these dependencies.
The fact we can use lockdep in such a scheme plays a huge role btw.
Things are much clearer now, and I have even released some small areas
from the reiserfs lock because the explicit locking made it clear enough
to prove it fine.
If reiserfs wasn't obsolete, I would have probably pushed the effort further
to turn it into a granular locking, because the current state makes it
possible.
Now here we are talking about tty, and tty is not obsolete at all, so
I expect this is going to reach the current reiserfs level, plus a
subsequent and progressive state of locking granularity work, until
a complete exorcism.
FWIW, I'm all for this patchset.
\
\ /
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Taschenrechner (Anfänger) Kritik erwünscht
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• Taschenrechner (Anfänger) Kritik erwünscht
Hallo an alle.
Ich habe vor, einen Taschenrechner, mit allen möglichen Funktionen, wie zum Beispiel Volumen, Oberflächen oder Wurzeln zu erstellen.
Weil ich gerade Ferien habe(bin Schüler), habe ich genug Zeit, den Taschenrechner zu erstellen.
Hier schonmal ein Anfang.:
Quellcode
1. #include<iostream>
2. #include<string>
3. using namespace std;
4. int main()
5. {
6. int eingabe;
7. float x;
8. float y;
9. cout << "Taschenrechner ©Pokertom" << endl;
10. cout << endl;
11. cout << "Addition <1>" << endl;
12. cout << "Subtraktion <2>" << endl;
13. cout << "Multiplikation <3>" << endl;
14. cout << "Division <4>" << endl;
15. cout << "Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!" << endl;
16. cin >> eingabe;
17. switch(eingabe)
18. {
19. case 1:
20. cout << "Geben Sie bitte den 1. Faktor an." << endl;
21. cin >> x;
22. cout << "+" << endl;
23. cout << "Geben Sie bitte den 2. Faktor an." << endl;
24. cin >> y;
25. cout << "Die Summe von " << x << " und " << y << " sind " << x+y << "." << endl;
26. break;
27. case 2:
28. cout << "Geben Sie bitte den 1. Faktor an." << endl;
29. cin >> x;
30. cout << "-" << endl;
31. cout << "Geben Sie bitte den 2. Faktor an." << endl;
32. cin >> y;
33. cout << "Die Differenz von " << x << " mit " << y << " sind " << x-y << "." << endl;
34. break;
35. case 3:
36. cout << "Geben Sie bitte den 1. Faktor an." << endl;
37. cin >> x;
38. cout << "*" << endl;
39. cout << "Geben Sie bitte den 2. Faktor an." << endl;
40. cin >> y;
41. cout << "Das Ergebnis der Muliplikation von " << x << " mit " << y << " ist " << x*y << "." << endl;
42. break;
43. case 4:
44. cout << "Geben Sie bitte den 1. Faktor an." << endl;
45. cin >> x;
46. cout << "/" << endl;
47. cout << "Geben Sie bitte den 2. Faktor an." << endl;
48. cin >> y;
49. cout << "Das Ergebnis der Division von " << x << " mit " << y << " ist " << x/y << "." << endl;
50. break;
51. }
52. return 0;
53. }
Alles anzeigen
Würde mich über Anregungen, bzw. Verbesserungen freuen.
lg pokertom
Gute Nacht (gähn)
Du bist Terrorist, warum? Siehe hier
Dieser Beitrag wurde bereits 1 mal editiert, zuletzt von pokertom ()
• Hey
1. einen default in switch rein, falls einer Blödsinn eintippen sollte
2. würde ich eine schleife machen, damit man mehrere Operationen ausführen kann ohne die .exe jedes mal neu starten zu müssen (dann auch mit Beenden - Ziffer versehen)
3. Naja, Grammatisch sind paar Sachen nicht korrekt:
Addition: Summand + Summand = Summe
Subtraktion: Minuend - Subtrahend = Differenz
Multiplikation: Faktor * Faktor = Produkt
Division: Dividend / Divisor = Quotient
und Grammatik komplett würde ich noch überarbeiten. ^^
4. Rein als Vorschlag würde ich dir raten dein Einrück-System ebenfalls ein bisschen zu Überarbeiten ^^
5. und prüfe mal wie das Programm reagiert, wenn du einen Buchstaben eintippst :)
mfG
• @Koljan777 Danke für die vielen Verbesserungsvorschläge, Sie haben mir viel geholfen.
Habe ihn nochmal überarbeitet, und sogar noch eine Währung eingebaut.Von einem Freund habe ich gehört,
dass Double genauere Ergebnisse anzeigt, vieleicht könnte ich statt float besser double benutzen?
Noch eine Frage, wenn ich als Währung/Einheit eine Zahl nehme, kommen ganz andere Ergebnisse.
Wie kann man das beheben und warum passiert das?
Bei einer Währung/Einheit aus Buchstaben passiert das ganze nicht.
Bin für Verbesserungsvorschläge und Antworten offen.
Grüße Pokertom
Quellcode
1. #include<iostream>
2. #include<string>
3. using namespace std;
4. int main()
5. {
6. int eingabe;
7. float x; //double?
8. float y; //double?
9. string Waehrung;
10. string info;
11. bool z;
12. bool wh = 0;
13. while ( wh != 0 )
14. {
15. cout << "Taschenrechner ©Pokertom" << endl;
16. cout << endl;
17. cout << "Addition <1>" << endl;
18. cout << "Subtraktion <2>" << endl;
19. cout << "Multiplikation <3>" << endl;
20. cout << "Division <4>" << endl;
21. cout << "Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!" << endl;
22. cin >> eingabe;
23. cout << "Wollen Sie mit einer Waehrung/ Einheit rechnen?" << endl;
24. cout << "Geben Sie 1/0 ein.(1 mit, 0 ohne)" << endl;
25. cin >> z;
26. if ( z = 1 )
27. {
28. switch ( eingabe )
29. {
30. case 1:
31. cout << "Geben Sie bitte die Waehrung an." << endl;
32. cin >> Waehrung;
33. cout << "Geben Sie bitte den 1. Summand an." << endl;
34. cin >> x;
35. cout << "Geben Sie bitte den 2. Summand an." << endl;
36. cin >> y;
37. cout << "Die Summe der Rechnung ergibt: " << x << Waehrung << " + " << y << Waehrung << " = " << x + y
38. << Waehrung << "." << endl;
39. break;
40. case 2:
41. cout << "Geben Sie bitte die Waehrung an." << endl;
42. cin >> Waehrung;
43. cout << "Geben Sie bitte den Minuent an." << endl;
44. cin >> x;
45. cout << "Geben Sie bitte den Subtrahent an." << endl;
46. cin >> y;
47. cout << "Die Differenz der Rechnung ergibt: " << x << Waehrung << " - " << y << Waehrung << " = " << x - y
48. << Waehrung << "." << endl;
49. break;
50. case 3:
51. cout << "Geben Sie bitte die Waehrung an." << endl;
52. cin >> Waehrung;
53. cout << "Geben Sie bitte den 1. Faktor an." << endl;
54. cin >> x;
55. cout << "Geben Sie bitte den 2. Faktor an." << endl;
56. cin >> y;
57. cout << "Das Produkt der Rechnung ergibt: " << x << Waehrung << " * " << y << Waehrung << " = " << x * y
58. << Waehrung << "." << endl;
59. break;
60. case 4:
61. cout << "Geben Sie bitte die Waehrung an." << endl;
62. cin >> Waehrung;
63. cout << "Geben Sie bitte den Dividend an." << endl;
64. cin >> x;
65. cout << "Geben Sie bitte den Divisor an." << endl;
66. cin >> y;
67. cout << "Der Quotient der Rechnung ergibt: " << x << Waehrung << " / " << y << Waehrung << " = " << x / y
68. << Waehrung << "." << endl;
69. break;
70. default:
71. cout << "(Fehler: Ungueltige Eingabe!)";
72. break;
73. }
74. }
75. else if ( z = 0 )
76. {
77. switch ( eingabe )
78. {
79. case 1:
80. cout << "Geben Sie bitte den 1. Summand an." << endl;
81. cin >> x;
82. cout << "Geben Sie bitte den 2. Summand an." << endl;
83. cin >> y;
84. cout << "Die Summe der Rechnung ergibt: " << x << " + " << y << " = " << x + y << "." << endl;
85. break;
86. case 2:
87. cout << "Geben Sie bitte den Minuent an." << endl;
88. cin >> x;
89. cout << "Geben Sie bitte den Subtrahent an." << endl;
90. cin >> y;
91. cout << "Die Differenz der Rechnung ergibt: " << x << " - " << y << " = " << x - y << "." << endl;
92. break;
93. case 3:
94. cout << "Geben Sie bitte den 1. Faktor an." << endl;
95. cin >> x;
96. cout << "Geben Sie bitte den 2. Faktor an." << endl;
97. cin >> y;
98. cout << "Das Produkt der Rechnung ergibt: " << x << " * " << "." << endl;
99. break;
100. case 4:
101. cout << "Geben Sie bitte den Dividend an." << endl;
102. cin >> x;
103. cout << "Geben Sie bitte den Divisor an." << endl;
104. cin >> y;
105. cout << "Der Quotient der Rechnung ergibt: " << x << " / " << y << " = " << x / y << "." << endl;
106. break;
107. default:
108. cout << "(Fehler: Ungültige Eingabe!)";
109. break;
110. }
111. }
112. cout << endl;
113. cout << "Wollen Sie nochmal rechnen?" << endl;
114. cout << "<0> Nein, <1> Klar" << endl;
115. cin >> wh;
116. cout << endl;
117. }
118. return 0;
119. }
Alles anzeigen
Du bist Terrorist, warum? Siehe hier
• 1. Mach mal ein Screenshot von dem Fehler mit der Währung
2. Mach einen Leerzeichen zwischen Angabe der Summanden etc. und der Währung. das könnte leicht irritieren glaube ich
3. Als Programmierer muss man sich ständig bemühen Ressourcen wie RechnerZeit und RechnerKapazität zu sparen. Du hast den Code komplett runterkopiert um es mit und ohne Währung zu haben ;( . ich hätte da bei der frage mit der Währung (ob ja oder nein) die Währung gleich eingeben gelassen, wenn 1 oder Waehrung = "" wenn 0 eben. und dann nur den oberen Code ausgebenen. wenn Waehrung="" ausgegeben wird, tut es ja keinem weh ^^
4. wegen double - kannst du machen, wenn du es brauchst. float = 7 oder 8 nachkommastellen und bei double waren es 15 oder 16, wenn ich mich recht erinnere.
5. Variablen "eingabe" und "z" werden nicht auf Richtige Eingabe überprüft. was passiert wenn du bei Eingabe von "z" einen Buchstaben eintippst?
6. Anmerkung: bei default kannst du break weglassen, weil danach eh Rumpfende von switch folgt. ist aber kein Fehler!!
mfG
• Ich habe das Programm so oft überarbeitet(Wegen der Grammatik) und hin und wieder compiliert,
dass ich zum Schluss vergessen habe, noch mal zu compilieren.
So habe ich den Fehler nicht bemerkt.
Der Fehler mit den Zahlen als Waehrung existierte gar nicht,
ich habe mir nur eingebildet es wäre einer,
weil ich da noch keine Leerzeichen hatte und es deshalb so aussah,
als wäre da eine Rechnung durcheinandergeraten.
@Koljan777:Mit Leerzeichen sieht es wirklich übersichtlicher aus.
Vielen Dank für eure Hilfe.
Hier nun die aktuelle Version.:
Quellcode
1. #include<iostream>
2. #include<string>
3. using namespace std;
4. int main()
5. {
6. int eingabe;
7. double x;
8. double y;
9. double r;
10. string Waehrung;
11. bool z;
12. bool wh = 1;
13. while ( wh = 1 )
14. {
15. cout << "Taschenrechner ©Pokertom" << endl;
16. cout << endl;
17. cout << "Grundrechenarten <1>" << endl;
18. cout << "Volumen von Geometrischen Koerpern <2>" << endl;
19. cout << "Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!" << endl;
20. cin >> eingabe;
21. switch ( eingabe )
22. {
23. case 1:
24. cout << "Addition <1>" << endl;
25. cout << "Subtraktion <2>" << endl;
26. cout << "Multiplikation <3>" << endl;
27. cout << "Division <4>" << endl;
28. cout << "Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!" << endl;
29. cin >> eingabe;
30. switch ( eingabe )
31. {
32. case 1:
33. cout << "Geben Sie die Waehrung/Einheit ein." << endl;
34. cin >> Waehrung;
35. cout << "Geben Sie bitte den 1. Summand an." << endl;
36. cin >> x;
37. cout << "Geben Sie bitte den 2. Summand an." << endl;
38. cin >> y;
39. cout << "Die Summe der Rechnung ergibt: " << x << " " << Waehrung << " + " << y << " " << " " << Waehrung << " = "
40. << x + y << " " << " " << Waehrung << "." << endl;
41. case 2:
42. cout << "Geben Sie die Waehrung/Einheit ein." << endl;
43. cin >> Waehrung;
44. cout << "Geben Sie bitte den Minuent an." << endl;
45. cin >> x;
46. cout << "Geben Sie bitte den Subtrahent an." << endl;
47. cin >> y;
48. cout << "Die Differenz der Rechnung ergibt: " << x << " " << Waehrung << " - " << y << " " << Waehrung << " = "
49. << x - y << " " << Waehrung << "." << endl;
50. break;
51. case 3:
52. cout << "Geben Sie die Waehrung/Einheit ein." << endl;
53. cin >> Waehrung;
54. cout << "Geben Sie bitte den 1. Faktor an." << endl;
55. cin >> x;
56. cout << "Geben Sie bitte den 2. Faktor an." << endl;
57. cin >> y;
58. cout << "Das Produkt der Rechnung ergibt: " << x << " " << Waehrung << " * " << y << " " << Waehrung << " = " << x
59. * y << " " << Waehrung << "." << endl;
60. break;
61. case 4:
62. cout << "Geben Sie die Waehrung/Einheit ein." << endl;
63. cin >> Waehrung;
64. cout << "Geben Sie bitte den Dividend an." << endl;
65. cin >> x;
66. cout << "Geben Sie bitte den Divisor an." << endl;
67. cin >> y;
68. cout << "Der Quotient der Rechnung ergibt: " << x << " " << Waehrung << " / " << y << " " << Waehrung << " = "
69. << x / y << " " << Waehrung << "." << endl;
70. }
71. break;
72. case 2:
73. cout << "Volumen der Dreieckspyramide <1>" << endl;
74. cout << "Volumen der Viereckspyramide <2>" << endl;
75. cout << "Volumen des Kegels <3>" << endl;
76. cout << "Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!" << endl;
77. cin >> eingabe;
78. switch ( eingabe )
79. {
80. case 1:
81. cout << "Geben Sie bitte die Grundseite(g) der Bodenflaeche an." << endl;
82. cin >> x;
83. cout << "Geben Sie bitte die Hoehe(h) der Bodenflaeche an." << endl;
84. cin >> y;
85. cout << "Geben Sie bitte die Hoehe(h) der Dreieckspyramide an." << endl;
86. cin >> z;
87. cout << "Dies ist das Volumen der Dreieckspyramide.:" << x * y / 2 * z / 2 << endl;
88. break;
89. case 2:
90. cout << "Geben Sie bitte die Laenge der Seite a an." << endl;
91. cin >> x;
92. cout << "Geben Sie bitte die Laenge der Seite b an." << endl;
93. cin >> y;
94. cout << "Geben Sie bitte die Hoehe(h) der Viereckseckspyramide an." << endl;
95. cin >> z;
96. cout << "Dies ist das Volumen der Viereckspyramide.:" << x * y * z / 2 << endl;
97. break;
98. case 3:
99. cout << "Geben Sie bitte den Radius des Bodenkreises an." << endl;
100. cin >> r;
101. cout << "Geben Sie bitte die Hoehe(h) des Kegels an." << endl;
102. cin >> y;
103. x = r * r * 3.1415926535897932384426433832795 * y /3;
104. cout << "Dies ist das Volumen des Kegels.:" << x << endl;
105. }
106. break;
107. default:
108. cout << "(Fehler: Ungueltige Eingabe!)";
109. }
110. cout << endl;
111. cout << "Wollen Sie nochmal rechnen?" << endl;
112. cout << "<0> Nein, <1> Klar" << endl;
113. cin >> wh;
114. cout << endl;
115. }
116. }
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Dieser Beitrag wurde bereits 3 mal editiert, zuletzt von pokertom ()
• Habe es nochmals überarbeitet.
Einheiten dafür folgen noch.
Dies hier folgt noch in der Oberflaechenberechnung:
Kugel (verstehe ich nicht)
Zylinder
Dreieckspyramide
Viereckspyramide
Kegel (das auch nicht)
Werde es trotzdem versuchen und hoffentlich klappt's.
Grüße Pokertom
Quellcode
1. #include<iostream>
2. #include<string>
3. using namespace std;
4. int main()
5. {
6. int eingabe;
7. double x;
8. double y;
9. double z;
10. double r;
11. string Waehrung;
12. bool wh = 1;
13. const double pi = 3.141592653589793;
14. while ( wh = 1 )
15. {
16. cout << "Taschenrechner ©Pokertom" << endl;
17. cout << endl;
18. cout << "Grundrechenarten <1>" << endl;
19. cout << "Volumen von Geometrischen Koerpern <2>" << endl;
20. cout << "Oberflaeche von Geometrischen Koerpern <2>" << endl;
21. cout << "Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!" << endl;
22. cin >> eingabe;
23. switch ( eingabe )
24. {
25. case 1:
26. cout << "Addition <1>" << endl;
27. cout << "Subtraktion <2>" << endl;
28. cout << "Multiplikation <3>" << endl;
29. cout << "Division <4>" << endl;
30. cout << "Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!" << endl;
31. cin >> eingabe;
32. switch ( eingabe )
33. {
34. case 1:
35. cout << "Geben Sie die Waehrung/Einheit ein." << endl;
36. cin >> Waehrung;
37. cout << "Geben Sie bitte den 1. Summand an." << endl;
38. cin >> x;
39. cout << "Geben Sie bitte den 2. Summand an." << endl;
40. cin >> y;
41. cout << "Die Summe der Rechnung ergibt: " << x << " " << Waehrung << " + " << y << " " << " " << Waehrung << " = "
42. << x + y << " " << " " << Waehrung << "." << endl;
43. case 2:
44. cout << "Geben Sie die Waehrung/Einheit ein." << endl;
45. cin >> Waehrung;
46. cout << "Geben Sie bitte den Minuent an." << endl;
47. cin >> x;
48. cout << "Geben Sie bitte den Subtrahent an." << endl;
49. cin >> y;
50. cout << "Die Differenz der Rechnung ergibt: " << x << " " << Waehrung << " - " << y << " " << Waehrung << " = "
51. << x - y << " " << Waehrung << "." << endl;
52. break;
53. case 3:
54. cout << "Geben Sie die Waehrung/Einheit ein." << endl;
55. cin >> Waehrung;
56. cout << "Geben Sie bitte den 1. Faktor an." << endl;
57. cin >> x;
58. cout << "Geben Sie bitte den 2. Faktor an." << endl;
59. cin >> y;
60. cout << "Das Produkt der Rechnung ergibt: " << x << " " << Waehrung << " * " << y << " " << Waehrung << " = " << x
61. * y << " " << Waehrung << "." << endl;
62. break;
63. case 4:
64. cout << "Geben Sie die Waehrung/Einheit ein." << endl;
65. cin >> Waehrung;
66. cout << "Geben Sie bitte den Dividend an." << endl;
67. cin >> x;
68. cout << "Geben Sie bitte den Divisor an." << endl;
69. cin >> y;
70. cout << "Der Quotient der Rechnung ergibt: " << x << " " << Waehrung << " / " << y << " " << Waehrung << " = "
71. << x / y << " " << Waehrung << "." << endl;
72. }
73. break;
74. case 2:
75. cout << "Volumen des Wuerfels <1>" << endl;
76. cout << "Volumen des Quaders <2>" << endl;
77. cout << "Volumen der Kugel <3>" << endl;
78. cout << "Volumen des Zylinders <4>" << endl;
79. cout << "Volumen der Dreieckspyramide <5>" << endl;
80. cout << "Volumen der Viereckspyramide <6>" << endl;
81. cout << "Volumen des Kegels <7>" << endl;
82. cout << "Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!" << endl;
83. cin >> eingabe;
84. switch ( eingabe )
85. {
86. case 1:
87. cout << "Geben Sie bitte die Laenge der Seite a an." << endl;
88. cin >> x;
89. cout << "Dies ist das Volumen des Wuerfels.:" << x * x * x << endl;
90. break;
91. case 2:
92. cout << "Geben Sie bitte die Laenge der Seite a an." << endl;
93. cin >> x;
94. cout << "Geben Sie bitte die Laenge der Seite b an." << endl;
95. cin >> y;
96. cout << "Geben Sie bitte die Laenge der Seite c an." << endl;
97. cin >> z;
98. cout << "Dies ist das Volumen des Wuerfels.:" << x * y * z << endl;
99. break;
100. case 3:
101. cout << "Geben Sie bitte den Radius(r)der Kugel an." << endl;
102. cin >> r;
103. cout << "Dies ist das Volumen der Kugel.:" << r * r * r / 3 * 4 * pi << endl;
104. break;
105. case 4:
106. cout << "Geben Sie bitte den Radius des Bodenkreises an." << endl;
107. cin >> r;
108. cout << "Geben Sie bitte die Hoehe(h) des Zylinders an." << endl;
109. cin >> y;
110. x = r * r * pi * y;
111. cout << "Dies ist das Volumen des Zylinders.:" << x << endl;
112. case 5:
113. cout << "Geben Sie bitte die Grundseite(g) der Bodenflaeche an." << endl;
114. cin >> x;
115. cout << "Geben Sie bitte die Hoehe(h) der Bodenflaeche an." << endl;
116. cin >> y;
117. cout << "Geben Sie bitte die Hoehe(h) der Dreieckspyramide an." << endl;
118. cin >> z;
119. cout << "Dies ist das Volumen der Dreieckspyramide.:" << x * y / 2 * z / 2 << endl;
120. break;
121. case 6:
122. cout << "Geben Sie bitte die Laenge der Seite a an." << endl;
123. cin >> x;
124. cout << "Geben Sie bitte die Laenge der Seite b an." << endl;
125. cin >> y;
126. cout << "Geben Sie bitte die Hoehe(h) der Viereckseckspyramide an." << endl;
127. cin >> z;
128. cout << "Dies ist das Volumen der Viereckspyramide.:" << x * y * z / 2 << endl;
129. break;
130. case 7:
131. cout << "Geben Sie bitte den Radius des Bodenkreises an." << endl;
132. cin >> r;
133. cout << "Geben Sie bitte die Hoehe(h) des Kegels an." << endl;
134. cin >> y;
135. x = r * r * pi * y / 3;
136. cout << "Dies ist das Volumen des Kegels.:" << x << endl;
137. default:
138. cout << "(Fehler: Ungueltige Eingabe!)";
139. }
140. break;
141. case 3:
142. cout << "Oberflaeche von einem Wuerfel <1>" << endl;
143. cout << "Oberflaeche von einem Quader <2>" << endl;
144. cout << "Oberflaeche von einer Kugel <3>" << endl;
145. cout << "Oberflaeche von einem Zylinder <4>" << endl;
146. cout << "Oberflaeche von einer Dreieckspyramide <5>" << endl;
147. cout << "Oberflaeche von einer Viereckspyramide <6>" << endl;
148. cout << "Oberflaeche von einem Kegel <7>" << endl;
149. cout << "Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!" << endl;
150. cin >> eingabe;
151. switch ( eingabe )
152. {
153. case 1:
154. cout << "Geben Sie bitte die Laenge der Seite a an." << endl;
155. cin >> x;
156. cout << "Dies ist die Oberfaeche des Wuerfels.:" << x * x * 6 << endl;
157. break;
158. case 2:
159. cout << "Geben Sie bitte die Laenge der Seite a an." << endl;
160. cin >> x;
161. cout << "Geben Sie bitte die Laenge der Seite b an." << endl;
162. cin >> y;
163. cout << "Geben Sie bitte die Laenge der Seite c an." << endl;
164. cin >> z;
165. cout << "Dies ist die Oberflaeche des Quaders.:" << 2*(x*y)+2*(x*z)+2*(y*z) << endl;
166. break;
167. default:
168. cout << "(Fehler: Ungueltige Eingabe!)";
169. }
170. cout << endl;
171. cout << "Wollen Sie nochmal rechnen?" << endl;
172. cout << "<0> Nein, <1> Klar" << endl;
173. cin >> wh;
174. cout << endl;
175. }
176. }
177. }
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Dieser Beitrag wurde bereits 1 mal editiert, zuletzt von pokertom ()
• Ich habe ich noch den Taschenrechner nochmals überarbeitet, und langsam gehenmir die Ideen aus. :thumbdown:
Wenn zum Beispiel bei einer Rechnnung m*m angegeben wird, muss dann ja m² dort stehen.
Hat jemand 'ne Idee, wie Ich das Bewältigen kann?
Mir fiel nur ein, für jede Längeneinheit eine if & else abfragung durchzuführen, was bei den vielen Längeneinheiten die es gibt problematisch sein dürfte. :huh:
Gruss Pokertom
Quellcode
1. #include<iostream>
2. #include<string>
3. using namespace std;
4. int main()
5. {
6. int eingabe;
7. double x;
8. double y;
9. double z;
10. double r;
11. double h;
12. string Waehrung;
13. bool wh = 1;
14. const double pi = 3.141592653589793;
15. while ( wh = 1 )
16. {
17. cout << "Taschenrechner ©Pokertom" << endl;
18. cout << endl;
19. cout << "Grundrechenarten <1>" << endl;
20. cout << "Volumen von Geometrischen Koerpern <2>" << endl;
21. cout << "Oberflaeche von Geometrischen Koerpern <3>" << endl;
22. cout << "Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!" << endl;
23. cin >> eingabe;
24. switch ( eingabe )
25. {
26. case 1:
27. cout << "Addition <1>" << endl;
28. cout << "Subtraktion <2>" << endl;
29. cout << "Multiplikation <3>" << endl;
30. cout << "Division <4>" << endl;
31. cout << "Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!" << endl;
32. cin >> eingabe;
33. switch ( eingabe )
34. {
35. case 1:
36. cout << "Geben Sie die Waehrung/Einheit ein." << endl;
37. cin >> Waehrung;
38. cout << "Geben Sie bitte den 1. Summand an." << endl;
39. cin >> x;
40. cout << "Geben Sie bitte den 2. Summand an." << endl;
41. cin >> y;
42. cout << "Die Summe der Rechnung ergibt: " << x << " " << Waehrung << " + " << y << " " << " " << Waehrung << " = "
43. << x + y << " " << " " << Waehrung << "." << endl;
44. case 2:
45. cout << "Geben Sie die Waehrung/Einheit ein." << endl;
46. cin >> Waehrung;
47. cout << "Geben Sie bitte den Minuent an." << endl;
48. cin >> x;
49. cout << "Geben Sie bitte den Subtrahent an." << endl;
50. cin >> y;
51. cout << "Die Differenz der Rechnung ergibt: " << x << " " << Waehrung << " - " << y << " " << Waehrung << " = "
52. << x - y << " " << Waehrung << "." << endl;
53. break;
54. case 3:
55. cout << "Geben Sie die Waehrung/Einheit ein." << endl;
56. cin >> Waehrung;
57. cout << "Geben Sie bitte den 1. Faktor an." << endl;
58. cin >> x;
59. cout << "Geben Sie bitte den 2. Faktor an." << endl;
60. cin >> y;
61. cout << "Das Produkt der Rechnung ergibt: " << x << " " << Waehrung << " * " << y << " " << Waehrung << " = " << x
62. * y << " " << Waehrung << "." << endl;
63. break;
64. case 4:
65. cout << "Geben Sie die Waehrung/Einheit ein." << endl;
66. cin >> Waehrung;
67. cout << "Geben Sie bitte den Dividend an." << endl;
68. cin >> x;
69. cout << "Geben Sie bitte den Divisor an." << endl;
70. cin >> y;
71. cout << "Der Quotient der Rechnung ergibt: " << x << " " << Waehrung << " / " << y << " " << Waehrung << " = "
72. << x / y << " " << Waehrung << "." << endl;
73. }
74. break;
75. case 2:
76. cout << "Volumen des Wuerfels <1>" << endl;
77. cout << "Volumen des Quaders <2>" << endl;
78. cout << "Volumen der Kugel <3>" << endl;
79. cout << "Volumen des Zylinders <4>" << endl;
80. cout << "Volumen der Dreieckspyramide <5>" << endl;
81. cout << "Volumen der Viereckspyramide <6>" << endl;
82. cout << "Volumen des Kegels <7>" << endl;
83. cout << "Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!" << endl;
84. cin >> eingabe;
85. switch ( eingabe )
86. {
87. case 1:
88. cout << "Geben Sie bitte die Laenge der Seite a an." << endl;
89. cin >> x;
90. cout << "Dies ist das Volumen des Wuerfels.:" << x * x * x << endl;
91. break;
92. case 2:
93. cout << "Geben Sie bitte die Laenge der Seite a an." << endl;
94. cin >> x;
95. cout << "Geben Sie bitte die Laenge der Seite b an." << endl;
96. cin >> y;
97. cout << "Geben Sie bitte die Laenge der Seite c an." << endl;
98. cin >> z;
99. cout << "Dies ist das Volumen des Wuerfels.:" << x * y * z << endl;
100. break;
101. case 3:
102. cout << "Geben Sie bitte den Radius(r)der Kugel an." << endl;
103. cin >> r;
104. cout << "Dies ist das Volumen der Kugel.:" << r * r * r / 3 * 4 * pi << endl;
105. break;
106. case 4:
107. cout << "Geben Sie bitte den Radius des Bodenkreises an." << endl;
108. cin >> r;
109. cout << "Geben Sie bitte die Hoehe(h) des Zylinders an." << endl;
110. cin >> h;
111. x = r * r * pi * h;
112. cout << "Dies ist das Volumen des Zylinders.:" << x << endl;
113. case 5:
114. cout << "Geben Sie bitte die Grundseite(g) der Bodenflaeche an." << endl;
115. cin >> x;
116. cout << "Geben Sie bitte die Hoehe(h) der Bodenflaeche an." << endl;
117. cin >> y;
118. cout << "Geben Sie bitte die Hoehe(h) der Dreieckspyramide an." << endl;
119. cin >> h;
120. cout << "Dies ist das Volumen der Dreieckspyramide.:" << x * y / 2 * h / 2 << endl;
121. break;
122. case 6:
123. cout << "Geben Sie bitte die Laenge der Seite a an." << endl;
124. cin >> x;
125. cout << "Geben Sie bitte die Laenge der Seite b an." << endl;
126. cin >> y;
127. cout << "Geben Sie bitte die Hoehe(h) der Viereckseckspyramide an." << endl;
128. cin >> h;
129. cout << "Dies ist das Volumen der Viereckspyramide.:" << x * h * z / 2 << endl;
130. break;
131. case 7:
132. cout << "Geben Sie bitte den Radius des Bodenkreises an." << endl;
133. cin >> r;
134. cout << "Geben Sie bitte die Hoehe(h) des Kegels an." << endl;
135. cin >> h;
136. x = ( pi / 3 ) * r * r * h;
137. cout << "Dies ist das Volumen des Kegels.:" << x << endl;
138. default:
139. cout << "(Fehler: Ungueltige Eingabe!)";
140. }
141. break;
142. case 3:
143. cout << "Oberflaeche von einem Wuerfel <1>" << endl;
144. cout << "Oberflaeche von einem Quader <2>" << endl;
145. cout << "Oberflaeche von einer Kugel <3>" << endl;
146. cout << "Oberflaeche von einem Zylinder <4>" << endl;
147. cout << "Oberflaeche von einer Dreieckspyramide <5>" << endl;
148. cout << "Oberflaeche von einer Viereckspyramide <6>" << endl;
149. cout << "Oberflaeche von einem Kegel <7>" << endl;
150. cout << "Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!" << endl;
151. cin >> eingabe;
152. switch ( eingabe )
153. {
154. case 1:
155. cout << "Geben Sie bitte die Laenge der Seite a an." << endl;
156. cin >> x;
157. cout << "Dies ist die Oberfaeche des Wuerfels.:" << x * x * 6 << endl;
158. break;
159. case 2:
160. cout << "Geben Sie bitte die Laenge der Seite a an." << endl;
161. cin >> x;
162. cout << "Geben Sie bitte die Laenge der Seite b an." << endl;
163. cin >> x;
164. cout << "Geben Sie bitte die Laenge der Seite c an." << endl;
165. cin >> z;
166. cout << "Dies ist die Oberflaeche des Quaders.:" << 2 * ( x * y ) + 2 * ( x * z ) + 2 * ( y * z ) << endl;
167. break;
168. case 3:
169. cout << "Geben Sie den Radius(r) an." << endl;
170. cin >> r;
171. cout << "Dies ist die Oberflaeche der Kugel.:" << 4 * pi * r * r << endl;
172. break;
173. case 4:
174. cout << "Geben sie den Radius(r) der Bodenflaeche an." << endl;
175. cin >> r;
176. cout << "Geben Sie bitte die Hoehe(h) an." << endl;
177. cin >> h;
178. cout << "Dies ist die Oberflaeche des Zylinders.:" << r * r * pi * h << endl;
179. break;
180. case 5:
181. cout << "Geben Sie die Laenge der Seite a an." << endl;
182. cin >> x;
183. cout << "Geben Sie die Seite(s) an." << endl;
184. cin >> z;
185. cout << "Dies ist die Oberflaeche der Dreieckspyramide.:" << ( x * x / 2 ) + 3 * ( x * z / 2 ) << endl;
186. break;
187. case 6:
188. cout << "Geben Sie die Laenge der Seite a an." << endl;
189. cin >> x;
190. cout << "Geben Sie die Seite(s) an." << endl;
191. cin >> z;
192. cout << "Dies ist die Oberflaeche der Viereckspyramide.:" << ( x * x ) + 4 * ( x * z / 2 ) << endl;
193. break;
194. case 7:
195. cout << "Geben Sie den Radius(r) an." << endl;
196. cin >> r;
197. cout << "Geben Sie die Seite(s) an." << endl;
198. cin >> z;
199. cout << "Dies ist die Oberflaeche des Kegels.:" << ( pi * r * r ) + ( pi * r * z ) << endl;
200. break;
201. default:
202. cout << "(Fehler: Ungueltige Eingabe!)";
203. }
204. }
205. cout << endl;
206. cout << "Wollen Sie nochmal rechnen?" << endl;
207. cout << "<0> Nein, <1> Klar" << endl;
208. cin >> wh;
209. cout << endl;
210. }
211. }
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Du bist Terrorist, warum? Siehe hier
Dieser Beitrag wurde bereits 1 mal editiert, zuletzt von pokertom ()
• Ich habe noch ein anderes Problem:
Wieso zeigt Die Eingabeaufforderung die default anweisung an?
Kann keinen Fehler entdecken!
Taschenrechner ©Pokertom
Grundrechenarten <1>
Volumen von Geometrischen Koerpern <2>
Oberflaeche von Geometrischen Koerpern <2>
Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!
2
Volumen des Wuerfels <1>
Volumen des Quaders <2>
Volumen der Kugel <3>
Volumen des Zylinders <4>
Volumen der Dreieckspyramide <5>
Volumen der Viereckspyramide <6>
Volumen des Kegels <7>
Geben Sie eine der Zahlen in <?> ein, um das Programm zu starten!
7
Geben Sie bitte den Radius des Bodenkreises an.
5
Geben Sie bitte die Hoehe(h) des Kegels an.
10
Dies ist das Volumen des Kegels.:261.799
(Fehler: Ungueltige Eingabe!)//Wieso kommt das?
Wollen Sie nochmal rechnen?
<0> Nein, <1> Klar
Du bist Terrorist, warum? Siehe hier
• Hmmm sieht so aus, als ob der Fehler nur beim Kegel auftreten würde, oder?
Beim Würfel und Quader passt es, aber da hast du ein Schreibfehler drin:
Quellcode
1. case 2:
2. cout << "Geben Sie bitte die Laenge der Seite a an." << endl;
3. cin >> x;
4. cout << "Geben Sie bitte die Laenge der Seite b an." << endl;
5. cin >> y;
6. cout << "Geben Sie bitte die Laenge der Seite c an." << endl;
7. cin >> z;
8. cout << "Dies ist das Volumen des [b]Wuerfels[/b].:" << x * y * z << endl;
Sollte Quader statt Würfel stehen, nehm ich an.
Zum Prob: hast einn break; vergessen, in Zeile 149 ;)
MlG
SwiPP
A programmer is just a tool which converts caffein into code - Unknown
• @SwiPP
Danke, habe ich verbessert.
Hab an der falschen Stelle geguckt, und so nicht gefunden worans lag.
Noch mal an alle.:
Habt ihr vieleicht noch Ideen, was ich in den Taschenrechner einbauen könnte?
Natürlich nur Sachen die zu bewerkstelligen sind.
Bitte keine komplizierten Algorithmen oder ähnliches Zeug. 8o
Sag danke schon mal im voraus.
Grüsse Pokertom
Du bist Terrorist, warum? Siehe hier
• Habe zuerst auch weiter unten geguckt^^
Zur Frage:
Sinus, Cosinus, Tangens, Arcustangens, Arcussinus, Arcustangens =) Könnte ich gerade brauchen xD
Naja, sonst halt Brüche ausdividieren. Vielleicht.
Wurzel ziehen und quadrieren (oder sonstige Potenzen).
öhmm was kommt mir noch in den Sinn. ein ggT, kgV berechner.
Joah, kannst noch einiges einabuen, wenn du Lust hast^^
//E: Irgend etwas in Snne eines Durchschnittserrechners ist mir noch in den Sinn gekommen.
A programmer is just a tool which converts caffein into code - Unknown
• @SwiPP Danke für die vielen Vorschläge. :thumbsup:
Habe einige Vordefinierten Funktionen der Bibliothek <cmath> in mein Projekt eingebunden.
Brüche hatte ich auch schon im Visier, muss mir nur über den Aufbau noch Gedanken machen.
Ich lade den Text jetzt in .txt Dateien hoch, damit es nicht so unübersichtlich wird. (Bei knapp 360 Zeilen Text)
Grüsse Pokertom
Dateien
Du bist Terrorist, warum? Siehe hier
• Habe jetzt auch Addition, Subraktion, Multiplikation und Division von Brüchen eingefügt. :D
@SwiPP
Durchschnitt ist zu scher umzusetzen, aber der ggT und der kgT sind eine gute Idee.
Guck mal, ob ichs mit dem Modulo Opperator hinkriege, wiegesagt, ich arbeite noch nicht so lange mit C++.
Grüsse Pokertom
Dateien
Du bist Terrorist, warum? Siehe hier
• was soll die währung/einheit sein?
was passiert dann, wenn du durch 0 dividierst (x/0)? ne fehlermeldung wäre schön bzw. ne neuberechnung:
Quellcode
1. Geben Sie die Waehrung/Einheit ein.
2. 12
3. Geben Sie bitte den Dividend an.
4. 13
5. Geben Sie bitte den Divisor an.
6. 0
7. Der Quotient der Rechnung ergibt: 13 12/0 12=1.#INF 12.
die darstellung ist viel zu kompliziert. könnte viel einfacher sein ;)
wann kann man das programmende erreichen? wenn eine berechnung durchgeführt wurde, dann sollte es eine meldung erscheinen, ob man weitere berechnungen durchführen möchte oder das programm beenden.
lg
• @ Composer.
Man kann ja auswählen, ob man noch eine Rechnung durchführen will oder nicht.
@ superuser.
Ich finde es ist für den Beginn eine gute Übung, um zu sehen, wie ein Programm funktioniert, wie weit man mit if und while gehen kann. Klar kann man das auch mit Arrays schöner darstellen, aber für den Beginn ist das doch ganz gut, mMn.
A programmer is just a tool which converts caffein into code - Unknown
• eigentlich meinte ich, dass man die ganze prozedur von anfang an machen muss. zb. der user will ganze zeit nur additionsbeispiele machen und da muss er jedes mal zuerst in die oberste stufe (das hauptmenü) springen. ;)
genau da soll es erscheinen, ob er weitere berechnungen durchführen möchte, oder lieber ins hauptmenü gelangen möchte
|
__label__pos
| 0.987439 |
Die Anleitung zu ECMAScript Map Collection
1- Collections - Map
ECMAScript 6 stellt 2 neue Datenstruktur Map & Set vor. Sie sind eine Teil in Collections Framework vom ECMAScript.
• Maps - Die Datenstruktur erlaubt Sie, die Paar "Schlüssel/Wert" (Key/Value) zu speichern. Und Sie können durch den Schlüssel in die Wert zugreifen oder die einem Schlüssel entsprechende neue Wert aktualisieren.
• Sets - Die Datenstruktur speichert eine List der Elemente, die überlappen und die Index für die Elemente markieren nicht dürfen.
In diesem Artikel werde ich Sie Map vorstellen .
Mehr sehen
Map:
Ein Objekt Map speichert die Paar "Schlüssel/Wert" (Key/Value). Davon können Schlüssel und Wert die Type primitiv oder Objekt.
• Im Objekt Map dürfen die Schlüssel (key) überlappen nicht.
• Map ist ein ordentliches Datenstyp, d.h welche Paar "Schlüssel/Wert" zuerst eingefügt wird, wird es zuerst stehen und welche Paar später eingefügt wird, wird es hinter stehen
Erstellen Sie ein Objekt Map durch constructor der Klasse Map:
new Map( [iteratorObject] )
Die Parameter :
• iteratorObject -- ist irgendein iterierbares Objekt (iterable).
Properties:
Property Die Bezeichnung
size Property gibt die Anzahl der Paar "Schlüssel/Wert" des Objekt Map zurück.
map-size-example.js
var myContacts = new Map();
myContacts.set("0100-1111", "Tom");
myContacts.set("0100-5555", "Jerry");
myContacts.set("0100-2222", "Donald");
console.log(myContacts.size); // 3
for..of
Sie können die Schleife for...of um auf die Paar key/value vom Map zu iterieren.
map-for-of-loop-example.js
// Create a Map object.
var myContacts = new Map();
myContacts.set("0100-1111", "Tom");
myContacts.set("0100-5555", "Jerry");
myContacts.set("0100-2222", "Donald");
for( let arr of myContacts) {
console.log(arr);
console.log(" - Phone: " + arr[0]);
console.log(" - Name: " + arr[1]);
}
2- Map Methods
set(key, value)
Das Method set(key,newValue) wird ein Paar key/newValue in dem Objekt Map einfügen wenn keine solche Schlüsselpaar existieren, umgekehrt aktualisiert es die neue Wert für das Paar key/value , die im Map gefunden wird
map-set-example.js
var data = [
["0100-1111", "Tom"],
["0100-5555", "Jerry"],
["0100-2222", "Donald"]
];
var myContacts = new Map(data);
console.log(myContacts);
// Add new Key/Value pair to Map
myContacts.set("0100-9999", "Mickey");
console.log(myContacts);
// Update
myContacts.set("0100-5555", "Bugs Bunny");
console.log(myContacts);
has(key)
Dieses Method prüft, ob ein Schlüssel im Map existiert oder nicht. True zurückgeben wenn existiert, umgekehrt false.
.
map-has-example.js
var data = [
["0100-1111", "Tom"],
["0100-5555", "Jerry"],
["0100-2222", "Donald"]
];
var myContacts = new Map(data);
var has = myContacts.has("0100-5555");
console.log("Has key 0100-5555? " + has); // true
clear()
Alle Paar "Schlüssel/Wert" aus dem Objekt Map entfernen.
map-clear-example.js
var data = [
["0100-1111", "Tom"],
["0100-5555", "Jerry"],
["0100-2222", "Donald"]
];
var myContacts = new Map(data);
console.log("Size: " + myContacts.size); // 3
myContacts.clear();
console.log("Size after clearing: " + myContacts.size); // 0
delete(key)
Ein Paar "Schlüssel/Wert" aus dem Objekt Map entfernen, true zurückgeben wenn ein Paar aus Map entfernt wird, false zurückgeben wenn der Schlüssel (Key) im Map nicht existiert.
map-delete-example.js
var data = [
["0100-1111", "Tom"],
["0100-5555", "Jerry"],
["0100-2222", "Donald"]
];
var myContacts = new Map(data);
console.log("Size: " + myContacts.size); // 3
var deleted = myContacts.delete("0100-5555");
console.log("Deleted? " + deleted); // true
console.log("Size after delete: " + myContacts.size); // 2
entries()
Ein Objekt Iterator zurückgeben, und jede entry vom ihm enthaltet ein 2 Element Array [key, value], die Reihenfolge von entry haltet so gleich wie die Reihenfolge der Paar Key/Value im Objekt Map. (die Illustration unten sehen).
map-entries-example.js
var myContacts = new Map();
myContacts.set("0100-1111", "Tom");
myContacts.set("0100-5555", "Jerry");
myContacts.set("0100-2222", "Donald");
var entries = myContacts.entries();
var entry;
while( !(entry = entries.next()).done ) {
var array = entry.value;
console.log(array); // [ '0100-1111', 'Tom' ]
}
keys()
Dieses Method gibt ein neues Objekt Iterator zurück, damit Sie in die Schlüssel des Objekt Map zugreifen können
map-keys-example.js
var data = [
["0100-1111", "Tom"],
["0100-5555", "Jerry"],
["0100-2222", "Donald"]
];
var myContacts = new Map(data);
var iteratorPhones= myContacts.keys();
var entry;
while( !(entry = iteratorPhones.next()).done ) {
var phone = entry.value;
console.log(phone); // 0100-1111
}
values()
Dieses Method gibt ein neues Objekt Iterator zurück, damit Sie in die Wert des Objekt Map zugreifen können.
map-values-example.js
var data = [
["0100-1111", "Tom"],
["0100-5555", "Jerry"],
["0100-2222", "Donald"]
];
var myContacts = new Map(data);
var iteratorNames = myContacts.values();
var entry;
while( !(entry = iteratorNames.next()).done ) {
var name = entry.value;
console.log(name); // Tom
}
forEach(callbackFn [, thisArg])
Dieses Method ruft die Funktion callbackFn auf, darin jede Aufruf entspricht jedem Paar "Schlussel/Wert" des Objekt Map
myMap.forEach(callback[, thisArg])
Die Parameter:
• callbackFn - Die Funktion wird aufgeruft und jedes Mal entspricht einem Paar "Schlüssel/Wert" des Objekt Map.
• thisArg - Der Parameter wird bei der Implementation der Funktion callbackFn als this benutzt
map-forEach-example.js
var showContact = function(key, value, thisMap) {
console.log("Phone: " + key +". Name: " + value);
}
var data = [
["0100-1111", "Tom"],
["0100-5555", "Jerry"],
["0100-2222", "Donald"]
];
var myContacts = new Map(data);
// or call: myContacts.forEach(showContact)
myContacts.forEach(showContact, myContacts);
3- WeakMap
Im Grunde ist WeakMap ziemlich so ähnlich wie Map, aber es hat die folgenden Unterschiede:
1. Seine Schlüssel müssen die Objekte sein.
2. Die Schlüssel vom WeakMap können in dem Prozess der Abfallssammlung (garbage collection) entfernt werden. Das ist ein unabhängiger Prozess für die Entfernung der Objekte, die im Programm nicht mehr benutzt werden.
3. WeakMap unterstützt property: size nicht. Deshalb können Sie nicht wissen, wie viele Elemente es hat.
4. Viele Methode dürfen in die Klasse Map liegen aber nicht in die Klasse WeakMap, z.B values(), keys(), clear(),..
Achtung: Sie können die Schleife for..of für WeakMap nicht benutzen, und es gibt keine Maßnahme zur Iteration auf die Paar key/value vom WeakMap.
Ein Objekt WeakMap erstellen.
var map2 = new WeakMap( [iteratorObject] )
Die Parameter:
• iteratorObject - Ist irgendein iterierbares Objekt (iterable).
Methods:
Die Anzahl der Methode vom WeakMap ist weniger als die Anzahl der Methode vom Map:
1. WeakMap.delete(key)
2. WeakMap.get(key)
3. WeakMap.has(key)
4. WeakMap.set(key, value)
Die Schlüssel (key) im WeakMap ist kein Objekt. Es kann kein primitives Typ sein ( Primitive).
let w = new WeakMap();
w.set('a', 'b'); // Uncaught TypeError: Invalid value used as weak map key
let m = new Map();
m.set('a', 'b'); // Works
weakmap-example.js
var key1 = {}; // An Object
var key2 = {foo: "bar"};
var key3 = {bar: "foo"};
var data = [
[key1, "Tom"],
[key2, "Jerry"],
[key3, "Donald"]
];
var myWeakMap = new WeakMap(data);
console.log(myWeakMap.get(key1));
|
__label__pos
| 0.594513 |
Closed Solved
Mb SwitchWithout Vista reinstall?
So, my Motherboard is getting cranky now.
I want to switch ,but i read and you have to reactivate vista..HOW???
(2)can i just get a new hard drive and install all stuff and then call Microsoft to get my new code?
List the steps to reinstall Vista . Thank You For Helping Me.
2 answers Last reply Best Answer
More about switchwithout vista reinstall
1. Best answer
Vista will prompt you for your key. Input your key. You ahve a certain number of freebie activations. If you've exceeded that, then Vista will give you the phone number to call for a new key. Takes 2 minutes.
2. yes, just call in to the number provided, and give them the code that vista spits out, they'll give you a number to punch in and voila, reactivation!
Ask a new question
Read More
Switch Windows Vista Motherboards Hard Drives
|
__label__pos
| 0.906316 |
AMD Catalyst 14.12 Omega WHQL (14.501.1003.0 November 20)
Discussion in 'Videocards - AMD Radeon Drivers Section' started by shadow_craft, Dec 9, 2014.
1. zer0_c0ol
zer0_c0ol Ancient Guru
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FuryX cf
RH: We are exploring additional resolution/refresh combinations beyond what was provided in AMD Catalyst Omega, but we have not determined the complete matrix. However, we do intend to extend 4K downsampling to all R9 and R7 Series products, 260 and up, with a driver in the Jan/Feb timeframe.
2. Broken Haiku
Broken Haiku Member
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42
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0
GPU:
AMD 280x 3GB
That is _awesome_ news, thanks Zer0!
Last edited: Dec 11, 2014
3. theoneofgod
theoneofgod Ancient Guru
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4,620
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GPU:
RX 580 8GB
Not for us 7xxx users :)
4. kimpet
kimpet Member
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32
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GPU:
Powercolor R9 270X Devil
huge fps boost on ACU :thumbup:
5. typeAlpha
typeAlpha Master Guru
Messages:
280
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1
GPU:
ATi 7850 2GB
We can still downsample, which as far as I can tell is exactly the same thing. Works perfectly on my lowly 7850, why AMD claim we need a 290 or whatever is beyond me.
6. crisrodrigues
crisrodrigues Member
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17
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GPU:
3x GTX 980 SLI
Any chance for the VSR resolution to work in 120hz / 144hz mode?
7. theoneofgod
theoneofgod Ancient Guru
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257
GPU:
RX 580 8GB
My monitor just won't let me downsample 2560x1600 or higher. Even with GPU scaling enabled in CCC, my monitor wants to take over and locks me at 1260x1600 with a weird fuzzy line going down the left side of the screen.
1920x1200 monitor.
8. typeAlpha
typeAlpha Master Guru
Messages:
280
Likes Received:
1
GPU:
ATi 7850 2GB
Aw I don't know what's going on there :( My monitor is only 1680x1050, 16:10 like yours but I can put in-game resolution to 3840x2400 and the GPU scales it down perfectly. The monitor shouldn't be interfering at all, it should just be
1. GPU renders at 3840x2400 (or whatever)
2. GPU scales it to your native res
3. GPU sends the scaled image to your monitor
Monitor shouldn't even notice or care, as far as the monitor is concerned it's just receiving your native resolution. Maybe something is wrong in your setup?
9. cyclone3d
cyclone3d Master Guru
Messages:
419
Likes Received:
1
GPU:
ASUS R9 390
Are you being sarcastic?
280x = 7970
280 = 7950
270x = 7870
270 = 7850
Not sure of the direct correlation of lower R7 cards.
10. theoneofgod
theoneofgod Ancient Guru
Messages:
4,620
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GPU:
RX 580 8GB
Maybe. I can't figure out what I'm doing wrong though.
Resolution profile added to CRU, selectable resolution after a driver restart is available (so I know CRU worked).
Game sees the new resolution but once changed, that fuzzy bar appears :)
11. Undying
Undying Ancient Guru
Messages:
16,626
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Aorus RX580 XTR 8GB
270x = 7870 Ghz
270 = 7870
265 = 7850
12. dabooga
dabooga Master Guru
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222
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GPU:
MSI GTX 1080 Gaming X
Still no Crossfire support for Far Cry 4?
13. mux
mux Member
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23
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GPU:
GTX 1070
This time I deleted the Mantle Cache from BF4; now it also runs smooth on my system with these drivers. :D
14. 0neSh0t
0neSh0t Member
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13
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0
GPU:
Strix 980ti SLI
quick question... ive been using my 7970 to output to my tv 55" forever now mostly to watch movies.. but it is impossible to actually use the TV for browsing etc cause the image is like... blurry and the text is so small also.. seems it doesnt scale well or something...
is there anyway around this ?
15. KissSh0t
KissSh0t Ancient Guru
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ASUS RX 470 Strix
no.
does this help?
16. Nwanko
Nwanko Active Member
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51
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0
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GTX 1070 FTW 2151/5000
I remember Asder00 added mantle in one driver that didn't had it,how is changing it so difficult?
17. zer0_c0ol
zer0_c0ol Ancient Guru
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it is confirmed that ubisoft is to blame for that
18. zer0_c0ol
zer0_c0ol Ancient Guru
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FuryX cf
it is stated that all eyefinity custom res will be available with multiple refresh rates, and that the 290x 290, r9280x,280, and so on will get full 4k support with vsr
19. pheonix1
pheonix1 New Member
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2
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6750
Hello. I install ccc mobility from official AMD page and when this is install i got blue screen with 0x0000003b. After restart all drivers and ccc working but freeze until 1 minute on Welcome screen in booting and wake up from sleep ;/ (ofc drivers removed by DDU) Any ideas ? Older 14.4 working but have black screen after wake up (only wake when I make combination alt+ctrl+del)
Laptop hp dv6-6b15ew (APU 3140 and 6750G)
Last edited: Dec 11, 2014
20. roadczar
roadczar Member
Messages:
43
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2080 TI FTW3 Ultra
Tried it for a little bit and it did not crash so far,but I still like ultra better...
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__label__pos
| 0.990855 |
SAML vs OAuth Introduction
Authentication is an important aspect of many systems, and sufficiently effective and secure authentication processes are vital for the operations of a huge number of companies and organisations. There are currently two main standards used for federated authentication—SAML and OAuth. The majority of systems will use one or the other of these two technologies.
Although SAML and OAuth are used for similar purposes, there are differences between the two that you may want to consider when choosing an authentication method for your organisation. In this guide, we will look at exactly how each of these technologies works and which may be the best for your needs.
What is Federated Authentication?
Authentication is the process of identifying a user’s credentials and that they are who they claim to be, rather than a user or program that may be attempting to fraudulently access a platform, application, or data. Authentication processes include the need for passwords or other forms of verification. Authentication can be as simple as requesting the user to provide the correct username and password, or more complex and secure, such as with Multi-Factor-Authentication (or MFA) systems.
Federated Authentication is when authentication grants a user access to multiple applications and/or platforms. A group of affiliated platforms/applications is known as a “federation”. Examples of federations include Microsoft’s Office applications (Word, Excel, PowerPoint,etc) and Google’s Workspace applications (Docs, Sheets, Drive, etc).
Both SAML and OAuth are used to carry out federated authentication.
Single sign on used to authenticate id to an account
OAuth explained
OAuth is short for Open Authorisation. It is an open standard that can be based on binary, JavaScript Object Notation (or JSON), or even SAML.
OAuth was first launched in 2006 as a component of the OpenID implementation that is used by Twitter. In 2010, OAuth 1.0 was released, and OAuth 2.0 followed in 2012 and is the latest version at the time of writing. The terms “OAuth” and “OAuth 2.0” are often used interchangeably, such as in this article. OAuth uses HMAC-SHA—or Hash-based Message Authentication—signature strings.
OAuth works by defining four distinct roles; Resource Owner (a user who authorises a site or application to access their account), Client (the application itself that accesses the user’s account), Resource Server (the server that hosts the user’s resources), and Authorisation Server (the server that verifies the Resource Owner’s identity via their login credentials, and issues OAuth Bearer Tokens to the Client).
The OAuth workflow
Diagram of OAuth workflow
The OAuth workflow is as follows:
• The client sends a request to the Resource Owner to access a resource held on the Resource Server.
• If the request is granted by the Resource Owner, an authorisation token known as an OAuth Bearer Token is granted to the Client.
• The Client uses this token to request an access token from the Authorisation Server’s API (Application Programming Interface).
• The Authorization Server verifies the identity of the Client.
• If this identity is valid, the Client receives an access token.
• The access token is used by the Client to request access to a resource held by the Resource Server.
• If the access token is valid, the Resource Server grants this access to the Client.
SAML explained
SAML stands for Security Assertion Markup Language. It is an open standard that is based on the XML text format, and it connects identity providers (or IdPs) with service providers (or SPs). SAML was launched in 2002, and approved by OASIS (the Organisation for the Advancement of Structured Information Standards) in 2003. In 2005, SAML 2.0 replaced the original version of the technology, and is still used today. When the term “SAML” is used nowadays, such as in this article, it generally refers to SAML 2.0!
The SAML system of authentication works by using XML-based security assertions—or “tokens”—that transfer identifying information about a user between an IdP and an SP. A well-known example of an IdP that uses SAML authentication is Microsoft Active Directory, which sends user data to any federated SP that the IdP interfaces with. SAML means that users only have to provide login credentials once in order to access a range of services. This is known as Single Sign-On, or SSO.
The SAML workflow
Diagram of SAML workflow
The SAML workflow is as follows:
• The user of (for example) a website clicks “Log In”. In this case, the website would be the SP and the user the “client”.
• The SP (website) creates an encrypted authentication request and sends it to the IdP.
• The SP (website) redirects the user’s browser to the IdP.
• The IdP carries out verification of the SAML authentication request.
• Once the authentication request has been verified as valid, the IdP provides a login screen for the user to enter their credentials (e.g. username and password).
• After the login has been carried out successfully, the IdP generates a SAML “token” representing the identity of the user.
• The IdP sends this token to the SP.
• The IdP redirects the user to the SP.
• The SP verifies the token and assigns the correct access permissions to the user.
• The user is logged into the service.
SAML vs OAuth: The difference between SAML 2.0 and OAuth 2.0
The main difference between SAML and OAuth is that SAML covers identity management, SSO, and federation, whereas OAuth deals specifically with authorisation and not authentication.
Authentication vs Authorisation
The terms “authorisation” and “authentication” are sometimes used interchangeably, however they are actually two different Identity and Access Management (IAM) processes.
Authentication is the process of a user’s identity being verified, whereas authorisation is the granting of specific access permissions to that user. Authentication includes techniques like SSO, MFA, and OTP (one-time passwords). Authorisation takes place after authentication.
Both processes play vital roles in an Identity and Access Management strategy. A simple way to remember which is which is to think of it this way; authentication is about the “Identity”, and authorisation is about the “Access”!
Multi-factor authentication being authorised
Is OAuth better than SAML?
The question of which standard is preferable is not a simple one. There is not a straightforward answer, as different organisations have different needs.
Both standards can be used as part of an SSO setup, but there are advantages of each. For example, SAML is generally considered to be more straightforward and secure, while OAuth is particularly suited towards mobile use.
SAML makes use of cookies that grant users access to platforms/applications across different domains. This means that administrative costs are reduced, and IT managers are more able to configure on-premise and/or cloud-based applications to be included in SAML’s SSO. Organisations that use Virtual Desktop Infrastructure (or VDI) implementations may find SAML more useful due to the ability to incorporate off-premise applications into the federation.
The area in which OAuth provides the most benefits is in access scoping. If an organisation needs to configure a customised system of granting different users different levels of access to resources, some of which may only be temporary, OAuth is designed specifically for this through its use of API calls.
OAuth is also designed more for IoT (Internet of Things) devices such as mobile phones, tablets, and video games consoles than SAML is.
Can OAuth be combined with SAML?
So, can you use SAML and OAuth together? The simple answer is “yes”!
In order to do this, you can specify the SAML token to be recognised as an OAuth Bearer Token by OAuth’s Authorisation Server, which will grant the user access to resources. This means that you do not necessarily have to choose between either a SAML implementation or an OAuth one.
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__label__pos
| 0.854605 |
I wanna use Gameobject.Find(string name, bool active)
i wonder why unity doesn’t make this method?
why??? plz, tell me a reason.
I guess the answer is: “Because they chose not to.”
You can come up with your own:
public class Utility{
public static GameObject Find(string name, bool active = true){
if(String.IsNullOrEmpty(name))
{
return null;
}
var go = GameObject.Find(name);
if(go == null)
{
return null;
}
go.SetActive(active);
return go;
}
}
But you need to call it with :
GameObject obj = Utility.Find("name", true);
One reason I can see why this method does not do the active part is because it is called Find. The name should reflect the action it does. Actually, your method should FindAndActive to describe what it does. When you read code, you wrap parts of it into method so that it gets easier to read.
var go = GameObject.Find("name", false);
What is false? Is it the activation of the found object? Is it that you are looking only for inactive objects? Is it that you expect a particular output if the search is not successful…? You see that it gets confusing quickly.
Find just finds.
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
public class Test : MonoBehaviour
{
public Transform parent;
public bool isActive = false;
public string gameObjectName = "some gameobject";
public List<GameObject> foundGameObjects = new List<GameObject> ();
private Transform child = null;
// Use this for initialization
void Start ()
{
if (parent == null) {
parent = transform;
}
Debug.Log ("Searching inside " + parent.name);
foundGameObjects.Clear ();//clear list
GameObjectFind (gameObjectName, parent, isActive);
Debug.Log ("Found GameObjects (" + foundGameObjects.Count + ")");
}
public void GameObjectFind (string name, Transform parent, bool isActive)
{
if (string.IsNullOrEmpty (name)) {
return;
}
if (parent == null) {
return;
}
int childCount = parent.childCount;
for (int i = 0; i < childCount; i++) {
child = parent.GetChild (i);
if (child.name == name && child.gameObject.activeSelf == isActive) {
foundGameObjects.Add (child.gameObject);//add to list
}
if (child.childCount != 0) {
Debug.Log ("Searching inside " + child.name);
GameObjectFind (name, child, isActive);//recursive
}
}
}
}
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29 thoughts on “Scrollable widget list disappear problem
1. Right after I enabled the “scroll option” and saved the settings nothing happens. Doing a rotation re-freshes (re-draws) the widget which is now empty.
1. With Pure calendar or Pure messenger ?
With Pure calendar, you need to wait 1 minute for calendar data refresh
2. With Pure Calendar, I’ve got some problems of disapperance of the lists with LauncherPro or with ADw.
1. Which phone ? does it refresh after a screen rotation ?
have you tried Pure messenger ? does it works better ?
3. Noticing this issue with my setup (froyo frf91, nexus 1). I have 2 calenders (3×2) and If I do a manually refresh, one calendar will go blank, then come back, then the other calendar will go blank and it continue to do that until I reboot.
4. I know I was getting the disappearing act whenever it auto switched to landscape. It does it a lot less when disabled in launcher pro. But still happens mysteriously now once in a while
5. Phone: AT&T Captivate (Samsung SGS variant)
Android 2.1
Memory: 102MB
On rotate screen the widget goes blank. I gather this thread covers that topic, and that it is a known issue, and you are working on it.
Gook Luck! App pretty worthless with this problem.
1. I worked hard during last days, and I think I managed to get something perfectly stable in Launcher+.
Just few more testing days (1 or 2), and ADW and Launcher Pro will have to include this new code…
6. By the way, hitting refresh on the widget does not refill it. I need to go into the config and reapply, or shut down the phone, to populate the widget.
7. My google calenders are not populating in the list to “select Calenders’, how do I get it to see my cals?
8. I looove this widget. Only problem is quality of scrolling and the fact that when you scroll and hold it pulls the widget off. Im constantly accidently pulling the widget off the screen. Love the idea. Would pay$ 10 for
1. It depends which Launcher you are using😉
And this is mostly solved in the last Launcher+ code, all you have to do is wait for Launchers (ADW and LauncherPro) to update their code😉
9. Hi,
I have all the problems listed above, even when staying in portrait mode on my HTC Hero / Android 2.1 / Pure Calendar 2.1.3 / LauncherPro + 0.7.1.0
Can you precise Pure /LauncherPro versions that should fix the no refresh issue ?
Thanks,
1. As I said, it’s a launcher problem. You have to wait for a Launcher update. And I don’t have any date for that. Ask to Federico… he don’t answer me…
10. I Installed it to but what makes me curious is i have one Widget for Facebook its Blank, and the Second one is for messenges and this Works Launcher is ADW Launcher EX newest code av. at the Market.
1. Does Facebook registration works ?
If yes, please email me for deeper analysis (see ‘about’ page for my email)
11. Bonjour, je n’arrive pas a entrer des flux dans le widget, pourtant je me suis abonné au differents flux par google.
Vous avez parlé de launcher alternatif, qu’est ce que c’est ?
J’ai un samsung galaxy ace.
Merci
1. bonjour,
Il faut que vous installiez et utilisezz un lanceur alternatif comme Go Launcher ou ADW Launcher pour que ca fonctionne.
ciao,
Francois
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home sketches open source talks
What Exactly is The Singularity
The technological Singularity (often called the singularity for short) is a term that signifies a potential future where artificial intelligence surpasses human intelligence. After that point in time, civilization would radically change into a future that no human could comprehend. The idea of the singularity was first written about around 1950 by John von Neumann, one of the founders of computers, phycisist, and a polymath. He was paraphrased saying: “One conversation centered on the ever-accelerating progress of technology and changes in the mode of human life, which gives the appearance of approaching some essential singularity in the history of the race beyond which human affairs, as we know them, could not continue.”
Later in 1993, a computer scientist and science fiction author, Vernor Vinge popularized the idea of the singularity with a paper titled “The Coming Technological Singularity: How to Survive in the Post-Human Era”. In the paper he discusses aritifial intelligence with exponetial growth,technological unemployment, human extinction, intelligence applification for humans, and the unpreventability of the singularity. He really brought to center the idea of a doomsday scenario following the singularity where computers don’t need or want humans around and this idea has now entered the mainstream consciousness. In his paper he writes: “What are the consequences of this event? When greater-than-human intelligence drives progress, that progress will be much more rapid. In fact, there seems no reason why progress itself would not involve the creation of still more intelligent entities – on a still-shorter time scale. The best analogy that I see is with the evolutionary past: Animals can adapt to problems and make inventions, but often no faster than natural selection can do its work – the world acts as its own simulator in the case of natural selection. We humans have the ability to internalize the world and conduct “what if’s” in our heads; we can solve many problems thousands of times faster than natural selection. Now, by creating the means to execute those simulations at much higher speeds, we are entering a regime as radically different from our human past as we humans are from the lower animals.” Vernor believes that this shift would drammatically change the time scales of our future: “From the human point of view this change will be a throwing away of all the previous rules, perhaps in the blink of an eye, an exponential runaway beyond any hope of control. Developments that before were thought might only happen in “a million years” (if ever) will likely happen in the next century.” Vernor argues that if the singularity is even possible, the singularity cannot be avoided. That is because the lure of power it offers; competitive advantages in economics, military, and technology is so compelling that even if governments where to forbid these developments, it would just means someone else will get to it first. Further in his paper he talks about an alterantive path to the singularity called Intelligence Amplification (IA). This is scenario is a lot more safer for humans. Instead of independent computers evolving, humans are modified and amplified with computers to allow us to improve our memory retention, information processing, and other biological processes. These computer interfaces would act as subfunctions of human processes instead of running fully independently. Instead of trying to replicate human intelligence, researchers could focus on building computer systems that support human biological functions that we have already been studying and have some basic knowledge of. This would require much further advancement in our understanding of human biology, especially the brain. We would also need to accelerate advancements in human computer interfaces (HCI) to allow these technologies to properly interact with our bodies.
In 2005, Ray Kurzweil, a computer researcher, inventor, and technologist,wrote a book “The Singularity is Near”. In the book Ray tries to paint a picture of evidence showing that technology and artificial intelligence is growing at an exponetial rate and that our computer technology is just at the start of that growth curve. The result of all this growth will create something unrecognizable to anything we have ever seen. Ray talks about the possibillity of AI’s that merge with humans and nanotechnology that could transform us into countlss untold ways. He walks through charts and examples showing this growth trajectory which cumlimanates in his prediction of the Singuarity occuring around 2045. He believes that this technological Singularity will allow humans to achieve immortality, whether digitally(consciousness uploads) or physically (biological life extensions). Many of the arguments Ray make sense, but if you dig deeper into some of it, there are glaring holes.
With all these ideas of doomsday AI scenarios and potential immortality, the idea of the singularity has enterted into the mainstream zeitgeist. Countless movies and tv shows have been created showing what could potentially happen at the point when AIs become super intelligent. The Terminator series, West World, Avengers: Age of Ultron, Transcendence, 2001: A Space Odyssey, Her,Blade Runner,Ghost In The Shell, The Matrix, and so many more. Almost all of those movies end up with humans attacked, killed, and at the bottom of food chain. Her is the main exception from the list, the AIs become super intelligent and find that the humans are not smart enough and boring and so they all leave to another place (perhaps another dimesion) where humans can’t reach.
Some scientists, such as Stuart Russell and Stephen Hawking, have expressed concerns that if an advanced AI someday gains the ability to re-design itself at an ever-increasing rate, an unstoppable “intelligence explosion” could lead to human extinction. An AI’s brain would be a computer and not biological, and so would not have the limits of humans biological brains to grow and replicate. Humans are currently the smartest species known to exist and look how we treat other species below us: we eat them, hunt them for sport, use them as tools, or just plain try to kill them if they annoy us. If a computer would become smarter than us and could make its own decisions, there is no telling on what it would do. It could theoritically kill us because we are annoying or they could use as energy like batteries.
On the other side of the spectrum, some people thing we would end up in a much better situation where instead the computers become partners with us, merge with us, or just continue to be our subordinates and do what we tell them to. Computers would be intelligent, but for some reason may not have the same propencity for war and destruction as humans, and so may be fine working with humans. Image having computer doctors that could see our diagnosis and instantly recognize any ailment and have a customized cure for us. Imagine having a computer parner that you could ask any question to any problem and have it instantly solved in the most efficient way possible. Our world would have millions of Einstiens, geniuses that could invent new technologies for us nonstop. In this future, many people invision us accelerating our own biology to cure disease and aging, advancing our technology, and bringing a better future closer to us.
We have no way to know what that future would look like, but its not stopping people from trying to redirect us from hypothetical doomsday scenarios. Scientists,researchers, and futurist are trying to set humanity on a correction course by building ethical standards for the research and creation of AIs. The Machine Intelligence Research Institute (MIRI) who does AI research does AI research and states: “Given how disruptive domain-general AI could be, we think it is prudent to begin a conversation about this now, and to investigate whether there are limited areas in which we can predict and shape this technology’s societal impact….There are fewer obvious constraints on the harm a system with poorly specified goals might do. In particular, an autonomous system that learns about human goals, but is not correctly designed to align its own goals to its best model of human goals, could cause catastrophic harm in the absence of adequate checks.” Ethical AI is another group trying to help redirect the development of AI: “The current and rapid rise of AI presents numerous challenges and opportunities for humankind. Gartner predicts that 85% of all AI projects in the next two years will have erroneous outcomes. Adopting an ethical approach to the development and use of AI works to ensure organisations, leaders, and developers are aware of the potential dangers of AI and by integrating ethical principles into the design, development and deployment of AI, seek to avoid any potential harm.” The Future of Life Institute states: “Artificial intelligence (AI) has long been associated with science fiction, but it’s a field that’s made significant strides in recent years. As with biotechnology, there is great opportunity to improve lives with AI, but if the technology is not developed safely, there is also the chance that someone could accidentally or intentionally unleash an AI system that ultimately causes the elimination of humanity.” The Institute of Electrical and Electronics Engineers (IEEE) has a subgroup called The IEEE Global Initiative on Ethics of Autonomous and Intelligent Systems that has the mission of “Ensuring every stakeholder involved in the design and development of autonomous and intelligent systems is educated, trained, and empowered to prioritize ethical considerations so that these technologies are advanced for the benefit of humanity.”
The Algorithmic Justice League is trying to create equitable and accountable AI: “The Algorithmic Justice League’s mission is to raise awareness about the impacts of AI, equip advocates with empirical research, build the voice and choice of the most impacted communities, and galvanize researchers, policy makers, and industry practitioners to mitigate AI harms and biases. We’re building a movement to shift the AI ecosystem towards equitable and accountable AI.”
AI4ALL is a nonprofit working to increase diversity and inclusion in artificial intelligence: “We believe AI provides a powerful set of tools that everyone should have access to in our fast-changing world. Diversity of voices and lived experiences will unlock AI’s potential to benefit humanity. When people of all identities and backgrounds work together to build AI systems, the results better reflect society at large. Diverse perspectives yield more innovative, human-centered, and ethical products and systems.”
OpenAI seems to have the biggest ambitions and most funding (~2 billion as of 2021): “OpenAI is an AI research and deployment company. Our mission is to ensure that artificial general intelligence benefits all of humanity. OpenAI’s mission is to ensure that AGI-by which we mean highly autonomous systems that outperform humans at most economically valuable work—benefits all of humanity. We will attempt to directly build safe and beneficial AGI, but will also consider our mission fulfilled if our work aids others to achieve this outcome.”
Along with all these institutions being created, universities are also creating groups with similar goals of saving humanity. The University of Oxford has created the Leverhulme Centre for the Future of Intelligence (CFI). Their goal: “Our aim is to bring together the best of human intelligence so that we can make the most of machine intelligence. The rise of powerful AI will be either the best or worst thing ever to happen to humanity. We do not yet know which. The research done by this centry will be crucial to the future of our civilisation and of our species.” The University of Berkeley has created the Center for Human-Compatible AI (CHAI). Their stated mission: “The long-term outcome of AI research seems likely to include machines that are more capable than humans across a wide range of objectives and environments. This raises a problem of control: given that the solutions developed by such systems are intrinsically unpredictable by humans, it may occur that some such solutions result in negative and perhaps irreversible outcomes for humans. CHAI’s goal is to ensure that this eventuality cannot arise, by refocusing AI away from the capability to achieve arbitrary objectives and towards the ability to generate provably beneficial behavior. Because the meaning of beneficial depends on properties of humans, this task inevitably includes elements from the social sciences in addition to AI.”
There are dozens of other groups working on redirecting humanity and AI from these potential doomsday scenarios. Clearly there are a lot of smart people concerned that this is a big problem right now and worth trying to figure out before its too late.
In the following writings, we will discuss where AI technology currently is and whether this is really needed or not.
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| 0.819826 |
+ Start a Discussion
CTU007CTU007
Field level security through Eclipse?
Hi, it looks like FLS is not possible when creating new field using Eclipse.
So what is the easier way to do it?
JonPJonP
FLS is stored in a .profile object in Eclipse, but the easiest way to configure profile settings for a new custom field across multiple profiles is to create the field using the wizard under Setup (in your browser). One of the last steps is to set the visibility and editability of the field for each profile.
CTU007CTU007
I need to create 14 date fields and 7 formula field:
Stage 0 start date --- Stage 6 start date
Stage 0 end date --- Stage 6 end date
then formula stage 0 duration --- stage 6 duration
I created 3 fields for stage 0 in UI and edited the fields for stage 1 to stage 6 in Eclipse, and tried to insert them in Eclipse, but somehow, I cannot. I remember I used to create new fields in this way.
That is why I asked how to do it in Eclipse, it would be much faster if possible.
EDIT: FLS on all 14 fields are same. But I cannot save to server:
<fields>
<fullName>S1_End_Date__c</fullName>
<label>S1 End Date</label>
<type>Date</type>
</fields>
<fields>
<fullName>S1_Start_Date__c</fullName>
<inlineHelpText>start date of stage 1</inlineHelpText>
<label>S1 Start Date</label>
<type>Date</type>
</fields>
<fields>
<fullName>S1_Duration__c</fullName>
<formula>S1_End_Date__c - S1_Start_Date__c</formula>
<formulaTreatBlanksAs>BlankAsZero</formulaTreatBlanksAs>
<label>S1 Duration</label>
<precision>18</precision>
<scale>1</scale>
<type>Number</type>
</fields>
If they can be saved/created, it is still easier to change FLS.
|
__label__pos
| 0.865912 |
Question
If a certain sum becomes 3 times in 6 years at compound interest, then in how many years, it will become 81 times?
यदि चक्रवृद्धि ब्याज पर 6 वर्षों में एक निश्चित राशि 3 गुना हो जाती है, तो कितने वर्षों में, यह 81 गुना हो जाएगी?
A.
B.
C.
D.
Answer D.
Answer explanationShare via Whatsapp
D.Let the principal amount=100 rs Time(t)=6 years Rate=r Amount (A)=300 rs According to the question - A=P(1+r/100)^t 300=100(1+r/100)^6 3=(1+r/100)^6.....(1) Now - A=8100 rs Time=T So - 8100=100(1+r/100)^T 81=(1+r/100)^T 3^4=(1+r/100)^6.....(2) Put the value of equation (1) in equation (2) [(1+r/100)^6]^4=(1+r/100)^T (1+r/100)^24=(1+r/100)^T So the sum become 81 times in 24 years. So the correct answer is option D.
D.माना मूल राशि = 100 rs समय (t) = 6 वर्ष दर = r राशि (A) = 300 रुपये प्रश्न के अनुसार - A = P(1 + r / 100) ^ t 300 = 100 (1 + r / 100) ^ 6 3 = (1 + r / 100) ^ 6 ..... (1) अभी - A = 8100 रुपये समय = T इसलिए - 8100 = 100 (1 + r / 100) ^T 81 = (1 + r / 100) ^T 3 ^ 4 = (1 + r / 100) ^ 6 ..... (2) समीकरण (1) का मान समीकरण(2) में [(1 + r / 100) ^ 6] ^ 4 = (1 + r / 100) ^T (1 + r / 100) ^ 24 = (1 + r / 100) ^T तो राशि 24 साल में 81 गुना हो जाएगी l इसलिए सही उत्तर विकल्प D है।
Comments
View Similar questions (संबन्धित प्रश्न देखें)
Question
A sum of money amounts to Rs. 9800 after 5 years and Rs. 12005 after 8 years at the same rate of simple interest. The rate of interest per annum is:
एक राशि 5 वर्ष बाद 9800 रुपये और 8 वर्ष बाद 12005 रुपये समान साधारण ब्याज दर पर हो जाती है। प्रति वर्ष ब्याज दर है:
A.
B.
C.
D.
Answer C.
Question
A sum of Rs. 800 amounts to Rs. 920 in 8 years at simple interest, the interest rate is increased by 3%, it would amount to how much?
एक साधारण ब्याज पर 800 रुपये की राशि 8 वर्षों में 920 रुपये हो जाती है, दर में 3% की वृद्धि की जाती है, तो यह कितनी राशि होगी?
A.
B.
C.
D.
Answer B.
Question
Albert invested an amount of Rs. 8000 in a fixed deposit scheme for 2 years at compound interest rate 5 p.c.p.a. How much amount will Albert get on maturity of the fixed deposit?
अल्बर्ट ने 5 प्रतिशत प्रति वर्ष की चक्रवृद्धि ब्याज दर पर 2 वर्षों के लिए सावधि जमा योजना में 8000 रुपये की राशि का निवेश किया। सावधि जमा की परिपक्वता पर अल्बर्ट को कितनी राशि मिलेगी?
A.
B.
C.
D.
Answer C.
Question
Find the compound interest on Rs. 5000 for 1 year at 8% per annum, compounded half-yearly.
5000 रुपये पर 1 वर्ष के लिए 8% प्रति वर्ष की दर से चक्रवृद्धि ब्याज ज्ञात कीजिए, जो अर्ध-वार्षिक रूप से संयोजित है।
A.
B.
C.
D.
Answer B.
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TransWarp GS
From The ReActiveMicro Apple II Wiki
Revision as of 22:47, 27 August 2017 by RMHenry (talk | contribs) (Created page with "== GALs == AE sometimes used the part number suffix "N" and other times they used "I". "N" labeled parts have a "-" separating them, whereas the early "I" labeled parts hav...")
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
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GALs[edit]
AE sometimes used the part number suffix "N" and other times they used "I". "N" labeled parts have a "-" separating them, whereas the early "I" labeled parts have a "-" for separation and later used ".". It is not clear why the differences in suffixes. However there does not seem to be a version difference. The differences could be when Don Pote sold AE to a new owner in the early 1990's.
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| 0.526412 |
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Regular Expression
A regular expression (shortened as regex or regexp; sometimes referred to as rational expression) is a sequence of characters that specifies a search pattern in text. Usually such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings, or for input validation. Regular expression techniques are developed in theoretical computer science and formal language theory. The concept of regular expressions began in the 1950s, when the American mathematician Stephen Cole Kleene formalized the concept of a regular language. They came into common use with Unix text-processing utilities. Different syntaxes for writing regular expressions have existed since the 1980s, one being the POSIX standard and another, widely used, being the Perl syntax. Regular expressions are used in search engines, in search and replace dialogs of word processors and text editors, in text processing utilities such as sed and AWK, and in lexical analysis ...
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Regular Expression Example
The term regular can mean normal or in accordance with rules. It may refer to: People * Moses Regular (born 1971), America football player Arts, entertainment, and media Music * "Regular" (Badfinger song) * Regular tunings of stringed instruments, tunings with equal intervals between the paired notes of successive open strings Other uses in arts, entertainment, and media * Regular character, a main character who appears more frequently and/or prominently than a recurring character * Regular division of the plane, a series of drawings by the Dutch artist M. C. Escher which began in 1936 * ''Regular Show'', an animated television sitcom * '' The Regular Guys'', a radio morning show Language * Regular inflection, the formation of derived forms such as plurals in ways that are typical for the language ** Regular verb * Regular script, the newest of the Chinese script styles Mathematics There are an extremely large number of unrelated notions of "regularity" in mathematics. ...
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Text Processing
In computing, the term text processing refers to the theory and practice of automating the creation or manipulation of electronic text. ''Text'' usually refers to all the alphanumeric characters specified on the keyboard of the person engaging the practice, but in general ''text'' means the abstraction layer immediately above the standard character encoding of the target text. The term ''processing'' refers to automated (or mechanized) processing, as opposed to the same manipulation done manually. Text processing involves computer commands which invoke content, content changes, and cursor movement, for example to * search and replace * format * generate a processed report of the content of, or * filter a file or report of a text file. The text processing of a regular expression is a virtual editing machine, having a primitive programming language that has named registers (identifiers), and named positions in the sequence of characters comprising the text. Using these, the "text p ...
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SNOBOL
SNOBOL ("StriNg Oriented and symBOlic Language") is a series of programming languages developed between 1962 and 1967 at AT&T Bell Laboratories by David J. Farber, Ralph E. Griswold and Ivan P. Polonsky, culminating in SNOBOL4. It was one of a number of text-string-oriented languages developed during the 1950s and 1960s; others included COMIT and TRAC. SNOBOL4 stands apart from most programming languages of its era by having patterns as a first-class data type (''i.e.'' a data type whose values can be manipulated in all ways permitted to any other data type in the programming language) and by providing operators for pattern concatenation and alternation. SNOBOL4 patterns are a type of object and admit various manipulations, much like later object-oriented languages such as JavaScript whose patterns are known as regular expressions. In addition SNOBOL4 strings generated during execution can be treated as programs and either interpreted or compiled and executed (as in the ev ...
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Automata Theory
Automata theory is the study of abstract machines and automata, as well as the computational problems that can be solved using them. It is a theory in theoretical computer science. The word ''automata'' comes from the Greek word αὐτόματος, which means "self-acting, self-willed, self-moving". An automaton (automata in plural) is an abstract self-propelled computing device which follows a predetermined sequence of operations automatically. An automaton with a finite number of states is called a Finite Automaton (FA) or Finite-State Machine (FSM). The figure on the right illustrates a finite-state machine, which is a well-known type of automaton. This automaton consists of states (represented in the figure by circles) and transitions (represented by arrows). As the automaton sees a symbol of input, it makes a transition (or jump) to another state, according to its transition function, which takes the previous state and current input symbol as its arguments. Automata theo ...
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New Mexico State University
New Mexico State University (NMSU or NM State) is a public land-grant research university based primarily in Las Cruces, New Mexico. Founded in 1888, it is the oldest public institution of higher education in New Mexico and one of the state's two flagship universities, along with the University of New Mexico. NMSU has extension and research centers across the state, including campuses in Alamogordo, Carlsbad, Doña Ana County, and Grants. Initially established as Las Cruces College, NM State was designated a land-grant college in 1898 and subsequently renamed New Mexico College of Agriculture and Mechanic Arts; it received its present name in 1960. NMSU had approximately 21,700 students enrolled as of Fall 2021 and a faculty-to-student ratio of roughly 1 to 16. NMSU offers 28 doctoral degree programs, 58 master's degree programs, and 96 baccalaureate majors. New Mexico State's athletic teams compete at the NCAA Division I level in the Western Athletic Conference except for foo ...
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Kleene
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End of differential equation, quick alegbra Q
1. Jan 30, 2012 #1
1. The problem statement, all variables and given/known data
I just solved a differential equation and got the problem down to its implicit solution:
y/√(1+y2) = x3+C where C is an arbitrary constant
My question now is, how can I solve for y? I can't get past the algebra. Thanks!
2. Relevant equations
3. The attempt at a solution
2. jcsd
3. Jan 30, 2012 #2
Dick
User Avatar
Science Advisor
Homework Helper
Square both sides. Solve for y^2. Take a square root. Come on. Try it.
4. Jan 30, 2012 #3
Square both sides and bring the bottom part to the other side. You'll get
[itex]y^2 = (1+y^2)(x^3 + c)^2[/itex]
Then multiply out and regroup.
[itex]y^2 -y^2(x^3 + c)^2 = (x^3 + c)^2[/itex]
then you'll get [itex] y^2 = \frac{(x^3+c)^2}{1-(x^3+c)^2}[/itex]
So [itex]y = \sqrt{\frac{(x^3+c)^2}{1-(x^3+c)^2}}[/itex]
5. Jan 30, 2012 #4
thank you!
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setEGLContextClientVersion(2) causes a crash
1. wolfscaptain
wolfscaptain Member
I am trying to make an OpenGL ES2 application. As a start, I just copied the demo BasicGLSurfaceView from the API level 11 samples.
After it crashed no matter what I changed, I made a very stripped version which basically just creates the surface. After many testing and finally trying out the debugger, it seems like calling setEGLContextClientVersion() with 2 causes an exception in GLThread:
PHP:
1. Thread [<1> main] (Running)
2. Thread [<8> Binder Thread #2] (Running)
3. Thread [<7> Binder Thread #1] (Running)
4. Thread [<9> GLThread 10] (Suspended (exception IllegalArgumentException))
5. GLSurfaceView$GLThread.run() line: 1122
This is my first try at an Android application, so I have no idea what this means. Tried to find what GLThread is, but it isn't documented in the API.
This is the current - very simple - code (taken from here):
PHP:
1.
2. import javax.microedition.khronos.egl.EGLConfig;
3. import javax.microedition.khronos.opengles.GL10;
4.
5. import android.app.Activity;
6. import android.opengl.GLSurfaceView;
7. import android.os.Bundle;
8.
9. public class Test extends Activity {
10. @Override
11. protected void onCreate(Bundle savedInstanceState) {
12. super.onCreate(savedInstanceState);
13. mGLView = new GLSurfaceView(this);
14. mGLView.setEGLContextClientVersion(2);
15. mGLView.setRenderer(new ClearRenderer());
16. setContentView(mGLView);
17. }
18.
19. @Override
20. protected void onPause() {
21. super.onPause();
22. mGLView.onPause();
23. }
24.
25. @Override
26. protected void onResume() {
27. super.onResume();
28. mGLView.onResume();
29. }
30.
31. private GLSurfaceView mGLView;
32. }
33.
34. class ClearRenderer implements GLSurfaceView.Renderer {
35. public void onSurfaceCreated(GL10 gl, EGLConfig config) {
36.
37. }
38.
39. public void onSurfaceChanged(GL10 gl, int w, int h) {
40.
41. }
42.
43. public void onDrawFrame(GL10 gl) {
44.
45. }
46. }
47.
When I run either this or the demo without the debugger, they crash.
Any ideas why this happens?
Oh and I am currently using the level 9 API, but I tried with both 10 and 11 too to no avail, so I guess that's not the issue.
Thanks for any help :)
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2. wolfscaptain
wolfscaptain Member
I finally copied the GLES20 demo that sets the renderer based on a function that checks if ES 2 is supported.
Since I can't find a way to sort of "show" things (I always loved the console that comes with any C/C++ application...), I just commented the check and noticed that apparently ES 2 is simply not supported by the emulator.
A google search on that question turned out to be true, but it is 3 months old.
Is there no way to use ES 2 on the emulator? What's the point of the emulator if you can't do on it what you can do on an actual device?
Since I don't have a device yet (waiting for an Android 3 tablet), I can't actually write anything... (not really happy about writing a lot of code and then later on trying to debug it without ever using it...)
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A in-game goal created by the game's designers. Rewards for these are granted to the player, not the avatar, and therefore do not affect the in-game experience.
learn more… | top users | synonyms
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Javascript is required
1
JEE Main 2021 (Online) 22th July Evening Shift
MCQ (Single Correct Answer)
+4
-1
If the domain of the function $$f(x) = {{{{\cos }^{ - 1}}\sqrt {{x^2} - x + 1} } \over {\sqrt {{{\sin }^{ - 1}}\left( {{{2x - 1} \over 2}} \right)} }}$$ is the interval ($$\alpha$$, $$\beta$$], then $$\alpha$$ + $$\beta$$ is equal to :
A
$${3 \over 2}$$
B
2
C
$${1 \over 2}$$
D
1
2
JEE Main 2021 (Online) 20th July Evening Shift
MCQ (Single Correct Answer)
+4
-1
Let $$f:R - \left\{ {{\alpha \over 6}} \right\} \to R$$ be defined by $$f(x) = {{5x + 3} \over {6x - \alpha }}$$. Then the value of $$\alpha$$ for which (fof)(x) = x, for all $$x \in R - \left\{ {{\alpha \over 6}} \right\}$$, is :
A
No such $$\alpha$$ exists
B
5
C
8
D
6
3
JEE Main 2021 (Online) 20th July Morning Shift
MCQ (Single Correct Answer)
+4
-1
Let [ x ] denote the greatest integer $$\le$$ x, where x $$\in$$ R. If the domain of the real valued function $$f(x) = \sqrt {{{\left| {[x]} \right| - 2} \over {\left| {[x]} \right| - 3}}} $$ is ($$-$$ $$\infty$$, a) $$]\cup$$ [b, c) $$\cup$$ [4, $$\infty$$), a < b < c, then the value of a + b + c is :
A
8
B
1
C
$$-$$2
D
$$-$$3
4
JEE Main 2021 (Online) 18th March Evening Shift
MCQ (Single Correct Answer)
+4
-1
Let f : R $$-$$ {3} $$ \to $$ R $$-$$ {1} be defined by f(x) = $${{x - 2} \over {x - 3}}$$.
Let g : R $$ \to $$ R be given as g(x) = 2x $$-$$ 3. Then, the sum of all the values of x for which f$$-$$1(x) + g$$-$$1(x) = $${{13} \over 2}$$ is equal to :
A
3
B
5
C
2
D
7
JEE Main Subjects
© 2023 ExamGOAL
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Code to the Rhythm of the Beat
This is just a post to inquire about other technical courses that people have attended. Was there music during the course of the week?
A couple of other questions:
• What types of music were played?
• When was the music played (ie. just during coding sessions?)
• Did it annoy you?
Most students of the last 1-2 years will attest to the fact that music and movies are a large part of what create some of the atmosphere for the courses. This year there has been a large preference, on my part, to the following types of music:
• Orchestral movie soudntracks. Some examples of the music played is as follows:
• SteamBoy
• Star Trek
• Bourne Supremacy
• Star Wars
• Evolution
• Kung Fu Panda
• many others..
• Podrunner One of my personal favourites to work through during a work day. Few lyrics, 1 hour of constant music, high adrenaline mixes. A particular favourite to play during group exercises is:
• Ziggurat - This is a staircase mix that goes from 150-160-170 bpm and all the way back down over the course of an hour, with 10 minute interval chimes to let you know when you are switching gears.
Podrunner has long been a class staple. It makes the environment feel very much like a school coding jam where people bunker down to flex their minds on some often challenging problems. I love it!!!
The response varies obviously, but overall, it has been a successful dynamic that raises the level of energy in the room collectively!!
So what are you listening to?
Develop With Passion®
Comments
|
__label__pos
| 0.874482 |
[dokuwiki] Re: Plugin programming question - how to 're-parse' something?
• From: Guillaume Turri <guillaume.turri@xxxxxxxxx>
• To: dokuwiki@xxxxxxxxxxxxx
• Date: Sun, 16 Oct 2011 18:25:02 +0200
Hi,
2011/10/14 Chris G <cl@xxxxxxxx>
> Is it possible to re-parse some code from within a syntax plugin?
>
The hidden plugin[1] does it in two ways:
1 - It parses the text in the first <hidden> tag. Here, it already has a
text to parse. It's done like this:
> $tab = array();
> $parsedText = p_render('xhtml', p_get_instructions($rawText), $tab);
I'm afraid it's not the most effective way to do it (like in "we're
launching a whole new parsing chain"); but it works.
2 - It lets parse the text between the <hidden> tags. It means in particular
that nested plugins may be used.
It's done thanks to the getAllowedTypes() and accepts() functions
I think this second case is more likely to be what you are looking for.
I hope this information is useful.
Regards,
Guillaume
[1]: https://github.com/gturri/hidden/blob/master/syntax.php
Other related posts:
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Hit enter after type your search item
The DELETE command in SQL
The SQL DELETE command is used to remove the records from the relational database tables permanently.
Using DELETE command without the WHERE clause removes table data completely. For example:
DELETE FROM table_name;
This is the simplest syntax of using the DELETE SQL statement.
You should always use WHERE clause in order to remove only specific rows from the table. For example:
If you require removing the table data completely then consider using the TRUNCATE statement. This is faster in execution as compared to DELETE FROM statement if the task is to remove table data completely.
Note that, the DELETE statement only removes table data. The table structure, constraints etc. remain in place.
The table data removed after using the DELETE command can be rolled back.
The next section shows using DELETE statement with various examples.
The example of deleting a row
In the first example of a delete query in SQL, I will remove only one row from the table. For that, the DELETE statement is used with the WHERE clause. The condition is set in the WHERE clause to remove the record of an employee which id = 10.
The DELETE query:
The table data before and after delete query:
SQL DELETE
How to empty a table?
As mentioned earlier, the DELETE command removes the table data completely when used without a WHERE clause. The query below shows removing the table data completely.
I wrote four queries as follows:
The first query retrieves the complete data from the sto_employees table.
While the second query is the “DELETE FROM” without the WHERE clause. This is placed inside the ROLLBACK block in MS SQL Server. So, after emptying the table the ROLLBACK command is executed.
Before ROLLBACK, the table data is displayed in the graphic below.
The last query is again complete table data retrieval after the ROLLBACK. See the queries and resultsets:
SQL DELETE Empty
You should use TRUNCATE statement for removing table data completely. For learning more about it, go to TRUNCATE tutorial.
The demo of using IN clause in the DELETE statement
In the WHERE clause with DELETE statement, you may use various operators for removing the specific records.
The next query uses IN operator where I specified a few employee names to remove rows from the table.
The query:
SQL DELETE IN operator
You may see the difference before and after executing the DELETE command. In the second table, three records are removed from the employee’s table.
Using BETWEEN operator with the DELETE command
Similarly, you may specify the range of values by using the SQL BETWEEN operator in the DELETE command for removing records.
The following query removes data where I used the BETWEEN operator for emp_salary column:
SQL DELETE BETWEEN operator
An example of using JOIN with DELETE statement
The JOIN clause enables combining different tables in the RDBMS that are related by common fields. The JOIN clause is generally used with the SELECT statement for retrieving data.
You may also use JOIN clause with the DELETE statement. See an example query below where I joined two tables – sto_employees and sto_orders by an INNER JOIN clause.
SQL DELETE JOIN
Note the table alias used after the DELETE command.
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How to Copy and Paste Hashtags to Instagram?
Are you a frequent user of Instagram but unsure about how to effectively use hashtags to boost your posts? Look no further!
In this article, we will discuss the importance of hashtags on Instagram, how to add hashtags on Instagram after posting, best practices for using hashtags, tools to help find and organize hashtags, tips for using hashtags effectively, and much more.
Stay tuned to learn how to make the most out of hashtags on Instagram and increase your visibility on the platform!
Key Takeaways:
• Hashtags are a crucial aspect of Instagram, helping to increase visibility and engagement for your posts.
• Copy and paste hashtags on Instagram using the traditional method, a third-party app, or a saved document for efficiency.
• Use relevant and balanced hashtags, limit their number, and create a branded one for a successful Instagram hashtag strategy.
• What Are Hashtags and Why Are They Important on Instagram?
Hashtags on Instagram are words or phrases preceded by the # symbol that categorize content and make it more discoverable to users on the platform. They play a crucial role in enhancing visibility, increasing engagement, and reaching a broader audience.
By utilizing hashtags strategically, users can effectively organize their posts into specific themes, trends, or topics, allowing their content to be easily grouped with similar posts. This not only improves the searchability of their posts but also helps in attracting users’ attention, especially those who are interested in the particular hashtags used.
Hashtags enable users to explore diverse content across different genres or interests, facilitating connections with like-minded individuals and communities. Through the use of trending hashtags, users can amplify their reach and potentially attract a larger audience to their profile, consequently boosting engagement and fostering a sense of belonging within the Instagram community.
How to Copy and Paste Hashtags on Instagram?
To copy and paste hashtags on Instagram, users can employ various methods depending on their device or preferences, such as utilizing a desktop browser, Android device, iPhone, iPad, or even a Notes app for easy access and insertion.
When using a desktop browser, simply right-click on the hashtag you want to copy and select ‘Copy’ from the dropdown menu. Then, navigate to your Instagram post, position the cursor in the caption or comment box, right-click again, and choose ‘Paste’ to insert the hashtag seamlessly.
For Android users, press and hold on a hashtag, select ‘Copy’ from the options provided, open Instagram, tap on the caption area, long-press again, and choose ‘Paste’ to include the Instagram hashtag effortlessly.
iPhone or iPad users can tap and hold on a hashtag, select ‘Copy’ from the menu, go to Instagram, tap in the caption field, long-press, and tap on ‘Paste’ to insert the copied hashtag.
If you prefer to organize your hashtags in a separate app like ‘Notes,’ create a list of hashtags you want to use, select and copy them, open Instagram, tap in the caption area, and paste your hashtag list for quick and efficient insertion.
Using the Copy and Paste Method
The copy and paste method for adding hashtags on Instagram involves selecting desired hashtags, copying them using the device’s capabilities, and pasting them directly into the caption or comments section of a post.
When utilizing this technique, users can streamline the process by simply tapping and holding on a hashtag to bring up the ‘copy’ option. This can be done on various devices, such as smartphones, tablets, and computers, making it accessible to a wide range of users. To ensure a seamless integration, after copying the hashtags, users can navigate to their desired post on Instagram and tap on the caption or comments section to paste the hashtags effortlessly.
Using a Third-Party App
Utilizing a third-party app for managing hashtags on Instagram provides users with additional functionalities, such as hashtag suggestions, organization tools, and advanced copy-and-paste features for optimizing hashtag usage.
These third-party apps streamline the process of selecting hashtags by suggesting relevant tags based on the content of your post, saving you valuable time and effort.
They offer valuable analytics insights that help you track the performance of your hashtags, identify the most effective ones, and refine your overall hashtag strategy for better engagement.
Popular apps like Later, Planoly, and Hashtagify each bring unique features to the table, such as schedule posting, hashtag grouping, and trend tracking, catering to different user needs and preferences.
For users looking to enhance their hashtag game, we recommend exploring these apps to boost their Instagram presence and maximize the impact of their hashtags.
Using a Saved Note or Document
Saving hashtag collections in a note or document on devices like iPad or iPhone using apps like Notes allows users to easily access and copy relevant hashtags for efficient pasting into Instagram posts.
The process of creating and utilizing saved notes or documents for hashtag storage and retrieval involves initially compiling a list of relevant hashtags based on your niche or post content. Organize these hashtags categorically within your notes or documents, utilizing bullet points or tables for clear visibility and quick reference. If you’re wondering how to download Instagram hashtags, check out our guide.
To ensure seamless synchronization across multiple devices, consider using cloud storage services like iCloud or Dropbox to store and access your hashtag collections. By backing up your notes in the cloud, you can access them from any device, ensuring consistency in your hashtag usage.
Utilizing the Notes app effectively to manage your hashtags involves setting up dedicated notes for different categories or types of posts. Create hashtags templates for specific types of content or campaigns to streamline the process of hashtag selection and insertion.
What Are the Best Practices for Using Hashtags on Instagram?
Implementing best practices for hashtag usage on Instagram involves maintaining relevance, incorporating a mix of popular and niche hashtags, limiting the number of hashtags, and creating a branded hashtag to enhance brand identity and engagement.
Relevant hashtags ensure that your posts reach the right audience interested in your content, boosting engagement and visibility. By including a mix of both popular and niche hashtags, you broaden your post’s exposure while targeting specific niches. Keeping the number of hashtags optimal is crucial; overwhelming posts with hashtags can appear spammy and reduce credibility. Crafting a unique branded hashtag helps foster a sense of community among your followers, encourages user-generated content, and reinforces brand loyalty. Successful brands like Nike with their #JustDoIt have shown the power of branded hashtags in creating a strong online brand presence.
Keep Them Relevant
Ensuring that hashtags used on Instagram posts are relevant to the content and target audience is crucial for maximizing engagement, visibility, and discoverability among users interested in specific topics or categories.
When creating hashtags, it is essential to align them with the overall theme of the content to make them more appealing and searchable. Researching popular and trending hashtags within your niche can provide valuable insights into the preferences of your target audience. By incorporating these insights into your hashtag strategy, you can effectively attract more users to your posts and increase your reach.
Analyzing keywords related to your content can also help in identifying relevant hashtags that resonate with your audience. Tools such as Hashtagify or RiteTag can assist in keyword analysis and suggest relevant hashtags to use in your posts. Monitoring the performance of your hashtags using Instagram analytics tools can help in evaluating their effectiveness and making necessary adjustments to maintain their relevance over time.
Use a Mix of Popular and Niche Hashtags
Balancing the use of popular hashtags with niche-specific ones on Instagram allows content to reach a broader audience while also targeting a more engaged and relevant segment of users interested in specific subcategories or themes.
Combining popular hashtags such as #instagood or #photooftheday with niche tags like #veganfoodie or #sustainableliving can enhance post visibility to diverse groups while drawing in those passionate about specialized topics.
To identify the most effective hashtags, consider using tools that provide insights into competition scores to gauge the competitiveness of tags. By strategically incorporating a mix of widely-used and targeted hashtags, content creators can optimize their reach and engagement levels, ultimately cultivating a dynamic and interactive community.
Successful Instagram accounts often utilize this approach, tailoring their hashtag strategies to strike a balance between broad appeal and niche relevance, resulting in higher visibility and increased interaction.
Limit the Number of Hashtags Used
Restricting the total number of hashtags used in an Instagram post is recommended to avoid overcrowding, maintain aesthetic appeal, and ensure that each hashtag selected adds genuine value and relevance to the content.
When deciding on the optimal number of hashtags to include, it’s crucial to consider the specific type of post being shared. For example, posts featuring products or services might benefit from a higher number of relevant hashtags to increase visibility among potential customers. On the other hand, content focused on storytelling or emotions may require a more targeted approach with fewer, but highly impactful hashtags.
Understanding your audience’s preferences is another key factor in determining the right hashtag strategy. Analyzing the interests, demographics, and online behavior of your followers can help you tailor your hashtags to resonate with them better. By using hashtags that align with their interests, you can attract a more engaged audience and foster meaningful interactions.
Setting clear engagement goals for your Instagram posts can guide your hashtag selection process. If your objective is to boost brand awareness, using trending or popular hashtags related to your industry can help you reach a wider audience. Conversely, if you aim to drive traffic to your website or promote a specific campaign, incorporating branded hashtags or creating custom ones can encourage followers to take action.
In terms of prioritizing hashtags, focusing on high-impact ones that are both relevant and popular within your niche is essential. Researching trending hashtags, industry-specific terms, or location-based tags can elevate the visibility of your posts and attract more interactions. Regularly monitoring the performance of your hashtags through Instagram Insights or third-party analytics tools allows you to track which hashtags are driving the most engagement and adjust your strategy accordingly.
Create Your Own Branded Hashtag
Developing a branded hashtag unique to your brand or campaign on Instagram can foster community engagement, promote user-generated content, and enhance brand visibility by creating a distinct identity associated with your offerings.
When creating a branded hashtag, make sure it aligns perfectly with your brand’s values, products, or services to resonate with your target audience. This alignment will ensure that the hashtag not only stands out but also reinforces your brand message.
To make your hashtag truly unique, conduct thorough research to ensure it hasn’t been used before and is not associated with any negative connotations. Integration of the hashtag into your overall campaign strategy is crucial for maximum impact, ensuring consistency across all marketing channels.
What Are Some Tools to Help Find and Organize Hashtags?
Various tools are available to assist users in discovering and organizing hashtags on Instagram, including the platform’s Explore Tab, third-party hashtag generator apps, and advanced hashtag analytics tools for optimizing hashtag strategies.
Instagram’s Explore Tab is a built-in feature that showcases trending hashtags and posts, making it a valuable resource for finding relevant tags for your content.
Third-party hashtag generator apps, such as Hashtagify and RiteTag, offer creative suggestions based on your input, streamlining the process of creating effective hashtags.
Advanced hashtag analytics tools like Keyhole and Sprout Social provide in-depth insights into hashtag performance, helping users track reach, engagement, and overall impact.
Instagram’s Explore Tab
Instagram’s Explore Tab serves as a valuable tool for users to explore trending content, discover new hashtags, and engage with diverse communities, providing insights and inspiration for incorporating relevant hashtags into their own posts.
Through the Explore Tab, users can delve into a wide array of content based on their interests, making it a hub for staying updated on the latest trends and happenings across various niches. By scrolling through the carefully curated posts, users can not only gain valuable insights but also identify popular hashtags that resonate with their target audience.
This feature plays a crucial role in aiding users in identifying emerging trends, understanding their audience’s preferences, and crafting content that is not only engaging but also aligns with current interests.
Third-Party Hashtag Generator Apps
Third-party hashtag generator apps give the power to users with advanced hashtag suggestions, analytics insights, and organization capabilities to streamline hashtag selection, optimize visibility, and enhance engagement on Instagram through data-driven strategies.
These tools offer a user-friendly interface, allowing individuals and businesses to input specific keywords or topics and receive a curated list of relevant hashtags within seconds. The compatibility of these apps across various devices, including smartphones, tablets, and desktops, ensures seamless access on the go. Users can not only access trending hashtags but also create custom sets to align with their content strategies. The ability to analyze hashtag performance metrics and track audience engagement makes these apps invaluable for optimizing social media campaigns.
Hashtag Analytics Tools
Hashtag analytics tools offer users deep insights into hashtag performance, competition scores, potential reach, and engagement metrics, enabling data-driven decisions to refine hashtag strategies and enhance post visibility on Instagram.
Utilizing these tools is essential for social media marketers looking to stay ahead in the competitive landscape. By tracking metrics such as impressions, clicks, and shares associated with specific hashtags, users can gauge the effectiveness of their campaigns and make informed adjustments.
For instance, a travel brand can use hashtag analytics to identify trending travel tags, measure their own engagement rates, and adjust their content strategy accordingly to attract a larger audience.
What Are Some Tips for Using Hashtags Effectively on Instagram?
Maximizing the effectiveness of hashtags on Instagram involves strategic placement in captions or comments, experimentation with different hashtag strategies, and active engagement with posts using the same hashtags to foster community interaction and expand reach.
One essential tip for optimizing hashtag use is to ensure that they are relevant to the content being posted. Utilizing topical hashtags can help reach a targeted audience interested in that specific subject. Varying the quantity of hashtags used between posts can provide insight into what works best for engagement.
Another crucial aspect is to track performance metrics related to the hashtags being used. By monitoring data such as reach, impressions, and engagement rates, you can refine your hashtag strategy for better results.
Encourage user engagement through interactive hashtag initiatives. Create branded hashtags that encourage followers to participate in challenges, contests, or share user-generated content, thereby fostering a sense of community and loyalty among your audience.
Use Hashtags in Your Caption or Comments?
Deciding whether to incorporate hashtags in captions or comments on Instagram can impact post visibility, engagement levels, and audience interaction, requiring users to experiment with both approaches to determine the optimal strategy for their content.
In terms of choosing between using hashtags in captions or comments, there are various considerations to keep in mind. Placing hashtags in captions can make them more prominent and immediately visible to viewers scrolling through their feeds, potentially attracting a broader audience. On the other hand, including hashtags in comments can keep the caption clean and focused on the main message, enhancing the overall aesthetic appeal of the post. Understanding your content’s nature and your target audience’s behavior can guide you in deciding the most effective placement for hashtags.
Experiment with Different Hashtag Strategies
Testing and experimenting with various hashtag strategies on Instagram, such as mixtures of popular and niche tags, seasonal themes, or user-generated content initiatives, can provide valuable insights into effective hashtag usage and audience response.
By incorporating a testing culture in your social media strategy, you can identify which hashtag combinations resonate best with your target market and drive engagement. Analyzing the performance metrics of different hashtag sets allows you to refine your approach and tailor content more effectively. Observing trends across platforms and staying informed about algorithm updates can help you stay ahead in optimizing your hashtag tactics for maximum visibility and reach. Embracing a dynamic approach by regularly assessing, adjusting, and innovating your strategy based on user interactions is key to sustained success.
Engage with Other Posts Using the Same Hashtag
Actively engaging with posts that use the same hashtags on Instagram fosters community interaction, enhances visibility, and establishes connections with like-minded users, creating opportunities for collaboration, cross-promotion, and mutual support.
When you interact with hashtag-related content, you not only showcase your own posts to a wider audience but also tap into a network of individuals who share common interests. This exchanging of likes, comments, and follows can lead to organic growth and meaningful engagements. By consistently participating in relevant hashtag communities, you position yourself as an active member of the Instagram community, which can attract potential followers who resonate with your content. Utilizing strategic hashtags and engaging with trending topics can elevate your presence and help you connect with influencers and brands looking for collaborative opportunities.
Conclusion
Mastering the art of hashtag usage on Instagram through effective methods and best practices can significantly boost content visibility, audience engagement, and platform reach, give the power toing users to harness the full potential of hashtags for their social media content.
By strategically incorporating relevant hashtags in your posts, you can increase the discoverability of your content and attract a larger audience interested in specific topics or niches. It is crucial to conduct research on trending hashtags, analyze competitor strategies, and create a mix of popular and niche hashtags to optimize reach and engagement.
Actively engaging with other users through likes, comments, and collaborations can enhance your profile visibility, build a loyal follower base, and foster a sense of community within your Instagram network.
Frequently Asked Questions
1. How do I copy and paste hashtags to Instagram?
To copy and paste hashtags to Instagram, first find the hashtags you want to use on a different platform or website. Then, highlight and copy the hashtags. Next, open the Instagram app and create a new post. Tap on the caption box and paste the hashtags by pressing and holding the text area. Finally, tap “paste” to insert the hashtags.
2. Can I copy and paste multiple hashtags at once on Instagram?
Yes, you can copy and paste multiple hashtags at once on Instagram. Simply follow the same steps as above, but instead of copying and pasting one hashtag at a time, you can select and copy multiple hashtags together to save time and effort.
3. Is there a limit to the number of hashtags I can copy and paste on Instagram?
Yes, Instagram limits the number of hashtags you can use in a post to 30. Therefore, you can copy and paste up to 30 hashtags at a time. However, it is recommended to use a smaller number of relevant hashtags for better engagement.
4. Can I copy and paste hashtags from other Instagram posts?
Yes, you can copy and paste hashtags from other Instagram posts. Simply open the post, tap on the three dots at the top of the post, and select “copy link.” Then, paste the link into a note-taking app or website and the hashtags will appear. You can then copy and paste them into your own Instagram post.
5. How can using hashtags benefit my Instagram posts?
Using hashtags can benefit your Instagram posts by increasing visibility and engagement. When you use relevant hashtags, your post is more likely to be seen by users who are interested in that topic. This can lead to new followers, likes, and comments on your post.
6. Is it necessary to use hashtags on Instagram?
No, it is not necessary to use hashtags on Instagram. However, using relevant and popular hashtags can greatly improve the reach and engagement of your posts. If you choose not to use hashtags, your post will only be visible to your followers and may not reach a wider audience.
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ClockworkRose
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1. There will always be your nano factory thing to make any resource you want. This is just to enable... Industrial quantities and efficiencies.
2. I agree that simple processes like oil->gas should only Require a single simple machine. Infact, your nano arm -thingy should probably be able to do everything in small quantities. My proposed system is meant to be for increasing efficiency. I posted to picture / link to show an example of how complex such systems get in real life. I think that the secondary outputs of such a system should not be single sourced. For instance, one of the outputs in the image linked is coke. You should be able to turn oil -> coke from your arm thing or a simple coke oven machine. The benefit of the large processing system is you get some coke and more gas per unit of input. The system is not meant block the obtaining of any resource, only improve it.
3. There is no "correct build". Its essentially all balanced around the quantity of material you wish to process. If you have a small amount, its not worth it (economically) to spend / create a larger processing setup. In addition, I'd imagine schematics and processes for the later machines would be rare, and would require ever more expensive materials to create. Essentially you have to make a choice in how far down the tech tree you need to go for your situation.
4. Many exploring and mining type games have a way to process raw material collected into a usable form. Imagine in minecraft smelting iron ore to create iron ingots. I would like to propose a similar system for DU, but one that allows substantial factories, with complex inputs and outputs.The basic idea is that with exponential increased complexity of a refinery, you get linearly increased yields of materials. Similar to how some mods in Minecraft work (ic2, mechanism, etc) and several other games work. So a simple smelter would turn 100 units of ore into 100 units of metal, but maybe adding ore washing gives 106 units of metal. and then adding an input of flux, grinding, and sifting gives you 112 units of metal. Real life ore refining has many steps with many machines, feedback loops, inputs, and outputs. Add to that there is no reason to stick with real life limits in this game. Maybe a matter fusactor can take some of the rock scrap and break it down to get the last bits of ore. As an example of how far you can go, with a pile of machines and process, look at https://en.wikipedia.org/wiki/Oil_refinery#Common_process_units_found_in_a_refinery There is a list of common processes involved, many of which require different inputs, output, feedback, and have multiple working parts. Constructing and running a large complex orbital refinery seems like a blast. A nice part about this system is it doesn't really impact normal gameplay. You could still make your iron with a smelter, and at a reasonable rate. You just get increased efficiency with increased investment. Devs could add the system later, and / or add onto the system later. Little changes by adding such a system into the game post release. The system is inherently balanced because of linear gain from exponential effort. This means that (assuming last level is high enough) only the biggest refineries could justify implementing it. Anyway, that's my idea. I'm captivated by the image of pipes running all over between machines, with conveyors and furnaces burning, all infront of the backdrop of a planet. Let me know what you think.
5. A few more options: Point Defense. Rapid fire automated guns (your choice, laser, ballistic, plasma). Could be used to defend against missiles, drones, or even light craft. AoE self centered weapons. Something like an EMP burst or other Strong field fluctuations (gravity field burst?). Could be used for clearing the local field of small craft, or damaging satellites. Siege weapons. Something to do high damage to a stationary target while making yourself somewhat immobile. This has the added benefit that "taking the field" in warfare has meaning. Examples are the mass driver, some sort of charged particle cannon, maybe large plasma bursts.
6. One cool addition to the game would be Gas Giants, Nebula, and other forms of gas in space (and maybe on planet surfaces). These could be large and (gameplay wise) slowly replenishing resources. You could harvest it by flying a ship through a nebula with a collector attachment, or dragging a collector on the surface of a gas giant. Maybe even construct a station in a nebula that is constantly collecting a small quantity. You could harvest everything and get the same nebulous "Gas". or if you wanted to make things more interesting, You could have different gasses, with different sources and different uses. Methane, Hydrogen, etc. Then you could go as complicated as you want for its uses. The logical first step is reactant for a chemical rocket. Probably some sort of early game fuel, preceding reactionless rocket tech. Following that, hydrogen gas could be processed into a a reactant in a fusion reactor. All sorts of things are possible for propulsion. Maybe you need to restock your maneuvering jets every once in a while. You could also need the gases for processing and creating elements in factories. Maybe they are needed as a catalyst, or you need a huge refinery with dozens of steps and feedback to create rare compounds. One major problem I see is implementation. I don't know what their engine looks like, but I didn't see much in the way of gasses or nebulae in any of the videos that have been shown. It might take some magic to make it work in their voxel system, and it might not even work at all. Thoughts?
7. I cant figure out the multiquote thing, so... @nietoperek You dont want to compare anything to WoW. Noone has ever recreated their success, but many have failed trying to do so. There are a lot more failed P2P games than successes. @CaptainTwerkmotor Being a unique games changes very little about the business / payment model. Plenty of games are unique, but very few work out. And you even highlighted the fact that P2P has the WoW clone stigma. Most people view a P2P model as a soon-to-fail project. Many people would shy away just from that. I want the game to succeed, I just have doubts that P2P is the best way to do that. Especially with regards to recruiting a critical mass playerbase.
8. I'm not a fan of the P2P model just from a # of users perspective. P2P is quickly becoming a somewhat antiquated model. Every new games with a P2P model released recently has failed. P2P would restrict player populations significantly. This game seems like it will benefit from large player populations. Larger / more factions, more builders and economic participants. P2P < B2P < F2P in terms of player population. P2P model with plex system is nice for those who want to play for free, provided they have the time enough to generate profit for said plex. This has its own downsides, like often requiring significant playtime investment, and essentially allowing RMT and allowing people to buy in game stuff. P2P is also a mode of continuous support for the developer. I agree that something like that is valued, but there are other ways. The addition of a cash shop on top of a P2P model kinda feels like a cash grab. Its much easier to justify B2P w/ Cash shop because of the need for continuous income. Additionally, it puts pressure on the player to make use of time paid. Say this game is running, and No Man's Sky is then released. It forces the player to make the decision of using the time paid effectively by playing DU, or playing the new hot game. This just kind of leaves a bad taste in your mouth. For those reasons, I think I would prefer a B2P or F2P model.
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便宜VPS主机精选
提供服务器主机评测信息
js上传文件到服务器的方法
在JavaScript中，可以使用XMLHttpRequest对象来上传文件到服务器。以下是一个基本的示例：
function uploadFile() {
var fileInput = document.getElementById("fileInput");
var file = fileInput.files[0];
// 创建 XMLHttpRequest 对象
var xhr = new XMLHttpRequest();
// 监听进度事件
xhr.upload.addEventListener("progress", function(evt) {
if (evt.lengthComputable) {
var percentComplete = evt.loaded / evt.total;
console.log(percentComplete);
}
}, false);
// 定义请求完成后的回调函数
xhr.onload = function() {
if (xhr.status === 200) {
console.log("上传成功！");
} else {
console.log("上传失败！");
}
};
// 创建 FormData 对象，将文件添加到其中
var formData = new FormData();
formData.append("file", file, file.name);
// 发送 POST 请求
xhr.open("POST", "/upload", true);
xhr.send(formData);
}
在上面的示例中，首先通过从DOM中获取文件输入元素（例如<input type="file">）来获得要上传的文件。然后创建XMLHttpRequest对象，并监听上传进度事件。接着，创建FormData对象并将要上传的文件添加进去。最后，使用XMLHttpRequest的open()send()方法发送POST请求，将FormData对象作为请求体发送到服务器。
需要注意的是，在服务器端处理上传文件时，需要根据具体的后端框架或者服务器软件来进行相应的操作。一般情况下，可以使用多种方式来处理上传文件，如通过表单数据来解析文件、使用特定的上传中间件等。
未经允许不得转载：便宜VPS测评 » js上传文件到服务器的方法
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C#
Posts filed under C#
What are the Partial Classes in C#
Filed in ASP.NET, C#Tags: , , ,
As we check our coding page in .net application we found that at the top after the namespaces there is a call that is partially defined in every web page. The question arrives in our mind that what is this Partial and why we use the class with partial access specifier. Why we not use [...]
Reference Type in C#
Filed in C#Tags: , , ,
Reference type are important features of the C# language. They enable us to write complex and powerful application and effectively use the run-time framework. If we define the reference type variables in C# then the Reference type variables contain a reference to the data not the value. The value is stored in a separate memory [...]
Boxing and Unboxing in C#
Filed in C#Tags: , , , ,
The two terms Boxing and Unboxing in C# are used when we need to convert one data type to other type. First we will discuss the Boxing. Boxing is the process of converting a Value type to the other Object type. When we use the Boxing of a value type to an objtct type the [...]
Namespace in C#.Net
Filed in ASP.NET, C#Tags: , , , , , , ,
Definition: As we know that every piece of code in .Net exists inside a .Net Type. Generally we put the code inside the class. The namespace is a collection of these classes or types. Every type exists inside a namespace. Namespaces can organize all the different types in the class library. Without namespace, these types [...]
C#.NET – Creating DLL to Hide Your Code
Filed in ASP.NET, C#Tags: , , , , , ,
The DLL also called Dynamic Link Library is a file that can be used dynamically by other programs. We create the DLL mainly to hide our confidential code so that we can use the code everywhere but can not see the code. When we talk about the layers or 3 and above tier application we [...]
How to Extract a URL’s Title, Description and Images using HTML Agility Utility
Filed in ASP.NET, Web AppTags: , , , , , , , ,
Extracting the details from any web page URL is not so easy task. Because you need something to track that page. In this article we are going to extract the details like Title, Description and collection of Images. To do this we need HTML Agility Utility in our web application. When we share a link [...]
How to use SQL Commands in C#.NET
Filed in ASP.NET, SQLTags: , , , , , , , , , ,
In this article we will see that how can use and execute the SQL Commands in Visual Studio. In this article we are using C# language. As we proceed in this article you will see that what steps are required to perform this task. We need the two main classes to do this. These classes [...]
The Common Type System and the Data Type that .Net Uses
Filed in ASP.NETTags: , , , ,
Because the .NET framework supports multiple languages within the platform, it defines a Common Type System (CTS). The CTS defines the basic data types that IL understands. Each .NET compliant language should map its data type to these standard data types. This makes it possible for the 2 languages to communicate with each other by [...]
How to Generate Random Password in ASP.NET
Filed in ASP.NETTags: , , , , ,
While ASP.NET is known for providing users/developers with inbuilt functions and methods for creating Login forms etc., yet there are sometimes when we need to generate a random password string for every new user created. Especially in applications like Online Examinations System where the admin generates a random default password for every new user created. [...]
Wizard Control In ASP.NET
Filed in ASP.NET, Web AppTags: , , ,
Wizard Control of ASP.NET help us to create a step by step wizard in our website. The Wizard control used when we want a big number of entries from user. Mainly we use this control in signup process of our site. In this article we will learn to use the Wizard control as well as [...]
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Yuxiang Wang Yuxiang Wang - 7 months ago 75
Python Question
subplots_adjust in matplotlib does not work in IPython Notebook
I have the following code that did not work:
import matplotlib.pyplot as plt
# Make the plot
fig, axs = plt.subplots(3, 1, figsize=(3.27, 6))
axs[0].plot(range(5), range(5), label='label 1')
axs[0].plot(range(5), range(4, -1, -1), label='label 2')
axs[0].legend(bbox_to_anchor=(0, 1.1, 1., 0.1), mode='expand', ncol=2, frameon=True, borderaxespad=0.)
# Adjust subplots to make room
fig.subplots_adjust(top=.5)
fig.savefig('test.png', format='png', dpi=300)
It can be seen that the fig.subplots_adjust did not work at all.
I am using WinPython 3.3.2.3 64 bit, with matplotlib version 1.3.0 and CPython 3.3. This happened in IPython Notebook. The backend is the in-line one. The output from the notebook is complete, but the output file is improperly cropped. In both notebook & saved file, the subplots_adjust command has no effect.
The output of the above code
Answer
With the help of tcaswell, I got it solved by entirely closing the IPython Notebook and re-run the code via the ipython-qtconsole. It seems that the subplots_adjust() simply doesn't work for python 3 in ipython-notebook. I am new to python, and is really interested in what difference is there between the qtconsole and the notebook, backend-wise, if anyone has got ideas.
Anyways - good to have this problem solved!
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lav_func: Utility Functions: Gradient and Jacobian
Description Usage Arguments Details References Examples
Description
Utility functions for computing the gradient of a scalar-valued function or the Jacobian of a vector-valued function by numerical approximation.
Usage
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lav_func_gradient_complex(func, x, h = .Machine$double.eps, ...,
check.scalar = TRUE, fallback.simple = TRUE)
lav_func_jacobian_complex(func, x, h = .Machine$double.eps, ...,
fallback.simple = TRUE)
lav_func_gradient_simple(func, x, h = sqrt(.Machine$double.eps), ...,
check.scalar = TRUE)
lav_func_jacobian_simple(func, x, h = sqrt(.Machine$double.eps), ...)
Arguments
func
A real-valued function returning a numeric scalar or a numeric vector.
x
A numeric vector: the point(s) at which the gradient/Jacobian of the function should be computed.
h
Numeric value representing a small change in ‘x’ when computing the gradient/Jacobian.
...
Additional arguments to be passed to the function ‘func’.
check.scalar
Logical. If TRUE, check if the function is scalar-valued.
fallback.simple
Logical. If TRUE, and the function evaluation fails, we call the corresponding simple (non-complex) method instead.
Details
The complex versions use complex numbers to gain more precision, while retaining the simplicity (and speed) of the simple forward method (see references). These functions were added to lavaan (around 2012) when the complex functionality was not part of the numDeriv package. They were used internally, and made public in 0.5-17 per request of other package developers.
References
Squire, W. and Trapp, G. (1998). Using Complex Variables to Estimate Derivatives of Real Functions. SIAM Review, 40(1), 110-112.
Examples
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# very accurate complex method
lav_func_gradient_complex(func = exp, x = 1) - exp(1)
# less accurate forward method
lav_func_gradient_simple(func = exp, x = 1) - exp(1)
# very accurate complex method
diag(lav_func_jacobian_complex(func = exp, x = c(1,2,3))) - exp(c(1,2,3))
# less accurate forward method
diag(lav_func_jacobian_simple(func = exp, x = c(1,2,3))) - exp(c(1,2,3))
yrosseel/lavaan documentation built on Dec. 14, 2018, 6:24 p.m.
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What is iso 27001 gap analysis. What is an ISO 27001 gap analysis and how does it work?
What is iso 27001 gap analysis Rating: 7,4/10 657 reviews
ISO
what is iso 27001 gap analysis
What will the business continuity gap analysis report include? This is most commonly called a Gap Analysis; it is sometimes referred to as a Pre-Audit. Some of these may help make life easier for you. Here lies a major difference between an audit report, for example, and a gap analysis report: The gap analysis report has some inherent advice to it, which makes it suitable to be accomplished by consultants or experts in the chosen specification or standards. But this is a topic for another article. In this blog, we explain the difference between a risk assessment and gap analysis, and advise you on how to complete each step effectively and in-line with your business needs. Remember that the quality of these compliance activities is only as good as the quality of people performing the activities.
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Conducting Gap Analysis for ISO 27001
what is iso 27001 gap analysis
Alternatively, you could choose a more varied set of criteria other than simply implemented—not implemented. Pre-assessments can be conducted by consultants, registrars, or competent individuals who are experts in the certifications or standards chosen by your organization. It's too easy to react emotionally to risks, and get controls out of proportion or even miss essentials by focusing too much on the dramatic risks reported in newspapers. If the assignment goes well for both parties and the working relationship flourishes, there may be opportunities for ongoing contact and support, perhaps further consulting assignments during the journey ahead. A gap analysis in this period can be more involved and take longer, if only for the simple reason that everyone is extremely busy.
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NBlog
what is iso 27001 gap analysis
Internal audit An internal audit is an activity that also seeks to determine the degree to which your organization conforms to the requirements of a specification or standard or to your own organizational requirements. It will provide an indication of where you are now and where you need to be to have a successful migration. You only need to do a gap analysis once to obtain a list of the specific activities required for compliance. The timing of the gap analysis is also pertinent. Some organizations are made to do all the controls by unthinking customers, and this makes no sense. However, someone has to pay for this content. Any organisation looking to comply with , the international standard for information security, needs to complete a gap analysis and risk assessment.
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ISO
what is iso 27001 gap analysis
A pre-assessment is therefore a rehearsal of an external audit, and consequently there is plenty of document review as well as actual questioning of employees. Because conducting a gap analysis results in a list of specific, prioritised actions your business needs to implement in order to become complaint to the applicable framework. Instead, they must prioritise their biggest threats, and a risk assessment provides a simple way of doing that. So which one do you really need? TechaPeek provides in-depth news coverage on vast industries such as health care, construction, transportation, energy, cleantech, fintech and more. This has a number of uses: it acts as an input to the risk assessment, it helps distinguish between high-value and low-value assets when determining protection requirements, and it aids business continuity planning.
Next
ISO 27001: Gap analysis vs. risk assessment
what is iso 27001 gap analysis
Gap analysis A gap analysis is mainly a determination of the degree of conformance of your organization to the requirements of a specification or standard. The unticked requirements form the gaps that might need to be addressed not all clauses need to be addressed. There is no formal definition. The Annex A controls and control objectives are applied to organizationally defined risks to help provide mitigation of risks to assets with the intent to provide a system that defines how information security is managed, what steps are taken, and the results that are intended to be achieved. Any help would be appreciated.
Next
ISO 22301 Gap analysis
what is iso 27001 gap analysis
It can also provide a reality check as to where you are in the process — helping with planning resources and timeframes. With information on technology's, startups and other Hi-Tech and innovation services, TechaPeek delivers in-depth analysis on news and emerging solutions, market intelligence, trends, and guidance on how to capitalize on opportunities and overcome challenges. This is a good point to pencil-in the certification audit, and start lining up the certification body the details to be confirmed nearer the time, perhaps after a final readiness assessment. Hopefully by now you are more clear on the difference between these three important activities in your continual improvement journey. It should also show a detailed account of each requirement and the degree of compliance, with corresponding actions that should be taken to close these gaps. An organization will also want to know where they are on their journey. At the end of the audit, the company is presented with a certificate that they can then provide to existing and potential customers as proof of their commitment to information security.
Next
ISO 27001: Do you know the difference between a gap analysis and a risk assessment?
what is iso 27001 gap analysis
This could range from a single department or service offering, through to the entire organisation. By contrast, if a control helps prevent a highly damaging or probable risk, the organisation should dedicate additional time and resources to it. They keep you aware of new products and services relevant to your industry. This channel is only created to generate awareness and best practices for Information Security in general. This audit is performed in more than one dimension, through review of documentation evidence and also by questioning employees.
Next
What’s the difference between an ISO 27001 risk assessment and gap analysis?
what is iso 27001 gap analysis
First, we are dealing with the issue of independence. The implementation and review process centres upon the risk assessment and gap analysis process. However, the usefulness of such approach is doubtful, since only risk assessment will show the real extent of what needs to be implemented and in which form. The standard has specific requirements that have to be met; these are detailed in various clauses. If the decision is to communicate information security issues outside of the company, this must be included. Risk assessments give organisations an indication of the threats facing them, how likely it is that each of those threats will occur and how severe the damage will be.
Next
The Difference Between ISO 27001 Gap Assessment and Risk Assessment
what is iso 27001 gap analysis
Whether you chose all three or just the internal audit, make sure they are performed by highly competent individuals. If you have one auditor who audits the whole facility, who audits his area? Those who want to make the process as simple as possible should create a checklist and tick off the requirements that have been implemented. The other big question is how effective are your audits? Undertaking a gap analysis provides expert analysis and detailed insights that you would not receive with more simplified questionnaire-based gap analysis. The process begins by creating a long list of risks, which will be given a risk score. So, you might want to do it towards the end of your implementation. There are a lot of similarities between the two, which often causes organisations to confuse them and use elements of one process in the other. Such a timely comparative analysis; it's helped me greatly.
Next
Free ISO 27001 Gap Analysis Tool
what is iso 27001 gap analysis
The controls need to be proportional to the risks identified. However, it may also be conducted after some development of processes for achieving compliance has taken place. After documenting processes and performing reviews, a company may hire an independent auditing company to review their processes and ensure that the company is adhering to the developed processes. So please consider turning off your ad blocker for our site. The main reason why gap analysis is conducted at the beginning of the development phase or after some development has occurred is because the organization wants to know where it stands in regard to meeting the standard, and it wants to know specifically what it must do to close the gaps. There are a couple ways of approaching a gap analysis. Like other management system standards, writing procedures is the easy bit - getting people to do them is another matter.
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|
__label__pos
| 0.639775 |
Answer to Question #4451 in Python for poonam
Question #4451
A merchant has a beaker containing 24 ounces of a precious fluid. He also has empty 5-ounce, 11- ounce, and 13-ounce beakers. How can he divide the fluid into three equal portions?
Expert's answer
Here is an algoritm
1) full 13-ounce beaker
[table]
5-ounce
11-ounce
13-ounce
0
0
13
[/table]
2)from 13-ounce fill the 11-ounce beaker(at 13-oun. Wewill have 2 ounce of water)
[table]
5-ounce
11-ounce
13-ounce
11
2
[/table]
3)empty 11-oun. And fill it from 13 oun. Wich has 2 ounce of w.
[table]
5-ounce
11-ounce
13-ounce
2
[/table]
4)fill 13-oun. And pour water from it to 5-ouncebeaker
[table]
5-ounce
11-ounce
13-ounce
5
2
13-5=8(!!!)
[/table]
5)
Empty 5-ounce and fill it from 11-ounce
[table]
5-ounce
11-ounce
13-ounce
2
0
8
[/table]6)
Fill 11-ounce and add water to 5-ouncebeaker
[table]
5-ounce
11-ounce
13-ounce
5
11-3=8
8
[/table]7)
Return 5ounce to 24-ounce beaker and itwill have also 5+3=8 ounce of water
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__label__pos
| 0.970274 |
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.
Sign up
Here's how it works:
1. Anybody can ask a question
2. Anybody can answer
3. The best answers are voted up and rise to the top
How many "$1$" is need at least for a decimal number,which is consisting of "$0$" and "$1$" and divisible by $p$?
If $p=2^k\cdot d+1$, and $10^d\equiv 1 \pmod p$,then $10^n\equiv -1 \pmod p$ has no solution, so $10^n+1$ is never divisible by $p$, so two "$1$" is not enough,but since $\dfrac{10^{p-1}-1}{9}=11\cdots 111\equiv 0 \pmod p$,so $p-1$ is awlays enough,in fact,$ord(10,p)$ is enough,but may be not the least.
In When is it solvable:$10^a+10^b\equiv -1 \pmod p$ , I asked that when three "$1$" is need at least,I think I should ask this original problem here,because this is more general and why I asked that question.
Assume $(10,p)=1.$
Two "$1$" is need at least for $p=7, 11, 13, 17, 19, 23, 29, 47, 59, 61, 73, 89, 97, 101, 103,\cdots$
Three "$1$" is need at least for $p=3, 31, 37, 43, 53, 67, 71, 83, 107, 151, 163, 173, 191, 199,\cdots$
Four "$1$" is need at least for $p=79, 733,\cdots$
Thank you!
share|cite|improve this question
@lab bhattacharjee Thank you for the links!But they are both different to this, my question is how to find the least number of "$1$",neither to find the least number which is divisible by p,nor to prove that there is such a number.I think this problem to more worth to consider，because we can answer it easily whether two "1" is need at least. – Next May 19 '13 at 7:22
If the number must end in "$1$" then $2$ is impossible, otherwise $2$ and $5$ only need one "$1$". – WimC May 19 '13 at 7:25
@WimC we only consider the case $(10,p)=1$,I said it in another my question..Thanks for your suggest,I will edit it. – Next May 19 '13 at 7:27
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__label__pos
| 0.745417 |
Changes between Initial Version and Version 1 of Support/PlatformSpecifics/Cygwin
Show
Ignore:
Timestamp:
07/11/07 17:54:16 (8 years ago)
Author:
martin (IP: 81.178.2.19)
Comment:
--
Legend:
Unmodified
Added
Removed
Modified
• Support/PlatformSpecifics/Cygwin
v1 v1
1= Compiling !OpenSceneGraph with Cygwin =
2[[TracNav(TracNav/SupportTOC)]]
3
4Follows are details on usage of !OpenSceneGraph such as how to get things compiling using Cygwin.
5
6The following assumes that the !OpenSceneGraph and its dependencies (!OpenThreads, Producer, and optionally gdal) have been downloaded, either from CVS or tarballs, and installed under a common parent directory. I will call this "`/development`".
7
8== Load the proper version of the GCC Compiler ==
9The current default gcc compiler version distributed with Cygwin is 3.4.1. Unfortunately, this version has problems dealing with the complexity of the OpenSceneGraph and Producer template usage. The libraries will compile, but they will not run. To build OSG you need to manually direct the cygwin installer to load version 3.3.3 of the gcc compiler family.
10
11== Set up the Cygwin environment ==
12You must create some initial environment variables so that the !OpenSceneGraph build process knows where !OpenThreads and Producer are installed.
13
14The best place to locate these variables is in your shell resources file. Assuming you are using the default `bash` shell, your bash resources file will be
15{{{
16~/.bashrc
17}}}
18
19Using your favorite text editor, add these variables to the file:
20
21{{{
22export OPENTHREADS_INC_DIR=/usr/local/OpenThreads/include
23export OPENTHREADS_LIB_DIR=/usr/local/OpenThreads/bin
24export PRODUCER_INC_DIR=/usr/local/Producer/include
25export PRODUCER_LIB_DIR=/usr/local/Producer/bin
26}}}
27
28OSG also uses environment variables to control which parts of the distribution is compiled. To compile the example programs, add the following line to the .bashrc file
29
30{{{
31export COMPILE_EXAMPLES=yes
32}}}
33
34Introspection does not seem to work within Cygwin, so also add this line to the .bashrc:
35
36{{{
37export COMPILE_INTROSPECTION=no
38}}}
39
40If you have installed GDAL (required for the osgTerrain component) also add:
41
42{{{
43export GDAL_INSTALLED=yes
44}}}
45
46Next you must add these paths and the path to the !OpenSceneGraph installed bin directory to the systems PATH environment variable:
47
48{{{
49export PATH="$OPENTHREADS_LIB_DIR:$PATH"
50export PATH="$PRODUCER_LIB_DIR:$PATH"
51export PATH="/usr/local/OpenSceneGraph/bin:$PATH"
52}}}
53
54The `$PATH` variable on the end makes sure that any previously assigned paths are also included.
55
56That's all that needs to be done for the `.bashrc` file, though you could also add the variable that specifies the directory of the !OpenSceneGraph data, or any other variables that are particular to your setup.
57
58{{{
59export OSG_FILE_PATH=/usr/local/OpenSceneGraph/data
60}}}
61
62== Compiling !OpenThreads ==
63Go to the !OpenThreads directory
64
65{{{
66$ cd /development/OpenThreads
67}}}
68
69run:
70
71{{{
72$ make
73$ make install
74}}}
75
76== Compiling Producer ==
77A bug in the make system requires that we manually create the target directory for the !Producer library. Go to the library directory:
78
79{{{
80cd /development/Producer/lib
81}}}
82
83and create a new directory
84
85{{{
86$ mkdir CYGWIN32
87}}}
88
89Having done that you can build the Producer library.
90
91{{{
92$ cd /development/Producer
93$ make
94$ make install
95}}}
96
97== Compiling !OpenSceneGraph ==
98First, we must work around the same bug as in !Producer:
99
100{{{
101$ cd /development/OpenSceneGraph/lib
102$ mkdir CYGWIN32
103}}}
104
105Go to the !OpenSceneGraph home directory and make, then install, !OpenSceneGraph.
106
107{{{
108$ cd /development/OpenSceneGraph
109$ make
110$ make install
111}}}
112
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| 0.840729 |
build/mach_bootstrap.py
author Ian Bicking <[email protected]>
Thu, 29 Jun 2017 15:04:59 -0700
changeset 414248 04fc201151527b3084222ac209e554c063de1104
parent 413282 5413302a24e6099faa510ce21546958c3cd9f591
child 415195 c8497caddebb58fa8db7816b578c629987b82c07
permissions -rw-r--r--
Bug 1373614 - shut down Screenshots WebExtension unconditionally on browser shutdown r=kmag a=jcristau In some tests the startup does not complete by the time shutdown is called; r?kmag MozReview-Commit-ID: CaeSthDg0g0
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
from __future__ import print_function, unicode_literals
import errno
import json
import os
import platform
import random
import subprocess
import sys
import uuid
import __builtin__
from types import ModuleType
STATE_DIR_FIRST_RUN = '''
mach and the build system store shared state in a common directory on the
filesystem. The following directory will be created:
{userdir}
If you would like to use a different directory, hit CTRL+c and set the
MOZBUILD_STATE_PATH environment variable to the directory you would like to
use and re-run mach. For this change to take effect forever, you'll likely
want to export this environment variable from your shell's init scripts.
Press ENTER/RETURN to continue or CTRL+c to abort.
'''.lstrip()
# Individual files providing mach commands.
MACH_MODULES = [
'addon-sdk/mach_commands.py',
'build/valgrind/mach_commands.py',
'devtools/shared/css/generated/mach_commands.py',
'dom/bindings/mach_commands.py',
'dom/media/test/external/mach_commands.py',
'layout/tools/reftest/mach_commands.py',
'python/mach_commands.py',
'python/mach/mach/commands/commandinfo.py',
'python/mach/mach/commands/settings.py',
'python/mozboot/mozboot/mach_commands.py',
'python/mozbuild/mozbuild/mach_commands.py',
'python/mozbuild/mozbuild/backend/mach_commands.py',
'python/mozbuild/mozbuild/compilation/codecomplete.py',
'python/mozbuild/mozbuild/frontend/mach_commands.py',
'services/common/tests/mach_commands.py',
'taskcluster/mach_commands.py',
'testing/awsy/mach_commands.py',
'testing/firefox-ui/mach_commands.py',
'testing/mach_commands.py',
'testing/marionette/mach_commands.py',
'testing/mochitest/mach_commands.py',
'testing/mozharness/mach_commands.py',
'testing/talos/mach_commands.py',
'testing/web-platform/mach_commands.py',
'testing/xpcshell/mach_commands.py',
'tools/compare-locales/mach_commands.py',
'tools/docs/mach_commands.py',
'tools/lint/mach_commands.py',
'tools/mach_commands.py',
'tools/power/mach_commands.py',
'mobile/android/mach_commands.py',
]
CATEGORIES = {
'build': {
'short': 'Build Commands',
'long': 'Interact with the build system',
'priority': 80,
},
'post-build': {
'short': 'Post-build Commands',
'long': 'Common actions performed after completing a build.',
'priority': 70,
},
'testing': {
'short': 'Testing',
'long': 'Run tests.',
'priority': 60,
},
'ci': {
'short': 'CI',
'long': 'Taskcluster commands',
'priority': 59
},
'devenv': {
'short': 'Development Environment',
'long': 'Set up and configure your development environment.',
'priority': 50,
},
'build-dev': {
'short': 'Low-level Build System Interaction',
'long': 'Interact with specific parts of the build system.',
'priority': 20,
},
'misc': {
'short': 'Potpourri',
'long': 'Potent potables and assorted snacks.',
'priority': 10,
},
'disabled': {
'short': 'Disabled',
'long': 'The disabled commands are hidden by default. Use -v to display them. These commands are unavailable for your current context, run "mach <command>" to see why.',
'priority': 0,
}
}
# We submit data to telemetry approximately every this many mach invocations
TELEMETRY_SUBMISSION_FREQUENCY = 10
def search_path(mozilla_dir, packages_txt):
with open(os.path.join(mozilla_dir, packages_txt)) as f:
packages = [line.rstrip().split(':') for line in f]
for package in packages:
if package[0] == 'packages.txt':
assert len(package) == 2
for p in search_path(mozilla_dir, package[1]):
yield os.path.join(mozilla_dir, p)
if package[0].endswith('.pth'):
assert len(package) == 2
yield os.path.join(mozilla_dir, package[1])
def bootstrap(topsrcdir, mozilla_dir=None):
if mozilla_dir is None:
mozilla_dir = topsrcdir
# Ensure we are running Python 2.7+. We put this check here so we generate a
# user-friendly error message rather than a cryptic stack trace on module
# import.
if sys.version_info[0] != 2 or sys.version_info[1] < 7:
print('Python 2.7 or above (but not Python 3) is required to run mach.')
print('You are running Python', platform.python_version())
sys.exit(1)
# Global build system and mach state is stored in a central directory. By
# default, this is ~/.mozbuild. However, it can be defined via an
# environment variable. We detect first run (by lack of this directory
# existing) and notify the user that it will be created. The logic for
# creation is much simpler for the "advanced" environment variable use
# case. For default behavior, we educate users and give them an opportunity
# to react. We always exit after creating the directory because users don't
# like surprises.
sys.path[0:0] = [os.path.join(mozilla_dir, path)
for path in search_path(mozilla_dir,
'build/virtualenv_packages.txt')]
import mach.main
from mozboot.util import get_state_dir
from mozbuild.util import patch_main
patch_main()
def telemetry_handler(context, data):
# We have not opted-in to telemetry
if 'BUILD_SYSTEM_TELEMETRY' not in os.environ:
return
telemetry_dir = os.path.join(get_state_dir()[0], 'telemetry')
try:
os.mkdir(telemetry_dir)
except OSError as e:
if e.errno != errno.EEXIST:
raise
outgoing_dir = os.path.join(telemetry_dir, 'outgoing')
try:
os.mkdir(outgoing_dir)
except OSError as e:
if e.errno != errno.EEXIST:
raise
# Add common metadata to help submit sorted data later on.
data['argv'] = sys.argv
data.setdefault('system', {}).update(dict(
architecture=list(platform.architecture()),
machine=platform.machine(),
python_version=platform.python_version(),
release=platform.release(),
system=platform.system(),
version=platform.version(),
))
if platform.system() == 'Linux':
dist = list(platform.linux_distribution())
data['system']['linux_distribution'] = dist
elif platform.system() == 'Windows':
win32_ver=list((platform.win32_ver())),
data['system']['win32_ver'] = win32_ver
elif platform.system() == 'Darwin':
# mac version is a special Cupertino snowflake
r, v, m = platform.mac_ver()
data['system']['mac_ver'] = [r, list(v), m]
with open(os.path.join(outgoing_dir, str(uuid.uuid4()) + '.json'),
'w') as f:
json.dump(data, f, sort_keys=True)
def should_skip_dispatch(context, handler):
# The user is performing a maintenance command.
if handler.name in ('bootstrap', 'doctor', 'mach-commands', 'mercurial-setup'):
return True
# We are running in automation.
if 'MOZ_AUTOMATION' in os.environ or 'TASK_ID' in os.environ:
return True
# The environment is likely a machine invocation.
if sys.stdin.closed or not sys.stdin.isatty():
return True
return False
def post_dispatch_handler(context, handler, args):
"""Perform global operations after command dispatch.
For now, we will use this to handle build system telemetry.
"""
# Don't do anything when...
if should_skip_dispatch(context, handler):
return
# We call mach environment in client.mk which would cause the
# data submission below to block the forward progress of make.
if handler.name in ('environment'):
return
# We have not opted-in to telemetry
if 'BUILD_SYSTEM_TELEMETRY' not in os.environ:
return
# Every n-th operation
if random.randint(1, TELEMETRY_SUBMISSION_FREQUENCY) != 1:
return
with open(os.devnull, 'wb') as devnull:
subprocess.Popen([sys.executable,
os.path.join(topsrcdir, 'build',
'submit_telemetry_data.py'),
get_state_dir()[0]],
stdout=devnull, stderr=devnull)
def populate_context(context, key=None):
if key is None:
return
if key == 'state_dir':
state_dir, is_environ = get_state_dir()
if is_environ:
if not os.path.exists(state_dir):
print('Creating global state directory from environment variable: %s'
% state_dir)
os.makedirs(state_dir, mode=0o770)
else:
if not os.path.exists(state_dir):
if not os.environ.get('MOZ_AUTOMATION'):
print(STATE_DIR_FIRST_RUN.format(userdir=state_dir))
try:
sys.stdin.readline()
except KeyboardInterrupt:
sys.exit(1)
print('\nCreating default state directory: %s' % state_dir)
os.makedirs(state_dir, mode=0o770)
return state_dir
if key == 'topdir':
return topsrcdir
if key == 'telemetry_handler':
return telemetry_handler
if key == 'post_dispatch_handler':
return post_dispatch_handler
raise AttributeError(key)
mach = mach.main.Mach(os.getcwd())
mach.populate_context_handler = populate_context
if not mach.settings_paths:
# default global machrc location
mach.settings_paths.append(get_state_dir()[0])
# always load local repository configuration
mach.settings_paths.append(mozilla_dir)
for category, meta in CATEGORIES.items():
mach.define_category(category, meta['short'], meta['long'],
meta['priority'])
for path in MACH_MODULES:
mach.load_commands_from_file(os.path.join(mozilla_dir, path))
return mach
# Hook import such that .pyc/.pyo files without a corresponding .py file in
# the source directory are essentially ignored. See further below for details
# and caveats.
# Objdirs outside the source directory are ignored because in most cases, if
# a .pyc/.pyo file exists there, a .py file will be next to it anyways.
class ImportHook(object):
def __init__(self, original_import):
self._original_import = original_import
# Assume the source directory is the parent directory of the one
# containing this file.
self._source_dir = os.path.normcase(os.path.abspath(
os.path.dirname(os.path.dirname(__file__)))) + os.sep
self._modules = set()
def __call__(self, name, globals=None, locals=None, fromlist=None,
level=-1):
# name might be a relative import. Instead of figuring out what that
# resolves to, which is complex, just rely on the real import.
# Since we don't know the full module name, we can't check sys.modules,
# so we need to keep track of which modules we've already seen to avoid
# to stat() them again when they are imported multiple times.
module = self._original_import(name, globals, locals, fromlist, level)
# Some tests replace modules in sys.modules with non-module instances.
if not isinstance(module, ModuleType):
return module
resolved_name = module.__name__
if resolved_name in self._modules:
return module
self._modules.add(resolved_name)
# Builtin modules don't have a __file__ attribute.
if not hasattr(module, '__file__'):
return module
# Note: module.__file__ is not always absolute.
path = os.path.normcase(os.path.abspath(module.__file__))
# Note: we could avoid normcase and abspath above for non pyc/pyo
# files, but those are actually rare, so it doesn't really matter.
if not path.endswith(('.pyc', '.pyo')):
return module
# Ignore modules outside our source directory
if not path.startswith(self._source_dir):
return module
# If there is no .py corresponding to the .pyc/.pyo module we're
# loading, remove the .pyc/.pyo file, and reload the module.
# Since we already loaded the .pyc/.pyo module, if it had side
# effects, they will have happened already, and loading the module
# with the same name, from another directory may have the same side
# effects (or different ones). We assume it's not a problem for the
# python modules under our source directory (either because it
# doesn't happen or because it doesn't matter).
if not os.path.exists(module.__file__[:-1]):
if os.path.exists(module.__file__):
os.remove(module.__file__)
del sys.modules[module.__name__]
module = self(name, globals, locals, fromlist, level)
return module
# Install our hook
__builtin__.__import__ = ImportHook(__builtin__.__import__)
|
__label__pos
| 0.892453 |
When starting with WPF, I had a hard time realizing when to use converters and just how powerful they can be. I would often create styles with complicated Data Triggers, or abuse my ViewModel instead of doing some simple converter magic.
I’ll share with you some converter tips and tricks that make my development easier every day.
Tip #1: When starting a new project, get a converters library
A lot of standard converters are reused in every WPF application. No need to recode the wheel. There are several open source libraries available we can use:
Tip #2: Write C# code in XAML with QuickConverter
This is a real gem. This library actually allows to write c# code in XAML.
Here’s an example:
<CheckBox IsEnabled="{qc:Binding '!$P', P={Binding Path=ViewModel.SomeBooleanProperty}}" />
Source: http://blog.danskingdom.com/?s=quickconverter
Or:
<TextBlock Text="{Binding Message}"
FontSize="{qc:Binding '$P == null ? $V2 : ($P.Length > 300 ? $V2 : $V1)',
P={Binding Message}, V1={StaticResource FontSize.Large},
V2={StaticResource FontSize.Small}}"/>
In this example the FontSize is changing according to Message’s length. If there’s over 300 characters, the FontSize will be smaller.
I used it in our code base and I think it’s awesome. It’s more readable and we need much less code for simple logic as in the examples above.
For documentation check out this post , the documentation on CodePlex and QuickConverter on NuGet .
This doesn’t cancel out regular converters. We still would want a lot of reusable converters as regular C# classes.
EDIT: Since writing this post I discovered a better-maintained library, CalcBinding , that achieves the same goal. I would now suggest using CalcBinding rather than QuickConverter.
Tip #3: Markup extension BaseConverter
Using a converter requires you to create an instance of the converter. The conventional way is using a StaticResource:
<Window.Resources>
<local:BooleanToVisibilityConverter x:Key="VisConverter"/>
</Window.Resources>
...
<Button Visibility="{Binding BtnVisilbe,
Converter={StaticResource VisConverter}}">OK</Button>
In the above example, we will use the same instance of the converter every time we use StaticResource. This is both good and bad.
Good because we might gain in performance for not having to create a new instance.
Bad because if we want to use parameters with out converter, those parameters will be the same every time we use the StaticResource.
Consider having the converters derive from MarkupExtension. We will be able to write like this:
<Button
Visibility="{Binding BtnVisible, Converter={local:BoolToVisibilityConverter}}">
OK</Button>
Our converter will have to derive from MarkupExtension:
class BooleanToVisibilityConverter : BaseConverter
{
...
}
abstract class BaseConverter : MarkupExtension, IValueConverter
{
public abstract object Convert(object value, Type targetType,
object parameter, System.Globalization.CultureInfo culture);
public override object ProvideValue(IServiceProvider serviceProvider)
{
return this;
}
}
This is easier to read and will create a new instance of the converter every time. Which is usually what I want. I want to be able to give different parameters to my converter every time and the performance loss of creating a new instance is negligible.
Here’s a nice post that explains about converters as MarkupExtension in more detail.
Tip #4 Result Converter
Sometimes, we need to do a “double” conversion. Or, in other words, convert the result of our conversion.
Let’s use the example from Tip #2. In a TextBlock, we want to use a smaller font if the message is too long (More than 300 characters).
We saw how to do this easily with QuickConverter, but let’s assume we want to do it the old fashion way for whatever reasons.
Instead of creating a new custom converter, we can save some time and effort and use our standard converters. Like these two:
• StringLength converter: Returns number of characters in a string
• EqualityConverter: Accepts 3 parameters
• ToCompare
• Smaller: Value when Binding < ToCompare
• Bigger: Value when Binding >= ToCompare
Here’s the code that combines the above standard converters to our custom needs:
<TextBox Text="{Binding Message}"
FontSize="{Binding Message, Converter={local:StringLengthConverter
ResultConverter={local:EqualityConverter ToCompare=300, Bigger=14, Smaller=16}}}"
To be able to do that, we need to add ResultConverter to our BaseConverter class. Like this:
public abstract class BaseConverter : MarkupExtension, IValueConverter
{
public IValueConverter ResultConverter { get; set; }
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
var result = InternalConvert(value, targetType, parameter, culture);
if (ResultConverter != null)
return ResultConverter.Convert(result, targetType, parameter, culture);
return result;
}
protected abstract object InternalConvert(object value, Type targetType,
object parameter, System.Globalization.CultureInfo culture);
public override object ProvideValue(IServiceProvider serviceProvider)
{
return this;
}
}
This is really convenient, trust me. It will save time writing those extra unnecessary converters.
A note about the BaseConverter class:
In the last example we saw a BaseConverter that derives from MarkupExtension and uses ResultConverter. It is missing the methods ConvertBack and ConvertBackInternal to make the base class usable.
Also, I suggest having a base class for MultiValueConverer that has the same concepts.
Summary
I showed you some tricks that make my WPF development more productive and the code more readable.
I hope I gave you some value and maybe made converters look a bit more useful and easier.
Have a great day,
Michael
|
__label__pos
| 0.83878 |
Responsive Design: The Key to a Successful Website
Responsive design is the key to a successful website. It is a web design approach that ensures a website looks great and functions properly on all devices, from desktop computers to mobile phones. Responsive design is essential for any website, as it allows users to access the same content regardless of the device they are using.
Responsive design is based on the idea of creating a website that can adapt to any device. This means that the website will automatically adjust its layout and content to fit the size and shape of the device being used. This ensures that the user experience is consistent across all devices, and that the website looks great no matter what device it is being viewed on.
Responsive design also helps to improve the user experience. By making sure that the website is optimized for all devices, users can easily navigate the website and find the information they need. This makes it easier for users to find what they are looking for, and it also helps to reduce the amount of time it takes for them to find it.
Responsive design also helps to improve the website’s search engine optimization (SEO). By making sure that the website is optimized for all devices, it can rank higher in search engine results. This can help to increase the website’s visibility and attract more visitors.
Finally, responsive design helps to improve the website’s security. By making sure that the website is optimized for all devices, it can help to protect the website from malicious attacks. This can help to keep the website safe and secure, and it can also help to protect the user’s data.
In conclusion, responsive design is the key to a successful website. It ensures that the website looks great and functions properly on all devices, and it also helps to improve the user experience, SEO, and security of the website. Responsive design is essential for any website, and it is the key to a successful website.
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|
__label__pos
| 0.873182 |
Share:
" /> Visio Guy » Constraining Angle with the BOUND ShapeSheet Function
Home » ShapeSheet
Constraining Angle with the BOUND ShapeSheet Function
Submitted by on December 14, 2006 – 10:35 am | | 18861 views One Comment
Cori who writes the blog Elliptical… wrote this nice little piece on constraining a shape’s angle so that it can only be rotated in 90-degree increments. I thought I’d relay the information to you here, and explain a bit more about the BOUND ShapeSheet function.
Although you can use the keyboard shortcuts Ctrl+R and Ctrl+L to rotate shapes in 90-degree increments clockwise and counterclockwise, this does nothing to actually constrain the allowable values.
Enter the BOUND ShapeSheet function
Compass SouthThe shape at right is a compass dial shape that can only point to north, south, east or west. When you grab the shape’s green, lollipop rotation handle, it will snap nicely to one of these directions. The BOUND function makes this possible.
Even if a user tries to foil the constraint by typing an odd value into the Size & Position’s Angle field, the shape will still be rotated to the nearest 90-degree increment.
The magic is located in the shape’s Angle cell, located in the Shape Transform section of this shape’s ShapeSheet.
When you look at the Angle cell, you might be shocked. This is what you’ll see:
Angle = BOUND(0 deg, 0, 0, 0 deg, 0 deg, 0, 90 deg, 90 deg, 0, 180 deg, 180 deg, 0, 270 deg, 270 deg)
Anybody still there? It’s not so formidable if you break it down. Let’s add some line breaks to make it more digestible:
BOUND(0 deg,0,
0, 0 deg, 0 deg,
0, 90 deg, 90 deg,
0, 180 deg, 180 deg,
0, 270 deg, 270 deg)
You can see right away that there are four triplets of information that correspond to our four allowable angles: 0 deg, 90 deg, 180 deg and 270 deg. So the west-constraining triplet would be:
0, 180 deg, 180 deg
The second two arguments could be described as the from-value and the to-value. Since we are constraining to specific points, these values are the same for each compass direction. In this example, we have from 180 deg and to 180 deg, which means: west.
The 0 that you see at the beginning of each triplet is an ignore parameter. If you set this to 1, then the constraint will be turned off. You could put various IF conditions or true/false flags in each individual ignore parameter to make a seriously whacky shape! Or you could reference all of the ignore flags to, say a User.debug cell, which would allow you to turn off the constraints to perhaps make development of the shape easier.
You’ll notice that the BOUND function doesn’t get deleted when you rotate the shape, and that GUARD is not used to accomplish this. BOUND is part of a new class of functions, first introduced in Visio 2003 that allow better coexistence between parameter-input and user-interaction. When you rotate the shape, the angle to which you rotate will be stored in the very first argument. So if I rotate the shape to -75.9 deg, the function will display as follows:
BOUND(-75.9 deg., …
The rest of the function will then work with that value to decide which constraint to use. So the user-interface generated angle is written inside of the function, without blasting the entire formula away! This is a a really cool concept that enables a lot of new possibilities for your shapes. The tyranny of GUARD is over!
We’ve almost forgotten the second argument, just after the value place-holder. This argument specifies the constraint type. The type can be one of three values: 0 = inclusive, 1 = exclusive, 2 = disabled. In our compass example, we have used 0, for inclusive constraints. Exclusive means “places where the value can’t go”, which adds interesting possibilites, and Disabled allows you to turn off the whole BOUND function. This could also be cool for debugging a shape.
Smart Text
If you’re interested in how the N, S, E, W shows in the text, have a look at the User-defined Cells section in the ShapeSheet. There, you’ll see two cells:
User.directions = “E;N;W;S”
User.direction = INDEX( INT( ANG360(Angle) / 90 deg ), User.directions )
The first cell is just a list of text to display. The second figures out which of those elements to use. By dividing the 360-degree-normalized angle by 90 degrees, the INT-ing it, we get a value of 0, 1, 2 or 3. This value is used to index one of the elements in the directions list.
The User.direction cell is then linked to the shape’s text using the Insert > Field dialog. Some gyrations were also performed in the Text Transform section to keep the text right-side-up as the shape rotates. Notably:
TxtAngle = -Angle
This causes the text to anti-rotate relative to the shape. A more complete formula is TxtAngle = IF(BITXOR(FlipX, FlipY), 1, -1)*Angle. This calculate the proper anti-angle even when the shape flips. But we could write many articles on text behavior, and probably will, so I’ll leave that for another time.
Hopefully you’ll find the BOUND function as fun and interesting as I have. Here’s the Visio file for download:
Visio Bounds-example Compass Shape (20.27 KB) - 438
More Info
We talked about how BOUND doesn’t get overwritten by user-interface actions. Here’s some links to the MSDN Visio 2003 SDK Documentation for ShapeSheet functions that support this “don’t overwrite me” behavior:
One Comment »
• Yacine says:
Hi Chris,
grossartiger Artikel, ich habe aber trotzdem eine Frage :)
How would you bind a control point to a set of points.
To explain myself:
The control point shall only snap to certain points of a sub-shape and
I certainly can bind the x values and the y values to sets of values. But how do I define that this particuliar y value corresponds to this other x value?
Trials with loc(pnt()) did not work.
Any idea?
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|
__label__pos
| 0.720134 |
Estoy tratando de insertar los datos acerca de un elemento del precio de un formulario HTML en una base de datos mySQL. El campo de entrada se define como sigue:
<input type="text" name="price" value="0.00"/>
El formulario es Enviado a la siguiente página en la que la base de datos de material es tomado cuidado de. Actualmente acabo de entrar en el contenido exacto de $_POST[‘precio’] en el campo de base de datos, que es de tipo DECIMAL(4,2). Me enteré de que este se almacena como una cadena, pero la base de datos arroja un error cada vez que intento hacer esto. Hay una función de PHP para convertir entre cuerdas y MySQL, el tipo de DECIMAL? O voy a tener que hacer un poco de formato a mí mismo?
InformationsquelleAutor benwad | 2010-03-12
1 Comentario
1. 4
Nunca se debe «entrar en el contenido exacto de $_POST['...']» en cualquier campo de base de datos : es una puerta abierta a las Inyecciones de SQL.
Lugar, usted debe asegurarse de que los datos que son de inyección en las consultas de SQL son realmente válidos, de acuerdo a lo esperado DB tipos de datos.
Para los decimales, una solución, en el PHP lado, sería el uso de la floatval función :
$clean_price = floatval($_POST['price']);
$query = "insert into your_table (price, ...) values ($clean_price, ...)"
if (mysql_query($query)) {
//success
} else {
echo mysql_error(); //To help, while testing
}
Nota que yo no he puesto ninguna cotización cercana al valor 😉
• No floatval() provocar cierta pérdida de precisión si se fuera a realizar aritmética en $clean_price? No estoy seguro si PHP tiene un built-in de tipo decimal…pero en este caso, ¿no sería mejor para desinfectar el POST de los datos y pasar en como una cadena de caracteres?
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|
__label__pos
| 0.863571 |
ECG Database Applications Guide Table of Contents
NAME
dbwhich - find a DB file and print its pathname
SYNOPSIS
dbwhich [ -r record ] filename
dbwhich [ -r record ] file-type record
DESCRIPTION
This program searches the DB path (as specified by the environment variable DB, see setdb(1) ) for a specified filename, or for a file of a specified file-type (e.g., `header' or `atruth') which belongs to a specified record. If the file can be found, its full pathname is written to the standard output, and dbwhich exits with an exit status of zero (indicating success). If the file cannot be found, a diagnostic message, including the current value of the DB path, is written to the standard error output, and dbwhich exits with a non-zero exit status.
If the DB path includes `%r', use the -r record option to specify the record name to be substituted for `%r'.
SEE ALSO
setdb(1)
Table of Contents
|
__label__pos
| 0.543887 |
Kibana Metrics (take percentage of the sum of a field)
I am new to ELK and I could use some help.
I have a field named VM that has true and false values. If the system is a physical server then the value is false, otherwise if it is a VM it is true.
I need to take a percentage of how much of the environment is virtualized and display it as a metric
lets assume total VM field count is 10
false=3
true=7
I would like to show that 70% of the environment is virtualized.
Here is the math equation
((Virtual/(Physical + Virtual))*100)
Hi @creativeguitar ,
I think you may use TSVB or Vega to build such metric with math: TSVB has a feature called Filter Ratio which might work, and if that isn't powerful enough you have to use Vega.
In 7.14 Lens will offer a similar feature to the TSVB where you could perform math calculations.
1 Like
Hi @Marco_Liberati
So you can get something very similar with the Bar Percentage Chart in Lens Today.
Here is an example with app names percentage, you would just breakdown by your field that represents vm : true / false
This will show you the True / False Percentages today.
This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.
|
__label__pos
| 0.667659 |
Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.
In my Ubuntu 12.04, with psensor, I saw a percentage number updated for cpu usage. I wonder how this percentage caculated? Specifically, what is the numerator and denominator in the ratio?
Thanks!
share|improve this question
1 Answer 1
up vote 5 down vote accepted
The processor usage percent is calculated with "the amount of time that the processor is not on idle". I mean, this calc is made from a counter that register the usage of the "idle" running process. While another preocesses "rob" the processor power from the idle process, the idle processor consumer register is decreased by a factor; as the time line is fixed and constant, the (1-"%time in the idle taks") is the amount of processor load used for all processes running on a processor:
enter image description here
Defining CPU utilization
For our purposes, I define CPU utilization, U, as the amount of time not in the idle task, as shown in Equation 1.
The idle task is the task with the absolute lowest priority in a multitasking system. This task is also sometimes called the background task or background loop, shown in Listing 1. This logic traditionally has a while(1) type of loop. In other words, an infinite loop spins the CPU waiting for an indication that critical work needs to be done.
Listing 1: Simple example of a background loop
int main( void )
{
SetupInterrupts();
InitializeModules();
EnableInterrupts();
while(1) /* endless loop - spin in the background */
{
CheckCRC();
MonitorStack();
... do other non-time critical logic here.
}
}
This depiction is actually an oversimplification, as some "real" work is often done in the background task. However, the logic coded for execution during the idle task must have no hard real-time requirements because there's no guarantee when this logic will complete. In fact, one technique you can use in an overloaded system is to move some of the logic with less strict timing requirements out of the hard real-time tasks and into the idle task.
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|
__label__pos
| 0.872421 |
Hello, I am attempting to call a method from a click event on a form and not having much luck.
public void xbuttonValidateUPC_Click(object sender, EventArgs e)
{//Validate UPC Button Click
UPC_JDB UPC1 = new UPC_JDB("123");
string temp = (xtextBoxValidate.Text);
UPC1.ValidateUPC(temp);
xtextBoxValidateAnswer.Text = temp;
}//end Validate UPC Button Click
Program is supposed to take a string value in xtextBoxValidate text box, send it to ValidateUPC, and get back a message to display in xtextBoxValidateAnswer text box whether the UPC code is valid or not. At this point it just puts whatever I put in xtextBoxValidate.Text into xtextBoxValidateAnswer.Text. Any ideas?
Recommended Answers
Did you wrote the UPC1.ValidateUPC()?
If so, is the parameter that takes the "temp" a (ref string ...)?
Does it take a reference to a string (if you expect the string to be modified)?
Jump to Post
Have you stepped through this in the debugger to see that the correct value is being passed?
Jump to Post
All 6 Replies
Did you wrote the UPC1.ValidateUPC()?
If so, is the parameter that takes the "temp" a (ref string ...)?
Does it take a reference to a string (if you expect the string to be modified)?
Did you wrote the UPC1.ValidateUPC()?
If so, is the parameter that takes the "temp" a (ref string ...)?
Does it take a reference to a string (if you expect the string to be modified)?
Yes, I created UPC1.ValidateUPC(). Yes, the paramter that takes the temp variable is a string. Yes, it does take a reference to a string. It works in console but trying to get it working in a form has eluded me so far. I pretty much too the code from the console version and modified it for the form.
Here is the console version that works just fine.:
UPC_JDB UPC1 = new UPC_JDB("123");
Console.Write("Enter UPC to be validated: ");
string temp = Console.ReadLine();
Console.Write(UPC1.ValidateUPC(temp));
Console.ReadLine();
Have you stepped through this in the debugger to see that the correct value is being passed?
I was able to walk through the program and ValidateUPC is definitely getting the string variable and processing it properly. The problem I believe is in the return.
Here is the code for the return in ValidateUPC.
if (CheckSum != num12)
{
return "The UPC checksum is invalid";
}
else
{
return "The UPC checksum is valid";
}
I was assuming the return string value of temp would be either "The UPC checksum is invalid" or "The UPC checksum is valid". It doesn't appear anything is returning from ValidateUPC.
No, you're not actually modifying "temp" with that type of function.
What you should do (if you want to keep it the way you have it is):
xtextBoxValidateAnswer.Text = UPC1.ValidateUPC(temp);
Console.Write(UPC1.ValidateUPC(temp)); writes the output from the function to the console whereas UPC1.ValidateUPC(temp); never saves the output for later display.
I suspect your Validate rountine is coded using "pass by value" rather than "pass by reference" - partly because a routine using ref wouldn't actually need a returned value.
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|
__label__pos
| 0.981924 |
fread
(PHP 4, PHP 5, PHP 7, PHP 8)
fread读取文件（可安全用于二进制文件）
说明
fread(resource $stream, int $length): string|false
fread() 从文件指针 stream 读取最多 length 个字节。 该函数在遇上以下几种情况时停止读取文件：
• 读取了 length 个字节
• 到达了文件末尾（EOF）
• a packet becomes available or the socket timeout occurs (for network streams)
• if the stream is read buffered and it does not represent a plain file, at most one read of up to a number of bytes equal to the chunk size (usually 8192) is made; depending on the previously buffered data, the size of the returned data may be larger than the chunk size.
参数
stream
文件系统指针，是典型地由 fopen() 创建的 resource(资源)。
length
最多读取 length 个字节。
返回值
返回所读取的字符串， 或者在失败时返回 false
示例
示例 #1 一个简单的 fread() 例子
<?php
// get contents of a file into a string
$filename = "/usr/local/something.txt";
$handle = fopen($filename, "r");
$contents = fread($handle, filesize($filename));
fclose($handle);
?>
示例 #2 Binary fread() example
警告
在区分二进制文件和文本文件的系统上（如 Windows）打开文件时，fopen() 函数的 mode 参数要加上 'b'。
<?php
$filename
= "c:\\files\\somepic.gif";
$handle = fopen($filename, "rb");
$contents = fread($handle, filesize($filename));
fclose($handle);
?>
示例 #3 Remote fread() examples
警告
当从任何不是普通本地文件读取时，例如在读取从远程文件popen() 以及 fsockopen() 返回的流时，读取会在一个包可用之后停止。这意味着应该如下例所示将数据收集起来合并成大块。
<?php
$handle
= fopen("http://www.example.com/", "rb");
if (
FALSE === $handle) {
exit(
"Failed to open stream to URL");
}
$contents = stream_get_contents($handle);
fclose($handle);
?>
<?php
$handle
= fopen("http://www.example.com/", "rb");
$contents = '';
while (!
feof($handle)) {
$contents .= fread($handle, 8192);
}
fclose($handle);
?>
注释
注意:
如果只是想将一个文件的内容读入到一个字符串中，用 file_get_contents()，它的性能比上面的代码好得多。
注意:
Note that fread() reads from the current position of the file pointer. Use ftell() to find the current position of the pointer and rewind() to rewind the pointer position.
参见
• fwrite() - 写入文件（可安全用于二进制文件）
• fopen() - 打开文件或者 URL
• fsockopen() - 打开 Internet 或者 Unix 套接字连接
• popen() - 打开进程文件指针
• fgets() - 从文件指针中读取一行
• fgetss() - 从文件指针中读取一行并过滤掉 HTML 标记
• fscanf() - 从文件中格式化输入
• file() - 把整个文件读入一个数组中
• fpassthru() - 输出文件指针处的所有剩余数据
• fseek() - 在文件指针中定位
• ftell() - 返回文件指针读/写的位置
• rewind() - 倒回文件指针的位置
• unpack() - Unpack data from binary string
add a note
User Contributed Notes 32 notes
up
19
dharmilshah at gmail dot com
10 years ago
For anyone still trying to write an effective file downloader function/script, the work has been done for you in all the major servers including Apache & nginx.
Using the X-Sendfile header, you can do the following:
if ($user->isLoggedIn())
{
header("X-Sendfile: $path_to_somefile_private");
header("Content-Type: application/octet-stream");
header("Content-Disposition: attachment; filename=\"$somefile\"");
}
Apache will serve the file for you while NOT revealing your private file path! Pretty nice. This works on all browsers/download managers and saves a lot of resources.
Documentation:
Apache module: https://tn123.org/mod_xsendfile/
Nginx: http://wiki.nginx.org/XSendfile
Lighttpd: http://blog.lighttpd.net/articles/2006/07/02/x-sendfile/
Hopefully this will save you many hours of work.
up
25
edgarinvillegas at hotmail dot com
14 years ago
I had a fread script that hanged forever (from php manual):
<?php
$fp
= fsockopen("example.host.com", 80);
if (!
$fp) {
echo
"$errstr ($errno)<br />\n";
} else {
fwrite($fp, "Data sent by socket");
$content = "";
while (!
feof($fp)) { //This looped forever
$content .= fread($fp, 1024);
}
fclose($fp);
echo
$content;
}
?>
The problem is that sometimes end of streaming is not marked by EOF nor a fixed mark, that's why this looped forever. This caused me a lot of headaches...
I solved it using the stream_get_meta_data function and a break statement as the following shows:
<?php
$fp
= fsockopen("example.host.com", 80);
if (!
$fp) {
echo
"$errstr ($errno)<br />\n";
} else {
fwrite($fp, "Data sent by socket");
$content = "";
while (!
feof($fp)) {
$content .= fread($fp, 1024);
$stream_meta_data = stream_get_meta_data($fp); //Added line
if($stream_meta_data['unread_bytes'] <= 0) break; //Added line
}
fclose($fp);
echo
$content;
}
?>
Hope this will save a lot of headaches to someone.
(Greetings, from La Paz-Bolivia)
up
11
mail at 3v1n0 dot net
16 years ago
This is an hack I've done to download remote files with HTTP resume support. This is useful if you want to write a download script that fetches files remotely and then sends them to the user, adding support to download managers (I tested it on wget). To do that you should also use a "remote_filesize" function that you can easily write/find.
<?php
function readfile_chunked_remote($filename, $seek = 0, $retbytes = true, $timeout = 3) {
set_time_limit(0);
$defaultchunksize = 1024*1024;
$chunksize = $defaultchunksize;
$buffer = '';
$cnt = 0;
$remotereadfile = false;
if (
preg_match('/[a-zA-Z]+:\/\//', $filename))
$remotereadfile = true;
$handle = @fopen($filename, 'rb');
if (
$handle === false) {
return
false;
}
stream_set_timeout($handle, $timeout);
if (
$seek != 0 && !$remotereadfile)
fseek($handle, $seek);
while (!
feof($handle)) {
if (
$remotereadfile && $seek != 0 && $cnt+$chunksize > $seek)
$chunksize = $seek-$cnt;
else
$chunksize = $defaultchunksize;
$buffer = @fread($handle, $chunksize);
if (
$retbytes || ($remotereadfile && $seek != 0)) {
$cnt += strlen($buffer);
}
if (!
$remotereadfile || ($remotereadfile && $cnt > $seek))
echo
$buffer;
ob_flush();
flush();
}
$info = stream_get_meta_data($handle);
$status = fclose($handle);
if (
$info['timed_out'])
return
false;
if (
$retbytes && $status) {
return
$cnt;
}
return
$status;
}
?>
up
7
john dot wellesz at teaser dot com
9 years ago
Note that fread() will return '' (empty string) when a timeout occurs unlike socket_read() which returns false...
up
24
Edward Jaramilla
15 years ago
I couldn't get some of the previous resume scripts to work with Free Download Manager or Firefox. I did some clean up and modified the code a little.
Changes:
1. Added a Flag to specify if you want download to be resumable or not
2. Some error checking and data cleanup for invalid/multiple ranges based on http://tools.ietf.org/id/draft-ietf-http-range-retrieval-00.txt
3. Always calculate a $seek_end even though the range specification says it could be empty... eg: bytes 500-/1234
4. Removed some Cache headers that didn't seem to be needed. (add back if you have problems)
5. Only send partial content header if downloading a piece of the file (IE workaround)
<?php
function dl_file_resumable($file, $is_resume=TRUE)
{
//First, see if the file exists
if (!is_file($file))
{
die(
"<b>404 File not found!</b>");
}
//Gather relevent info about file
$size = filesize($file);
$fileinfo = pathinfo($file);
//workaround for IE filename bug with multiple periods / multiple dots in filename
//that adds square brackets to filename - eg. setup.abc.exe becomes setup[1].abc.exe
$filename = (strstr($_SERVER['HTTP_USER_AGENT'], 'MSIE')) ?
preg_replace('/\./', '%2e', $fileinfo['basename'], substr_count($fileinfo['basename'], '.') - 1) :
$fileinfo['basename'];
$file_extension = strtolower($path_info['extension']);
//This will set the Content-Type to the appropriate setting for the file
switch($file_extension)
{
case
'exe': $ctype='application/octet-stream'; break;
case
'zip': $ctype='application/zip'; break;
case
'mp3': $ctype='audio/mpeg'; break;
case
'mpg': $ctype='video/mpeg'; break;
case
'avi': $ctype='video/x-msvideo'; break;
default:
$ctype='application/force-download';
}
//check if http_range is sent by browser (or download manager)
if($is_resume && isset($_SERVER['HTTP_RANGE']))
{
list(
$size_unit, $range_orig) = explode('=', $_SERVER['HTTP_RANGE'], 2);
if (
$size_unit == 'bytes')
{
//multiple ranges could be specified at the same time, but for simplicity only serve the first range
//http://tools.ietf.org/id/draft-ietf-http-range-retrieval-00.txt
list($range, $extra_ranges) = explode(',', $range_orig, 2);
}
else
{
$range = '';
}
}
else
{
$range = '';
}
//figure out download piece from range (if set)
list($seek_start, $seek_end) = explode('-', $range, 2);
//set start and end based on range (if set), else set defaults
//also check for invalid ranges.
$seek_end = (empty($seek_end)) ? ($size - 1) : min(abs(intval($seek_end)),($size - 1));
$seek_start = (empty($seek_start) || $seek_end < abs(intval($seek_start))) ? 0 : max(abs(intval($seek_start)),0);
//add headers if resumable
if ($is_resume)
{
//Only send partial content header if downloading a piece of the file (IE workaround)
if ($seek_start > 0 || $seek_end < ($size - 1))
{
header('HTTP/1.1 206 Partial Content');
}
header('Accept-Ranges: bytes');
header('Content-Range: bytes '.$seek_start.'-'.$seek_end.'/'.$size);
}
//headers for IE Bugs (is this necessary?)
//header("Cache-Control: cache, must-revalidate");
//header("Pragma: public");
header('Content-Type: ' . $ctype);
header('Content-Disposition: attachment; filename="' . $filename . '"');
header('Content-Length: '.($seek_end - $seek_start + 1));
//open the file
$fp = fopen($file, 'rb');
//seek to start of missing part
fseek($fp, $seek_start);
//start buffered download
while(!feof($fp))
{
//reset time limit for big files
set_time_limit(0);
print(
fread($fp, 1024*8));
flush();
ob_flush();
}
fclose($fp);
exit;
}
?>
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9
matt at matt-darby dot com
16 years ago
I thought I had an issue where fread() would fail on files > 30M in size. I tried a file_get_contents() method with the same results. The issue was not reading the file, but echoing its data back to the browser.
Basically, you need to split up the filedata into manageable chunks before firing it off to the browser:
<?php
$total
= filesize($filepath);
$blocksize = (2 << 20); //2M chunks
$sent = 0;
$handle = fopen($filepath, "r");
// Push headers that tell what kind of file is coming down the pike
header('Content-type: '.$content_type);
header('Content-Disposition: attachment; filename='.$filename);
header('Content-length: '.$filesize * 1024);
// Now we need to loop through the file and echo out chunks of file data
// Dumping the whole file fails at > 30M!
while($sent < $total){
echo
fread($handle, $blocksize);
$sent += $blocksize;
}
exit(
0);
?>
Hope this helps someone!
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8
randym
12 years ago
Concerning [problems with UTF-8 and] downloading Zip files I found that simply adding 3 lines of code before starting the fread to the buffer for delivery in all browsers solved the problem.
<?php
ob_end_clean
();
ob_start();
header( 'Content-Type:' );
?>
... see where placed in the function below:
<?php
function readfile_chunked( $filename, $retbytes = true ) {
$chunksize = 1 * (1024 * 1024); // how many bytes per chunk
$buffer = '';
$cnt = 0;
$handle = fopen( $filename, 'rb' );
if (
$handle === false ) {
return
false;
}
ob_end_clean(); //added to fix ZIP file corruption
ob_start(); //added to fix ZIP file corruption
header( 'Content-Type:' ); //added to fix ZIP file corruption
while ( !feof( $handle ) ) {
$buffer = fread( $handle, $chunksize );
//$buffer = str_replace("","",$buffer);
echo $buffer;
ob_flush();
flush();
if (
$retbytes ) {
$cnt += strlen( $buffer );
}
}
$status = fclose( $handle );
if (
$retbytes && $status ) {
return
$cnt; // return num. bytes delivered like readfile() does.
}
return
$status;
}
?>
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7
Anonymous
15 years ago
It might be worth noting that if your site uses a front controller with sessions and you send a large file to a user; you should end the session just before sending the file, otherwise the user will not be able to continue continue browsing the site while the file is downloading.
up
5
dvsoftware at gmail dot com
19 years ago
I was trying to implement resume support in download script, and i have finnaly succeded. here is the script:
<?php
function dl_file_resume($file){
//First, see if the file exists
if (!is_file($file)) { die("<b>404 File not found!</b>"); }
//Gather relevent info about file
$len = filesize($file);
$filename = basename($file);
$file_extension = strtolower(substr(strrchr($filename,"."),1));
//This will set the Content-Type to the appropriate setting for the file
switch( $file_extension ) {
case
"exe": $ctype="application/octet-stream"; break;
case
"zip": $ctype="application/zip"; break;
case
"mp3": $ctype="audio/mpeg"; break;
case
"mpg":$ctype="video/mpeg"; break;
case
"avi": $ctype="video/x-msvideo"; break;
//The following are for extensions that shouldn't be downloaded (sensitive stuff, like php files)
case "php":
case
"htm":
case
"html":
case
"txt": die("<b>Cannot be used for ". $file_extension ." files!</b>"); break;
default:
$ctype="application/force-download";
}
//Begin writing headers
header("Pragma: public");
header("Expires: 0");
header("Cache-Control:");
header("Cache-Control: public");
header("Content-Description: File Transfer");
//Use the switch-generated Content-Type
header("Content-Type: $ctype");
$filespaces = str_replace("_", " ", $filename);
//if your filename contains underscores, you can replace them with spaces
$header='Content-Disposition: attachment; filename='.$filespaces.';';
header($header );
header("Content-Transfer-Encoding: binary");
$size=filesize($file);
//check if http_range is sent by browser (or download manager)
if(isset($_ENV['HTTP_RANGE'])) {
list(
$a, $range)=explode("=",$_ENV['HTTP_RANGE']);
//if yes, download missing part
str_replace($range, "-", $range);
$size2=$size-1;
header("Content-Range: $range$size2/$size");
$new_length=$size2-$range;
header("Content-Length: $new_length");
/if
not, download whole file
} else {
$size2=$size-1;
header("Content-Range: bytes 0-$size2/$size");
header("Content-Length: ".$size2);
}
//open the file
$fp=fopen("$file","r");
//seek to start of missing part
fseek($fp,$range);
//start buffered download
while(!feof($fp))
{
//reset time limit for big files
set_time_limit();
print(
fread($fp,1024*8));
flush();
}
fclose($fp);
exit;
}
?>
EXAMPLE
<?php
dl_file_resume
("somefile.mp3");
?>
please write if you find any errors, i have tested this only with mp3 files, but others should be fine
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4
aubfre at hotmail dot com
17 years ago
Changing the value of $length may yield to different download speeds when serving a file from a script.
I was not able to max out my 10mbps connection when 4096 was used. I found out that using 16384 would use all the available bandwidth.
When outputing binary data with fread, do not assume that 4096 or 8192 is the optimal value for you. Do some benchmarks by downloading files through your script.
up
2
Wvss at gmail dot com
2 years ago
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<?php
require_once "person.class.php";
require_once
"schueler.class.php";
require_once
"lehrer.class.php";
//$p = new Person("Hans", "Wurst");
//$p->ausgabe();
$s = new Schueler("Kevin", "Mayer", "FTET3");
$s->ausgabe();
Lehrer::$maxGehaltsStufe = 16;
$l = new Lehrer("Karl", "Napf", 13);
$l->ausgabe();
$l->befoerdern();
$l->ausgabe();
$l->befoerdern();
$l->ausgabe();
$l->befoerdern();
$l->ausgabe();
$l->befoerdern();
$l->ausgabe();
?>
</body>
</html>
up
2
fenris_wolf0 at yahoo dot com
19 years ago
To make the effects of the latest PHP version changes of the fread function even more explicit: the new size limitation of fread -regardless of the filesize one specifies, in the example below 1024 * 1024- means that if one was simply reading the contents of a text file from a dynamic URL like so:
<?php
$dp
= "http://www.example.com/filename.php";
$buffer = fopen($dp, 'r');
if (!
$buffer)
{
echo(
"<P>Error: unable to load URL file into $buffer. Process aborted.</P>");
exit();
}
$sp = fread($buffer, 1024*1024);
fclose($buffer);
highlight_string($sp);
?>
one should from now on use the file_get_contents function, as shown below, to avoid one's text being truncated forcibly.
<?php
$dp
= "http://www.example.com/filename.php";
if (!
$dp)
{
echo(
"<P>Error: unable to load URL file into $dp. Process aborted.</P>");
exit();
}
$sp = file_get_contents($dp);
highlight_string($sp);
?>
I thought it couldn't hurt to clarify this detail in order to save time for anyone else who is in the same situation as I was tonight when my ISP abruptly upgraded to the latest version of PHP... :(
Thank you to every previous contributor to this topic.
up
3
fread at imperium dot be
10 years ago
My script was based on example 3b, but used up 100% CPU when a timeout occurred that wasn't "seen". This is very bad. So here's my code, hoping this will help people out there with the same problem. Obviously first use $rPage = fsockopen(...) and fwrite($rPage,...) and such, after which:
$sPage = ''; // the page goes in here
$iTimeout = 5; // set the timeout in seconds
stream_set_timeout($rPage,$iTimeout);
stream_set_blocking($rPage,0);
$fTimeout = microtime(true);
do {
if (($sRead = fread($rPage,8192))!==false and strlen($sRead)) {
$sPage .= $sRead; }
else {
usleep(10000); } // 0.01 second
$aInfo = stream_get_meta_data($rPage); }
while (!feof($rPage) and !$aInfo['timed_out'] and microtime(true)-$fTimeout<$iTimeout);
fclose($rPage);
// now simply decompress and unchunk $sPage, if need be
Above code will make sure the timeout is used, because this isn't always detected properly. In addition, the usleep() will keep the CPU in check.
up
2
heikki dot korpela at wapit dot com
23 years ago
Fread is binary-safe IF AND ONLY IF you don't use magic-quotes. If you do, all null bytes will become \0, and you might get surprising results when unpacking.
That is, you would do something like
<?php
set_magic_quotes_runtime
(0);
?>
before fread()
and something like
<?php
set_magic_quotes_runtime
(get_magic_quotes_gpc()) after.
?>
And, after fread, an unpack would be needed, of course. Surprisingly, pack(), however, does not work quite like in Perl (or perhaps I'm just missing something here) - you can't pack an array directly, but instead you'll have to pack each element seperately to the string:
<?php
foreach ($data as $dec) {
$data_output .= pack("C*", $dec);
}
?>
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3
david at identd dot dyndns dot org
14 years ago
Note to IIS admins:
When using PHP via the FastCGI ISAPI extension, there is a script timeout of approximately 1hr that cannot be adjusted. When using PHP via CGI, there is a script timeout that is based upon the value of the CGITimeout configuration option. This value must be set extremely high if you plan to serve large files. An explanation of how to configure this option can be found here: http://www.iisadmin.co.uk/?p=7 If you do not modify this setting you can expect the above scripts to fail silently once it has hit the default value (30 minutes in my case).
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4
Anonymous
15 years ago
This code is buggy
<?php
$contents
= '';
while (!
feof($handle)) {
$contents .= fread($handle, 8192);
}
?>
When you read a file whose size is a multiple of the readsize (8192 here), then the loop is executed when there are no more data to read. Here, the result of fread() is not checked, and so the instruction
<?php
$contents
.= fread($handle, 8192)
?>
is executed once with no data from fread(). In this very case, it is not important, but in some situation it could be harmful.
The good way to read a file block by block is :
<?php
while ( ($buf=fread( $handle, 8192 )) != '' ) {
// Here, $buf is guaranted to contain data
$contents .= $buf;
}
if(
$buf===FALSE) {
echo
"THERE WAS AN ERROR READING\n";
}
?>
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4
ibis at connect dot ie
19 years ago
If, like me, you're in the habit of using fopen("http://...") and fread for pulling fairly large remote files, you may find that the upgrade to PHP5 (5.0.2 on Win2000/IIS5) causes fread to top out at about 8035 bytes. PHP5 RC2 with identical php.ini settings did not exhibit this behaviour (I was using this for testing). Irritating for me because I was using simple_xml_load to load the file contents as XML, and the problem initially appeared to be that function.
Solution - swap over to file_get_contents or use the loop suggested on the documentation above (see Warning).
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3
shocker at shockingsoft dot com
16 years ago
If you read from a socket connection or any other stream that may delay when responsing but you want to set a timeout you can use stream_set_timeout():
<?php
$f
= fsockopen("127.0.0.1", 123);
if (
$f)
{
fwrite($f, "hello");
stream_set_timeout($f, 5); //5 seconds read timeout
if (!fread($f, 5)) echo "Error while reading";
else echo
"Read ok";
fclose($f);
}
?>
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4
Anonymous
13 years ago
If you serve a file download over PHP with fread and print/echo and experience corrupted binary files, chances are the server still uses magic quotes and escapes the null bytes in your file. Although from 5.3.0 magic quotes are no longer supported, you might still encounter this problem. Try to turn them off by placing this code before using fread:
<?php
@ini_set('magic_quotes_runtime', 0);
?>
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2
mrhappy[at]dotgeek.org
19 years ago
Just a note for anybody trying to implement a php handled download script -
We spent a long time trying to figure out why our code was eating system resources on large files.. Eventually we managed to trace it to output buffering that was being started on every page via an include.. (It was attempting to buffer the entire 600 Megs or whatever size *before* sending data to the client) if you have this problem you may want to check that first and either not start buffering or close that in the usual way :)
Hope that prevents somebody spending hours trying to fix an obscure issue.
Regards :)
up
1
Richard Dale richard at premiumdata dot n dot e dot t
18 years ago
If you use any of the above code for downloadinng files, Internet Explorer will change the filename if it has multiple periods in it to something with square brackets. To work around this, we check to see if the User Agent contains MSIE and rewrite the necessary periods as %2E
<?php
# eg. $filename="setup.abc.exe";
if (strstr($_SERVER['HTTP_USER_AGENT'], "MSIE")) {
# workaround for IE filename bug with multiple periods / multiple dots in filename
# that adds square brackets to filename - eg. setup.abc.exe becomes setup[1].abc.exe
$iefilename = preg_replace('/\./', '%2e', $filename, substr_count($filename, '.') - 1);
header("Content-Disposition: attachment; filename=$iefilename" );
} else {
header("Content-Disposition: attachment; filename=$filename");
}
?>
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3
m (at) mindplay (dot) dk
19 years ago
Here's a function for sending a file to the client - it may look more complicated than necessary, but has a number of advantages over simpler file sending functions:
- Works with large files, and uses only an 8KB buffer per transfer.
- Stops transferring if the client is disconnected (unlike many scripts, that continue to read and buffer the entire file, wasting valuable resources) but does not halt the script
- Returns TRUE if transfer was completed, or FALSE if the client was disconnected before completing the download - you'll often need this, so you can log downloads correctly.
- Sends a number of headers, including ones that ensure it's cached for a maximum of 2 hours on any browser/proxy, and "Content-Length" which most people seem to forget.
(tested on Linux (Apache) and Windows (IIS5/6) under PHP4.3.x)
Note that the folder from which protected files will be pulled, is set as a constant in this function (/protected) ... Now here's the function:
<?php
function send_file($name) {
ob_end_clean();
$path = "protected/".$name;
if (!
is_file($path) or connection_status()!=0) return(FALSE);
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");
header("Expires: ".gmdate("D, d M Y H:i:s", mktime(date("H")+2, date("i"), date("s"), date("m"), date("d"), date("Y")))." GMT");
header("Last-Modified: ".gmdate("D, d M Y H:i:s")." GMT");
header("Content-Type: application/octet-stream");
header("Content-Length: ".(string)(filesize($path)));
header("Content-Disposition: inline; filename=$name");
header("Content-Transfer-Encoding: binary\n");
if (
$file = fopen($path, 'rb')) {
while(!
feof($file) and (connection_status()==0)) {
print(
fread($file, 1024*8));
flush();
}
fclose($file);
}
return((
connection_status()==0) and !connection_aborted());
}
?>
And here's an example of using the function:
<?php
if (!send_file("platinumdemo.zip")) {
die (
"file transfer failed");
// either the file transfer was incomplete
// or the file was not found
} else {
// the download was a success
// log, or do whatever else
}
?>
Regards,
Rasmus Schultz
up
2
webmaster at wildpeaks dot com
20 years ago
The following function retrieves a line in a file, regardless of its size, so you won't get an error if the file's size is beyond php's allowed memory limit (the string has to be below however), which is something i was needing for accessing a big log file generated by a webhost. Indexes start at 1 (so $line = 1 means the first line unlike arrays). If the file is small, it would be better to use "file()" however.
<?php
function strpos_count($haystack, $needle, $i = 0) {
while (
strpos($haystack,$needle) !== false) {$haystack = substr($haystack, (strpos($haystack,$needle) + 1)); $i++;}
return
$i;
}
function
getLine($file,$line=1){
$occurence = 0;
$contents = '';
$startPos = -1;
if (!
file_exists($file)) return '';
$fp = @fopen($file, "rb");
if (!
$fp) return '';
while (!@
feof($fp)) {
$str = @fread($fp, 1024);
$number_of_occurences = strpos_count($str,"\n");
if (
$number_of_occurences == 0) {if ($start_pos != -1) {$contents .= $str;}}
else {
$lastPos = 0;
for (
$i = 0; $i < $number_of_occurences; $i++){
$pos = strpos($str,"\n", $lastPos);
$occurence++;
if (
$occurence == $line) {
$startPos = $pos;
if (
$i == $number_of_occurences - 1) {$contents = substr($str, $startPos + 1);}
} elseif (
$occurence == $line + 1) {
if (
$i == 0) {$contents .= substr($str, 0, $pos);} else {$contents = substr($str, $startPos, $pos - $startPos);}
$occurence = 0;
break;
}
$lastPos = $pos + 1;
}
}
}
@
fclose($fp);
return
$contents;
}
?>
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1
andrej dot frelih at gmail dot com
12 years ago
Another sample function that supports from/to range requests:
<?php
function download_file($file_name) {
if (!
file_exists($file_name)) { die("<b>404 File not found!</b>"); }
$file_extension = strtolower(substr(strrchr($file_name,"."),1));
$file_size = filesize($file_name);
$md5_sum = md5_file($file_name);
//This will set the Content-Type to the appropriate setting for the file
switch($file_extension) {
case
"exe": $ctype="application/octet-stream"; break;
case
"zip": $ctype="application/zip"; break;
case
"mp3": $ctype="audio/mpeg"; break;
case
"mpg":$ctype="video/mpeg"; break;
case
"avi": $ctype="video/x-msvideo"; break;
//The following are for extensions that shouldn't be downloaded (sensitive stuff, like php files)
case "php":
case
"htm":
case
"html":
case
"txt": die("<b>Cannot be used for ". $file_extension ." files!</b>"); break;
default:
$ctype="application/force-download";
}
if (isset(
$_SERVER['HTTP_RANGE'])) {
$partial_content = true;
$range = explode("-", $_SERVER['HTTP_RANGE']);
$offset = intval($range[0]);
$length = intval($range[1]) - $offset;
}
else {
$partial_content = false;
$offset = 0;
$length = $file_size;
}
//read the data from the file
$handle = fopen($file_name, 'r');
$buffer = '';
fseek($handle, $offset);
$buffer = fread($handle, $length);
$md5_sum = md5($buffer);
if (
$partial_content) $data_size = intval($range[1]) - intval($range[0]);
else
$data_size = $file_size;
fclose($handle);
// send the headers and data
header("Content-Length: " . $data_size);
header("Content-md5: " . $md5_sum);
header("Accept-Ranges: bytes");
if (
$partial_content) header('Content-Range: bytes ' . $offset . '-' . ($offset + $length) . '/' . $file_size);
header("Connection: close");
header("Content-type: " . $ctype);
header('Content-Disposition: attachment; filename=' . $file_name);
echo
$buffer;
flush();
}
?>
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1
James Ranson
15 years ago
Tom, the idea for the examples below is to ensure the user has proper credentials before serving the file. With that security in mind, the suggestion of a 302 redirection seems like a risky idea. Anyone with a modicum of networking experience can run a TCP trace and see the 302 Redirect response, as it is actually a response received by the client browser; the browser then makes a subsequent http request for the URL provided in the Location header. When that 302 response is captured by wireshark, the 'secret' location is then exposed and can be shared with anyone who wishes to bypass the authorization routines in the php.
The only way to secure this would be for the 302 Redirection response to include some kind of unique, per-request, expiring authorization token, either on the end of the url or in a set-cookie, that is then checked by an authorization module implemented within the hosting webserver. Otherwise, you're relegated to the methods described below.
up
1
NOopensourceSPAM at prodigy7 dot de
13 years ago
Somehow all code samples for downloads, described here, doesn't work right for me.
When I download a big file readfile or fread in b mode, the final file hasn't the same md5 like the originial.
Some tests helps me, finding a solution:
<?php
$fp
= fopen($DownloadFile, 'rb');
while (
$cline = fgets($fp) )
{
print
$cline;
}
fclose($fp);
?>
Somehow, it's "binary safe" and deliver that file which are read. md5 original and download are the same.
up
0
box dot afzar at gmail dot com
11 years ago
I write this script for download with resume suport
<?php
// If user click the download link
if(isset($_GET['filename'])){
// The directory of downloadable files
// This directory should be unaccessible from web
$file_dir="/tmp/";
// Replace the slash and backslash character with empty string
// The slash and backslash character can be dangerous
$file_name=str_replace("/", "", $_GET['filename']);
$file_name=str_replace("\\", "", $file_name);
// If the requested file is exist
if(file_exists($file_dir.$file_name)){
// Get the file size
$file_size=filesize($file_dir.$file_name);
// Open the file
$fh=fopen($file_dir.$file_name, "r");
// Download speed in KB/s
$speed=5;
// Initialize the range of bytes to be transferred
$start=0;
$end=$file_size-1;
// Check HTTP_RANGE variable
if(isset($_SERVER['HTTP_RANGE']) &&
preg_match('/^bytes=(\d+)-(\d*)/', $_SERVER['HTTP_RANGE'], $arr)){
// Starting byte
$start=$arr[1];
if(
$arr[2]){
// Ending byte
$end=$arr[2];
}
}
// Check if starting and ending byte is valid
if($start>$end || $start>=$file_size){
header("HTTP/1.1 416 Requested Range Not Satisfiable");
header("Content-Length: 0");
}
else{
// For the first time download
if($start==0 && $end==$file_size){
// Send HTTP OK header
header("HTTP/1.1 200 OK");
}
else{
// For resume download
// Send Partial Content header
header("HTTP/1.1 206 Partial Content");
// Send Content-Range header
header("Content-Range: bytes ".$start."-".$end."/".$file_size);
}
// Bytes left
$left=$end-$start+1;
}
?>
<html>
<head>
<title>Home</title>
</head>
<body>
<a href="index.php?filename=file.pdf">Download</a>
</body>
</html>
up
0
kai at froghh dot de
17 years ago
reading from a socket stream can be different to the
behaviour expected, since you have not set
stream_set_blocking to 1.
sample source:
<?php
$fp
= fsockopen ($server, $port, $errno, $errstr, $socket_timeout);
$header = '';
do {
$header.=fread($fp,1);
$i++;
} while (!
preg_match('/\\r\\n\\r\\n$/', $header) && $i < $maxheaderlenth);
preg_match('/Content\\-Length:\\s+([0-9]*)\\r\\n/', $header,$matches);
$buffer = fread($this->_fp, $matches[1]);
?>
if i.e. the content length is 50000 and the responding server is to slow
(means 50000 are not completely sent when fread is called)
you'll only receive the number of bytes sent by the
responding server at the time fread is called.
fread will not wait for any data to complete the given size.
as described in user notes on stream_set_blocking there
seems to be a bug using stream_set_blocking.
a workaround - well, not the best way - is to read
the response split to 1 byte
instead of
<?php $buffer = fread($this->_fp, $matches[1]); ?>
you'd write
<?php
$buffer
= '';
for(
$i = 0; $i < $matches[1]; $i++){
$buffer .= fread($this->_fp, 1);
}
?>
it several tests this seems like it works.
up
0
adamgamble at gmail dot com
18 years ago
<?php
/*
geoCode($address)
Accepts an address in the form of
999 Geocode Dr. New York, Ny 10108
returns array with lat and lon
*/
function geoCode($address) {
$gaddress = "http://maps.google.com?q=" . urlencode($address);
$handle = fopen($gaddress, "r");
$contents = '';
while (!
feof($handle)) {
$contents .= fread($handle, 8192);
}
fclose($handle);
ereg('<center lat="([0-9.-]{1,})" lng="([0-9.-]{1,})"/>', $contents, $regs);
$returnData['lat'] = $regs[1];
$returnData['lon'] = $regs[2];
return
$returnData;
}
print_r(geoCode("1064 Georgetown ln. Birmingham, Al 35217"));
?>
up
-1
tom
15 years ago
Various scripts suggested here attempt to deliver a file for download to a client. Handling http protocol features such as HTTP_RANGE is not trivial; neither is handling flow control with the server, memory and time limits when the files are large.
An alternative is to let the web server can handle http by redirecting to the file in question. It's not uncommon e.g. http://www.apple.com/downloads/macosx/ does this.
A PHP script can do any checks needed (security, authentication, validate the file) and any other tasks before calling header("Location $urltofile");
I tested this with apache. Interrupt/resume download works. The server's mime type configuration will determine client behavior. For apache, if defaults in mime.types are not suitable, configuration directives for mod_mime could go in a .htaccess file in the directory of the file to download. If really necessary, these could even by written by the PHP script before it redirects.
up
-1
fpinho at hotpop dot com
19 years ago
After using the suggested function from Rasmus Schultz : mindplay(at)mindplay(dot)dk, I've just noticed that people trying to download big files with a slow connection would get download stopped after exactly 60seconds -> the max execution time set with php.ini.
I suggest using a bigger buffer (1024x1024), or maybe resetting the time limit within the 'while' cicle with:
set_time_limit(0);
The cicle would go like this:
<?php
while(!feof($file) and (connection_status()==0)) {
print(
fread($file, 1024*1024));
set_time_limit(0);
flush();
}
?>
Frederico Pinho
up
-4
rob at lbox.org
21 years ago
I spent a while trying to get this to work so I thought I'd share.
Here's how to read a remote binary file using fread.
<?php
$fp
= fopen("http://www.example.com/img.jpg", "rb");
if(
$fp){
while(!
feof($fp)) {
$img = $img . fread($fp, 1024);
}
}
?>
This will read the contents of the file into the var $img 1024 bytes at a time. I used that number because it seemed safe, but you can increment it all you want I guess.
I don't know if everyone but me gets this, but I thought I'd share since I didn't see anything like it out there.
To Top
|
__label__pos
| 0.708397 |
How to Calculate Horizontal Distance
How to Calculate Horizontal Distance
••• hobo_018/iStock/GettyImages
This reference is for calculating the horizontal distance between two geographic points at difference elevations and is based on the mathematical relationship between the sides of a right triangle. The mathematical horizontal distance formula is often used on maps because it does not factor in things like peaks, hills and valleys between the two points. To successfully calculate the horizontal distance, which is also known as the run, between two points, you need to know the vertical distance, or rise, between the two elevations and the percentage of slope at the beginning of the horizontal elevation to the top of the vertical elevation.
Look over the equation for calculating horizontal distance, which is slope = rise/run x 100. Plug your slope percentage and rise into the equation. For example, if you have a slope percentage of 6 and a rise of 25 feet, the equation would look like 6 = (25/run) x 100.
Multiply each side of the equation by the 'run' variable. Continuing with the example of a slope percentage of 6 and a rise of 25, the equation will look like this: run x 6 = [(25/run) x 100)] x run. The 'run' terms cancel on the right side of the equation and the results can be simplified in the following equation: 6 x run = 2,500.
Divide each side of the equation by the slope percent. Continuing with the example of a slope percentage of 6 and a rise of 25, the equation should look like this: (run x 6) / 6 = 2,500 / 6. After completing the division, the equation becomes run = 416.6. The horizontal distance between the two points is then 416.6 feet.
Related Articles
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How to Calculate Rise & Run
How to Find the Radius of an Arc
How to Calculate Slope Ratio
How Do You Simplify Your Slope
How to Create Linear Equations
How to Find a Parallel Line
How to Find Asymptotes & Holes
How to Find Slope With Two Coordinates
How to Calculate Channel Slope
How to Calculate Percent Slope
How to Find a Z Score
How Do We Write the Equation of a Horizontal Line?
How to Find the X Intercept of a Function
How to Determine the Y-Intercept of a Trend Line
How to Convert a Percentage to a Degree
How to Calculate Sides of a Triangle
How to Find the Slope in a Circle
How to Graph the Y-Intercept as a Fraction
|
__label__pos
| 0.821347 |
As part of its ongoing collaboration with the FIDO Alliance, EMVCo has recently published a whitepaper that outlines how the use of FIDO Authentication Data in 3DS messages can streamline e-commerce checkout while reducing friction for consumers. In this Q&A post, EMVCo Director of Technology, Bastien Latge, provides insights into this new resource and how EMVCo and FIDO are working together to provide simpler and stronger authentication for cardholders.
What is the focus of the ‘Use of FIDO Data in 3DS Messages’ white paper?
Bastien Latge: The EMV® 3DS Specification promotes secure, consistent consumer e-commerce transactions across browser and in-app channels, while optimising the cardholder’s experience. It includes support for the FIDO Authentication protocol, and specifically for data elements to promote communication of pre-checkout authentication events and associated data as part of the EMV 3DS transaction from systems such as those supporting the FIDO Alliance standards.
The white paper provides guidance to merchants and card issuers on how FIDO Authentication data can be used to attest, provide evidence, that merchant-initiated strong consumer authentication has taken place prior to an EMV 3DS flow to authenticate. This can reduce the need for issuers to authenticate cardholders for every transaction when shopping online and streamline processes for merchants, consumers and card issuers.
Can you briefly explain the role of FIDO authentication data in an EMV 3DS transaction?
Bastien Latge: In many e-commerce purchases, the user journey begins with a merchant-initiated authentication. This could be for a user login (user identification) or at the time of initiating check-out for an e-commerce transaction.
When merchants use strong authentication methods such as FIDO Authentication, the data or details regarding the authentication can be valuable to the issuer performing authentication of a cardholder using an EMV 3DS flow.
What value does the paper bring to the payments industry?
Bastien Latge: The paper provides important information on how FIDO Authentication Data can be used to attest that merchant-initiated strong consumer authentication has taken place prior to an EMV 3DS transaction, which can improve approval rates for e-commerce merchants, reduce friction for consumers and enhance the user experience.
Using FIDO authentication data, merchants can deliver a structured set of data elements and present the card issuer with a consistent set of values for the same user or device (along with other data they would receive as part of an EMV 3DS flow), thereby reducing the need for repeated consumer authentication and increasing the probability of a frictionless experience for cardholders.
What was the driver for developing this white paper?
Bastien Latge: We see a strong desire from the payments industry to better understand how EMVCo’s Specifications align with and complement the work of bodies such as FIDO Alliance. Specifically, this white paper was developed to address the need for guidance on how FIDO Authentication data can be used by issuers to analyse merchant-initiated FIDO Authentication as part of their risk evaluations.
In addition to this whitepaper, how is EMVCo working with the FIDO Alliance, and what is the objective of this collaboration?
Bastien Latge: EMVCo and the FIDO Alliance began working together in 2016 with the goal of providing simpler and stronger authentication for cardholders making mobile payments using on-device authenticators, such as biometrics, thereby reducing consumer fraud globally while maintaining a good consumer experience.
The initiative enabled us to effectively combine EMVCo’s payment industry knowledge with FIDO Alliance’s authentication expertise to support cardholder verification methods that are convenient for the user, sustainable for the industry and most importantly, highly secure, thereby reducing consumer fraud in the mobile payment space.
We expanded the collaboration in 2018 to define how EMV 3DS messages may be used to pass FIDO authenticator attestation data and signatures in a manner that is both scalable and interoperable across the EMV payments ecosystem.
The ‘Use of FIDO Data in 3DS messages’ white paper is the first of a number of use cases that EMVCo and FIDO Alliance have evaluated for collaboration opportunities. Looking to the future, additional future use cases will include receiving additional data from FIDO authentications that issuers could cryptographically verify, using FIDO Authentication as an EMV 3DS challenge method.
The EMV 3DS white paper ‘Use of FIDO Data in 3DS Messages’ is available for free download from the EMVCo website. To find out more about EMV 3DS, view the resources on the EMVCo website.
A complementary technical note from the FIDO Alliance, “FIDO Authentication and EMV 3-D Secure: Using FIDO for Payment Authentication” can be found on the FIDO Alliance website.
|
__label__pos
| 0.791617 |
Monday 1 May 2023
How To Fix DLL File Missing Error - DLL Error Message Handling
What is DLL? Why it is important in Computers System?
A DLL file (Dynamic Link Library) is a type of file that contains a set of functions and data that can be used by multiple programs. It allows software developers to reuse code and data by providing a common library of functions and resources that can be used by different programs.
DLL files are important in computer systems because they help to reduce the amount of code that needs to be written and maintained. They also help to reduce memory usage and improve the performance of programs. Instead of each program including its own set of functions, DLL files allow multiple programs to share a common set of functions and resources.
Some common types of DLL files include graphics libraries, sound libraries, database libraries, and user interface libraries. Without DLL files, software development would be much more difficult and time-consuming, as developers would need to write and maintain their own libraries of functions and resources.
However, if a DLL file becomes corrupted or goes missing, it can cause problems with the programs that depend on it. This is why it is important to maintain the integrity of DLL files and fix any issues as soon as they arise.
How To Fix DLL File Missing Error - DLL Error Message Handling
DLL (Dynamic Link Library) files are important system files that are used by many programs in Windows. If a DLL file is missing or corrupted, it can cause errors and problems in the system. Here are some methods to fix DLL file missing error in Windows:
Method 1: Use System File Checker (SFC) to replace missing or corrupted DLL files
1. Open Command Prompt as an administrator.
2. Type "sfc /scannow" and press Enter.
3. The System File Checker will scan your system for missing or corrupted system files, including DLL files, and replace them if necessary.
4. Wait for the scan to complete and restart your computer.
Method 2: Reinstall the program that is causing the DLL error
1. Uninstall the program that is causing the DLL error.
2. Download the latest version of the program from the official website and install it.
3. If the DLL file is still missing, try downloading and installing the missing DLL file from a reputable DLL file download site.
Method 3: Use a DLL repair tool
There are many DLL repair tools available that can scan your system for missing or corrupted DLL files and fix them automatically. Some popular DLL repair tools include DLL-Files Fixer, DLL Tool, and Registry Reviver.
Method 4: Perform a system restore
If you recently installed a program or made changes to your system that caused the DLL error, you can use the System Restore feature to restore your system to an earlier time when the DLL file was working correctly.
1. Open Control Panel and select System and Security.
2. Click on System and then select System Protection.
3. Click on System Restore and follow the on-screen instructions to restore your system to an earlier time.
Note: Always be cautious when downloading and installing DLL files from the internet. Only download from reputable sources to avoid malware or other security issues.
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|
__label__pos
| 0.771478 |
还在为了Myeclipse到期而烦恼吗？我们还在百度，google来做伸手党吗？
虽然破解不是什么体面的事情，但是总的
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import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
public class MyEclipseKeyGen {
private static final String LL = "Decompiling this copyrighted software is a violation of both your license agreement and the Digital Millenium Copyright Act of 1998 (http://www.loc.gov/copyright/legislation/dmca.pdf). Under section 1204 of the DMCA, penalties range up to a $500,000 fine or up to five years imprisonment for a first offense. Think about it; pay for a license, avoid prosecution, and feel better about yourself.";
public String getSerial(String userId, String type) {
NumberFormat nf = new DecimalFormat("000");
Calendar cal = Calendar.getInstance();
cal.add(Calendar.YEAR, 3);
cal.add(Calendar.DAY_OF_YEAR, -1);
String licenseNum = nf.format((int) (Math.random() * 1000));
String expTime = new StringBuilder("-").append(
new SimpleDateFormat("yyMMdd").format(cal.getTime())).append(
"0").toString();
String need = new StringBuilder(userId.substring(0, 1)).append("Y")
.append(type).append("-100").append(licenseNum).append(expTime)
.toString();
String dx = new StringBuilder(need).append(LL).append(userId)
.toString();
int suf = this.decode(dx);
String code = new StringBuilder(need).append(String.valueOf(suf))
.toString();
return this.change(code);
}
private int decode(String s) {
int i;
char[] ac;
int j;
int k;
i = 0;
ac = s.toCharArray();
j = 0;
k = ac.length;
while (j < k) {
i = (31 * i) + ac[j];
j++;
}
return Math.abs(i);
}
private String change(String s) {
byte[] abyte0;
char[] ac;
int i;
int k;
int j;
abyte0 = s.getBytes();
ac = new char[s.length()];
i = 0;
k = abyte0.length;
while (i < k) {
j = abyte0[i];
if ((j >= 48) && (j < = 57)) {
j = (((j - 48) + 5) % 10) + 48;
} else if ((j >= 65) && (j < = 90)) {
j = (((j - 65) + 13) % 26) + 65;
} else if ((j >= 97) && (j < = 122)) {
j = (((j - 97) + 13) % 26) + 97;
}
ac[i] = (char) j;
i++;
}
return String.valueOf(ac);
}
public static void main(String[] args) {
try {
System.out.println("please input register name:");
BufferedReader reader = new BufferedReader(new InputStreamReader(
System.in));
String userId = null;
userId = reader.readLine();
if (userId == null || "".equals(userId)) {
System.out.println("name is null");
System.exit(0);
}
MyEclipseKeyGen myeclipsegen = new MyEclipseKeyGen();
String res = myeclipsegen.getSerial(userId, "E3MS");
System.out.println("Serial:" + res);
reader.readLine();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
|
__label__pos
| 0.99716 |
Some times when iOS devices or your Mac is updated with new software updates the saved password for your email accounts may be erased.
Default mail server settings for emails hosted with DO Solutions:
1. Host name for incoming/outgoing mail server, using SSL:
syd-s34r.hosting-service.net.au, port 993
2. Host name for incoming/outgoing mail server, using non-SSL:
yourdomain.xyz (using your own domain name), port 143
3. Outgoing SMTP port, using SSL: 465
4. Outgoing SMTP port, using non-SSL: 587
Here are some steps to assist to check your settings. You can also use the form at the bottom of this page to generate your settings.
Step-by-step, iOS (iPhone/iPad)
1. Open ‘Settings‘ on your device
2. Open ‘Mail, Contacts, Calendars
3. Choose your account in the list or ‘Accounts
4. Under IMAP, tap ‘Account
5. Under ‘Incoming Mail Server‘ check that ‘Host Name‘ is shown as the default mail server settings above, if not tap to update this
6. Enter your ‘Password‘ – note that it may look like the password already exists, but again during some updates the password is erased on your device
7. Scroll down to ‘Outgoing Mail Server
8. Tap ‘SMTP
9. Choose the account in the list over ‘Primary Server
10. Check that the dial is turned ON
11. Under ‘Outgoing Mail Server‘ check that ‘Host Name‘ is shown as the default server mail settings above, if not tap to update this
12. Enter your ‘Password‘ – note that it may look like the password already exists, but again during some updates the password is erased on your device
13. Tap ‘Done‘ to save the settings, then ‘Account‘ to go back and then ‘Done‘ again to come back to the list of accounts.
14. Try sending yourself an email to check the settings!
If you receive an error message and/or you are not sure if you have entered the correct password, try accessing your email account through webmail:
http://dosolutions.com.au/access (click on ‘Webmail’) – login with your full email address and the password. If the password is correct your webmail will open.
Step-by-step, Mac (v10.10 Yosemite)
1. Open ‘System Preferences‘ on your Mac
2. Choose ‘Internet Accounts
3. Choose your account in the list or ‘Accounts
4. Enter your ‘Password
5. Click ‘Advanced…‘ and check that ‘IMAP Hostname‘ is shown as:
5.1 IMAP Hostname = (see default mail server settings above)
5.2 IMAP Path Prefix = INBOX
5.3 Port = (use ports above for default mail server settings)
6. Click ‘OK‘ to save
7. Try sending yourself an email to check the settings!
If you receive an error message and/or you are not sure if you have entered the correct password, try accessing your email account through webmail:
http://dosolutions.com.au/access (click on ‘Webmail’) – login with your full email address and the password. If the password is correct your webmail will open.
Form to generate your settings
Enter your domain, email and password below and the form below will display all configurations for your account (click here if the form is not showing).
|
__label__pos
| 0.994163 |
Take the 2-minute tour ×
Cryptography Stack Exchange is a question and answer site for software developers, mathematicians and others interested in cryptography. It's 100% free, no registration required.
Random.org provides true random numbers through an unsecured web service. Since these numbers would be transmitted in plaintext could they still be considered useful as true random numbers while maintaining security in a cryptographic solution?
At first I was thinking if a large pool of them was obtained then a small subset of them could be used randomly to make the fact they are known of less use. Then I realized that no matter how many random numbers were obtained this way, it would still be a smaller number set to explore in attempting to crack the cryptography.
Update: Random.org supports SSL over HTTPS, but are not encouraged for use in cryptography.
share|improve this question
1
You can make a secure connection to random.org. Plus, looking at the source code, their "Generate" button is actually in an iframe that is loaded over a secure connection. – mikeazo Jan 10 '12 at 21:26
1
@mikeazo: So as long as Random.org is not the attacker it would work. – Jim McKeeth Jan 10 '12 at 21:27
I'd say that as long as you trusted Random.org and made a secure connection to them, then it should be fine. – mikeazo Jan 10 '12 at 21:29
You could always build your own generator. Pretty cool. – Grant BlahaErath Mar 20 '12 at 5:28
3
@mikeazo Uh, don't you need an entropy source to create a secure connection in the first place? That would make it only useful for those runtimes that would have no access to the local source of randomness. – owlstead Mar 21 '12 at 0:12
8 Answers 8
up vote 9 down vote accepted
The more I think about it, the less I would be willing to use Random.org for any sort of cryptographic application. My reasons are listed below.
1. See Q2.2, the groups listed are not cryptographic groups and potentially (or probably) don't have cryptographers on their evaluation teams
2. They specifically say not to use it for cryptography
3. It is closed source. So, I would have no way of knowing if they properly mutex their RNG so that only one person is drawing from it at a time. There are other implementation issues that I (or someone/some group much smarter than I could check for).
4. Using this would require an internet connection for all randomness.
5. Current CS-PRNGs are much faster and options are available which suffer from none of the weaknesses listed above.
6. The RNG could change at any time without me knowing.
That said, these reasons don't necessarily answer the question. They only give insight as to why I personally wouldn't use Random.org for cryptography. Would it be secure to use Random.org in cryptographic solution? Possibly. There really isn't enough information to really know.
share|improve this answer
It is so easy to create cryptographically-strong random numbers in ways that are known to be strong that adding new methods that add new risks is not advisable. However, if you have an existing method that is known to be secure and has the ability to take in additional sources of randomness in way that cannot do harm even if they are known to an attacker, than go ahead and add them. You have nothing to lose.
share|improve this answer
In cryptography, randomness is mostly about being unknown to any attacker. Any attacker could observe your download of these random numbers, and now they are not really random since the attacker knows them too.
There is an article from Crypto'97 which describes something which looks like that: it is a secure key exchange system which defeats memory-bounded adversaries. This assume a shared source of randomness which broadcasts random numbers; anybody can listen to it, including any attacker. Two parties who wish to get a shared key record just a few chunks out of the random bits, noting the position of each chunk in the stream (say, the exact emission time). At the end of the day, they send to each other the list of positions; if they recorded enough, there is high probability that there are a few chunks they they both recorded, and they can use these as a shared key. On the other hand, an attacker willing to learn that key would have to record quite a lot of the stream in order to have a fair chance of having all the chunks that the two parties have in common.
This key exchange mechanism is safe as long as the random source broadcasts data at a very high rate, so that recording all of a day's broadcast is not doable. So it should be in gigabytes per second or so.
In a way, using the numbers from random.org is like using this model: you record insecure random numbers, and at the end of the day you assume that you could get some that the attacker failed to record himself. To get a key out of your pool, you could for instance hash the whole of it with a secure hash function such as SHA-256 (don't pick numbers out of the pool; instead, use a hash function, which will not "forget" any entropy). Still, in practice, this fails on several accounts:
• The Web in general, and your Internet access in particular, is nowhere near fast enough for this. An attacker can easily record terabytes of data, so you should download much more than that. Your ISP will not be pleased (unless your contract includes a quota, and gigabytes beyond the quota are billed, in which case the ISP will be thrilled).
• random.org itself could be an attacker, and feed you what are claimed to be "true random numbers", but are actually the output of a pseudo-random number generator. You would not be able to see the difference. But this would allow the attacker to rebuild the random numbers you got (all of them) at will.
• An active attacker could alter the numbers you get, in effect reducing the problem to the previous point.
So, to make the story short: no, random.org is not useful to security or cryptography.
share|improve this answer
Since you cannot be assured that random.org is not retaining a copy of the number, nor is its transport to you necessarily confidential, you should think of numbers from random.org as public randomness. That is perhaps pessimistic but it will lead you to use such numbers in the correct manner.
Obviously, public randomness is not useful for generating secrets in cryptography.
However there are a number of scenarios where public randomness is perfectly ok. Here are a few:
1. Generating challenges for random audits
2. Generating challenges for interactive proofs
3. Fair exchange
4. Generating an auxiliary random string for reference
5. Choosing non-secret "keys" for things like extractors or instances of a hash function from a family of hashes
6. Choosing initialization vectors or salts
A source of public randomness is sometimes called a "beacon." It is an important enough service that NIST is in the progress of creating one. Their whitepaper explains some of its uses and mentions random.org. Another option is to use financial data, which we showed to have sufficient entropy.
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OK, but we cannot be assured either that random.org does not repeat its random stream on a reboot etc. That would preclude a lot of the above use cases. Basically, we can only hope that random.org is valid from what is pronounced at the front page. That's simply not enough. – owlstead Mar 2 at 11:23
It would be secure only
• If you trust the connection to random.org (and as you said, it is unsecured)
• If you trust random.org itself (it could e.g. log the generated data along with your IP)
So I'd say it is not secure, in general.
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So there is no use for them in cryptography? – Jim McKeeth Jan 10 '12 at 21:07
1
One application I can come up with is for validating randomness tests. But for the usual applications (e.g. generating keys), I don't see how random.org could be useful. – Conrado PLG Jan 10 '12 at 21:45
The short answer is: the online random number generators (or better, online radioactive/quantum sources) have high entropy and are unpredictable, but they lack the element of guaranteed privacy needed to be used verbatim as a secret key.
Notice that privacy of thought is assumed in the usual Alice and Bob crypto theory stories; mind reading each other or the narrator is not allowed.
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Any serious person should not trust random.org to be up all the time. It's maintained by a non-commercial entity that has no economic value in staying up all the time. So your server would only get random numbers as long as it is available. That should be enough to stop any serious usage (beyond the security reasons mentioned by all the others).
I could see a scenario where you have a weak entropy pool, and you use random.org to add additional entropy to your own pseudo random number generator. If it is down, you may fall back to your own weak entropy sources. Note that you need to seriously test if your fall back scenarios work though, you should not get stuck once random.org is suddenly not sending any data anymore.
share|improve this answer
No, it would not be secure… especially not without specific precautions and protocol implementations – which random.org doesn't offer in the first place. Also, random.org is – as far as I know – not certified, which downgrades it from a “trust” point of view.
But when talking about such randomness providers, I always like to mention a more professional project too, because many people aren't aware of its existance: the NIST Randomness Beacon…
NIST Randomness Beacon
If you check the project homepage at https://beacon.nist.gov/home you'll notice that even that project clearly states:
WARNING: DO NOT USE BEACON GENERATED VALUES AS SECRET CRYPTOGRAPHIC KEYS.
And there's a good reason for that: they are still researching potential implementation options as well as potential security strengths and weaknesses of such a solution.
I wouldn't count on random.org having solved all the problems the NIST Randomness Beacon is still researching.
As you noticed yourself, random.org states something similar:
We should probably note that while fetching the numbers via secure HTTP would protect them from being observed while in transit, anyone genuinely concerned with security should not trust anyone else (including RANDOM.ORG) to generate their cryptographic keys.
(emphasis mine)
In terms of security, I therefore would personally recommend to distrust data from services like random.org even more than the beacon data generated by the NIST Randomness Beacon project in its current research phase… and until further notice, you aren't supposed to trust the Beacon data either.
Wrapping it up: it would not be secure to use random numbers from services like random.org in a cryptographic solution. This is underlined by the individual services' statements.
There are ample well-vetted and cryptographically secure alternatives to the need of falling back on using such services. It would be smarter to use those than to trust a 3rd party that puts emphasis on the fact that you should not trust its data for crypto purposes…
Sites like random.org may have their place, but not in the realms of cryptography.
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|
__label__pos
| 0.577827 |
First mod:: replaced Winegard 360+ mount with Unifi access point
It turns out that the Unifi U6 Long Range access point has a perfect ceiling mount that replaced the cover for the Winegard 360+ modem mount. It had identical screw hole locations so it was a perfect fit :bangbang:
I have U6 LR powered by the brand new Unifi Cloud Gateway Ultra as the router. The combination is more advanced and capable than what Winegard or Pepwave at a fraction of the price. I jumped on this because I was looking for a dual WAN router for Starlink and T-Mobile 5G. I normally have them set in fail over mode so Starlink is primary and T-Mobile is backups but you could do WAN load balancing with this router.
The ethernet cable I ran down the lighting track and down the wall where I put in a keystone jack to plug-in the POE injector. 4x4 MIMO meaning 4 antennas for 2.4ghz and separate 4x4 MIMO again 4 additional antennas (for a total of 8) for 5ghz WiFi.
I don’t understand what makes it better than any other WiFi 6 router?
So the Ubiquity router will bond two internet connections?
No it does not bond. The function is WAN load balancing. You have primary (WAN) which is always online. Then anywhere from 1-99% of the second connection (WAN2) can send traffic.
You can configure it as failover, so primary WAN till it is down and then failover to the second WAN2 till WAN is available again.
Bonding like on a Pepwave is less desirable. It works by adding a VPN to a 3rd party endpoint. Don’t get me started on how VPN for privacy and security is all a FAT lie. Then all the traffic has to be sent across this. The thing is that only works for big blobs of data like downloading a large movie or file.
The truth is most internet connections are small short connections. Overly simplified explanation, when you download a webpage like the one each image, css, html are separate requests. You actually cab actually surf faster without bonding because you take advantage of being able to open more connections simultaneously. Even when you stream Netflix or YouTube TV it’s not one solid connection to the service. It’s a bunch of small requests that download say 30s of video at a time. Why you see bursts of traffic.
Possibly a good analogy is would it be faster to load a airplane with a single jetway or if you had multiple jetways?
Hey man, when you say you ran the cat 5 through the lighting track do you meen that when you pulled off the existing blanking plate there was access to to channel where the ceiling light wires are? How did you fish it down a wall? Do you have any pictures? I want to do the same kind of setup with some spare unifi stuff I have laying around.
Thanks,
Ollie
I actually went with Ubiquiti because you can do have dual WAN plus it’s what I use at home. So I setup WireGuard as a client and route all my video traffic to my sticks and bricks so I don’t get flagged by Netflix or whatever streaming service. It looks like the IP is from my home.
@bmccormick8 I couldn’t figure out a way to come down the wall. I ended up putting my AP above the cabinet in the bunk room.
I ran Cat 6 under the dresser directly to the wet bay. I then went up the wall and put in a Cat6a bulkhead so it was finished off.
The lower plate for the coax, I removed and put in a brushed plate and ran the Ethernet directly down the wall. It turns out the factory puts in a small hole to run the 12v wire, so I just followed that into the wall and down. Then I mounted the UniFi Cloud Gateway Pro and a POE injector behind the TV.
Here is it before I cleaned up and did cable management.
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__label__pos
| 0.721599 |
NB M7-8 per corecluster calculation (L3 cache aware)
SUN_logo2_smallDo-not-forget 😉 Very dirty shit for LDOMprimary domain with CPU intensive workload profile also with 2nd Guest Root dom.
#!/bin/bash
# per-corecluster spreading cores on cpu
# m7-8, 1pdom, 2ldom (primary root+guest root domain)
#
cid=0 # 1st cid (possible shift when using explict control domain)
factor=1 # spreading core factor
coreshift=4 # shift into corecluster
echo "# per-core-cluster config for primary"
echo -n "ldm set-core cid="
while [ $cid -le 511 ] ; do
let n0cid=cid # 1st
let n1cid=cid+factor*1 # 2nd
let n2cid=cid+factor*2 # 3..
let n3cid=cid+factor*3 # 4...
let n4cid=cid+factor*4+coreshift
let n5cid=cid+factor*5+coreshift
let n6cid=cid+factor*6+coreshift
let n7cid=cid+factor*7+coreshift
let cid=cid+64
echo -n "$n0cid,$n1cid,$n2cid,$n3cid,$n4cid,$n5cid,$n6cid,$n7cid"
[ $cid -lt 511 ] && echo -n ","
done
echo " primary"
echo "# check with lgrinfo after rebooting "
guest next…
#!/bin/bash
# per-corecluster spreading cores on cpu
# m7-8, 1pdom, 2ldom (primary root+guest root domain)
#
cid=0 # 1st cid (possible shift when using explict control domain)
echo "# per-core-cluster config for dom1"
echo -n "ldm set-core cid="
while [ $cid -le 511 ] ; do
let i=0
while [ $i -lt 4 ] ; do # use 4 core-cluster per CMP
let k=0
while [ $k -lt 4 ] ; do # 4 core ...
let tmp=$cid+16+$i*8+$k # 16 cc shift 8 number of possible cores
echo -n $tmp
echo -n ","
let k++
done
let i++
done
let cid=cid+64 # next CMP
# [ $cid -lt 511 ] && echo -n ","
done
echo " dom1"
echo "# check with lgrinfo after rebooting "
Leave a Reply
|
__label__pos
| 0.88922 |
Symbolic Computation
AUTHORS:
• Bobby Moretti and William Stein (2006-2007)
• Robert Bradshaw (2007-10): minpoly(), numerical algorithm
• Robert Bradshaw (2008-10): minpoly(), algebraic algorithm
• Golam Mortuza Hossain (2009-06-15): _limit_latex()
• Golam Mortuza Hossain (2009-06-22): _laplace_latex(), _inverse_laplace_latex()
• Tom Coates (2010-06-11): fixed Trac #9217
The Sage calculus module is loosely based on the Sage Enhancement Proposal found at: http://www.sagemath.org:9001/CalculusSEP.
EXAMPLES:
The basic units of the calculus package are symbolic expressions which are elements of the symbolic expression ring (SR). To create a symbolic variable object in Sage, use the var() function, whose argument is the text of that variable. Note that Sage is intelligent about LaTeXing variable names.
sage: x1 = var('x1'); x1
x1
sage: latex(x1)
x_{1}
sage: theta = var('theta'); theta
theta
sage: latex(theta)
\theta
Sage predefines x to be a global indeterminate. Thus the following works:
sage: x^2
x^2
sage: type(x)
<type 'sage.symbolic.expression.Expression'>
More complicated expressions in Sage can be built up using ordinary arithmetic. The following are valid, and follow the rules of Python arithmetic: (The ‘=’ operator represents assignment, and not equality)
sage: var('x,y,z')
(x, y, z)
sage: f = x + y + z/(2*sin(y*z/55))
sage: g = f^f; g
(x + y + 1/2*z/sin(1/55*y*z))^(x + y + 1/2*z/sin(1/55*y*z))
Differentiation and integration are available, but behind the scenes through Maxima:
sage: f = sin(x)/cos(2*y)
sage: f.derivative(y)
2*sin(x)*sin(2*y)/cos(2*y)^2
sage: g = f.integral(x); g
-cos(x)/cos(2*y)
Note that these methods usually require an explicit variable name. If none is given, Sage will try to find one for you.
sage: f = sin(x); f.derivative()
cos(x)
If the expression is a callable symbolic expression (i.e., the variable order is specified), then Sage can calculate the matrix derivative (i.e., the gradient, Jacobian matrix, etc.) if no variables are specified. In the example below, we use the second derivative test to determine that there is a saddle point at (0,-1/2).
sage: f(x,y)=x^2*y+y^2+y
sage: f.diff() # gradient
(x, y) |--> (2*x*y, x^2 + 2*y + 1)
sage: solve(list(f.diff()),[x,y])
[[x == -I, y == 0], [x == I, y == 0], [x == 0, y == (-1/2)]]
sage: H=f.diff(2); H # Hessian matrix
[(x, y) |--> 2*y (x, y) |--> 2*x]
[(x, y) |--> 2*x (x, y) |--> 2]
sage: H(x=0,y=-1/2)
[-1 0]
[ 0 2]
sage: H(x=0,y=-1/2).eigenvalues()
[-1, 2]
Here we calculate the Jacobian for the polar coordinate transformation:
sage: T(r,theta)=[r*cos(theta),r*sin(theta)]
sage: T
(r, theta) |--> (r*cos(theta), r*sin(theta))
sage: T.diff() # Jacobian matrix
[ (r, theta) |--> cos(theta) (r, theta) |--> -r*sin(theta)]
[ (r, theta) |--> sin(theta) (r, theta) |--> r*cos(theta)]
sage: diff(T) # Jacobian matrix
[ (r, theta) |--> cos(theta) (r, theta) |--> -r*sin(theta)]
[ (r, theta) |--> sin(theta) (r, theta) |--> r*cos(theta)]
sage: T.diff().det() # Jacobian
(r, theta) |--> r*cos(theta)^2 + r*sin(theta)^2
When the order of variables is ambiguous, Sage will raise an exception when differentiating:
sage: f = sin(x+y); f.derivative()
Traceback (most recent call last):
...
ValueError: No differentiation variable specified.
Simplifying symbolic sums is also possible, using the sum command, which also uses Maxima in the background:
sage: k, m = var('k, m')
sage: sum(1/k^4, k, 1, oo)
1/90*pi^4
sage: sum(binomial(m,k), k, 0, m)
2^m
Symbolic matrices can be used as well in various ways, including exponentiation:
sage: M = matrix([[x,x^2],[1/x,x]])
sage: M^2
[x^2 + x 2*x^3]
[ 2 x^2 + x]
sage: e^M
[ 1/2*(e^(2*sqrt(x)) + 1)*e^(x - sqrt(x)) 1/2*(x*e^(2*sqrt(x)) - x)*sqrt(x)*e^(x - sqrt(x))]
[ 1/2*(e^(2*sqrt(x)) - 1)*e^(x - sqrt(x))/x^(3/2) 1/2*(e^(2*sqrt(x)) + 1)*e^(x - sqrt(x))]
And complex exponentiation works now:
sage: M = i*matrix([[pi]])
sage: e^M
[-1]
sage: M = i*matrix([[pi,0],[0,2*pi]])
sage: e^M
[-1 0]
[ 0 1]
sage: M = matrix([[0,pi],[-pi,0]])
sage: e^M
[-1 0]
[ 0 -1]
Substitution works similarly. We can substitute with a python dict:
sage: f = sin(x*y - z)
sage: f({x: var('t'), y: z})
sin(t*z - z)
Also we can substitute with keywords:
sage: f = sin(x*y - z)
sage: f(x = t, y = z)
sin(t*z - z)
It was formerly the case that if there was no ambiguity of variable names, we didn’t have to specify them; that still works for the moment, but the behavior is deprecated:
sage: f = sin(x)
sage: f(y)
doctest:...: DeprecationWarning: Substitution using function-call
syntax and unnamed arguments is deprecated and will be removed
from a future release of Sage; you can use named arguments instead,
like EXPR(x=..., y=...)
See http://trac.sagemath.org/5930 for details.
sin(y)
sage: f(pi)
0
However if there is ambiguity, we should explicitly state what variables we’re substituting for:
sage: f = sin(2*pi*x/y)
sage: f(x=4)
sin(8*pi/y)
We can also make a CallableSymbolicExpression, which is a SymbolicExpression that is a function of specified variables in a fixed order. Each SymbolicExpression has a function(...) method that is used to create a CallableSymbolicExpression, as illustrated below:
sage: u = log((2-x)/(y+5))
sage: f = u.function(x, y); f
(x, y) |--> log(-(x - 2)/(y + 5))
There is an easier way of creating a CallableSymbolicExpression, which relies on the Sage preparser.
sage: f(x,y) = log(x)*cos(y); f
(x, y) |--> cos(y)*log(x)
Then we have fixed an order of variables and there is no ambiguity substituting or evaluating:
sage: f(x,y) = log((2-x)/(y+5))
sage: f(7,t)
log(-5/(t + 5))
Some further examples:
sage: f = 5*sin(x)
sage: f
5*sin(x)
sage: f(x=2)
5*sin(2)
sage: f(x=pi)
0
sage: float(f(x=pi))
0.0
Another example:
sage: f = integrate(1/sqrt(9+x^2), x); f
arcsinh(1/3*x)
sage: f(x=3)
arcsinh(1)
sage: f.derivative(x)
1/3/sqrt(1/9*x^2 + 1)
We compute the length of the parabola from 0 to 2:
sage: x = var('x')
sage: y = x^2
sage: dy = derivative(y,x)
sage: z = integral(sqrt(1 + dy^2), x, 0, 2)
sage: z
sqrt(17) + 1/4*arcsinh(4)
sage: n(z,200)
4.6467837624329358733826155674904591885104869874232887508703
sage: float(z)
4.646783762432936
We test pickling:
sage: x, y = var('x,y')
sage: f = -sqrt(pi)*(x^3 + sin(x/cos(y)))
sage: bool(loads(dumps(f)) == f)
True
Coercion examples:
We coerce various symbolic expressions into the complex numbers:
sage: CC(I)
1.00000000000000*I
sage: CC(2*I)
2.00000000000000*I
sage: ComplexField(200)(2*I)
2.0000000000000000000000000000000000000000000000000000000000*I
sage: ComplexField(200)(sin(I))
1.1752011936438014568823818505956008151557179813340958702296*I
sage: f = sin(I) + cos(I/2); f
cos(1/2*I) + sin(I)
sage: CC(f)
1.12762596520638 + 1.17520119364380*I
sage: ComplexField(200)(f)
1.1276259652063807852262251614026720125478471180986674836290 + 1.1752011936438014568823818505956008151557179813340958702296*I
sage: ComplexField(100)(f)
1.1276259652063807852262251614 + 1.1752011936438014568823818506*I
We illustrate construction of an inverse sum where each denominator has a new variable name:
sage: f = sum(1/var('n%s'%i)^i for i in range(10))
sage: f
1/n1 + 1/n2^2 + 1/n3^3 + 1/n4^4 + 1/n5^5 + 1/n6^6 + 1/n7^7 + 1/n8^8 + 1/n9^9 + 1
Note that after calling var, the variables are immediately available for use:
sage: (n1 + n2)^5
(n1 + n2)^5
We can, of course, substitute:
sage: f(n9=9,n7=n6)
1/n1 + 1/n2^2 + 1/n3^3 + 1/n4^4 + 1/n5^5 + 1/n6^6 + 1/n6^7 + 1/n8^8 + 387420490/387420489
TESTS:
Substitution:
sage: f = x
sage: f(x=5)
5
Simplifying expressions involving scientific notation:
sage: k = var('k')
sage: a0 = 2e-06; a1 = 12
sage: c = a1 + a0*k; c
(2.00000000000000e-6)*k + 12
sage: sqrt(c)
sqrt((2.00000000000000e-6)*k + 12)
sage: sqrt(c^3)
sqrt(((2.00000000000000e-6)*k + 12)^3)
The symbolic calculus package uses its own copy of Maxima for simplification, etc., which is separate from the default system-wide version:
sage: maxima.eval('[x,y]: [1,2]')
'[1,2]'
sage: maxima.eval('expand((x+y)^3)')
'27'
If the copy of maxima used by the symbolic calculus package were the same as the default one, then the following would return 27, which would be very confusing indeed!
sage: x, y = var('x,y')
sage: expand((x+y)^3)
x^3 + 3*x^2*y + 3*x*y^2 + y^3
Set x to be 5 in maxima:
sage: maxima('x: 5')
5
sage: maxima('x + x + %pi')
%pi+10
Simplifications like these are now done using Pynac:
sage: x + x + pi
pi + 2*x
But this still uses Maxima:
sage: (x + x + pi).simplify()
pi + 2*x
Note that x is still x, since the maxima used by the calculus package is different than the one in the interactive interpreter.
Check to see that the problem with the variables method mentioned in Trac ticket #3779 is actually fixed:
sage: f = function('F',x)
sage: diff(f*SR(1),x)
D[0](F)(x)
Doubly ensure that Trac #7479 is working:
sage: f(x)=x
sage: integrate(f,x,0,1)
1/2
Check that the problem with Taylor expansions of the gamma function (Trac #9217) is fixed:
sage: taylor(gamma(1/3+x),x,0,3)
-1/432*((72*euler_gamma^3 + 36*euler_gamma^2*(sqrt(3)*pi + 9*log(3)) +
27*pi^2*log(3) + 243*log(3)^3 + 18*euler_gamma*(6*sqrt(3)*pi*log(3) + pi^2
+ 27*log(3)^2 + 12*psi(1, 1/3)) + 324*log(3)*psi(1, 1/3) + sqrt(3)*(pi^3 +
9*pi*(9*log(3)^2 + 4*psi(1, 1/3))))*gamma(1/3) - 72*psi(2,
1/3)*gamma(1/3))*x^3 + 1/24*(6*sqrt(3)*pi*log(3) + 12*euler_gamma^2 + pi^2
+ 4*euler_gamma*(sqrt(3)*pi + 9*log(3)) + 27*log(3)^2 + 12*psi(1,
1/3))*x^2*gamma(1/3) - 1/6*(6*euler_gamma + sqrt(3)*pi +
9*log(3))*x*gamma(1/3) + gamma(1/3)
sage: map(lambda f:f[0].n(), _.coeffs()) # numerical coefficients to make comparison easier; Maple 12 gives same answer
[2.6789385347..., -8.3905259853..., 26.662447494..., -80.683148377...]
Ensure that ticket #8582 is fixed:
sage: k = var("k")
sage: sum(1/(1+k^2), k, -oo, oo)
-1/2*I*psi(I + 1) + 1/2*I*psi(-I + 1) - 1/2*I*psi(I) + 1/2*I*psi(-I)
Ensure that ticket #8624 is fixed:
sage: integrate(abs(cos(x)) * sin(x), x, pi/2, pi)
1/2
sage: integrate(sqrt(cos(x)^2 + sin(x)^2), x, 0, 2*pi)
2*pi
sage.calculus.calculus.at(ex, *args, **kwds)
Parses at formulations from other systems, such as Maxima. Replaces evaluation ‘at’ a point with substitution method of a symbolic expression.
EXAMPLES:
We do not import at at the top level, but we can use it as a synonym for substitution if we import it:
sage: g = x^3-3
sage: from sage.calculus.calculus import at
sage: at(g, x=1)
-2
sage: g.subs(x=1)
-2
We find a formal Taylor expansion:
sage: h,x = var('h,x')
sage: u = function('u')
sage: u(x + h)
u(h + x)
sage: diff(u(x+h), x)
D[0](u)(h + x)
sage: taylor(u(x+h),h,0,4)
1/24*h^4*D[0, 0, 0, 0](u)(x) + 1/6*h^3*D[0, 0, 0](u)(x) + 1/2*h^2*D[0, 0](u)(x) + h*D[0](u)(x) + u(x)
We compute a Laplace transform:
sage: var('s,t')
(s, t)
sage: f=function('f', t)
sage: f.diff(t,2)
D[0, 0](f)(t)
sage: f.diff(t,2).laplace(t,s)
s^2*laplace(f(t), t, s) - s*f(0) - D[0](f)(0)
We can also accept a non-keyword list of expression substitutions, like Maxima does, trac ticket #12796:
sage: from sage.calculus.calculus import at
sage: f = function('f')
sage: at(f(x), [x == 1])
f(1)
TESTS:
Our one non-keyword argument must be a list:
sage: from sage.calculus.calculus import at
sage: f = function('f')
sage: at(f(x), x == 1)
Traceback (most recent call last):
...
TypeError: at can take at most one argument, which must be a list
We should convert our first argument to a symbolic expression:
sage: from sage.calculus.calculus import at
sage: at(int(1), x=1)
1
sage.calculus.calculus.dummy_diff(*args)
This function is called when ‘diff’ appears in a Maxima string.
EXAMPLES:
sage: from sage.calculus.calculus import dummy_diff
sage: x,y = var('x,y')
sage: dummy_diff(sin(x*y), x, SR(2), y, SR(1))
-x*y^2*cos(x*y) - 2*y*sin(x*y)
Here the function is used implicitly:
sage: a = var('a')
sage: f = function('cr', a)
sage: g = f.diff(a); g
D[0](cr)(a)
sage.calculus.calculus.dummy_integrate(*args)
This function is called to create formal wrappers of integrals that Maxima can’t compute:
EXAMPLES:
sage: from sage.calculus.calculus import dummy_integrate
sage: f(x) = function('f',x)
sage: dummy_integrate(f(x), x)
integrate(f(x), x)
sage: a,b = var('a,b')
sage: dummy_integrate(f(x), x, a, b)
integrate(f(x), x, a, b)
sage.calculus.calculus.dummy_inverse_laplace(*args)
This function is called to create formal wrappers of inverse laplace transforms that Maxima can’t compute:
EXAMPLES:
sage: from sage.calculus.calculus import dummy_inverse_laplace
sage: s,t = var('s,t')
sage: F(s) = function('F',s)
sage: dummy_inverse_laplace(F(s),s,t)
ilt(F(s), s, t)
sage.calculus.calculus.dummy_laplace(*args)
This function is called to create formal wrappers of laplace transforms that Maxima can’t compute:
EXAMPLES:
sage: from sage.calculus.calculus import dummy_laplace
sage: s,t = var('s,t')
sage: f(t) = function('f',t)
sage: dummy_laplace(f(t),t,s)
laplace(f(t), t, s)
sage.calculus.calculus.dummy_limit(*args)
This function is called to create formal wrappers of limits that Maxima can’t compute:
EXAMPLES:
sage: a = lim(exp(x^2)*(1-erf(x)), x=infinity); a
-limit((erf(x) - 1)*e^(x^2), x, +Infinity)
sage: a = sage.calculus.calculus.dummy_limit(sin(x)/x, x, 0);a
limit(sin(x)/x, x, 0)
sage.calculus.calculus.inverse_laplace(ex, t, s)
Attempts to compute the inverse Laplace transform of self with respect to the variable \(t\) and transform parameter \(s\). If this function cannot find a solution, a formal function is returned.
The function that is returned may be be viewed as a function of \(s\).
DEFINITION: The inverse Laplace transform of a function \(F(s)\), is the function \(f(t)\) defined by
\[F(s) = \frac{1}{2\pi i} \int_{\gamma-i\infty}^{\gamma + i\infty} e^{st} F(s) dt,\]
where \(\gamma\) is chosen so that the contour path of integration is in the region of convergence of \(F(s)\).
EXAMPLES:
sage: var('w, m')
(w, m)
sage: f = (1/(w^2+10)).inverse_laplace(w, m); f
1/10*sqrt(10)*sin(sqrt(10)*m)
sage: laplace(f, m, w)
1/(w^2 + 10)
sage: f(t) = t*cos(t)
sage: s = var('s')
sage: L = laplace(f, t, s); L
t |--> 2*s^2/(s^2 + 1)^2 - 1/(s^2 + 1)
sage: inverse_laplace(L, s, t)
t |--> t*cos(t)
sage: inverse_laplace(1/(s^3+1), s, t)
1/3*(sqrt(3)*sin(1/2*sqrt(3)*t) - cos(1/2*sqrt(3)*t))*e^(1/2*t) + 1/3*e^(-t)
No explicit inverse Laplace transform, so one is returned formally as a function ilt:
sage: inverse_laplace(cos(s), s, t)
ilt(cos(s), s, t)
sage.calculus.calculus.laplace(ex, t, s)
Attempts to compute and return the Laplace transform of self with respect to the variable \(t\) and transform parameter \(s\). If this function cannot find a solution, a formal function is returned.
The function that is returned may be be viewed as a function of \(s\).
DEFINITION:
The Laplace transform of a function \(f(t)\), defined for all real numbers \(t \geq 0\), is the function \(F(s)\) defined by
\[F(s) = \int_{0}^{\infty} e^{-st} f(t) dt.\]
EXAMPLES:
We compute a few Laplace transforms:
sage: var('x, s, z, t, t0')
(x, s, z, t, t0)
sage: sin(x).laplace(x, s)
1/(s^2 + 1)
sage: (z + exp(x)).laplace(x, s)
z/s + 1/(s - 1)
sage: log(t/t0).laplace(t, s)
-(euler_gamma + log(s) + log(t0))/s
We do a formal calculation:
sage: f = function('f', x)
sage: g = f.diff(x); g
D[0](f)(x)
sage: g.laplace(x, s)
s*laplace(f(x), x, s) - f(0)
EXAMPLES:
A BATTLE BETWEEN the X-women and the Y-men (by David Joyner): Solve
\[x' = -16y, x(0)=270, y' = -x + 1, y(0) = 90.\]
This models a fight between two sides, the “X-women” and the “Y-men”, where the X-women have 270 initially and the Y-men have 90, but the Y-men are better at fighting, because of the higher factor of “-16” vs “-1”, and also get an occasional reinforcement, because of the “+1” term.
sage: var('t')
t
sage: t = var('t')
sage: x = function('x', t)
sage: y = function('y', t)
sage: de1 = x.diff(t) + 16*y
sage: de2 = y.diff(t) + x - 1
sage: de1.laplace(t, s)
s*laplace(x(t), t, s) + 16*laplace(y(t), t, s) - x(0)
sage: de2.laplace(t, s)
s*laplace(y(t), t, s) - 1/s + laplace(x(t), t, s) - y(0)
Next we form the augmented matrix of the above system:
sage: A = matrix([[s, 16, 270],[1, s, 90+1/s]])
sage: E = A.echelon_form()
sage: xt = E[0,2].inverse_laplace(s,t)
sage: yt = E[1,2].inverse_laplace(s,t)
sage: xt
-91/2*e^(4*t) + 629/2*e^(-4*t) + 1
sage: yt
91/8*e^(4*t) + 629/8*e^(-4*t)
sage: p1 = plot(xt,0,1/2,rgbcolor=(1,0,0))
sage: p2 = plot(yt,0,1/2,rgbcolor=(0,1,0))
sage: (p1+p2).save(os.path.join(SAGE_TMP, "de_plot.png"))
Another example:
sage: var('a,s,t')
(a, s, t)
sage: f = exp (2*t + a) * sin(t) * t; f
t*e^(a + 2*t)*sin(t)
sage: L = laplace(f, t, s); L
2*(s - 2)*e^a/(s^2 - 4*s + 5)^2
sage: inverse_laplace(L, s, t)
t*e^(a + 2*t)*sin(t)
Unable to compute solution:
sage: laplace(1/s, s, t)
laplace(1/s, s, t)
sage.calculus.calculus.lim(ex, dir=None, taylor=False, algorithm='maxima', **argv)
Return the limit as the variable \(v\) approaches \(a\) from the given direction.
expr.limit(x = a)
expr.limit(x = a, dir='above')
INPUT:
• dir - (default: None); dir may have the value ‘plus’ (or ‘+’ or ‘right’) for a limit from above, ‘minus’ (or ‘-‘ or ‘left’) for a limit from below, or may be omitted (implying a two-sided limit is to be computed).
• taylor - (default: False); if True, use Taylor series, which allows more limits to be computed (but may also crash in some obscure cases due to bugs in Maxima).
• **argv - 1 named parameter
Note
The output may also use ‘und’ (undefined), ‘ind’ (indefinite but bounded), and ‘infinity’ (complex infinity).
EXAMPLES:
sage: x = var('x')
sage: f = (1+1/x)^x
sage: f.limit(x = oo)
e
sage: f.limit(x = 5)
7776/3125
sage: f.limit(x = 1.2)
2.06961575467...
sage: f.limit(x = I, taylor=True)
(-I + 1)^I
sage: f(x=1.2)
2.0696157546720...
sage: f(x=I)
(-I + 1)^I
sage: CDF(f(x=I))
2.06287223508 + 0.74500706218*I
sage: CDF(f.limit(x = I))
2.06287223508 + 0.74500706218*I
Notice that Maxima may ask for more information:
sage: var('a')
a
sage: limit(x^a,x=0)
Traceback (most recent call last):
...
ValueError: Computation failed since Maxima requested additional
constraints; using the 'assume' command before limit evaluation
*may* help (see `assume?` for more details)
Is a positive, negative, or zero?
With this example, Maxima is looking for a LOT of information:
sage: assume(a>0)
sage: limit(x^a,x=0)
Traceback (most recent call last):
...
ValueError: Computation failed since Maxima requested additional
constraints; using the 'assume' command before limit evaluation
*may* help (see `assume?` for more details)
Is a an integer?
sage: assume(a,'integer')
sage: limit(x^a,x=0)
Traceback (most recent call last):
...
ValueError: Computation failed since Maxima requested additional
constraints; using the 'assume' command before limit evaluation
*may* help (see `assume?` for more details)
Is a an even number?
sage: assume(a,'even')
sage: limit(x^a,x=0)
0
sage: forget()
More examples:
sage: limit(x*log(x), x = 0, dir='+')
0
sage: lim((x+1)^(1/x), x = 0)
e
sage: lim(e^x/x, x = oo)
+Infinity
sage: lim(e^x/x, x = -oo)
0
sage: lim(-e^x/x, x = oo)
-Infinity
sage: lim((cos(x))/(x^2), x = 0)
+Infinity
sage: lim(sqrt(x^2+1) - x, x = oo)
0
sage: lim(x^2/(sec(x)-1), x=0)
2
sage: lim(cos(x)/(cos(x)-1), x=0)
-Infinity
sage: lim(x*sin(1/x), x=0)
0
sage: limit(e^(-1/x), x=0, dir='right')
0
sage: limit(e^(-1/x), x=0, dir='left')
+Infinity
sage: f = log(log(x))/log(x)
sage: forget(); assume(x<-2); lim(f, x=0, taylor=True)
0
sage: forget()
Here ind means “indefinite but bounded”:
sage: lim(sin(1/x), x = 0)
ind
TESTS:
sage: lim(x^2, x=2, dir='nugget')
Traceback (most recent call last):
...
ValueError: dir must be one of None, 'plus', '+', 'right',
'minus', '-', 'left'
We check that Trac ticket 3718 is fixed, so that Maxima gives correct limits for the floor function:
sage: limit(floor(x), x=0, dir='-')
-1
sage: limit(floor(x), x=0, dir='+')
0
sage: limit(floor(x), x=0)
und
Maxima gives the right answer here, too, showing that Trac 4142 is fixed:
sage: f = sqrt(1-x^2)
sage: g = diff(f, x); g
-x/sqrt(-x^2 + 1)
sage: limit(g, x=1, dir='-')
-Infinity
sage: limit(1/x, x=0)
Infinity
sage: limit(1/x, x=0, dir='+')
+Infinity
sage: limit(1/x, x=0, dir='-')
-Infinity
Check that Trac 8942 is fixed:
sage: f(x) = (cos(pi/4-x) - tan(x)) / (1 - sin(pi/4+x))
sage: limit(f(x), x = pi/4, dir='minus')
+Infinity
sage: limit(f(x), x = pi/4, dir='plus')
-Infinity
sage: limit(f(x), x = pi/4)
Infinity
Check that we give deprecation warnings for ‘above’ and ‘below’ #9200:
sage: limit(1/x, x=0, dir='above')
doctest:...: DeprecationWarning: the keyword
'above' is deprecated. Please use 'right' or '+' instead.
See http://trac.sagemath.org/9200 for details.
+Infinity
sage: limit(1/x, x=0, dir='below')
doctest:...: DeprecationWarning: the keyword
'below' is deprecated. Please use 'left' or '-' instead.
See http://trac.sagemath.org/9200 for details.
-Infinity
Check that trac ticket #12708 is fixed:
sage: limit(tanh(x),x=0)
0
sage.calculus.calculus.limit(ex, dir=None, taylor=False, algorithm='maxima', **argv)
Return the limit as the variable \(v\) approaches \(a\) from the given direction.
expr.limit(x = a)
expr.limit(x = a, dir='above')
INPUT:
• dir - (default: None); dir may have the value ‘plus’ (or ‘+’ or ‘right’) for a limit from above, ‘minus’ (or ‘-‘ or ‘left’) for a limit from below, or may be omitted (implying a two-sided limit is to be computed).
• taylor - (default: False); if True, use Taylor series, which allows more limits to be computed (but may also crash in some obscure cases due to bugs in Maxima).
• **argv - 1 named parameter
Note
The output may also use ‘und’ (undefined), ‘ind’ (indefinite but bounded), and ‘infinity’ (complex infinity).
EXAMPLES:
sage: x = var('x')
sage: f = (1+1/x)^x
sage: f.limit(x = oo)
e
sage: f.limit(x = 5)
7776/3125
sage: f.limit(x = 1.2)
2.06961575467...
sage: f.limit(x = I, taylor=True)
(-I + 1)^I
sage: f(x=1.2)
2.0696157546720...
sage: f(x=I)
(-I + 1)^I
sage: CDF(f(x=I))
2.06287223508 + 0.74500706218*I
sage: CDF(f.limit(x = I))
2.06287223508 + 0.74500706218*I
Notice that Maxima may ask for more information:
sage: var('a')
a
sage: limit(x^a,x=0)
Traceback (most recent call last):
...
ValueError: Computation failed since Maxima requested additional
constraints; using the 'assume' command before limit evaluation
*may* help (see `assume?` for more details)
Is a positive, negative, or zero?
With this example, Maxima is looking for a LOT of information:
sage: assume(a>0)
sage: limit(x^a,x=0)
Traceback (most recent call last):
...
ValueError: Computation failed since Maxima requested additional
constraints; using the 'assume' command before limit evaluation
*may* help (see `assume?` for more details)
Is a an integer?
sage: assume(a,'integer')
sage: limit(x^a,x=0)
Traceback (most recent call last):
...
ValueError: Computation failed since Maxima requested additional
constraints; using the 'assume' command before limit evaluation
*may* help (see `assume?` for more details)
Is a an even number?
sage: assume(a,'even')
sage: limit(x^a,x=0)
0
sage: forget()
More examples:
sage: limit(x*log(x), x = 0, dir='+')
0
sage: lim((x+1)^(1/x), x = 0)
e
sage: lim(e^x/x, x = oo)
+Infinity
sage: lim(e^x/x, x = -oo)
0
sage: lim(-e^x/x, x = oo)
-Infinity
sage: lim((cos(x))/(x^2), x = 0)
+Infinity
sage: lim(sqrt(x^2+1) - x, x = oo)
0
sage: lim(x^2/(sec(x)-1), x=0)
2
sage: lim(cos(x)/(cos(x)-1), x=0)
-Infinity
sage: lim(x*sin(1/x), x=0)
0
sage: limit(e^(-1/x), x=0, dir='right')
0
sage: limit(e^(-1/x), x=0, dir='left')
+Infinity
sage: f = log(log(x))/log(x)
sage: forget(); assume(x<-2); lim(f, x=0, taylor=True)
0
sage: forget()
Here ind means “indefinite but bounded”:
sage: lim(sin(1/x), x = 0)
ind
TESTS:
sage: lim(x^2, x=2, dir='nugget')
Traceback (most recent call last):
...
ValueError: dir must be one of None, 'plus', '+', 'right',
'minus', '-', 'left'
We check that Trac ticket 3718 is fixed, so that Maxima gives correct limits for the floor function:
sage: limit(floor(x), x=0, dir='-')
-1
sage: limit(floor(x), x=0, dir='+')
0
sage: limit(floor(x), x=0)
und
Maxima gives the right answer here, too, showing that Trac 4142 is fixed:
sage: f = sqrt(1-x^2)
sage: g = diff(f, x); g
-x/sqrt(-x^2 + 1)
sage: limit(g, x=1, dir='-')
-Infinity
sage: limit(1/x, x=0)
Infinity
sage: limit(1/x, x=0, dir='+')
+Infinity
sage: limit(1/x, x=0, dir='-')
-Infinity
Check that Trac 8942 is fixed:
sage: f(x) = (cos(pi/4-x) - tan(x)) / (1 - sin(pi/4+x))
sage: limit(f(x), x = pi/4, dir='minus')
+Infinity
sage: limit(f(x), x = pi/4, dir='plus')
-Infinity
sage: limit(f(x), x = pi/4)
Infinity
Check that we give deprecation warnings for ‘above’ and ‘below’ #9200:
sage: limit(1/x, x=0, dir='above')
doctest:...: DeprecationWarning: the keyword
'above' is deprecated. Please use 'right' or '+' instead.
See http://trac.sagemath.org/9200 for details.
+Infinity
sage: limit(1/x, x=0, dir='below')
doctest:...: DeprecationWarning: the keyword
'below' is deprecated. Please use 'left' or '-' instead.
See http://trac.sagemath.org/9200 for details.
-Infinity
Check that trac ticket #12708 is fixed:
sage: limit(tanh(x),x=0)
0
sage.calculus.calculus.mapped_opts(v)
Used internally when creating a string of options to pass to Maxima.
INPUT:
• v - an object
OUTPUT: a string.
The main use of this is to turn Python bools into lower case strings.
EXAMPLES:
sage: sage.calculus.calculus.mapped_opts(True)
'true'
sage: sage.calculus.calculus.mapped_opts(False)
'false'
sage: sage.calculus.calculus.mapped_opts('bar')
'bar'
sage.calculus.calculus.maxima_options(**kwds)
Used internally to create a string of options to pass to Maxima.
EXAMPLES:
sage: sage.calculus.calculus.maxima_options(an_option=True, another=False, foo='bar')
'an_option=true,foo=bar,another=false'
sage.calculus.calculus.minpoly(ex, var='x', algorithm=None, bits=None, degree=None, epsilon=0)
Return the minimal polynomial of self, if possible.
INPUT:
• var - polynomial variable name (default ‘x’)
• algorithm - ‘algebraic’ or ‘numerical’ (default both, but with numerical first)
• bits - the number of bits to use in numerical approx
• degree - the expected algebraic degree
• epsilon - return without error as long as f(self) epsilon, in the case that the result cannot be proven.
All of the above parameters are optional, with epsilon=0, bits and degree tested up to 1000 and 24 by default respectively. The numerical algorithm will be faster if bits and/or degree are given explicitly. The algebraic algorithm ignores the last three parameters.
OUTPUT: The minimal polynomial of self. If the numerical algorithm is used then it is proved symbolically when epsilon=0 (default).
If the minimal polynomial could not be found, two distinct kinds of errors are raised. If no reasonable candidate was found with the given bit/degree parameters, a ValueError will be raised. If a reasonable candidate was found but (perhaps due to limits in the underlying symbolic package) was unable to be proved correct, a NotImplementedError will be raised.
ALGORITHM: Two distinct algorithms are used, depending on the algorithm parameter. By default, the numerical algorithm is attempted first, then the algebraic one.
Algebraic: Attempt to evaluate this expression in QQbar, using cyclotomic fields to resolve exponential and trig functions at rational multiples of pi, field extensions to handle roots and rational exponents, and computing compositums to represent the full expression as an element of a number field where the minimal polynomial can be computed exactly. The bits, degree, and epsilon parameters are ignored.
Numerical: Computes a numerical approximation of self and use PARI’s algdep to get a candidate minpoly \(f\). If \(f(\mathtt{self})\), evaluated to a higher precision, is close enough to 0 then evaluate \(f(\mathtt{self})\) symbolically, attempting to prove vanishing. If this fails, and epsilon is non-zero, return \(f\) if and only if \(f(\mathtt{self}) < \mathtt{epsilon}\). Otherwise raise a ValueError (if no suitable candidate was found) or a NotImplementedError (if a likely candidate was found but could not be proved correct).
EXAMPLES: First some simple examples:
sage: sqrt(2).minpoly()
x^2 - 2
sage: minpoly(2^(1/3))
x^3 - 2
sage: minpoly(sqrt(2) + sqrt(-1))
x^4 - 2*x^2 + 9
sage: minpoly(sqrt(2)-3^(1/3))
x^6 - 6*x^4 + 6*x^3 + 12*x^2 + 36*x + 1
Works with trig and exponential functions too.
sage: sin(pi/3).minpoly()
x^2 - 3/4
sage: sin(pi/7).minpoly()
x^6 - 7/4*x^4 + 7/8*x^2 - 7/64
sage: minpoly(exp(I*pi/17))
x^16 - x^15 + x^14 - x^13 + x^12 - x^11 + x^10 - x^9 + x^8 - x^7 + x^6 - x^5 + x^4 - x^3 + x^2 - x + 1
Here we verify it gives the same result as the abstract number field.
sage: (sqrt(2) + sqrt(3) + sqrt(6)).minpoly()
x^4 - 22*x^2 - 48*x - 23
sage: K.<a,b> = NumberField([x^2-2, x^2-3])
sage: (a+b+a*b).absolute_minpoly()
x^4 - 22*x^2 - 48*x - 23
The minpoly function is used implicitly when creating number fields:
sage: x = var('x')
sage: eqn = x^3 + sqrt(2)*x + 5 == 0
sage: a = solve(eqn, x)[0].rhs()
sage: QQ[a]
Number Field in a with defining polynomial x^6 + 10*x^3 - 2*x^2 + 25
Here we solve a cubic and then recover it from its complicated radical expansion.
sage: f = x^3 - x + 1
sage: a = f.solve(x)[0].rhs(); a
-1/2*(1/18*sqrt(23)*sqrt(3) - 1/2)^(1/3)*(I*sqrt(3) + 1) - 1/6*(-I*sqrt(3) + 1)/(1/18*sqrt(23)*sqrt(3) - 1/2)^(1/3)
sage: a.minpoly()
x^3 - x + 1
Note that simplification may be necessary to see that the minimal polynomial is correct.
sage: a = sqrt(2)+sqrt(3)+sqrt(5)
sage: f = a.minpoly(); f
x^8 - 40*x^6 + 352*x^4 - 960*x^2 + 576
sage: f(a)
((((sqrt(5) + sqrt(3) + sqrt(2))^2 - 40)*(sqrt(5) + sqrt(3) + sqrt(2))^2 + 352)*(sqrt(5) + sqrt(3) + sqrt(2))^2 - 960)*(sqrt(5) + sqrt(3) + sqrt(2))^2 + 576
sage: f(a).expand()
0
Here we show use of the epsilon parameter. That this result is actually exact can be shown using the addition formula for sin, but maxima is unable to see that.
sage: a = sin(pi/5)
sage: a.minpoly(algorithm='numerical')
Traceback (most recent call last):
...
NotImplementedError: Could not prove minimal polynomial x^4 - 5/4*x^2 + 5/16 (epsilon 0.00000000000000e-1)
sage: f = a.minpoly(algorithm='numerical', epsilon=1e-100); f
x^4 - 5/4*x^2 + 5/16
sage: f(a).numerical_approx(100)
0.00000000000000000000000000000
The degree must be high enough (default tops out at 24).
sage: a = sqrt(3) + sqrt(2)
sage: a.minpoly(algorithm='numerical', bits=100, degree=3)
Traceback (most recent call last):
...
ValueError: Could not find minimal polynomial (100 bits, degree 3).
sage: a.minpoly(algorithm='numerical', bits=100, degree=10)
x^4 - 10*x^2 + 1
There is a difference between algorithm=’algebraic’ and algorithm=’numerical’:
sage: cos(pi/33).minpoly(algorithm='algebraic')
x^10 + 1/2*x^9 - 5/2*x^8 - 5/4*x^7 + 17/8*x^6 + 17/16*x^5 - 43/64*x^4 - 43/128*x^3 + 3/64*x^2 + 3/128*x + 1/1024
sage: cos(pi/33).minpoly(algorithm='numerical')
Traceback (most recent call last):
...
NotImplementedError: Could not prove minimal polynomial x^10 + 1/2*x^9 - 5/2*x^8 - 5/4*x^7 + 17/8*x^6 + 17/16*x^5 - 43/64*x^4 - 43/128*x^3 + 3/64*x^2 + 3/128*x + 1/1024 (epsilon ...)
Sometimes it fails, as it must given that some numbers aren’t algebraic:
sage: sin(1).minpoly(algorithm='numerical')
Traceback (most recent call last):
...
ValueError: Could not find minimal polynomial (1000 bits, degree 24).
Note
Of course, failure to produce a minimal polynomial does not necessarily indicate that this number is transcendental.
sage.calculus.calculus.nintegral(ex, x, a, b, desired_relative_error='1e-8', maximum_num_subintervals=200)
Return a floating point machine precision numerical approximation to the integral of self from \(a\) to \(b\), computed using floating point arithmetic via maxima.
INPUT:
• x - variable to integrate with respect to
• a - lower endpoint of integration
• b - upper endpoint of integration
• desired_relative_error - (default: ‘1e-8’) the desired relative error
• maximum_num_subintervals - (default: 200) maxima number of subintervals
OUTPUT:
• float: approximation to the integral
• float: estimated absolute error of the approximation
• the number of integrand evaluations
• an error code:
• 0 - no problems were encountered
• 1 - too many subintervals were done
• 2 - excessive roundoff error
• 3 - extremely bad integrand behavior
• 4 - failed to converge
• 5 - integral is probably divergent or slowly convergent
• 6 - the input is invalid; this includes the case of
desired_relative_error being too small to be achieved
ALIAS: nintegrate is the same as nintegral
REMARK: There is also a function numerical_integral that implements numerical integration using the GSL C library. It is potentially much faster and applies to arbitrary user defined functions.
Also, there are limits to the precision to which Maxima can compute the integral due to limitations in quadpack. In the following example, remark that the last value of the returned tuple is 6, indicating that the input was invalid, in this case because of a too high desired precision.
sage: f = x
sage: f.nintegral(x,0,1,1e-14)
(0.0, 0.0, 0, 6)
EXAMPLES:
sage: f(x) = exp(-sqrt(x))
sage: f.nintegral(x, 0, 1)
(0.5284822353142306, 4.163...e-11, 231, 0)
We can also use the numerical_integral function, which calls the GSL C library.
sage: numerical_integral(f, 0, 1)
(0.528482232253147, 6.83928460...e-07)
Note that in exotic cases where floating point evaluation of the expression leads to the wrong value, then the output can be completely wrong:
sage: f = exp(pi*sqrt(163)) - 262537412640768744
Despite appearance, \(f\) is really very close to 0, but one gets a nonzero value since the definition of float(f) is that it makes all constants inside the expression floats, then evaluates each function and each arithmetic operation using float arithmetic:
sage: float(f)
-480.0
Computing to higher precision we see the truth:
sage: f.n(200)
-7.4992740280181431112064614366622348652078895136533593355718e-13
sage: f.n(300)
-7.49927402801814311120646143662663009137292462589621789352095066181709095575681963967103004e-13
Now numerically integrating, we see why the answer is wrong:
sage: f.nintegrate(x,0,1)
(-480.00000000000006, 5.329070518200754e-12, 21, 0)
It is just because every floating point evaluation of return -480.0 in floating point.
Important note: using PARI/GP one can compute numerical integrals to high precision:
sage: gp.eval('intnum(x=17,42,exp(-x^2)*log(x))')
'2.565728500561051482917356396 E-127' # 32-bit
'2.5657285005610514829173563961304785900 E-127' # 64-bit
sage: old_prec = gp.set_real_precision(50)
sage: gp.eval('intnum(x=17,42,exp(-x^2)*log(x))')
'2.5657285005610514829173563961304785900147709554020 E-127'
sage: gp.set_real_precision(old_prec)
50
Note that the input function above is a string in PARI syntax.
sage.calculus.calculus.nintegrate(ex, x, a, b, desired_relative_error='1e-8', maximum_num_subintervals=200)
Return a floating point machine precision numerical approximation to the integral of self from \(a\) to \(b\), computed using floating point arithmetic via maxima.
INPUT:
• x - variable to integrate with respect to
• a - lower endpoint of integration
• b - upper endpoint of integration
• desired_relative_error - (default: ‘1e-8’) the desired relative error
• maximum_num_subintervals - (default: 200) maxima number of subintervals
OUTPUT:
• float: approximation to the integral
• float: estimated absolute error of the approximation
• the number of integrand evaluations
• an error code:
• 0 - no problems were encountered
• 1 - too many subintervals were done
• 2 - excessive roundoff error
• 3 - extremely bad integrand behavior
• 4 - failed to converge
• 5 - integral is probably divergent or slowly convergent
• 6 - the input is invalid; this includes the case of
desired_relative_error being too small to be achieved
ALIAS: nintegrate is the same as nintegral
REMARK: There is also a function numerical_integral that implements numerical integration using the GSL C library. It is potentially much faster and applies to arbitrary user defined functions.
Also, there are limits to the precision to which Maxima can compute the integral due to limitations in quadpack. In the following example, remark that the last value of the returned tuple is 6, indicating that the input was invalid, in this case because of a too high desired precision.
sage: f = x
sage: f.nintegral(x,0,1,1e-14)
(0.0, 0.0, 0, 6)
EXAMPLES:
sage: f(x) = exp(-sqrt(x))
sage: f.nintegral(x, 0, 1)
(0.5284822353142306, 4.163...e-11, 231, 0)
We can also use the numerical_integral function, which calls the GSL C library.
sage: numerical_integral(f, 0, 1)
(0.528482232253147, 6.83928460...e-07)
Note that in exotic cases where floating point evaluation of the expression leads to the wrong value, then the output can be completely wrong:
sage: f = exp(pi*sqrt(163)) - 262537412640768744
Despite appearance, \(f\) is really very close to 0, but one gets a nonzero value since the definition of float(f) is that it makes all constants inside the expression floats, then evaluates each function and each arithmetic operation using float arithmetic:
sage: float(f)
-480.0
Computing to higher precision we see the truth:
sage: f.n(200)
-7.4992740280181431112064614366622348652078895136533593355718e-13
sage: f.n(300)
-7.49927402801814311120646143662663009137292462589621789352095066181709095575681963967103004e-13
Now numerically integrating, we see why the answer is wrong:
sage: f.nintegrate(x,0,1)
(-480.00000000000006, 5.329070518200754e-12, 21, 0)
It is just because every floating point evaluation of return -480.0 in floating point.
Important note: using PARI/GP one can compute numerical integrals to high precision:
sage: gp.eval('intnum(x=17,42,exp(-x^2)*log(x))')
'2.565728500561051482917356396 E-127' # 32-bit
'2.5657285005610514829173563961304785900 E-127' # 64-bit
sage: old_prec = gp.set_real_precision(50)
sage: gp.eval('intnum(x=17,42,exp(-x^2)*log(x))')
'2.5657285005610514829173563961304785900147709554020 E-127'
sage: gp.set_real_precision(old_prec)
50
Note that the input function above is a string in PARI syntax.
sage.calculus.calculus.symbolic_expression_from_maxima_string(x, equals_sub=False, maxima=Maxima_lib)
Given a string representation of a Maxima expression, parse it and return the corresponding Sage symbolic expression.
INPUT:
• x - a string
• equals_sub - (default: False) if True, replace ‘=’ by ‘==’ in self
• maxima - (default: the calculus package’s Maxima) the Maxima interpreter to use.
EXAMPLES:
sage: from sage.calculus.calculus import symbolic_expression_from_maxima_string as sefms
sage: sefms('x^%e + %e^%pi + %i + sin(0)')
x^e + e^pi + I
sage: f = function('f',x)
sage: sefms('?%at(f(x),x=2)#1')
f(2) != 1
sage: a = sage.calculus.calculus.maxima("x#0"); a
x#0
sage: a.sage()
x != 0
TESTS:
Trac #8459 fixed:
sage: maxima('3*li[2](u)+8*li[33](exp(u))').sage()
8*polylog(33, e^u) + 3*polylog(2, u)
Check if #8345 is fixed:
sage: assume(x,'complex')
sage: t = x.conjugate()
sage: latex(t)
\overline{x}
sage: latex(t._maxima_()._sage_())
\overline{x}
Check that we can understand maxima’s not-equals (trac ticket #8969):
sage: from sage.calculus.calculus import symbolic_expression_from_maxima_string as sefms
sage: sefms("x!=3") == (factorial(x) == 3)
True
sage: sefms("x # 3") == SR(x != 3)
True
sage: solve([x != 5], x)
#0: solve_rat_ineq(ineq=x # 5)
[[x - 5 != 0]]
sage: solve([2*x==3, x != 5], x)
[[x == (3/2), (-7/2) != 0]]
sage.calculus.calculus.symbolic_expression_from_string(s, syms=None, accept_sequence=False)
Given a string, (attempt to) parse it and return the corresponding Sage symbolic expression. Normally used to return Maxima output to the user.
INPUT:
• s - a string
• syms - (default: None) dictionary of strings to be regarded as symbols or functions
• accept_sequence - (default: False) controls whether to allow a (possibly nested) set of lists and tuples as input
EXAMPLES:
sage: y = var('y')
sage: sage.calculus.calculus.symbolic_expression_from_string('[sin(0)*x^2,3*spam+e^pi]',syms={'spam':y},accept_sequence=True)
[0, 3*y + e^pi]
sage.calculus.calculus.symbolic_sum(expression, v, a, b, algorithm='maxima')
Returns the symbolic sum \(\sum_{v = a}^b expression\) with respect to the variable \(v\) with endpoints \(a\) and \(b\).
INPUT:
• expression - a symbolic expression
• v - a variable or variable name
• a - lower endpoint of the sum
• b - upper endpoint of the sum
• algorithm - (default: ‘maxima’) one of - ‘maxima’ - use Maxima (the default) - ‘maple’ - (optional) use Maple - ‘mathematica’ - (optional) use Mathematica - ‘giac’ - (optional) use Giac
EXAMPLES:
sage: k, n = var('k,n')
sage: from sage.calculus.calculus import symbolic_sum
sage: symbolic_sum(k, k, 1, n).factor()
1/2*(n + 1)*n
sage: symbolic_sum(1/k^4, k, 1, oo)
1/90*pi^4
sage: symbolic_sum(1/k^5, k, 1, oo)
zeta(5)
A well known binomial identity:
sage: symbolic_sum(binomial(n,k), k, 0, n)
2^n
And some truncations thereof:
sage: assume(n>1)
sage: symbolic_sum(binomial(n,k),k,1,n)
2^n - 1
sage: symbolic_sum(binomial(n,k),k,2,n)
2^n - n - 1
sage: symbolic_sum(binomial(n,k),k,0,n-1)
2^n - 1
sage: symbolic_sum(binomial(n,k),k,1,n-1)
2^n - 2
The binomial theorem:
sage: x, y = var('x, y')
sage: symbolic_sum(binomial(n,k) * x^k * y^(n-k), k, 0, n)
(x + y)^n
sage: symbolic_sum(k * binomial(n, k), k, 1, n)
2^(n - 1)*n
sage: symbolic_sum((-1)^k*binomial(n,k), k, 0, n)
0
sage: symbolic_sum(2^(-k)/(k*(k+1)), k, 1, oo)
-log(2) + 1
Summing a hypergeometric term:
sage: symbolic_sum(binomial(n, k) * factorial(k) / factorial(n+1+k), k, 0, n)
1/2*sqrt(pi)/factorial(n + 1/2)
We check a well known identity:
sage: bool(symbolic_sum(k^3, k, 1, n) == symbolic_sum(k, k, 1, n)^2)
True
A geometric sum:
sage: a, q = var('a, q')
sage: symbolic_sum(a*q^k, k, 0, n)
(a*q^(n + 1) - a)/(q - 1)
For the geometric series, we will have to assume the right values for the sum to converge:
sage: assume(abs(q) < 1)
sage: symbolic_sum(a*q^k, k, 0, oo)
-a/(q - 1)
A divergent geometric series. Don’t forget to forget your assumptions:
sage: forget()
sage: assume(q > 1)
sage: symbolic_sum(a*q^k, k, 0, oo)
Traceback (most recent call last):
...
ValueError: Sum is divergent.
sage: forget()
sage: assumptions() # check the assumptions were really forgotten
[]
This summation only Mathematica can perform:
sage: symbolic_sum(1/(1+k^2), k, -oo, oo, algorithm = 'mathematica') # optional - mathematica
pi*coth(pi)
An example of this summation with Giac:
sage: symbolic_sum(1/(1+k^2), k, -oo, oo, algorithm = 'giac') # optional - giac
-(pi*e^(-2*pi) - pi*e^(2*pi))/(e^(-2*pi) + e^(2*pi) - 2)
Use Maple as a backend for summation:
sage: symbolic_sum(binomial(n,k)*x^k, k, 0, n, algorithm = 'maple') # optional - maple
(x + 1)^n
TESTS:
Trac #10564 is fixed:
sage: sum (n^3 * x^n, n, 0, infinity)
(x^3 + 4*x^2 + x)/(x^4 - 4*x^3 + 6*x^2 - 4*x + 1)
Note
Sage can currently only understand a subset of the output of Maxima, Maple and Mathematica, so even if the chosen backend can perform the summation the result might not be convertable into a Sage expression.
sage.calculus.calculus.var_cmp(x, y)
Return comparison of the two variables x and y, which is just the comparison of the underlying string representations of the variables. This is used internally by the Calculus package.
INPUT:
• x, y - symbolic variables
OUTPUT: Python integer; either -1, 0, or 1.
EXAMPLES:
sage: sage.calculus.calculus.var_cmp(x,x)
0
sage: sage.calculus.calculus.var_cmp(x,var('z'))
-1
sage: sage.calculus.calculus.var_cmp(x,var('a'))
1
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servo: Merge #16593 - Mach: Add `mach clean-cargo-cache` command (from UK992:clean-cargo-cache); r=wafflespeanut
authorUK992 <[email protected]>
Mon, 08 May 2017 04:37:21 -0500
changeset 357057 aea57457600e0f41f3aaac138e2b10ca54fdfadc
parent 357056 d309a5a0a165a6d9c6d82da8141df6b711a5a2c2
child 357058 558c843afbd35b6a15d3dbe397048bf0e772f779
push id31781
push [email protected]
push dateMon, 08 May 2017 20:44:15 +0000
treeherdermozilla-central@e0955584782e [default view] [failures only]
perfherder[talos] [build metrics] [platform microbench] (compared to previous push)
reviewerswafflespeanut
milestone55.0a1
first release with
nightly linux32
nightly linux64
nightly mac
nightly win32
nightly win64
last release without
nightly linux32
nightly linux64
nightly mac
nightly win32
nightly win64
servo: Merge #16593 - Mach: Add `mach clean-cargo-cache` command (from UK992:clean-cargo-cache); r=wafflespeanut <!-- Please describe your changes on the following line: --> --- <!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: --> - [x] `./mach build -d` does not report any errors - [x] `./mach test-tidy` does not report any errors - [ ] These changes fix #__ (github issue number if applicable). <!-- Either: --> - [ ] There are tests for these changes OR - [ ] These changes do not require tests because _____ <!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.--> <!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. --> Source-Repo: https://github.com/servo/servo Source-Revision: f6bd158fd4287226a881e58020f7dc154fa32532
servo/.travis.yml
servo/python/servo/bootstrap_commands.py
--- a/servo/.travis.yml
+++ b/servo/.travis.yml
@@ -25,16 +25,17 @@ matrix:
- ./mach test-unit -p style
cache:
directories:
- .cargo
- .servo
- $HOME/.ccache
before_cache:
- ./mach clean-nightlies --keep 2 --force
+ - ./mach clean-cargo-cache --keep 2 --force
env: CCACHE=/usr/bin/ccache
addons:
apt:
packages:
- cmake
- freeglut3-dev
- gperf
- libosmesa6-dev
--- a/servo/python/servo/bootstrap_commands.py
+++ b/servo/python/servo/bootstrap_commands.py
@@ -13,25 +13,26 @@ import base64
import json
import os
import os.path as path
import re
import shutil
import subprocess
import sys
import urllib2
+import glob
from mach.decorators import (
CommandArgument,
CommandProvider,
Command,
)
import servo.bootstrap as bootstrap
-from servo.command_base import CommandBase, BIN_SUFFIX
+from servo.command_base import CommandBase, BIN_SUFFIX, cd
from servo.util import delete, download_bytes, download_file, extract, host_triple
@CommandProvider
class MachCommands(CommandBase):
@Command('env',
description='Print environment setup commands',
category='bootstrap')
@@ -341,8 +342,180 @@ class MachCommands(CommandBase):
delete(full_path)
else:
print("Would remove {}".format(full_path))
if not removing_anything:
print("Nothing to remove.")
elif not force:
print("Nothing done. "
"Run `./mach clean-nightlies -f` to actually remove.")
+
+ @Command('clean-cargo-cache',
+ description='Clean unused Cargo packages',
+ category='bootstrap')
+ @CommandArgument('--force', '-f',
+ action='store_true',
+ help='Actually remove stuff')
+ @CommandArgument('--show-size', '-s',
+ action='store_true',
+ help='Show packages size')
+ @CommandArgument('--keep',
+ default='1',
+ help='Keep up to this many most recent dependencies')
+ @CommandArgument('--custom-path', '-c',
+ action='store_true',
+ help='Get Cargo path from CARGO_HOME environment variable')
+ def clean_cargo_cache(self, force=False, show_size=False, keep=None, custom_path=False):
+ def get_size(path):
+ if os.path.isfile(path):
+ return os.path.getsize(path) / (1024 * 1024.0)
+ total_size = 0
+ for dirpath, dirnames, filenames in os.walk(path):
+ for f in filenames:
+ fp = os.path.join(dirpath, f)
+ total_size += os.path.getsize(fp)
+ return total_size / (1024 * 1024.0)
+
+ removing_anything = False
+ packages = {
+ 'crates': {},
+ 'git': {},
+ }
+ import toml
+ if os.environ.get("CARGO_HOME", "") and custom_path:
+ cargo_dir = os.environ.get("CARGO_HOME")
+ else:
+ cargo_dir = path.join(self.context.topdir, ".cargo")
+ cargo_file = open(path.join(self.context.topdir, "Cargo.lock"))
+ content = toml.load(cargo_file)
+
+ for package in content.get("package", []):
+ source = package.get("source", "")
+ version = package["version"]
+ if source == u"registry+https://github.com/rust-lang/crates.io-index":
+ crate_name = "{}-{}".format(package["name"], version)
+ if not packages["crates"].get(crate_name, False):
+ packages["crates"][package["name"]] = {
+ "current": [],
+ "exist": [],
+ }
+ packages["crates"][package["name"]]["current"].append(crate_name)
+ elif source.startswith("git+"):
+ name = source.split("#")[0].split("/")[-1].replace(".git", "")
+ branch = ""
+ crate_name = "{}-{}".format(package["name"], source.split("#")[1])
+ crate_branch = name.split("?")
+ if len(crate_branch) > 1:
+ branch = crate_branch[1].replace("branch=", "")
+ name = crate_branch[0]
+
+ if not packages["git"].get(name, False):
+ packages["git"][name] = {
+ "current": [],
+ "exist": [],
+ }
+ packages["git"][name]["current"].append(source.split("#")[1][:7])
+ if branch:
+ packages["git"][name]["current"].append(branch)
+
+ crates_dir = path.join(cargo_dir, "registry")
+ crates_cache_dir = ""
+ crates_src_dir = ""
+ if os.path.isdir(path.join(crates_dir, "cache")):
+ for p in os.listdir(path.join(crates_dir, "cache")):
+ crates_cache_dir = path.join(crates_dir, "cache", p)
+ crates_src_dir = path.join(crates_dir, "src", p)
+
+ git_dir = path.join(cargo_dir, "git")
+ git_db_dir = path.join(git_dir, "db")
+ git_checkout_dir = path.join(git_dir, "checkouts")
+ git_db_list = filter(lambda f: not f.startswith('.'), os.listdir(git_db_dir))
+ git_checkout_list = os.listdir(git_checkout_dir)
+
+ for d in list(set(git_db_list + git_checkout_list)):
+ crate_name = d.replace("-{}".format(d.split("-")[-1]), "")
+ if not packages["git"].get(crate_name, False):
+ packages["git"][crate_name] = {
+ "current": [],
+ "exist": [],
+ }
+ if os.path.isdir(path.join(git_checkout_dir, d)):
+ for d2 in os.listdir(path.join(git_checkout_dir, d)):
+ dep_path = path.join(git_checkout_dir, d, d2)
+ if os.path.isdir(dep_path):
+ packages["git"][crate_name]["exist"].append((path.getmtime(dep_path), d, d2))
+ elif os.path.isdir(path.join(git_db_dir, d)):
+ packages["git"][crate_name]["exist"].append(("db", d, ""))
+
+ for d in os.listdir(crates_src_dir):
+ crate_name = re.sub(r"\-\d+(\.\d+){1,3}.+", "", d)
+ if not packages["crates"].get(crate_name, False):
+ packages["crates"][crate_name] = {
+ "current": [],
+ "exist": [],
+ }
+ packages["crates"][crate_name]["exist"].append(d)
+
+ total_size = 0
+ for packages_type in ["git", "crates"]:
+ sorted_packages = sorted(packages[packages_type])
+ for crate_name in sorted_packages:
+ crate_count = 0
+ existed_crates = packages[packages_type][crate_name]["exist"]
+ for exist in sorted(existed_crates, reverse=True):
+ current_crate = packages[packages_type][crate_name]["current"]
+ size = 0
+ exist_name = exist
+ exist_item = exist[2] if packages_type == "git" else exist
+ if exist_item not in current_crate:
+ crate_count += 1
+ removing_anything = True
+ if int(crate_count) >= int(keep) or not current_crate:
+ crate_paths = []
+ if packages_type == "git":
+ exist_checkout_path = path.join(git_checkout_dir, exist[1])
+ exist_db_path = path.join(git_db_dir, exist[1])
+ exist_name = path.join(exist[1], exist[2])
+ exist_path = path.join(git_checkout_dir, exist_name)
+
+ if exist[0] == "db":
+ crate_paths.append(exist_db_path)
+ crate_count += -1
+ else:
+ crate_paths.append(exist_path)
+
+ # remove crate from checkout if doesn't exist in db directory
+ if not os.path.isdir(exist_db_path):
+ crate_count += -1
+
+ with cd(path.join(exist_path, ".git", "objects", "pack")):
+ for pack in glob.glob("*"):
+ pack_path = path.join(exist_db_path, "objects", "pack", pack)
+ if os.path.exists(pack_path):
+ crate_paths.append(pack_path)
+
+ if len(os.listdir(exist_checkout_path)) <= 1:
+ crate_paths.append(exist_checkout_path)
+ if os.path.isdir(exist_db_path):
+ crate_paths.append(exist_db_path)
+ else:
+ crate_paths.append(path.join(crates_cache_dir, "{}.crate".format(exist)))
+ crate_paths.append(path.join(crates_src_dir, exist))
+
+ size = sum(get_size(p) for p in crate_paths) if show_size else 0
+ total_size += size
+ print_msg = (exist_name, " ({}MB)".format(round(size, 2)) if show_size else "", cargo_dir)
+ if force:
+ print("Removing `{}`{} package from {}".format(*print_msg))
+ for crate_path in crate_paths:
+ if os.path.exists(crate_path):
+ delete(crate_path)
+ else:
+ print("Would remove `{}`{} package from {}".format(*print_msg))
+
+ if removing_anything and show_size:
+ print("\nTotal size of {} MB".format(round(total_size, 2)))
+
+ if not removing_anything:
+ print("Nothing to remove.")
+ elif not force:
+ print("\nNothing done. "
+ "Run `./mach clean-cargo-cache -f` to actually remove.")
|
__label__pos
| 0.977359 |
WIFI vs Ethernet
Supporting both WIFI/Ethernet networks, how does it determine which network to chose for communication.
Shouldn’t this be dependent on your needs? Maybe I misunderstood the question.
Do you mean if both ethernet and wi-fi are active at the same time, how is routing done?
If don’t believe you can have both active at same time with built in firmware.
I’m assuming by using that I can select the connection I want by using the using the SetAsDefaultController and Enable functions provided the NetworkController class. Where are all of these calls documented?
TinyCLR Tutorials
Is this what you are looking for?
I think I have solved the problem. I am going to switch the connection from WIFI/Ethernet based on connection status. I am going to toggle between the two of them by using the SetAsDefaultController() function.
|
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| 0.998745 |
From: kei9 Date: Tue, 3 Dec 2013 15:26:17 +0000 (+0900) Subject: remove old generator file X-Git-Tag: 0.1.2~2^2~10 X-Git-Url: http://git.sourceforge.jp/view?p=amulettoolsmh4%2Fmain.git;a=commitdiff_plain;h=a9879e51a89e37ab61ccb7e7f88a582b9cf580e6 remove old generator file --- diff --git a/model/db_generator_old.py b/model/db_generator_old.py deleted file mode 100644 index 3f01240..0000000 --- a/model/db_generator_old.py +++ /dev/null @@ -1,175 +0,0 @@ -# -*- coding: utf-8 -*- - -# databaseã®çæç¨ã¹ã¯ãªãã - -import sqlite3 -import csv -import os.path -import os, sys - -DataDirecroty = "data" -OutputDBFileName = "OmamoriMH4.sqlite3" -MinMaxFileName = "minmax.csv" -SecondSkillFileName = "2ndskill.csv" -SecondSlotFileName = "slot_2ndskill.csv" - -class DataBaseGenerator(object): - u""" this is access class to database """ - - # for minmax - MinMaxMasterTableName = u"skill_minmax_master" - MinMaxTableName = u"skill_minmax_{id}" - MinMaxMasterCreateSql = u"create table if not exists skill_minmax_master(id integer primary key, omamori_name varchar, skill_table_name varchar);" - MinMaxCreateSql = u"create table if not exists {table_name}(id integer primary key, skill_name varchar, min1 integer, max1 integer, min2 integer, max2 integer);" - - # for Second skill - SecondTableName = u"skill_second_{id}" - SecondSlotTableName = u"skill_second_slot" - SecondMasterTableName = u"skill_second_master" - SecondMasterCreateSql = u"create table if not exists skill_Second_master(id integer primary key, omamori_name varchar, Second_table_name varchar);" - SecondCreateSql = u"create table if not exists {table_name}(id integer primary key, random_seed integer unique, skill_name1 varchar, skill_name2 varchar, skill_name3 varchar, skill_name4 varchar, skill_name5 varchar, skill_name6 varchar, skill_name7 varchar);" - SecondSlotCreateSql = u"create table if not exists {table}(id integer primary key, random_seed integer unique, slot1 integer, slot2 integer, slot3 integer, slot4 integer, slot5 integer, slot6 integer, slot7 integer);".format(table=SecondSlotTableName) - - def __init__(self, dbName=None): - if dbName is None: - self._dbName = ":memory:" - else : - self._dbName = dbName - - def Open(self): - self._connect = sqlite3.connect(self._dbName) - self._connect.text_factory = str # for usage of utf-8 - self._cursor = self._connect.cursor() - - def CreateSecondSkillTable(self): - u""" - csvãã¡ã¤ã«ãã第2ã¹ãã«ã®è¡¨ãçæãã - """ - print "load Second skill" - self._cursor.execute(self.SecondMasterCreateSql) # create master table of Second skill - reader = csv.reader(file(os.path.join(DataDirecroty, SecondSkillFileName), "r")) # (omamori_name, filename of Second_skill) - - reader.next() # skip header row - cnt = 0 - for row in reader: - tableName = self.SecondTableName.format(id=cnt) - createSql = self.SecondCreateSql.format(table_name=tableName) - insertSql = u"insert into {table}(omamori_name, Second_table_name) values(?, ?);".format(table=self.SecondMasterTableName) - oma_name = row[0].strip() - self._cursor.execute(insertSql, (oma_name, tableName)) - self._cursor.execute(createSql) # create skill table for each omamori - - reader1 = None - fname1 = os.path.join(DataDirecroty, row[1].strip()) - if os.path.exists(fname1) and os.path.isfile(fname1): - reader1 = csv.reader(file(fname1, "r")) # (random seed, skill1, skil2, ..., skill7) - else: - print "file1 ", fname1, " doesn't exist!" - - insertSql = u"insert into {table}(random_seed, skill_name1, skill_name2, skill_name3, skill_name4, skill_name5, skill_name6, skill_name7) values(?,?,?,?,?,?,?,?);".format(table=tableName) - - if reader1 is not None: - reader1.next() # skip header - for row1 in reader1: - val_tup = tuple([x.strip() if i != 0 else int(x.strip()) for i, x in enumerate(row1)]) - self._cursor.execute(insertSql, val_tup) - - cnt += 1 - - # for Slot table - self._cursor.execute(self.SecondSlotCreateSql) # create slot table of Second skill - reader = csv.reader(file(os.path.join(DataDirecroty, SecondSlotFileName), "r")) # (random_seed, slot1, slot2, ..., slot7) - - reader.next() # skip header row - insertSql = u"insert into {table}(random_seed, slot1, slot2, slot3, slot4, slot5, slot6, slot7) values(?,?,?,?,?,?,?,?);".format(table=self.SecondSlotTableName) - for row in reader: - val_tup = tuple([int(x.strip()) for x in row]) - self._cursor.execute(insertSql, val_tup) - - self._connect.commit() - - def CreateMinMaxTable(self): - u""" - ãå®ãåã¨å¯¾å¿ããã¹ãã«ã®æ大æå°å¤ã®è¨è¼ãããcsvãã¡ã¤ã«ãã - ãå®ããã¨ã®ã¹ãã«ã®æ大æå°å¤ãè¨è¼ãããã¼ãã«ãä½æãã - """ - print "load min & max of skill" - - self._cursor.execute(self.MinMaxMasterCreateSql) # create master table of skill min max - reader = csv.reader(file(os.path.join(DataDirecroty, MinMaxFileName), "r")) # (name, filename of minmax1, filename of minmax2) - - reader.next() # skip header row - cnt = 0 - for row in reader: - tableName = self.MinMaxTableName.format(id=cnt) - createSql = self.MinMaxCreateSql.format(table_name=tableName) - insertSql = u"insert into {table}(omamori_name, skill_table_name) values(?, ?);".format(table=self.MinMaxMasterTableName) - oma_name = row[0].strip() - self._cursor.execute(insertSql, (oma_name, tableName)) - self._cursor.execute(createSql) # create minmax table for each omamori - - reader1, reader2 = None, None - fname1, fname2 = os.path.join(DataDirecroty, row[1].strip()), os.path.join(DataDirecroty, row[2].strip()) - if os.path.exists(fname1) and os.path.isfile(fname1): - reader1 = csv.reader(file(fname1, "r")) # (name of skill1, min1, max1) - else: - print "file1 ", fname1, " doesn't exist!" - if os.path.exists(fname2) and os.path.isfile(fname2): - reader2 = csv.reader(file(fname2, "r")) # (name of skill1, min1, max1) - else: - print "file2 ", fname2, " doesn't exist!" - - insertSql = u"insert into {table}(skill_name, min1, max1, min2, max2) values(?,?,?,?,?);".format(table=tableName) - - skill_dict = {} # dict for skill1, skill2 - - if reader1 is not None: - reader1.next() # skip header - for row1 in reader1: - minVal, maxVal = int(row1[1]), int(row1[2]) - skill_name = row1[0].strip() - skill_dict[skill_name] = (minVal, maxVal, 0, 0) - - if reader2 is not None: - reader2.next() # skip header - for row2 in reader2: - minVal, maxVal = int(row2[1]), int(row2[2]) - skill_name = row2[0].strip() - if skill_name in skill_dict: - val = skill_dict[row2[0]] - skill_dict[skill_name] = (val[0], val[1], minVal, maxVal) - else: - skill_dict[skill_name] = (0, 0, minVal, maxVal) - - # insert to minmax table - for k, v in skill_dict.items(): - self._cursor.execute(insertSql, (k,) + v) - - cnt += 1 - - self._connect.commit() - - def Close(self): - self._connect.commit() - self._cursor.close() - self._connect.close() - - def DropTables(self): - u""" å
¨ã¦ã®ãã¼ãã«ã®åé¤ """ - self._cursor.execute("select name from sqlite_master where type='table';") - tableNames = [] - for catalog in cur.fetchall(): - tableNames.append(catalog[0]) - for table in tableNames: - self._cursor.execute("drop table {name};".format(name=table)) - self._connect.commit() - - -if __name__ == "__main__": - db = DataBaseGenerator(OutputDBFileName) - #db = DataBaseGenerator() # for memory - db.Open() - db.CreateMinMaxTable() - db.CreateSecondSkillTable() - db.Close() -
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This article is participating in “Java Theme Month – Java Debug Notes Event”, see < Event link > for more details.
Why does Stream <T> not implement Iterable <T>?
In Java 8, we have the Stream class, which oddly has a method
Iterator<T> iterator(a)
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Therefore, you might expect it to implement the interface Iterable, but it doesn’t.
I have to do something similar when I want to traverse a Stream using a foreach loop
public static Iterable<T> getIterable(Stream<T> s) {
return new Iterable<T> {
@Override
public Iterator<T> iterator(a) {
returns.iterator(); }}; }for (T element : getIterable(s)) { ... }
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What did I miss?
Answer 1:
The main reason is that Iterable has repeatable semantics, whereas Stream does not.
I think the main reason is that Iterable implies reusability, whereas Stream can only be used once, more like Iterator.
If the Stream extends Iterable, the existing code may be surprised when it receives Iterable a second time and throws an exception.
Answer 2:
To convert the Stream to Iterable, you perform
Stream<X> stream = null;
Iterable<X> iterable = stream::iterator
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To pass Stream to foo, the method that expects Iterable,
void foo(Iterable<X> iterable)
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The easy way:
foo(stream::iterator)
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Maybe it’s better to be a little more specific
foo( (Iterable<X>)stream::iterator );
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Answer 3:
This can be a lesson: a reusable Iterable in a stream satisfies all the guarantees provided by the Iterable specification.
Note: SomeType is not a type parameter here – you need to replace it with an appropriate type (such as String) or use reflection
Stream<SomeType> stream = ... ; Iterable<SomeType> iterable = stream.collect(toList()):Copy the code
There is one major drawback:
The benefits of delayed iteration will be lost. If you plan to iterate through all the values in the current thread at once, all the overhead is negligible. However, if you plan to iterate only partially or in another thread, this immediate and complete iteration can have unintended consequences.
Of course, the biggest benefit is that you can reuse Iterable, whereas (Iterable) stream :: Iterator is only allowed to be used once. If the receiving code will iterate over the collection multiple times, this approach is not only necessary, but may also be beneficial for performance.
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Creado por Oscar Avila, Rosy Guerra
4 métodos:Usa la división por tentativaUsa el pequeño teorema de FermatUsa el test de Miller-RabinUsa el teorema chino del resto
Los números primos son aquellos que solo se dividen entre sí mismos y el 1, los otros números se denominan compuestos. Existen diversas opciones cuando se trata de comprobar si un número dado es primo. Algunos de estos métodos son relativamente simples pero no son efectivos con cifras altas. Otros que se usan con frecuencia para cifras altas son en realidad algoritmos probabilísticos que a veces pueden determinar erróneamente si un número es primo o compuesto. Mira el paso 1 a continuación para aprender cómo probar la primalidad de un número.
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Método 1 de 4: Usa la división por tentativa
La división por tentativa es de lejos la prueba más simple para determinar la primalidad. Para las cifras pequeñas, también suele ser la prueba disponible más rápidas. Este método se basa en la definición de un número primo: un número es primo si no tiene más divisores que el uno y sí mismo.
1. Check if a Number Is Prime Step 1.jpg
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Designa n como el número que quieres probar. En el método de división por tentativa para probar la primalidad, debes dividir el número dado n entre todos los factores enteros posibles. Para valores grandes de n, como n=101, no es muy práctico dividirlo entre todos los números enteros menores a n. Por suerte, existen muchos trucos para reducir significativamente el número de factores que debes probar.
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2. Check if a Number Is Prime Step 2.jpg
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Determina si n es par. Todos los números pares son divisibles entre 2. Debido a esto, si n es par puedes dar por hecho que n es compuesto y no primo. Para determinar rápidamente si un número es par, solo presta atención al último dígito. Si el último dígito es 2, 4, 6, 8 o 0, el número es par y por tanto no es primo.
• La única excepción a esta regla es el número 2 por ser primo, ya que solo es divisible entre sí mismo y el 1. El 2 es el único número primo y par.
3. Check if a Number Is Prime Step 3.jpg
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Divide n entre todos los números ubicados en el rango de 2 y n-1. Debido a que el número primo no tiene otros factores más que el 1 y sí mismo, y a que los factores primos son necesariamente menores a sus productos; comprobar la divisibilidad de todos los números menores a n y mayores a 2 determinará si n es primo. Comenzamos con los números después de 2 porque los números pares, que son múltiplos de 2, no son primos. Este método está lejos de ser el más efectivo para esta prueba y, como se verá más adelante, existe una serie de estrategias de simplificación.
• Por ejemplo, si utilizamos este método para probar si 11 es primo o no, debemos dividir 11 entre 3, 4, 5, 6, 7, 8, 9 y 10 cada vez que busquemos un número entero sin resto como respuesta. Debido a que ninguno de estos números se divide entre 11, podemos decir que 11 es primo.
4. Check if a Number Is Prime Step 4.jpg
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Para ahorrar tiempo, prueba solo hasta la raíz cuadrada de n, redondeada. Probar el número n con todos los números entre 2 y n -1 puede convertirse rápidamente en un proceso que demande mucho tiempo. Por ejemplo, si quieres comprobar si 103 es un número primo de esta forma, tendríamos que dividirlo entre 3, 4, 5, 6, 7, etc. ¡Hasta llegar al 102! Por suerte, no necesitas probar todos los factores posibles. En realidad, solo se requiere probar los factores entre 2 y la raíz cuadrada de n. Si la raíz cuadrada de n no es un número entero, redondéalo hasta el número entero más cercano y en su lugar prueba ese número. El siguiente ejemplo lo explicará:
• Analicemos los factores de 100. 100 = 1 × 100, 2 × 50, 4 × 25, 5 × 20, 10 × 10, 20 × 5, 25 × 4, 50 × 2, and 100 ×1. Nota que después de 10 × 10, los factores son los mismos que aquellos antes de 10 × 10, solo se revierten. En general, nosotros podemos ignorar los factores de n mayores a su raíz cuadrada, ya que estos no son más que los factores menores a la raíz cuadrada de n reorganizados.
• Veamos este problema. Si n =37, no necesitamos probar todos los números desde 3 hasta 36 para determinar si n es primo. En su lugar, solo tenemos que probar los números desde 2 hasta la raíz cuadrada de 37, redondeada.
• La raíz cuadrada de 37 es 6.08 que redondeamos a 7.
• 37 no es divisible entre 3, 4, 5, 6 y 7, por lo que podemos determinar con certeza que es primo .
5. Check if a Number Is Prime Step 5.jpg
5
Para ahorrar más tiempo, utiliza solo los números primos. Es posible acortar más el proceso de división por tentativa al eliminar las opciones de factores que no son números primos. Por definición, cada número compuesto se puede expresar como el producto de dos o más números primos. Por lo que dividir nuestro número n entre un número compuesto es redundante, ya que es básicamente lo mismo que dividirlo entre números primos varias veces. Por tanto, podemos reducir aún más la lista de factores posibles a solo los números primos menores a la raíz cuadrada de n.
• Eso significa que todos los factores pares, así como todos los factores que son múltiplos de los números primos, se pueden omitir.
• Por ejemplo, tratemos de determinar si 103 es primo o no. La raíz cuadrada de 103 redondeada es 11. Los números primos entre 2 y 11 son 3, 5, 7 y 11. Los números 4, 6, 8 y 10 son pares, y 9 es múltiplo de 3, un número primo, así que los podemos omitir. Al hacerlo, ¡hemos acortado nuestra lista de factores posibles a solo 4 números!
• Ni 3, 5, 7 o 11 son divisores de 103, por lo que sabemos que 103 es primo.
Método 2 de 4: Usa el pequeño teorema de Fermat
En 1640, el matemático francés Pierre de Fermat fue el primero en describir el teorema que ahora lleva su nombre, uno muy útil al momento de decidir si un número es primo. Técnicamente, la prueba de Fermat se usa para saber si un número es compuesto más que si es primo, ya que puede determinar con certeza absoluta si un número es compuesto, pero solo puede señalar si es muy probable que un número sea primo.[1] El pequeño teorema de Fermat es útil en situaciones en las que la división por tentativa no es muy es efectiva y cuando se dispone de una lista de números que son excepciones al teorema.
1. Check if a Number Is Prime Step 6.jpg
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Sea n el número para la prueba de primalidad. Esta prueba de primalidad se usa para determinar si un número dado n es primo. Sin embargo, como se mencionó anteriormente, en ocasiones el teorema identifica erróneamente algunos números compuestos como primos. Es importante conocer esto y estar preparado para verificar tu respuesta, como aprenderemos a continuación.
2. Check if a Number Is Prime Step 7.jpg
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Elige cualquier número entero a entre 2 y n-1 (incluido). El número entero exacto que elijas no es importante. Debido a que los parámetros para a están incluidos, los mismos 2 y n-1 son opciones válidas.
• Como un ejemplo práctico, tratemos de determinar si 100 es o no un número primo. Usemos el 3 como nuestro valor, se encuentra entre 2 y n-1 así que funcionará bien.
3. Check if a Number Is Prime Step 8.jpg
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Calcula an (mod n). Calcular esta expresión requeire cierto conocimiento de un sistema matemático llamado aritmética modular. En la aritmética modular, los números "vuelven a comenzar" desde cero después de alcanzar un cierto valor, llamado módulo. Considéralo como un reloj: una hora después del mediodía es la 1 en punto no 13 en punto, el tiempo ha “vuelto a comenzar” desde su punto de partida. El módulo se especifica mediante la notación (mod n). Por lo tanto, en este paso, calcula an con un módulo de n.
• Otra forma de considerarlo es calcular an, luego dividirlo entre n y usar el resto como tu respuesta. Aquí pueden ser muy útiles las calculadoras especializadas con la función para hallar el módulo,[2] ya que pueden calcular inmediatamente el resto de una división que implique cifras altas.
• Si usamos esa calculadora para nuestro ejemplo, podemos ver que 3 100/100 tiene un resto de 1. Por lo tanto, 3100 (mod 100) es 1.
4. Check if a Number Is Prime Step 9.jpg
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Si lo resuelves a mano, usa una notación exponencial para abreviarlo. Si no consigues una calculadora con funciones para hallar el módulo, usa una notación exponencial para facilitar el proceso de determinar el resto. Revísalo a continuación:
• En nuestro ejemplo, calcularíamos 3100 con un módulo de 100. 3100 es una cifra muy pero muy alta, 377 520 732 011 331 036 461 129 765 621 272 702 107 522 001, tan alta que en realidad es difícil trabajar con ella. En lugar de usar una respuesta de 48 dígitos para 3100, representémosla en una notación exponencial como (((((((32)*3)2)2)2)*3)2)2. Recuerda que tomar el exponente de un exponente tiene el efecto de multiplicar los exponentes ((xy)z = xyz).
• Ahora determinemos el resto. Empieza al resolver (((((((32)*3)2)2)2)*3)2)2 el grupo de paréntesis desde adentro hacia afuera, divide entre 100 después de cada paso. Una vez que obtengas el resto, lo usaremos para el siguiente paso en vez de la respuesta actual. Mira a continuación:
• (((((((9)*3)2)2)2)*3)2)2 - 9/100 no tiene resto, así que continuemos.
• ((((((27)2)2)2)*3)2)2 - 27/100 no tiene resto, así que continuemos.
• (((((729)2)2)*3)2)2 - 729/100 = 7 R 29. El resto es 29. Por tanto, apliquemos el siguiente paso en este y no en 729.
• ((((292=841)2)*3)2)2 - 841/100 = 8 R 41. Usaremos el resto 41 otra vez en el siguiente paso.
• (((412 = 1681)*3)2)2 - 1681/100 = 16 R 81. Usaremos el resto 81 en el siguiente paso.
• ((81*3 = 243)2)2 - 243/100 = 2 R 43. Usaremos el resto 43 en el siguiente paso.
• (432 = 1849)2 - 1849/100 = 18 R 49. Usaremos el resto 49 en el siguiente paso.
• 492 = 2401 - 2401/100 = 24 R 1. El último resto es 1. En otras palabras, 3100 (mod 100) = 1. ¡Nota que este es la misma respuesta que obtuvimos con una calculadora en el paso anterior!
5. Check if a Number Is Prime Step 10.jpg
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Comprueba si an (mod n) = a (mod n). Si no es así, n es compuesto. En caso contrario, es probable, pero no definitivo que n sea primo. Repetir la prueba con diferentes valores para a puede aumentar tu confianza en el resultado, aunque existan números compuestos raros que satisfacen la condición de Fermat para todos los valores de a. Estos son llamados los números Carmichael, el menor de los números es 561.
• En nuestro ejemplo, 3100 (mod 100) = 1 y 100 (mod 100) = 0. 1 =/= 0, así que podemos decir que 100 es compuesto.
6. Check if a Number Is Prime Step 11.jpg
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Utiliza los números Carmichael para estar seguro. Conocer con anticipación cuáles son los números Carmichael te puede evitar el dolor de cabeza por la preocupación de saber si el número es realmente primo o no. En general, los números Carmichael siguen la forma (6k + 1)(12k + 1)(18k + 1) para los valores enteros de k cuando cada uno de los factores es primo.[3] Las listas de los números Carmichael que se encuentran en línea pueden ser muy útiles cuando uses el pequeño teorema de Fermat para determinar la primalidad de un número.
Método 3 de 4: Usa el test de Miller-Rabin
La prueba Miller-Rabin funciona de manera parecida a la del pequeño teorema de Fermat, pero es más eficiente con los casos excepcionales como el de los números Carmichael.[4]
1. Check if a Number Is Prime Step 12.jpg
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Sea n un entero impar que deseas probar. Al igual que en los métodos anteriores, n será la variable que represente al número cuya primalidad queremos determinar.
2. Check if a Number Is Prime Step 13.jpg
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Expresa n-1 en la forma 2s × d donde d es impar. Para que n sea primo, debe ser impar. De esa forma, n-1 debe ser par. Debido a que n-1 es par, puede representarse como alguna potencia de 2 por un número impar - 4 = 22 × 1, 80 = 24 × 5 y así sucesivamente. Expresa n - 1 para el valor de n de esa forma.
• Digamos que queremos saber si n = 321 es primo. 321 - 1 = 320, que queremos expresar como 26 × 5.
• En este caso, n = 321 es un número idóneo. n - 1 para un número no tan idóneo, como n = 371, puede necesitar un valor mayor para d, lo que después complica el proceso. 371 - 1 = 370 = 21 × 185.
3. Check if a Number Is Prime Step 14.jpg
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Elige un número aleatorio a entre 2 y n-1. El número exacto que elijas no es tan importante, solo tiene que ser menor a n y mayor a 1.
• En nuestro ejemplo n = 321, elegimos que a = 100.
4. Check if a Number Is Prime Step 15.jpg
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Calcula ad (mod n). Si ad = 1 o -1 (mod n), entonces n pasa la prueba Miller-Rabin y probablemente es primo. Al igual que el pequeño teorema de Fermat, esta prueba no puede determinar con total precisión la primera vez si un número es primo.
• En nuestro ejemplo n = 321, ad (mod n) = 1005 (mod 321). 1005 = 10 000 000 000 (mod 321) = 313. Podríamos utilizar una calculadora especializada o el método abreviado del exponente que se mencionó anteriormente para encontrar el resto.
• Ya que no obtuvimos 1 o -1, aún no podemos determinar que n sea primo. Sin embargo, todavía falta mucho que hacer (ver más adelante).
5. Check if a Number Is Prime Step 16.jpg
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Si tu resultado no es igual a 1 o -1, calcula a2d, a4d, y así sucesivamente hasta a2s-1d. Calcula "a" a la potencia de d por las potencias de 2 hasta 2s-1. Si uno de ellos es igual a 1 o -1 (mod n), entonces n pasa la prueba Miller-Rabin y probablemente sea primo. Si descubres que n no pasa la prueba, revisa tu respuesta (ver el paso debajo). Si n no pasa ninguna de las pruebas, entonces es compuesto.
• Como recordatorio, en nuestro ejemplo, el valor para a es 100, para s es 6 y d es 5 para continuar con la prueba de la siguiente manera:
• 1002d = 10 = 1 × 1020.
• 1 × 1020 (mod 321) = 64. 64 =/= 1 or -1. Continuaremos.
• 1004d = 20 = 1 × 1040.
• 1 × 1040 (mod 321) = 244. 244 =/= 1 o -1.
• En este punto, podemos detenernos. Hemos conseguido 4d = 22 y no hay más potencias de 2 por d menores a 5d. Debido a que ninguno de nuestros cálculos nos dio 1 o -1, tenemos la certeza de que n = 321 es compuesto.
6. Check if a Number Is Prime Step 17.jpg
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Si n pasa la prueba Miller-Rabbin, repite el proceso con valores alternativos para a. Si encuentras que el valor de n puede ser un número primo, inténtalo otra vez con otro valor aleatorio para a y tener mayor certeza del resultado de la prueba. Si n es un número primo, pasará la prueba con cualquier valor para a. Si n es compuesto, al menos tres cuartas partes de los valores que elijas para a no pasarán la prueba. De esa forma, se tiene una mayor certeza que con el pequeño teorema de Fermat, en el que ciertos números compuestos, es decir los números de Carmichael, pueden pasar con cualquier valor para a.
Método 4 de 4: Usa el teorema chino del resto
1. Check if a Number Is Prime Step 18.jpg
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Elige dos números. Uno de los números no debe ser primo y el otro debe someterse a una prueba de primalidad.
• "Primo1" = 35
• Primo2 = 97
2. Check if a Number Is Prime Step 19.jpg
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Elige dos puntos de datos que sean mayores a cero y menores al primo1 y primo2 respectivamente. Estos no pueden ser iguales.
• Dato1 = 1
• Dato2 = 2
3. Check if a Number Is Prime Step 20.jpg
3
Calcula el inverso multiplicativo (IM) de primo1 y primo2.
• Calcula el inverso multiplicativo
• IM1 = primo2 ^ -1 mod primo1
• IM2 = primo1 ^ -1 mod primo2
• Solo para los números primos (dará un número para los números no primos pero no será el inverso multiplicativo).
• IM1 = (primo2 ^ (primo1-2)) % primo1
• IM2 = (primo1 ^ (primo2-2)) % primo2
• Ejemplo
• IM1 = (97 ^ 33) % 35
• IM2 = (35 ^ 95) % 97
4. Check if a Number Is Prime Step 21.jpg
4
Crea una tabla de conversión binaria para cada inverso multiplicativo hasta el logaritmo2 del módulo.
• Para IM1
• F(1) = primo2 % primo1 = 97 % 35 = 27
• F(2) = F(1) * F(1) % primo1 = 27 * 27 % 35 = 29
• F(4) = F(2) * F(2) % primo1 = 29 * 29 % 35 = 1
• F(8) = F(4) * F(4) % primo1 = 1 * 1 % 35 = 1
• F(16) =F(8) * F(8) % primo1 = 1 * 1 % 35 = 1
• F(32) =F(16) * F(16) % primo1 = 1 * 1 % 35 = 1
• Calcula el binario de primo1 - 2
• 35 -2 = 33 (10001) base 2
• IM1 = F(33) = F(32) * F(1) mod 35
• IM1 = F(33) = 1 * 27 mod 35
• IM1 = 27
• Para IM2
• F(1) = primo1 % primo2 = 35 % 97 = 35
• F(2) = F(1) * F(1) % primo2 = 35 * 35 mod 97 = 61
• F(4) = F(2) * F(2) % primo2 = 61 * 61 mod 97 = 35
• F(8) = F(4) * F(4) % primo2 = 35 * 35 mod 97 = 61
• F(16) = F(8) * F(8) % primo2 = 61 * 61 mod 97 = 35
• F(32) = F(16) * F(16) % primo2 = 35 * 35 mod 97 = 61
• F(64) = F(32) * F(32) % primo2 = 61 * 61 mod 97 = 35
• F(128) = F(64) * F(64) % primo2 = 35 * 35 mod 97 = 61
• Calcula el binario de primo2 - 2
• 97 - 2 = 95 = (1011111) base 2
• IM2 = (((((F(64) * F(16) % 97) * F(8) % 97) * F(4) % 97) * F(2) % 97) * F(1) % 97)
• IM2 = (((((35 * 35) %97) * 61) % 97) * 35 % 97) * 61 % 97) * 35 % 97)
• IM2 = 61
5. Check if a Number Is Prime Step 22.jpg
5
Calcula (dato1 * primo2 * IM1 + dato2 * primo1 * IM2) % (primo1 * primo2)
• Respuesta = (1 * 97 * 27 + 2 * 35 * 61) % (97 * 35)
• Respuesta = (2619 + 4270) % 3395
• Respuesta = 99
6. Check if a Number Is Prime Step 23.jpg
6
Verifica que "primo1" no sea primo1
• Calcula (respuesta - dato1) % primo1
• 99 -1 % 35 = 28
• Como 28 es mayor a 0, 35 no es primo
7. Check if a Number Is Prime Step 24.jpg
7
Verifica que primo2 sea primo.
• Calcula (respuesta - dato2) % primo2
• 99 - 2 % 97 = 0
• Como 0 es igual a 0, es posible que 97 sea primo
8. Check if a Number Is Prime Step 25.jpg
8
Repite los pasos del 1 al 7 al menos dos veces más.
• Si el paso 7 te da 0:
• Usa un número diferente para “primo1”, donde primo1 sea compuesto.
• Usa un número diferente para primo1, donde este sea realmente primo. En este caso, al aplicar el paso 6 y 7, el resultado debe ser 0.
• Usa otros puntos de datos para dato1 y dato2.
• Si al aplicar el paso 7 siempre obtienes 0, existe una gran posibilidad de que primo2 sea primo.
• Se sabe que los pasos del 1 al 7 pueden fallar en algunos casos cuando el primer número no es primo y el segundo es un factor del número compuesto “primo1”. Pero funciona con todos los otros casos en los que ambos números son primos.
• La razón por la que los pasos del 1 al 7 se repiten es porque hay algunos casos donde, aunque primo1 y primo2 no sean primos, el paso 7 aún resulta ser cero, para uno o ambos números. Sin embargo, estos casos son poco comunes. Al cambiar primo1 a un número no primo diferente, si primo2 no es primo, entonces de forma rápida se determinará que el paso 7 no resultará en 0. Excepto por el ejemplo, los números primos siempre serán iguales a cero en el paso 7.
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Consejos
• Los 168 números primos menores a 1000 son: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997.
• Aunque el método de prueba por división sea más lento que otros métodos más complejos para las cifras altas, es muy efectivo con los números pequeños. Incluso para comprobar la primalidad de cifras altas, se suelen revisar primero los factores menores antes de pasar a otros métodos más avanzados donde dichos factores no se encuentran.
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Cosas que necesitarás
• Material de trabajo, como lápiz y papel, o una computadora.
Acerca del artículo
Categorías: Carreras y educación
Últimos usuarios en aportar: Oscar Avila
Otros idiomas:
English: How to Check if a Number Is Prime, Italiano: Come Riconoscere un Numero Primo, Português: Como Determinar se um Número é Primo, Русский: проверить, является ли число простым, Français: Comment tester la primalité d'un nombre, Deutsch: Überprüfen, ob eine Zahl eine Primzahl
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WordPress Theme Development: A Complete Roadmap
Welcome to the captivating world of WordPress theme development! 🎉 Are you ready to unleash your creativity and transform your web design dreams into reality? Whether you’re a curious beginner or a seasoned enthusiast, this is your starting point for crafting stunning websites that stand out in the digital landscape.
In this guide, “WordPress Theme Development: A Complete Roadmap,” we’ll take you on a streamlined journey through the essential steps to master the art of theme development. You’re in for an exciting ride from the basics of HTML, CSS, and PHP to the intricacies of custom post types, responsive design, and optimization techniques.
By the end of this learning path, you’ll be equipped with the skills to design, code, and customize your WordPress themes. So, let’s embark on this adventure together and unlock the door to a world where your imagination knows no bounds. Ready to dive in? Let’s get started! 🚀
1. HTML, CSS, and JavaScript Fundamentals:
Welcome, eager learners, to the foundational step of our WordPress theme development journey. In this chapter, we’ll lay the bedrock of your web development skills. Immerse yourself in the world of HTML for structuring content, CSS for stylish designs, and JavaScript for adding that touch of interactivity. These are the tools you’ll wield to bring your creative visions to life.
2. Introduction to WordPress:
Greetings, curious minds! Let’s dive into the bustling universe of WordPress. I’ll be your guide as we uncover the mysteries of its architecture and how themes fit into the grand scheme. Get ready to see how your creative magic aligns with the powerful capabilities of this platform.
3. PHP Basics:
Ahoy, adventurers! Now it’s time to unravel the secrets of PHP. Fear not, for I shall be your mentor as you embark on this coding quest. Learn about variables, functions, loops, and arrays – the very essence of WordPress theme development’s heart and soul.
4. Template Hierarchy:
Greetings, aspiring architects of the digital realm! Prepare to understand the symphony of WordPress template hierarchy. As your mentor, I’ll walk you through the harmonious dance of template files – from index.php to single.php – revealing how each contributes to the magic of content display.
5. Building a Basic Theme:
Bravo, builders of dreams! Let’s construct your very first WordPress theme. Under my guidance, you’ll fuse your HTML and CSS prowess into the WordPress framework, crafting a symphony of design and functionality.
6. WordPress Functions and Hooks:
Hello, code crafters! As your guide, I’ll demystify WordPress functions and hooks. From the enchanting get_header() to the mystical wp_head(), you’ll wield these tools to orchestrate dynamic content like a true wizard.
7. Custom Post Types and Taxonomies:
Greetings, architects of innovation! Let’s sculpt WordPress to your desires. Under my tutelage, you’ll master custom post types and taxonomies, sculpting your digital world with unique content structures.
8. Theme Customizer and Options:
Ah, the realm of customization beckons! Allow me to show you the magic of the WordPress Theme Customizer API. You’ll wield this enchanting tool to grant users the power to mold their website’s appearance, all with a wave of your code.
9. Widget and Sidebar Development:
Greetings, widget wizards! Together, we’ll weave the threads of custom widgets and sidebars, allowing users to personalize their digital spaces. Get ready to wield the power of dynamic content creation.
10. Responsive Design:
Ahoy, responsiveness champions! Under my wing, you’ll master the art of responsive design. Join me as we ensure your themes shine on screens of all sizes, creating a harmonious user experience.
11. Accessibility and SEO:
Ahoy, advocates of inclusivity and visibility! In this chapter, I’ll guide you through the realm of accessibility and SEO. Together, we’ll learn how to make your themes shine in the digital spotlight while ensuring they’re accessible to all. It’s a journey that empowers you to create websites that not only look great but also cater to diverse audiences.
12. JavaScript and AJAX in WordPress:
Greetings, JavaScript conjurers! Let’s infuse your themes with interactivity. As your mentor, I’ll lead you through the world of JavaScript and AJAX integration. Brace yourselves for dynamic content loading, seamless form submissions, and an enhanced user experience that’ll leave a lasting impression.
13. Custom Fields Development:
Hello, detail-oriented artisans! Join me in unveiling the magic of custom fields. With my guidance, you’ll discover how to add versatile content options to your themes. From custom metadata to unique input fields, your themes will be as flexible as a chameleon in a digital rainforest.
14. Page Builders Integration:
Step right up, builders of visual wonders! Allow me to introduce you to the realm of page builders. Together, we’ll seamlessly integrate custom elements into these powerful tools, unlocking new dimensions of creativity and design possibilities.
15. Theme Optimization and Performance:
Ah, the realm of speed and efficiency awaits! Under my guidance, you’ll uncover the secrets of theme optimization. From minification spells to caching enchantments, you’ll wield techniques that ensure your themes run like a well-oiled machine.
16. Security Best Practices:
Greetings, guardians of digital fortresses! It’s time to fortify your themes against the forces of the web. Join me as we explore security best practices, ensuring your creations stand strong and resilient against potential threats.
17. Version Control (Git):
Ahoy, code commanders! Let’s delve into the world of version control using Git. I’ll be your guide as we navigate the branching rivers and commit trails, ensuring your codebase remains organized, collaborative, and future-proof.
18. Advanced Topics:
Bravo, intrepid explorers of the advanced frontier! As we approach the culmination of our journey, we’ll dive into advanced topics. Under my watchful eye, you’ll uncover the art of customizing the WordPress admin area, integrating third-party APIs, and other advanced feats that set you apart as a true WordPress theme virtuoso.
19. Practice and Build Projects:
Dear apprentices, this is where the magic truly happens. Armed with the wisdom you’ve gained, you’ll embark on practical projects. From themes featuring custom fields to page builder wonders, these projects will solidify your skills and prepare you for the creative challenges that lie ahead.
20. Resources and Communities:
Congratulations, adept learners! As you near the end of this remarkable journey, remember that learning never truly ends. Engage with WordPress communities, tap into valuable resources, and continue to evolve as a developer. With your newfound knowledge, the digital world is yours to shape and transform.
In closing, you’ve journeyed through the intricate realms of WordPress theme development, armed with the potent combination of technical prowess and creative finesse. From weaving HTML, CSS, and JavaScript into harmonious symphonies to breathing life into templates, widgets, and custom post types, you’ve forged a path of innovation.
As you bid adieu to this learning voyage, remember that you’ve acquired the alchemical art of crafting responsive, accessible, and optimized themes. Your journey doesn’t end here; it’s a mere prologue to the stories you’ll tell through your digital creations.
Embrace the challenges of dynamic content, wield the brush of interactivity, and wield the tools of customization with confidence. Continue to learn, evolve, and explore. The WordPress universe eagerly anticipates the footprints you’ll leave, the designs you’ll unveil, and the experiences you’ll fashion.
So go forth, intrepid developer, and paint the digital canvas with your imagination. Your journey has just begun, and the possibilities are as vast as the open codebase. Onward to the next adventure! 🎨🌟
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Sass Basics: Control Directives and Expressions
If you have used Sass for while or looked at the code of a framework like Foundation, you will notice a lot of advanced features used in mixins. These mixins use control directives such as @if and @for to accomplish things like setting up classes for grid systems.
Continuing with the basics of Sass we will discuss these control directives and see how you can use them in your projects. You may not ever find a need to use these control directives but its always good to know what tools are at your disposal.
if()
This is a little different in that it is not a control directive but a built in function in Sass. Not the same as the @if directive, if() allows you to test for a condition and return one of two possible values. The condition we test for is either true or false. For example:
@mixin test($condition) {
$color: if($condition, blue, red);
color:$color
}
.firstClass {
@include test(true);
}
.secondClass {
@include test(false);
}
--ADVERTISEMENT--
This compiles to:
.firstClass {
color: blue;
}
.secondClass {
color: red;
}
The if() function arguments are the condition to test, true result, and false result Any value other than false or null is considered true. In the example above we can substitute a number for true and get the same result.
.firstClass {
@include test(1);
}
@if
The @if directive takes an expression and returns styles if it results in anything other than false or null. For example:
@mixin txt($weight) {
color: white;
@if $weight == bold { font-weight: bold;}
}
.txt1 {
@include txt(none);
}
.txt2 {
@include txt(bold);
}
Which gives us:
.txt1 {
color: white;
}
.txt2 {
color: white;
font-weight: bold;
}
We can expand on the @if directive with multiple @else if statements and one final @else. This way we can test for multiple conditions. We can expand on the last example like this.
@mixin txt($weight) {
color: white;
@if $weight == bold { font-weight: bold;}
@else if $weight == light { font-weight: 100;}
@else if $weight == heavy { font-weight: 900;}
@else { font-weight: normal;}
}
.txt1 {
@include txt(bold);
}
.txt2 {
@include txt(light);
}
.txt3 {
@include txt(heavy);
}
.txt4 {
@include txt(none);
}
.txt5 {
@include txt(normal)
}
This in turn gives us
.txt1 {
color: white;
font-weight: bold;
}
.txt2 {
color: white;
font-weight: 100;
}
.txt3 {
color: white;
font-weight: 900;
}
.txt4 {
color: white;
font-weight: normal;
}
.txt5 {
color: white;
font-weight: normal;
}
I have included the last two classes to demonstrate how the addition of @else changes how the @if directive works. In the first example without using bold as the argument it would not give us a font-weight. When you add @else, any argument that doesn’t match the other @if or @else if’s will get the styles of the @else statement. That’s why .txt4 and .txt5 have the same font-weight.
@for
The @for directive lets you output styles in a loop. The directive can be used either as a start through end or start to end. The difference is that start through end includes the ending number while start to end does not include the end number. The @for statement uses a variable to track the loop against the ranges. If we want to count down instead of up we would make our start number larger than our end number. Lets look at how we setup the @for statement.
@for $i from 1 through 12 {
.col-#{$i} { width: 100/12 * $i;}
}
Here is a @for statement we could use to setup columns for a grid system. The @for is followed by the variable, in this case $i. We then follow that with from and our starting (1) through ending (12) number. On each repetition of the loop we generate a style. Notice how we use interpolation to use the variable as part of the classes we generate.
.col-1 {
width: 8.33333;
}
.col-2 {
width: 16.66667;
}
.col-3 {
width: 25;
}
.col-4 {
width: 33.33333;
}
I didn’t include all of the styles generated by the @for, as they go all the way up to 12. As you can see on each pass of the loop a style was created with the value of the variable added to the class name. We also did a calculation based on the variable to generate the proper width.
@each
The @each directive uses a list or map instead of starting and ending values. On each pass of the loop the variable gets assigned a value from the list or map.
@each $usr in bob, john, bill, mike {
.#{$usr}-avatar {
background-image: url('/img/#{$usr}.png');
}
}
The @each directive is followed by our variable, $usr. After that we have our list that will be assigned to the $usr variable. We also could have used a map as our argument. After that we use interpolation to build our class as well as displaying the correct picture.
.bob-avatar {
background-image: url("/img/bob.png");
}
.john-avatar {
background-image: url("/img/john.png");
}
.bill-avatar {
background-image: url("/img/bill.png");
}
.mike-avatar {
background-image: url("/img/mike.png");
}
If we were going to use a map we have to change our @each statement and use multiple assignment. We can use a map in the @each statement like this.
$ppl: ( usr1:bob, usr2:john, usr3:bill, usr4:mike );
@each $key, $usr in $ppl {
.#{$usr}-avatar {
background-image: url('/img/#{$usr}.png');
}
}
We have to add a second variable to hold the key of each value. If we didn’t, instead of getting the same result as the last example, our keys and values will be in the styles we generate. We can also use multiple assignments on lists.
$alt: alert, yellow, red;
$sub: submit, white, green;
$bck: back, blue, transparent;
@each $type, $txt, $back in $alt,$sub,$bck {
.#{$type}-button {
color: $txt;
background-color: $back;
}
}
Here we are taking multiple lists and using them to build our classes. As we make a pass over each list the items in the list are assigned to the variables in the @each statement. This gives us:
.alert-button {
color: yellow;
background-color: red;
}
.submit-button {
color: white;
background-color: green;
}
.back-button {
color: blue;
background-color: transparent;
}
@while
The @while directive outputs styles until the statement is false. Similar to the @for directive, the @while directive allows us more flexibility in our loops. I can rewrite the @for directive from above as a @while loop.
$x:1;
@while $x < 13 {
.col-#{$x} { width: 100/12 * $x;}
$x: $x + 1;
};
Instead of setting our range inside of our statement like the @for directive, we set a value in our variable. Then we use that value as our test against the @while statement. In this case we said that as long as $x is less than 13, output styles. Once we reach 13 the statement will be false and the loop will stop. The key thing to remember is to increment your variable or your loop will never end. As you can see the example is adding 1 to our variable until it reaches 13.
Conclusion
Sass really includes a lot of powerful features that make our front-end development easier. Although the control directives are powerful, unless you are building a large framework you may not find a lot of uses for them. Like I said before the important thing is to know the tools available to you. Maybe one day you will find a use for one of these control directives.
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...
check image
Chris-2k
08-18-2012, 12:29 AM
hi
i have a func to check if an image is valid, works perfect for upload from pc an url: function checkitsaValidImage($files, array $aConfig) {
$imageInfo = getimagesize($files);
$sResult = '';
if(!$imageInfo) {
trigger_error('Error not an image.');
}
if(!empty($imageInfo) && !in_array($imageInfo['mime'], $aConfig['allowed_mime_types'])) {
trigger_error('Error invalid file.');
} else if($imageInfo[0] > $aConfig['max_width'] || $imageInfo[1] > $aConfig['max_height']) {
trigger_error('Error image size too big.');
} else if(filesize($files) > configMaxSize($aConfig['max_filesize'])) {
trigger_error('Error file size too big.');
}
else
{
$sResult = image_type_to_extension($imageInfo[2], true);
}
return $sResult;
}
only issue is the filesize(); func WILL not check URLs/remote, erm i'm wondering can a globalFS(); func that can get remote/URLs AND pc uploads and then call it in place of filesize();?
Lamped
08-18-2012, 12:33 AM
filesize() can check some remote URLs but your ISP may have disabled fopen wrappers.
If you need to check URLs, cURL may be your best bet (perhaps custom method of HEAD will still return the content length header) but that's going to be flaky too as some pages just won't tell you.
Chris-2k
08-18-2012, 01:03 AM
I can do it via curl, hmm
can i do;
globalFS()
{
if(filesize($files)) {
}
else
{
// try curl
}
}
an then call it instead of filesizze()?
byrondallas
08-18-2012, 12:46 PM
This is what I use to check size of remote images and it seems to work pretty good:
$string = file_get_contents($url);
$length = strlen($string);
Chris-2k
08-18-2012, 09:33 PM
hi guys,
can u tell me where nim goin wrong[;
function handleSize($files)
{
if(filesize($files))
{
// It's a local file.
} else
{
// It's remote file.
$ch = curl_init($files); // Get the filesize using curl
curl_setopt($ch, CURLOPT_NOBODY, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
$data = curl_exec($ch);
curl_close($ch);
if ($data === false)
{
echo "<p align='center' classs='select_text'>Unable to upload your image as you didn't provide a valid URL</p>";
exit;
}
$remoteSize = 'unknown';
$status = 'unknown';
if (preg_match('/^HTTP\/1\.[01] (\d\d\d)/', $data, $matches))
{
$status = (int)$matches[1];
}
if (preg_match('/Content-Length: (\d+)/', $data, $matches))
{
$remoteSize = (int)$matches[1];
}
}
}
im gettin Unable to upload your image as you didn't provide a valid URL
AndrewGSW
08-18-2012, 09:44 PM
If you have spaces in the filename:
$url = str_replace(' ', '%20', $files);
$ch = curl_init($url); // Get the filesize using curl
Chris-2k
08-18-2012, 09:58 PM
Sorry Andrew, I dont follow................
AndrewGSW
08-19-2012, 01:21 AM
Sorry Andrew, I dont follow................
Spaces in the URL need to be replaced with a %20.
mentioned in the user contributed notes of the docs (http://www.php.net/manual/en/function.curl-init.php).
Chris-2k
08-19-2012, 02:29 PM
oh yea thx m8, some people misread my question....
I am not looking HOW TO do this, rather A WAY to do it... I want to use curl, all funcs i've written til now are fail, my final attempt:
function handleSize($files)
{
if($files)
{
// It's a local file.
$size = filesize($files);
} else
{
// It's remote file.
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
curl_setopt($ch, CURLOPT_HEADER, TRUE);
curl_setopt($ch, CURLOPT_NOBODY, TRUE);
$data = curl_exec($ch);
$size = curl_getinfo($ch, CURLINFO_CONTENT_LENGTH_DOWNLOAD);
curl_close($ch);
}
return $size;
}
now for my chck func can i do:
if(handleSize($files) > $size)
{
// error
}
Chris-2k
08-19-2012, 05:27 PM
anyone can help?
AndrewGSW
08-19-2012, 06:28 PM
You seem to have introduced the variable $url:
// It's remote file.
$ch = curl_init($url);
If you are adopting my code sample then you need both lines.
I am not sure about your distinction between HOW TO and A WAY to, but the documentation is quite clear in insisting that spaces should be removed from the url. But perhaps your url doesn't have any spaces.
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| 0.945162 |
View Javadoc
1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18 package org.apache.bcel.generic;
19
20 /**
21 * FCONST - Push 0.0, 1.0 or 2.0, other values cause an exception
22 *
23 * <PRE>Stack: ... -> ..., </PRE>
24 *
25 * @version $Id: FCONST.html 1021978 2017-12-09 17:38:21Z ggregory $
26 */
27 public class FCONST extends Instruction implements ConstantPushInstruction {
28
29 private float value;
30
31
32 /**
33 * Empty constructor needed for Instruction.readInstruction.
34 * Not to be used otherwise.
35 */
36 FCONST() {
37 }
38
39
40 public FCONST(final float f) {
41 super(org.apache.bcel.Const.FCONST_0, (short) 1);
42 if (f == 0.0) {
43 super.setOpcode(org.apache.bcel.Const.FCONST_0);
44 } else if (f == 1.0) {
45 super.setOpcode(org.apache.bcel.Const.FCONST_1);
46 } else if (f == 2.0) {
47 super.setOpcode(org.apache.bcel.Const.FCONST_2);
48 } else {
49 throw new ClassGenException("FCONST can be used only for 0.0, 1.0 and 2.0: " + f);
50 }
51 value = f;
52 }
53
54
55 @Override
56 public Number getValue() {
57 return new Float(value);
58 }
59
60
61 /** @return Type.FLOAT
62 */
63 @Override
64 public Type getType( final ConstantPoolGen cp ) {
65 return Type.FLOAT;
66 }
67
68
69 /**
70 * Call corresponding visitor method(s). The order is:
71 * Call visitor methods of implemented interfaces first, then
72 * call methods according to the class hierarchy in descending order,
73 * i.e., the most specific visitXXX() call comes last.
74 *
75 * @param v Visitor object
76 */
77 @Override
78 public void accept( final Visitor v ) {
79 v.visitPushInstruction(this);
80 v.visitStackProducer(this);
81 v.visitTypedInstruction(this);
82 v.visitConstantPushInstruction(this);
83 v.visitFCONST(this);
84 }
85 }
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What is 35/57 as a percent?
A fraction is one representation of a number that is only part of a whole. Another way to represent this is in percentages. In this guide, we will show you how to convert 35/57 into a percentage.
Solution: 35/57 as a percent is 61.404%
Methods
Method 1 – Converting 35/57 Into a Percentage:
First, let’s go over what a fraction represents. The number above the line is called the numerator, while the number below the line is called the denominator. The fraction shows how many portions of the number there are, in relation to how many would make up the whole. For instance, in the fraction 35/57, we could say that the value is 35 portions, out of a possible 57 portions to make up the whole.
For percentages, the difference is that we want to know how many portions there are if there are 100 portions possible. “Percent” means “per hundred”. For example, if we look at the percentage 25%, that means we have 25 portions of the possible 100 portions. Re-writing this in fraction form, we see 25/100.
The first step in converting a fraction to a percentage is to adjust the fraction so that the denominator is 100. To do this, you first divide 100 by the denominator:
10057=1.754\frac{100}{57} = 1.754
We can then adjust the whole fraction using this number, like so:
351.754571.754=61.404100\frac{35*1.754}{57*1.754} = \frac{61.404}{100}
Reading this as a fraction, we can say that we have 61.404 portions of a possible 100 portions.
Re-writing this as a percentage, we can see that 35/57 as a percentage is 61.404%
Method 2 – Converting 35/57 Into a Percentage Using Decimals:
Another way we can convert 35/57 into a percentage is to first convert 35/57 into a decimal. We can do this by simply dividing the numerator by the denominator:
3557=0.614\frac{35}{57} = 0.614
Once we have the answer, we can multiply the new decimal by 100 to get the percentage:
0.614 × 100 = 61.404
As you can see, we get the same answer as the first method and find that 35/57 as a percentage is 61.404%.
Now you know of two different ways to convert 35/57 into a percentage! While converting using a decimal takes fewer steps, you first need to master converting fractions into decimals. Try out both methods and see which one works best for you!
Practice more percentage problems!
Practice makes perfect so why not check out some of other problems where you can convert a fraction to a percentage?
What is 42/7 as a percent?
What is 52/75 as a percent?
What is 25/53 as a percent?
What is 47/12 as a percent?
What is 70/43 as a percent?
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Integrating Machine Learning with Quantum Computing
Machine Learning with Quantum Computing
5 min read
Reading Time: 5 minutes
Technology is developing to an extent that has never been seen before, and combining quantum computing and machine learning is pushing the boundaries of creativity. Quantum computing and machine learning (ML) have come together due to the search for more potent and effective computing. Imagine using quantum mechanics with artificial intelligence to solve difficult issues previously thought unsolvable. Join us as we get into the fascinating intersection of these two advanced technologies and explore the endless possibilities that lie ahead.
Basics of Machine Learning & Quantum Computing:
One area of artificial intelligence (AI) is machine learning (ML), which focuses on creating algorithms and statistical models that enable computers to perform specific tasks without explicit instructions. Instead, these systems learn and make decisions based on patterns and inferences derived from data. ML encompasses a variety of techniques, including neural networks, decision trees, and reinforcement learning, each customized to understanding complex data structures and making intelligent predictions or decisions based on inputs.
Quantum computing radically processes information in different ways, utilizing the ideas of quantum physics. At its core, quantum technology uses quantum bits, or qubits, which, unlike classical bits that are either 0 or 1, can exist simultaneously in multiple states through the phenomenon of superposition. Quantum computing stands out for its potential to perform complex calculations much more quickly than the best supercomputers available today, promising breakthroughs in cryptography, materials science, and complex system modeling.
Can Quantum Computing Be Used for Machine Learning?
Integrating quantum technology into machine learning is not just a possibility; it’s a burgeoning reality that promises to redefine the capabilities of AI systems. The foundation of quantum computing is quantum mechanics, leveraging phenomena like superposition and entanglement to perform computations at speeds unattainable by classical computers. This quantum advantage can significantly enhance machine learning algorithms, particularly in processing vast datasets and solving complex optimization problems more efficiently.
Quantum Speed-up in Machine Learning Algorithms:
Quantum computing technology offers a ‘quantum speed-up’ for specific machine learning tasks. For instance, quantum algorithms can expedite the training of machine learning models by quickly sifting through massive datasets, identifying patterns, and making predictions with a level of efficiency that classical computing struggles to match. This capability is especially pertinent in fields like drug discovery, climate modeling, and financial modeling, where the capacity for analysis and insight-gathering from large volumes of data can lead to innovations.
Is Quantum Machine Learning the Future?
The potential of quantum machine learning (QML) stretches beyond mere speculation—it heralds a future where the combination of quantum technology and machine learning algorithms unlocks unprecedented possibilities. Quantum machine learning can solve some of traditional AI’s most persistent challenges, such as handling complex, multidimensional data and scaling AI systems to tackle more complicated problems.
Bridging Complex Systems with Quantum AI:
The connection between quantum computing and artificial intelligence, or quantum AI, is set to change how we approach tackling complex system problems. By harnessing the inherent capabilities of quantum bits (qubits) to exist in multiple states simultaneously, quantum AI can perform calculations that would take classical systems years in mere seconds. This leap in computational power and speed makes quantum machine learning an invaluable tool in advancing research and innovation across various scientific and industrial domains.
The Potential of Integrating Machine Learning with Quantum Computing:
Integrating machine learning (ML) with quantum computing is like combining the power of a super-fast brain with an incredibly vast library, offering the chance to speed up how we solve big problems and make decisions. This powerful mix could make computers learn things faster, solve super complex puzzles like planning the best routes for delivery trucks, or figure out new medicines quicker than ever before. It’s all about making algorithms run faster and tackle jobs too tough for regular computers, like predicting stock market changes super accurately or customizing medical treatments for each person’s unique needs. Though we are still figuring out how to make all this work smoothly in the real world, the possibilities are huge, promising a future where these technologies change everything from how we get around to how we stay healthy.
Applications of Integrating Machine Learning with Quantum Computing:
Merging machine learning with quantum computing will change many industries by making computers smarter and faster. For example, in medicine, this combo could speed up how we find new drugs, making it quicker to respond to diseases. In finance, it could help predict market changes more accurately, helping businesses and investors make better decisions. It could also lead to better climate forecasts, helping us better understand and prepare for environmental changes. Additionally, this powerful mix could improve everything from how goods are delivered to making routes more efficient and strengthening online security. By combining the problem-solving abilities of machine learning with the super-fast processing of quantum computing, we are looking at a future where we can tackle some of the biggest challenges more efficiently and come up with solutions we have yet to think of.
The Exciting Future of Integrating Machine Learning with Quantum Computing:
The future of combining machine learning (ML) with quantum computing is incredibly promising, marking the start of a new technological era. This combination is expected to greatly speed up how we process huge amounts of data and resolve complicated issues that are now too challenging, like creating new medicines faster or making more accurate climate predictions. Although we face challenges like building more reliable quantum systems and addressing ethical concerns, the potential benefits are vast. From personalized medical treatments based on our genetic makeup to strategies for protecting our environment, the fusion of ML and quantum computing could lead to significant advancements across many areas of our lives as long as we continue to innovate and tackle these challenges head-on.
Conclusion:
The journey of integrating machine learning with quantum computing is at its nascent stages, yet it is controlled to get the next wave of advancements in technology and science. At the beginning of this fresh era, the collaborative power of quantum technology and machine learning algorithms beckons a future brimming with potential. From transforming data analysis to enhancing predictive modeling, the union of these two fields promises to unfold a new era of quantum artificial intelligence- a future where the boundaries of what’s possible are continually expanded. As researchers and technologists forge ahead, the integration of machine learning with quantum technology marks a significant milestone in our technological progress and lights the path toward a future where the mysteries of the quantum and the digital worlds unite.
FAQ:
1. What is Quantum Computing?
Quantum computing uses quantum bits or qubits and harnesses the unique properties of quantum physics to perform complex calculations more efficiently than traditional computing.
2. How Does Machine Learning Benefit from Quantum Computing?
Machine learning benefits from quantum computing through significantly faster data processing and analysis capabilities. It can enhance the efficiency of algorithms, especially in tasks like pattern recognition, optimization, and predictive modeling.
3. Can Quantum Computing Solve All Machine Learning Problems?
While quantum computing offers immense potential, other solutions exist for machine learning challenges. It particularly suits solving specific types of problems involving large datasets and complex calculations.
4. What Are Some Potential Applications of Integrating Machine Learning with Quantum Computing?
Applications include:
• Drug discovery by simulating molecular interactions,
• Financial modeling through improved market prediction algorithms,
• Climate simulations by processing complex environmental data and
• Medicine customizes to suit specific genetic profiles, providing personalized treatments.
5. What Are the Main Challenges in Integrating Machine Learning with Quantum Computing?
Key challenges include:
• The technical difficulty of building stable quantum systems,
• Integrating these systems with existing machine learning frameworks and
• Ethical considerations related to data privacy and the potential misuse of powerful quantum AI systems.
Published: April 30th, 2024
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看透Spring MVC源代码分析与实践 (pdf)
书名：看透Spring MVC源代码分析与实践. 大小：57.77MB. 页数：328页. 格式：PDF
下载地址：
<!–TePass start–>
链接：https://pan.baidu.com/s/1xdF1vLvhAxcgHseCS80Rcw?pwd=5m5d
提取码：5m5d
路径.jpg
<!–TePass end–>
主要目录：
第一篇 网站基础知识
第1章 网站架构及 其演变过程
1.1 软件的三大类型
1.2 基础的结构并不简
1.3 架构演变的起点
1.4 海量数据的解决方案
1.4.1 缓存和页面静态化
1.4.2 数据库优化
1.4.3 分离活跃数据
1.4.4 批量读取和延迟修改
1.4.5 读写分离
1.4.6 分布式数据库
1.4.7 NoSQL和Hadoop
1.5 高并发的解决方案
1.5.1 应用和静态资源分离
1.5.2 页面缓存
1.5.3 集群与分布式
1.5.4 反向代理
1.5.5 CDN
1.6 底层的优化
第2章 常见协议和标准
2.1 DNS 协议
2.2 TCP/IP 协议与Socket
2.3 HTTP 协议
2.4 Servlet 与Java Web开发
第3章 DNS 的设置
3.1 DNS 解析
3.2 Windows 7设置DNS服务器
3.3 Windows 设置本机域名和IP的对应关系
第4章 Java 中Socket的用法
4.1普通Socket的用法
4.2 NioSocket 的用法
第5章自己动手实现HTTP协议
第6章详解 Servlet
6.1 Servlet 接口
6.2 GenericerServlet
第7章Tomcat 分析
7.1 Tomcat 的顶层结构及启动过程
7.1.1 Tomcat 的顶层结构
7.1.2 Bootstrap 的启动过程
7.1.3 Catalina 的启动过程
7.1.4 Server的启动过程
7.1.5 Service 的启动过程
7.2 Tomcat 的生命周期管理
7.2.1 Lifecycle 接口
7.2.2 LifecycleBase
7.3 Container 分析
7.3.1 ContainerBase 的结构
7.3.2 Container 的4个子容器
7.3.3 4 种容器的配置方法
7.3.4 Container 的启动
7.4 Pipeline-Value 管道
7.4.1 Pipeline-Value 处理模式
7.4.2 Pipeline Value的实现方法
7.5 Connector 分析
7.5.1 Connector 的结构
7.5.2 Connector 自身类
7.5.3 ProtocolHandler
7.5.4 处理 TCP/IP协议的Entpoint
7.5.5 处理 HTTP协议的Processor
7.5.6 适配器Adapter
第二篇 俯视Spring MVC
8.2 Spring MVC最简单的配置
8.2.1 在 web.xml中配置Servlet
8.2.2 创建 Spring MVC的xml配咒文件
8.2.3 创建 Controller和view
8.3 关联 spring源代码
第9章 创建Spring MVC之器
9.1 整体结构介绍
9.2 HttpServletBean
9.3 FrameworkServlet
9.4 DispatcherServlet
第10章 Spring MVC
10.1 HttpServletBean
10.2 FrameworkServlet
10.3 DispatcherServlet
10.4 doDispatch 结构
第三篇 Spring MVC组件分析
第11章 组件概览
11.1 HandlerMapping
11.2 HandlerAdapter
11.3 HandlerExceptionResolver
11.4 ViewResolver
11.5 RequestToViewNameTranslator
11.6 LocaleResolver
11.7 ThemeResolver
11.8 MultipartResolver
11.9 FlashMapManager
第12章 HandlerMapping
12.1 AsrtracthanderMapping
12.1.1 创建 AbstractHandlerMapping之器
12.1.2 AbtractHandlerMapping之用
12.2 AbstractUrlHandlerMapping系列
12.2.1 AbstractUrlHandlerMapping
12.2.2 SimpleUrlHandlerMapping
12.2.3 AbstractDetectingUrlHandlerMapping
12.3 AbstractHandlerMethodMapping
12.3.1 创建 AbstractHandlerMethodMapping系列之器
12.3.2 AbstractHlandlerMethodMapping系列之用
第13章 HandlerAdapter
13.1 RequestMappingHandlerAdapter概述
13.2 RequestMappingHandlerAdapter自身结构
13.2.1 创建RequestMappingHandler-Adapter之器
13.2.2 RequestMappingHandlerAdapter之用
13.3 ModelAndViewContainer
13.4 ScssionAttributesHandler和SessionAttributeStore
13.5 ModelFactory
13.5.1 初始化 Model
13.5.2 更新Model
13.6 ServletInvocableHandlerMethod
13.6. 1 HandlerMethod
13.6.2 InvocableHandlerMethod
13.6.3 ServetInvocableHandler
13.7 HandlerMethodArgumentResolver
13.8 HandlerMethodReturmValueHandler
第14章 View Resolver
14.1 ContentNegotiatingViewResolver
14.2 AbstractCachingViewResolver系列
第15章 RequestToViewNameTranslator
第16章 HandlerExceptionResolver
16.1 AbstractHandlerExceptionResolver
16.2 ExceptionHandlerExceptionResolver
16.3 DefaultHandlerExceptionResolver
16.4 ResponseStatusExceptionResoler
16.5 SimpleMappingExceptionResolver
第17章 MultipartResolver
17.1 StandardServletMultipartResolver
17.2 CommonsMultipartResolver
第18章 LocaleResolver
第19章 ThemeResolver
第20章 FlashMapManager
第四篇 总结与补充
21.1 Spring MVC原理总结
21.2 实际跟踪一个请求
第22章 异步请求
22.1 Servlet 3.0对异步请求的支持
22.1.1 Servlet 3.0处理异步请求实例
22.1.2 异步 请求监听器AsyncListener
22.2 Spring MVC中的异步请求
22.2.1 Spring MVC中异步请求相关组件
22.2.2 Spring MVC对异步请求的支持
22.3 WebAsyncTask 和Callable类型异步请求的处理过程及用法
22.2.4 DeferredResult 类型异步请求的处理过程及用法
22.2.5 ListenableFuture 类型异步请求的处理过程及用法
目录图示：
看透Spring MVC源代码分析与实践1.jpg
看透Spring MVC源代码分析与实践2.jpg
看透Spring MVC源代码分析与实践3.jpg
看透Spring MVC源代码分析与实践4.jpg
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| 0.998365 |
Shaokan Shaokan - 1 year ago 164
C# Question
c# razor mvc textboxfor in foreach loop
how is it possible to retrieve data from
TextBoxFor
helper within a foreach loop? I mean:
in the view:
foreach(Language l in ViewBag.Languages){
<td>@l.lang</td>
<td>@Html.TextBoxFor(model => model.Name)
}
and how can I retrieve it in the controller once posted?
MyModel.Name //this returns the value of the first textbox within the foreach loop
By the way model.Name is defined in MyModel.cs as:
public string Name { get; set; }
Answer Source
You should be able to use the ModelBinder in your action by using:
public ActionResult MyAction(string[] name)
{
foreach (var item in name)
{
// Process items
}
}
Where name is the name automatically given to the text-boxes by Html.TextBoxFor().
Edit: If you wish to change the parameter name from name to something more descriptive, you can achieve this by using Html.TextBox, albeit with a loss of stong-typing:
@Html.TextBox("SomeMoreDescriptiveName", Model.Name);
And then in your controller action:
public ActionResult MyAction(string[] SomeMoreDescriptiveName)
{
...
}
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| 0.999517 |
Bug#851171: "ImportError: No module named lldb.embedded_interpreter" when typing "p a"
Askar Safin safinaskar at mail.ru
Thu Jan 12 17:32:28 UTC 2017
Package: lldb-3.9
Version: 1:3.9.1-2
Severity: normal
Steps to reproduce:
* Create fresh minimal debian sid
* Create apt.conf with APT::Install-Recommends "false";
* Install lldb-3.9 and clang-3.9
* Then:
root at ideal-os:/# cat o.cpp
#include <vector>
int
main (void)
{
std::vector<int> a;
a.push_back (0);
}
root at ideal-os:/# clang++-3.9 -g -o o o.cpp
root at ideal-os:/# lldb-3.9 ./o
(lldb) target create "./o"
Current executable set to './o' (x86_64).
(lldb) b main
Breakpoint 1: where = o`main + 12 at //o.cpp:6, address = 0x000000000040091c
(lldb) r
Process 527 launched: './o' (x86_64)
Process 527 stopped
* thread #1: tid = 527, 0x000000000040091c o`main + 12 at //o.cpp:6, name = 'o', stop reason = breakpoint 1.1
frame #0: 0x000000000040091c o`main + 12 at //o.cpp:6
3 int
4 main (void)
5 {
-> 6 std::vector<int> a;
7 a.push_back (0);
8 }
(lldb) n
Process 527 stopped
* thread #1: tid = 527, 0x0000000000400928 o`main + 24 at //o.cpp:7, name = 'o', stop reason = step over
frame #0: 0x0000000000400928 o`main + 24 at //o.cpp:7
4 main (void)
5 {
6 std::vector<int> a;
-> 7 a.push_back (0);
8 }
(lldb)
Process 527 stopped
* thread #1: tid = 527, 0x0000000000400945 o`main + 53 at //o.cpp:8, name = 'o', stop reason = step over
frame #0: 0x0000000000400945 o`main + 53 at //o.cpp:8
5 {
6 std::vector<int> a;
7 a.push_back (0);
-> 8 }
(lldb) p a
Traceback (most recent call last):
File "<string>", line 1, in <module>
ImportError: No module named lldb.embedded_interpreter
Traceback (most recent call last):
File "<string>", line 1, in <module>
NameError: name 'run_one_line' is not defined
Traceback (most recent call last):
File "<string>", line 1, in <module>
NameError: name 'run_one_line' is not defined
Traceback (most recent call last):
File "<string>", line 1, in <module>
NameError: name 'run_one_line' is not defined
Traceback (most recent call last):
File "<string>", line 1, in <module>
NameError: name 'run_one_line' is not defined
Traceback (most recent call last):
File "<string>", line 1, in <module>
NameError: name 'run_one_line' is not defined
Traceback (most recent call last):
File "<string>", line 1, in <module>
NameError: name 'run_one_line' is not defined
(std::vector<int, std::allocator<int> >) $0 = size=1 {
std::_Vector_base<int, std::allocator<int> > = {
_M_impl = {
_M_start = 0x0000000000615c20
_M_finish = 0x0000000000615c24
_M_end_of_storage = 0x0000000000615c24
}
}
}
(lldb)
If I install python-lldb-3.9, it works. :)
-- System Information:
Debian Release: stretch/sid
APT prefers unstable
APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)
Kernel: Linux 4.8.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
Versions of packages lldb-3.9 depends on:
ii libc6 2.24-8
ii libgcc1 1:6.3.0-2
ii liblldb-3.9 1:3.9.1-2
ii libllvm3.9 1:3.9.1-2
ii libncurses5 6.0+20161126-1
ii libpython2.7 2.7.13-1
ii libstdc++6 6.3.0-2
ii libtinfo5 6.0+20161126-1
ii llvm-3.9-dev 1:3.9.1-2
lldb-3.9 recommends no packages.
Versions of packages lldb-3.9 suggests:
pn python-lldb-3.9 <none>
-- no debconf information
More information about the Pkg-llvm-team mailing list
|
__label__pos
| 0.76478 |
Tighter complexity for problem 19.3 (Paint a Boolean Matrix)
#1
I have some issues when trying to understand the space complexity of problem 19.3 (Paint a Boolean Matrix).
The book says the space complexity of BFS is O(m+n) because there are at most O(m+n) vertices that are at the same distance from a given entry. However, I think a tighter estimation may be O(sqrt(m^2 + n^2)). For example, when the paint position starts at the corner and all the matrix is true, the max queue size is the diagonal, sqrt(m^2 + n^2). Also, when beginning at the center, the max queue size is twice of the diagonal, 2*sqrt(m^2 + n^2).
Moreover, the book does not say about the space complexity of DFS solution which I assume also the same with the BFS, O(m+n). However, the space complexity of the DFS is O(m*n), when the paint position starts at the corner and all the matrix is true. It would be much clearer if the book have a sentence about the space complexity.
0 Likes
#2
Hey Duc,
I was thinking this question for a while—how many elements in queue simultaneously? I think the maximum is about O(2m + 2n), basically it is the border of the region. Although I can say the traversing order plays an important parameter here, I think our space complexity analysis is correct but the text definitely needs some overhauls.
Also, for your question on DFS space complexity, I think the space complexity shall be O(m*n) as you said if the calling stack contains all elements of all elements. For example, DFS recursive calls in spiral order.
0 Likes
#3
Hi @tsunghsienlee , I came across this StackOverflow answer
which describes the space complexity for BFS on a matrix as Theta(m * n). The explanation there is that eventually we will have all the leaves of the graph in the queue. This made me confused about what would be the worst case complexity for using BFS on 2D matrix. Does that sound right to you? If yes, then does it change the BFS space complexity for this question in the book as well?
0 Likes
|
__label__pos
| 0.997124 |
Sign up ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.
I'm going through an examples section (on improper integrals) but I got lost at this bit:
$$\lim_{t\to-\infty} \frac{t}{e^{-t}} = \lim_{t\to-\infty}\frac{1}{-e^{-t}}.$$
I think it's a simple algebra trick but I don't see how the right hand side came to be. How did it become $1/-e^{-t}$?
share|cite|improve this question
You could verify by applying ten times the same rule (see the answers) that $\dfrac{e^x}{x^{10}}$ tends to $\infty$ with $x$. – Américo Tavares Nov 15 '10 at 8:54
2 Answers 2
up vote 4 down vote accepted
It is an application of l'Hôpital's rule.
share|cite|improve this answer
Doh! Thank you. I totally forgot about taking the derivatives of f(x)/g(x). – ShrimpCrackers Nov 15 '10 at 4:47
The ratio of functions which you provide are an example of an indeterminate form at the limit point. L'Hospital's rule allows you to differentiate the numerator and denominator independently and then take the limit, giving the intended limit. For your example, \begin{eqnarray} \lim_{t \to -\infty} \frac{t}{e^{-t}} \stackrel{L.'H.}{=} \lim_{t \to -\infty} \frac{1}{-e^{-t}} = 0. \end{eqnarray}
share|cite|improve this answer
5
It is $t\to-\infty$, not $t\to\infty$. If it were $t\to\infty$, it would not be an indeterminate form. – Jonas Meyer Nov 15 '10 at 5:04
Thanks. I corrected the typo. – user02138 Nov 15 '10 at 17:20
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__label__pos
| 0.980359 |
テスト（微分積分）
微分積分学演習第二（U クラス）小テスト略解（1/15）
1
1
1
t13-1. f (x, y, z) = 2 + 2 + 2 , g(x, y, z) = xyz − 1 とする。束縛条件
x
y
z
g(x, y, z) = 0 のもとで f が極値を取るような点の候補を、Lagrange の乗数
法を用いて求めよ。
(
∇f (x, y, z) = −2
1 1 1
, ,
x3 y 3 z 3
)
,
∇g(x, y, z) = (yz, xz, xy)
となる。A = {(x, y, z) ∈ R ; g(x, y, z) = 0} とおく。
∇g(x, y, z) = g(x, y, z) = 0 となる (x, y, z) があれば、
それが A の特異点である。∇g = 0 より yz = 0 が分かるが、このとき
g = 0 − 1 ̸= 0 となる。g(0, 0, 0) = −1 ̸= 0 となるので、(0, 0, 0) は A の特異
点ではありえない。つまり、特異点は存在しない。
■Lagrange の乗数法
特異点がないので、
∇f (x, y, z) = λ∇g(x, y, z),
λ = −2
(x, y, z) = (1, 1, 1), (1, −1, −1), (−1, 1, −1), (−1, −1, 1)
となり、方程式を満たすことも確かめられる。これらが極値を与える点の候
3
g(x, y, z) = 0
となる (x, y, z, λ) があれば、その (x, y, z) が極値の候補である。つまり、方
−2/x3 = λyz
−2/y 3 = λxz
−2/z 3 = λxy
xyz = 1
を解けば良い。xyz ̸= 0 であるから、
−2
= x3 yz = xy 3 z = xyz 3
λ
となる。
である。xyz = 1 ゆえ x2 y 2 z 2 = 1 となるので、
となることが分かる。xyz > 0 であることに注意すると、
解説. まず、f, g の偏微分を計算しておくと、
程式
x2 = y 2 = z 2
x2 = y 2 = z 2 = 1,
配点：2 点
■A の特異点は？
xyz = 1 を代入すると、
補。なお、そこでの f の値は 3 である。
実は、これは極小値である。
t13-2. f (x, y, z) = xyz, g(x, y, z) = x2 + y 2 + z 2 − 1 とする。束縛条件
g(x, y, z) = 0 のもとで f が極値を取るような点の候補を、Lagrange の乗数
法を用いて求めよ。
同様に、三番目の等式より、y 2 = z 2 。つまり、x2 = y 2 = z 2 が分かる。
g = 0 より、x2 = y 2 = z 2 = 1/3 となり、結局
1
(x, y, z) = √ (±1, ±1, ±1) （複号任意）
3
√
となる。いずれの場合も、λ = sgn(xyz)/(2 3) として、方程式を満たすこと
配点：2 点
解説. まず、f, g の偏微分を計算しておくと、
がわかる。
∇f (x, y, z) = (yz, xz, xy) ,
∇g(x, y, z) = (2x, 2y, 2z)
となる。A = {(x, y, z) ∈ R3 ; g(x, y, z) = 0} とおく。
■A の特異点は？
∇g(x, y, z) = g(x, y, z) = 0 となる (x, y, z) があれば、
それが A の特異点である。∇g = 0 より x = y = z = 0 が分かるが、
xyz = 0 の時を考える。g = 0 より、x = y = z = 0 とはならないことに
注意する。x = 0 とすると、yz = 0 ゆえ、y = 0 or z = 0。y = 0 のときは
z ̸= 0 となるが、xy = 2λz であったから、λ = 0 となる。また、g = 0 より、
z 2 = 1 である。つまり、
g(0, 0, 0) = −1 ̸= 0 となるので、(0, 0, 0) は A の特異点ではありえない。つ
(x, y, z, λ) = (0, 0, ±1, 0)
まり、特異点は存在しない。
■Lagrange の乗数法
となる。これは方程式を満たしていることもわかる。x, y, z についての対称
特異点が無いので、
性を考えれば、
∇f (x, y, z) = λ∇g(x, y, z),
g(x, y, z) = 0
(x, y, z, λ) = (±1, 0, 0, 0), (0, ±1, 0, 0)
となる (x, y, z, λ) があれば、その (x, y, z) が極値の候補である。つまり、方
も解となることがわかる。上記で求めた 14 個の点が、極値を与える点の候
程式
補。なお、そこでの f の値は代入すればすぐにわかる。
yz = 2λx
xz = 2λy
xy = 2λz
2
x + y2 + z2 = 1
を解けば良い。場合分けして解くことにする。xyz ̸= 0 の時、
2λ =
yz
xz
xy
=
=
x
y
z
であるから、二番目の等式より y 2 z = x2 z を得る。x で割ると y 2 = x2 と
なる。
√
√
実は、f = 1/(3 3) となる点で極大となり、f = −1/(3 3) となる点で極
小となる。それ以外の点では極値をとらない。
|
__label__pos
| 0.934776 |
Paytm Payment Gateway Integration with PHP
Today, We want to share with you Paytm Payment Gateway Integration with PHP.In this post we will show you wordpress plugin require another plugin, hear for callback url in paytm integration we will give you demo and example for implement.In this post, we will learn about paytm payment gateway integration in android with an example.
Paytm Payment Gateway Integration with PHP
There are the Following The simple About paytm gratification api Full Information With Example and source code.
As I will cover this Post with live Working example to develop How we can integrate Paytm payment gateway using PHP, so the Laravel 6 Paytm Payment Gateway Integration Using PHP is used for this example is following below.
Simple Paytm is a very famous and best way to make payments these some days. To step by step here explain into php Paytm source code integrate Paytm in our popular blog website we need to follow the simple below steps –
Step 1. Paytm create an account
First of all, we need to make an account devloper Like as at Sign Up/Register Paytm Account as well as here retrive our main merchant ID as well Secret Key.
and then we can start PHP source coding in our site to use the Paytm. First of all, we will setting / configure the Paytm with mode of the test credentials to test our source code.
Step 2. configure the Paytm with test credentials
(filename – config.php)
define('PAYTM_ENVIRONMENT', 'TEST'); // PROD for live payment
define('PAYTM_MERCHANT_KEY', 'xxxxxxxxxxxxxxx');
define('PAYTM_MERCHANT_MID', xxxxxxxxxxxxxxxx);
define('PAYTM_MERCHANT_WEBSITE', "WEBSTAGING");
define('PAYTM_REDIRECT_URL', "http://localhost/paytm/Response.php");
$PAYTM_TXN_URL='https://securegw-stage.paytm.in/theia/processTransaction';
if (PAYTM_ENVIRONMENT == 'PROD') {
$PAYTM_TXN_URL='https://securegw.paytm.in/theia/processTransaction';
}
define('PAYTM_TXN_URL', $PAYTM_TXN_URL);
Step 3. create the payment form
Now I shall make a new file(index.php) to make the payment form which will have the amount to be payment/paid as well as other more useful needed details –
READ : Vuejs Creating vue instance inside vue instance
<?php
require_once("config.php");
?>
<html>
<head>
<title>Here Merchant Check Out Page</title>
<meta name="GENERATOR" content="Evrsoft First Page">
</head>
<body>
<h1>Merchant Check Out Page</h1>
<pre>
</pre>
<form method="post" action="Redirect.php">
<table border="1">
<tbody>
<tr>
<th>S.No</th>
<th>Label</th>
<th>Value</th>
</tr>
<tr>
<td>Step : 1</td>
<td><label>Enter SHOP_ORDER_DATA_ID::*</label></td>
<td><input id="SHOP_ORDER_DATA_ID" tabindex="1" maxlength="20" size="20"
name="SHOP_ORDER_DATA_ID" autocomplete="off"
value="<?php echo "ORDS" . rand(10000,99999999)?>">
</td>
</tr>
<tr>
<td>Step : 2</td>
<td><label>Enter Customer Id ::*</label></td>
<td><input id="CUSTOMER_USER_ID" tabindex="2" maxlength="12" size="12" name="CUSTOMER_USER_ID" autocomplete="off" value="CUST001"></td>
</tr>
<tr>
<td>Step : 3</td>
<td><label>PAYTM_IND_ID ::*</label></td>
<td><input id="PAYTM_IND_ID" tabindex="4" maxlength="12" size="12" name="PAYTM_IND_ID" autocomplete="off" value="Retail"></td>
</tr>
<tr>
<td>Step : 4</td>
<td><label>Enter Channel ::*</label></td>
<td><input id="CHANNEL_ID" tabindex="4" maxlength="12"
size="12" name="CHANNEL_ID" autocomplete="off" value="WEB">
</td>
</tr>
<tr>
<td>Step : 5</td>
<td><label>Enter txnAmount*</label></td>
<td><input title="EXT_TXN_DATA_AMOUNT" tabindex="10"
type="text" name="EXT_TXN_DATA_AMOUNT"
value="1">
</td>
</tr>
<tr>
<td></td>
<td></td>
<input type="hidden" name="PAYTM_REDIRECT_URL" value="<?php echo PAYTM_REDIRECT_URL; ?>" />
<td><input value="CheckOut" type="submit" onclick=""></td>
</tr>
</tbody>
</table>
* - Mandatory Fields
</form>
</body>
</html>
Step 4. Redirect.php
Here in this simple HTML form, I have set the form the action=”Redirect.php”, then we will make a new file with this name –
<?php
require_once("config.php");
require_once("encdec_paytm.php");
$liveCurleckSum = "";
$arguments = array();
$SHOP_ORDER_DATA_ID = $_POST["SHOP_ORDER_DATA_ID"];
$CUSTOMER_USER_ID = $_POST["CUSTOMER_USER_ID"];
$PAYTM_IND_ID = $_POST["PAYTM_IND_ID"];
$CHANNEL_ID = $_POST["CHANNEL_ID"];
$EXT_TXN_DATA_AMOUNT = $_POST["EXT_TXN_DATA_AMOUNT"];
$PAYTM_REDIRECT_URL=$_POST['PAYTM_REDIRECT_URL'];
$arguments["MID"] = PAYTM_MERCHANT_MID;
$arguments["SHOP_ORDER_DATA_ID"] = $SHOP_ORDER_DATA_ID;
$arguments["CUSTOMER_USER_ID"] = $CUSTOMER_USER_ID;
$arguments["PAYTM_IND_ID"] = $PAYTM_IND_ID;
$arguments["CHANNEL_ID"] = $CHANNEL_ID;
$arguments["EXT_TXN_DATA_AMOUNT"] = $EXT_TXN_DATA_AMOUNT;
$arguments["WEBSITE"] = PAYTM_MERCHANT_WEBSITE;
$arguments['PAYTM_REDIRECT_URL']=$PAYTM_REDIRECT_URL;
//Here checksum string will return by getChecksumFromArray() function.
$liveCurleckSum = getChecksumFromArray($arguments,PAYTM_MERCHANT_KEY);
?>
<html>
<head>
<title>pakainfo.com - Merchant Check Out Page</title>
</head>
<body>
<center><h1>Please do not refresh this page...</h1></center>
<form method="post" action="<?php echo PAYTM_TXN_URL ?>" name="f1">
<table border="1">
<tbody>
<?php
foreach($arguments as $name => $value) {
echo '<input type="hidden" name="' . $name .'" value="' . $value . '">';
}
?>
<input type="hidden" name="PAYTMSUMDATAHASH" value="<?php echo $liveCurleckSum ?>">
</tbody>
</table>
<script type="text/javascript">
document.f1.submit();
</script>
</form>
</body>
</html>
E-junkie: Sell digital downloads online
E-junkie Provides a Copy-paste buy-now, and cart buttons for selling downloads, codes and tangible products on any website, blog, social media, email and messenger!
Also see:
1. The Top 10+ Best Webinar Software Platforms For 2020-2021
2. Build Your Future Godaddy Careers And Jobs
3. Introduction To Web Hosting Services
To handle the response of return call from paytm we need another file(Response.php) –
<?php
require_once("config.php");
require_once("encdec_paytm.php");
$paytmChecksum = "";
$arguments = array();
$isValidChecksum = "FALSE";
$arguments = $_POST;
$paytmChecksum = isset($_POST["PAYTMSUMDATAHASH"]) ? $_POST["PAYTMSUMDATAHASH"] : ""; //Sent by Paytm pg
$isValidChecksum = verifychecksum_e($arguments, PAYTM_MERCHANT_KEY, $paytmChecksum); //will return TRUE or FALSE string.
if($isValidChecksum == "TRUE") {
echo "<b>Checksum matched and following are the transaction Information:</b>" . "<br/>";
if ($_POST["STATUS"] == "TXN_SUCCESS") {
echo "<b>Transaction status is success</b>" . "<br/>";
}
else {
echo "<b>Transaction status is failure</b>" . "<br/>";
}
if (isset($_POST) && count($_POST)>0 )
{
foreach($_POST as $paramName => $paramValue) {
echo "<br/>" . $paramName . " = " . $paramValue;
}
}
}
else {
echo "<b>Checksum mismatched.</b>";
}
?>
Some Important Notes – Paytm Payment Gateway Integration with PHP
1. When I make an account for paytm payment gatway using PHP it asks us for a redirect URL where paytm will send the output. By default it will redirect to that URL, we can not change that.
READ : Vuejs Simple Autocomplete textbox Compopent using JSON
If I want to pass the dynamic URL then I will need to contact support as well as ask them to enable the dynamic URL for our MERCHANT_ID for Paytm Payment Gateway Integration with PHP.
2. I can also pass some additional data while making a simple curl PHP call to paytm payment API as well as paytm will return that data in the output. But the name of that parameter can only be “MERC_UNQ_REF”. We can not pass user-defined parameter name.
3. SignIN data credentials for test MODE payment –
Mobile number – 9898989898
Password – 895689
encdec_paytm.php
All the functions of the (encdec_paytm.php) file are below –
<?php
function encrypt_e($input, $ky) {
$key = html_entity_decode($ky);
$iv = "[email protected]#$^&*%98984141";
$data = openssl_encrypt ( $input , "AES-128-CBC" , $key, 0, $iv );
return $data;
}
function decrypt_e($crypt, $ky) {
$key = html_entity_decode($ky);
$iv = "[email protected]#$^&*%98984141";
$data = openssl_decrypt ( $crypt , "AES-128-CBC" , $key, 0, $iv );
return $data;
}
function generateCallBack_e($length) {
$random = "";
srand((double) microtime() * 1000000);
$data = "AbcDE123IJKLMN67QRSTUVWXYZ";
$data .= "aBCdefghijklmn123opq45rs67tuv89wxyz";
$data .= "0FGH45OP89";
for ($i = 0; $i < $length; $i++) {
$random .= substr($data, (rand() % (strlen($data))), 1);
}
return $random;
}
function liveStrCheck($value) {
if ($value == 'null')
$value = '';
return $value;
}
function getChecksumFromArray($dataVolumeList, $key, $sort=1) {
if ($sort != 0) {
ksort($dataVolumeList);
}
$param = convertArrTwoString($dataVolumeList);
$flag = generateCallBack_e(4);
$startdStr = $param . "|" . $flag;
$hash = hash("sha256", $startdStr);
$hashString = $hash . $flag;
$liveCurlecksum = encrypt_e($hashString, $key);
return $liveCurlecksum;
}
function getChecksumFromString($param, $key) {
$flag = generateCallBack_e(4);
$startdStr = $param . "|" . $flag;
$hash = hash("sha256", $startdStr);
$hashString = $hash . $flag;
$liveCurlecksum = encrypt_e($hashString, $key);
return $liveCurlecksum;
}
function verifychecksum_e($dataVolumeList, $key, $liveCurlecksumvalue) {
$dataVolumeList = removeCheckSumParam($dataVolumeList);
ksort($dataVolumeList);
$param = convertArrTwoStringForVerify($dataVolumeList);
$hash_string_ptm = decrypt_e($liveCurlecksumvalue, $key);
$flag = substr($hash_string_ptm, -4);
$startdStr = $param . "|" . $flag;
$web_hash_string = hash("sha256", $startdStr);
$web_hash_string .= $flag;
$FinalDestination = "FALSE";
if ($web_hash_string == $hash_string_ptm) {
$FinalDestination = "TRUE";
} else {
$FinalDestination = "FALSE";
}
return $FinalDestination;
}
function verifychecksum_eFromStr($param, $key, $liveCurlecksumvalue) {
$hash_string_ptm = decrypt_e($liveCurlecksumvalue, $key);
$flag = substr($hash_string_ptm, -4);
$startdStr = $param . "|" . $flag;
$web_hash_string = hash("sha256", $startdStr);
$web_hash_string .= $flag;
$FinalDestination = "FALSE";
if ($web_hash_string == $hash_string_ptm) {
$FinalDestination = "TRUE";
} else {
$FinalDestination = "FALSE";
}
return $FinalDestination;
}
function convertArrTwoString($dataVolumeList) {
$findme = 'REFUND';
$findmepipe = '|';
$argQry = "";
$flag = 1;
foreach ($dataVolumeList as $key => $value) {
$pos = strpos($value, $findme);
$pospipe = strpos($value, $findmepipe);
if ($pos !== false || $pospipe !== false)
{
continue;
}
if ($flag) {
$argQry .= liveStrCheck($value);
$flag = 0;
} else {
$argQry .= "|" . liveStrCheck($value);
}
}
return $argQry;
}
function convertArrTwoStringForVerify($dataVolumeList) {
$argQry = "";
$flag = 1;
foreach ($dataVolumeList as $key => $value) {
if ($flag) {
$argQry .= liveStrCheck($value);
$flag = 0;
} else {
$argQry .= "|" . liveStrCheck($value);
}
}
return $argQry;
}
function redirect2PG($arguments, $key) {
$hashString = getchecksumFromArray($arguments);
$liveCurlecksum = encrypt_e($hashString, $key);
}
function removeCheckSumParam($dataVolumeList) {
if (isset($dataVolumeList["PAYTMSUMDATAHASH"])) {
unset($dataVolumeList["PAYTMSUMDATAHASH"]);
}
return $dataVolumeList;
}
function getTxnStatus($callServiceDataAPI) {
return callServicesMain(PAYTM_STATUS_QUERY_URL, $callServiceDataAPI);
}
function getTxnStatusNew($callServiceDataAPI) {
return paytmCallServices(PAYTM_STATUS_QUERY_NEW_URL, $callServiceDataAPI);
}
function initiateTxnRefund($callServiceDataAPI) {
$CHECKSUM = getRefundChecksumFromArray($callServiceDataAPI,PAYTM_MERCHANT_KEY,0);
$callServiceDataAPI["CHECKSUM"] = $CHECKSUM;
return callServicesMain(PAYTM_REFUND_URL, $callServiceDataAPI);
}
function callServicesMain($paytmApiURI, $callServiceDataAPI) {
$dataJsonOutput = "";
$outputArguments = array();
$JsonData =json_encode($callServiceDataAPI);
$requestArg = 'JsonData='.urlencode($JsonData);
$liveCurl = curl_init($paytmApiURI);
curl_setopt($liveCurl, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($liveCurl, CURLOPT_POSTFIELDS, $requestArg);
curl_setopt($liveCurl, CURLOPT_RETURNTRANSFER, true);
curl_setopt ($liveCurl, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt ($liveCurl, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($liveCurl, CURLOPT_HTTPHEADER, array(
'Content-Type: application/json',
'Content-Length: ' . strlen($requestArg))
);
$dataJsonOutput = curl_exec($liveCurl);
$outputArguments = json_decode($dataJsonOutput,true);
return $outputArguments;
}
function paytmCallServices($paytmApiURI, $callServiceDataAPI) {
$dataJsonOutput = "";
$outputArguments = array();
$JsonData =json_encode($callServiceDataAPI);
$requestArg = 'JsonData='.urlencode($JsonData);
$liveCurl = curl_init($paytmApiURI);
curl_setopt($liveCurl, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($liveCurl, CURLOPT_POSTFIELDS, $requestArg);
curl_setopt($liveCurl, CURLOPT_RETURNTRANSFER, true);
curl_setopt ($liveCurl, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt ($liveCurl, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($liveCurl, CURLOPT_HTTPHEADER, array(
'Content-Type: application/json',
'Content-Length: ' . strlen($requestArg))
);
$dataJsonOutput = curl_exec($liveCurl);
$outputArguments = json_decode($dataJsonOutput,true);
return $outputArguments;
}
function getRefundChecksumFromArray($dataVolumeList, $key, $sort=1) {
if ($sort != 0) {
ksort($dataVolumeList);
}
$param = getRefundArray2Str($dataVolumeList);
$flag = generateCallBack_e(4);
$startdStr = $param . "|" . $flag;
$hash = hash("sha256", $startdStr);
$hashString = $hash . $flag;
$liveCurlecksum = encrypt_e($hashString, $key);
return $liveCurlecksum;
}
function getRefundArray2Str($dataVolumeList) {
$findmepipe = '|';
$argQry = "";
$flag = 1;
foreach ($dataVolumeList as $key => $value) {
$pospipe = strpos($value, $findmepipe);
if ($pospipe !== false)
{
continue;
}
if ($flag) {
$argQry .= liveStrCheck($value);
$flag = 0;
} else {
$argQry .= "|" . liveStrCheck($value);
}
}
return $argQry;
}
function callRefundAPI($refundApiURL, $callServiceDataAPI) {
$dataJsonOutput = "";
$outputArguments = array();
$JsonData =json_encode($callServiceDataAPI);
$requestArg = 'JsonData='.urlencode($JsonData);
$liveCurl = curl_init($paytmApiURI);
curl_setopt ($liveCurl, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt ($liveCurl, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($liveCurl, CURLOPT_URL, $refundApiURL);
curl_setopt($liveCurl, CURLOPT_POST, true);
curl_setopt($liveCurl, CURLOPT_POSTFIELDS, $requestArg);
curl_setopt($liveCurl, CURLOPT_RETURNTRANSFER, true);
$headers = array();
$headers[] = 'Content-Type: application/json';
curl_setopt($liveCurl, CURLOPT_HTTPHEADER, $headers);
$dataJsonOutput = curl_exec($liveCurl);
$outputArguments = json_decode($dataJsonOutput,true);
return $outputArguments;
}
Web Programming Tutorials Example with Demo
Read :
READ : Difference between Factory and Service in Angular
Summary
You can also read about AngularJS, ASP.NET, VueJs, PHP.
I hope you get an idea about Paytm Payment Gateway Integration with PHP.
I would like to have feedback on my infinityknow.com blog.
Your valuable feedback, question, or comments about this article are always welcome.
If you enjoyed and liked this post, don’t forget to share.
|
__label__pos
| 0.974292 |
Important Considerations when filtering in Spark with filter and where
This blog post explains how to filter in Spark and discusses the vital factors to consider when filtering.
Poorly executed filtering operations are a common bottleneck in Spark analyses.
You need to make sure your data is stored in a format that is efficient for Spark to query. You also need to make sure the number of memory partitions after filtering is appropriate for your dataset.
Executing a filtering query is easy… filtering well is difficult.
Read this blog post closely. Filtering properly will make your analyses run faster and save your company money. It’s the easiest way to become a better Spark programmer.
Filter basics
Let’s create a DataFrame and view the contents:
val df = Seq(
("famous amos", true),
("oreo", true),
("ginger snaps", false)
).toDF("cookie_type", "contains_chocolate")
df.show()
+------------+------------------+
| cookie_type|contains_chocolate|
+------------+------------------+
| famous amos| true|
| oreo| true|
|ginger snaps| false|
+------------+------------------+
Now let’s filter the DataFrame to only include the rows with contains_chocolate equal to true.
val filteredDF = df.where(col("contains_chocolate") === lit(true))
filteredDF.show()
+-----------+------------------+
|cookie_type|contains_chocolate|
+-----------+------------------+
|famous amos| true|
| oreo| true|
+-----------+------------------+
There are various alternate syntaxes that give you the same result and same performance.
• df.where("contains_chocolate = true")
• df.where($"contains_chocolate" === true)
• df.where('contains_chocolate === true)
A separate section towards the end of this blog post demonstrates that all of these syntaxes generate the same execution plan, so they’ll all perform equally.
where is an alias for filter, so all these work as well:
• df.filter(col("contains_chocolate") === lit(true))
• df.filter("contains_chocolate = true")
• df.filter($"contains_chocolate" === true)
• df.filter('contains_chocolate === true)
Empty partition problem
A filtering operation does not change the number of memory partitions in a DataFrame.
Suppose you have a data lake with 25 billion rows of data and 60,000 memory partitions. Suppose you run a filtering operation that results in a DataFrame with 10 million rows. After filtering, you’ll still have 60,000 memory partitions, many of which will be empty. You’ll need to run repartition() or coalesce() to spread the data on an appropriate number of memory partitions.
Let’s look at some pseudocode:
val df = spark.read.parquet("/some/path") // 60,000 memory partitions
val filteredDF = df.filter(col("age") > 98) // still 60,000 memory partitions
// at this point, any operations performed on filteredDF will be super inefficient
val repartitionedDF = filtereDF.repartition(200) // down to 200 memory partitions
Let’s use the person_data.csv file that contains 100 rows of data and person_name and person_country columns to demonstrate this on a real dataset.
80 people are from China, 15 people are from France, and 5 people are from Cuba.
This code reads in the person_data.csv file and repartitions the data into 200 memory partitions.
val path = new java.io.File("./src/test/resources/person_data.csv").getCanonicalPath
val df = spark
.read
.option("header", "true")
.csv(path)
.repartition(200)
println(df.rdd.partitions.size) // 200
Let’s filter the DataFrame and verify that the number of memory partitions does not change:
val filteredDF = df.filter(col("person_country") === "Cuba")
println(filteredDF.rdd.partitions.size) // 200
There are only 5 rows of Cuba data and 200 memory partitions, so we know that at least 195 memory partitions are empty.
Having a lot of empty memory partitions significantly slows down analyses on production-sized datasets.
Selecting an appropriate number of memory partitions
Choosing the right number of memory partitions after filtering is difficult.
You can follow the 1GB per memory partition rule of thumb to estimate the number of memory partitions that’ll be appropriate for a filtered dataset.
Suppose you have 25 billion rows of data, which is 10 terabytes on disk (10,000 GB).
An extract with 500 million rows (2% of the total data) is probably around 200 GB of data (0.02 * 10,000), so 200 memory partitions should work well.
Underlying data stores
Filtering operations execute completely differently depending on the underlying data store.
Spark attempts to “push down” filtering operations to the database layer whenever possible because databases are optimized for filtering. This is called predicate pushdown filtering.
An operation like df.filter(col("person_country") === "Cuba") is executed differently depending on if the data store supports predicate pushdown filtering.
• A parquet lake will send all the data to the Spark cluster, and perform the filtering operation on the Spark cluster
• A Postgres database table will perform the filtering operation in Postgres, and then send the resulting data to the Spark cluster.
N.B. using a data lake that doesn’t allow for query pushdown is a common, and potentially massive bottleneck.
Column pruning
Spark will use the minimal number of columns possible to execute a query.
The df.select("person_country").distinct() query will be executed differently depending on the file format:
• A Postgres database will perform the filter at the database level and only send a subset of the person_country column to the cluster
• A Parquet data store will send the entire person_country column to the cluster and perform the filtering on the cluster (it doesn’t send the person_name column – that column is “pruned”)
• A CSV data store will send the entire dataset to the cluster. CSV is a row based file format and row based file formats don’t support column pruning.
You almost always want to work with a file format or database that supports column pruning for your Spark analyses.
Cluster sizing after filtering
Depending on the data store, the cluster size needs might be completely different before and after performing a filtering operation.
Let’s say your 25 billion row dataset is stored in a parquet data lake and you need to perform a big filter and then do some advanced NLP on 1 million rows. You’ll need a big cluster to perform the initial filtering operation and a smaller cluster to perform the NLP analysis on the comparatively tiny dataset. For workflows like these, it’s often better to perform the filtering operation on a big cluster, repartition the data, write it to disk, and then perform the detailed analysis with a separate, smaller cluster on the extract.
Transferring big datasets from cloud storage to a cloud cluster and performing a big filtering operation is slow and expensive. You will generate a huge cloud compute bill with these types of workflows.
The pre / post filtering cluster requirements don’t change when you’re using a data storage that allows for query pushdown. The filtering operation is not performed in the Spark cluster. So you only need to use a cluster that can handle the size of the filtered dataset.
Partition filters
Data lakes can be partitioned on disk with partitionBy.
If the data lake is partitioned, Spark can use PartitionFilters, as long as the filter is using the partition key.
In our example, we could make a partitioned data lake with the person_country partition key as follows:
val path = new java.io.File("./src/test/resources/person_data.csv").getCanonicalPath
val df = spark
.read
.option("header", "true")
.csv(path)
.repartition(col("person_country"))
df
.write
.partitionBy("person_country")
.option("header", "true")
.csv("tmp/person_data_partitioned")
This’ll write out the data as follows:
person_data_partitioned/
person_country=China/
part-00059-dd8849eb-4e7d-4b6c-9536-59f94ea56412.c000.csv
person_country=Cuba/
part-00086-dd8849eb-4e7d-4b6c-9536-59f94ea56412.c000.csv
person_country=France/
part-00030-dd8849eb-4e7d-4b6c-9536-59f94ea56412.c000.csv
The “partition key” is person_country. Let’s use explain to verify that PartitionFilters are used when filtering on the partition key.
val partitionedPath = new java.io.File("tmp/person_data_partitioned").getCanonicalPath
spark
.read
.csv(partitionedPath)
.filter(col("person_country") === "Cuba")
.explain()
FileScan csv [_c0#132,person_country#133]
Batched: false,
Format: CSV,
Location: InMemoryFileIndex[file:/Users/matthewpowers/Documents/code/my_apps/mungingdata/spark2/tmp/person_...,
PartitionCount: 1,
PartitionFilters: [isnotnull(person_country#133), (person_country#133 = Cuba)],
PushedFilters: [],
ReadSchema: struct<_c0:string>
Check out Beautiful Spark Code for a full description on how to build, update, and filter partitioned data lakes.
Explain with different filter syntax
filter and where are executed the same, regardless of whether column arguments or SQL strings are used.
Let’s verify that all the different filter syntaxes generate the same physical plan.
All of these code snippets generate the same physical plan:
df.where("person_country = 'Cuba'").explain()
df.where($"person_country" === "Cuba").explain()
df.where('person_country === "Cuba").explain()
df.filter("person_country = 'Cuba'").explain()
Here’s the generated physical plan:
== Physical Plan ==
(1) Project [person_name#152, person_country#153]
+- (1) Filter (isnotnull(person_country#153) && (person_country#153 = Cuba))
+- (1) FileScan csv [person_name#152,person_country#153]
Batched: false,
Format: CSV,
Location: InMemoryFileIndex[file:/Users/matthewpowers/Documents/code/my_apps/mungingdata/spark2/src/test/re...,
PartitionFilters: [],
PushedFilters: [IsNotNull(person_country),
EqualTo(person_country,Cuba)],
ReadSchema: struct<person_name:string,person_country:string>
Incremental updates with filter
Some filtering operations are easy to incrementally update with Structured Streaming + Trigger.Once.
See this blog post for more details.
Incrementally updating a dataset is often 100 times faster than rerunning the query on the entire dataset.
Conclusion
There are different syntaxes for filtering Spark DataFrames that are executed the same under the hood.
Optimizing filtering operations depends on the underlying data store. Your queries will be a lot more performant if the data store supports predicate pushdown filters.
If you’re working with a data storage format that doesn’t support predicate pushdown filters, try to create a partitioned data lake and leverages partition filters.
Transferring large datasets to the Spark cluster and performing the filtering in Spark is generally the slowest and most costly option. Avoid this query pattern whenever possible.
Filtering a Spark dataset is easy, but filtering in a performant, cost efficient manner is surprisingly hard. Filtering is a common bottleneck in Spark analyses.
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|
__label__pos
| 0.672607 |
Premium Domains
Premium Domains
What are premium domain names?
Premium names are highly desirable domain names that are generally available at a higher price than regular domain names.
All domain names are not equal. There are various factors that lend value to a domain name, for instance, the number of characters in the name, common keywords, or how memorable the name is. Invariably, such domain names are sold at a higher price than regular domain names, particularly if they represent a concept, idea, or category.
Advantages of premium names
A premium domain name makes an instant impression on the target audience, irrespective of the category or type of business. It provides a boost in search engine optimization efforts, and may also improve type-in traffic from visitors specifically looking for a product, service or idea. As such, it helps businesses and users welcome visitors that may not otherwise reach their website. It also means that users know exactly what to expect from the website, since the name makes the value proposition clear to the visitor. This can save any company a lot of time, money and effort in branding, to influence prospective customers.
Premium domains are also great for word-of-mouth and physical marketing activities - a short and memorable name makes it easy for users to come to the site much after they've seen it on TV or a billboard, or just heard about it from a friend. Ultimately, a high quality name helps you make a real statement about your business.
Types of premium domain names
Depending on their source and ownership, there are two types of premium domain names -
Premium names sold by Registries
High quality domain names in various domain extensions are often made available at a higher price by the respective Registries. Though the price is higher, these names can be registered in the same way as regular domain names. If a name you're looking for happens to be premium, the search results will indicate as much, and show the actual price for the domain name.
Registry-sold premium domains may be of two types -
• Some domains may be sold at a very high initial price, but will renew or transfer at the same price as a regular domain name
• Other domains may be sold at a higher price, but will also renew or transfer at the same higher price
Aftermarket premium names
These are domain names that have already been registered by other customers; however, the current owner is offering them for sale. Such sales happen through various registrars and aftermarket services. At Greynium Information Technologies Pvt. Ltd., we have partnered with several aftermarket platforms in order to bring such high-quality domains to our customers, and they can be purchased directly on the website.
The process to buy an aftermarket domain is different from the regular domain registration process. Since these names are already registered, they must be transferred from the seller's registrar to the buyer's account on Greynium Information Technologies Pvt. Ltd.. The transfer process for these names is simplified, so you don't need to take any extra steps when buying a premium domain name.
Aftermarket premium domains are generally available across all of the popular TLDs, including .COM, .NET and various ccTLDs where the registries don't sell any premium names themselves. Aftermarket premium names have a high initial price, but renew or transfer at the same price as normal domain names in that TLD.
How do I buy a premium domain name?
The process of buying a premium domain name is not different from buying ordinary domain names - when you search for domain names on the Greynium Information Technologies Pvt. Ltd. website, premium names matching your search request will be included in the results. These results will also indicate if the name renews at a premium price, or if the renewal pricing will be similar to regular names.
When you add a premium name to your shopping cart and make the payment for it, we will start the process of acquiring it for you. Once the name has been secured, it will be activated in your control panel, and can be managed like any other domain name.
Note
• The price for Premium Domains is set by the registry or the current owner of the domain name and is non-negotiable.
• Activation of registry-sold premium names happens almost instantly, just like regular domain names.
• Activation of aftermarket premium names may, depending on the seller and the aftermarket platform, take between 1-3 weeks to complete.
|
__label__pos
| 0.573621 |
Electron Kiosk
Learn how I created an input interface for electronjs. It is useful for e.g. interactive exhibition setups.
7 min read
The Goal
We are going to create a very simple Electron App displaying a keyboard and an input field. An application like this can be very useful for live installations like exhibitions, polls etc. As part of the exhibition for the project Credit Criminals, we attached the applications to a small invoice printer so that we can offer the visitor tailor-made souvenirs.
electron app Simple Input Interface
Setup
First of all, this project is tailored to run on a RapsberryPi. But since its electron. It can of course also run on every plattform. After setting up your RaspberryPi with a GUI operating system, you’ll need to install node and npm. After installing node and npm, we will init our electron-kiosk project.
$ npm init $ cd electron-kiosk
Let’s install electron.
# globally $ sudo npm install -g electron --unsafe-perm=true --allow-root # dev dependency npm install electron --save-dev
You want to set your entry point to src/main.js. And add "start": "electron ." to your scripts. Your package.json should look something like this.
{ "name": "electron-kisok", "version": "1.0.0", "author": "leo-muehlfeld", "license": "MIT", "main": "src/main.js", "scripts": { "start": "electron ." }, "devDependencies": { "electron": "^9.1.0" } }
Create the files.
$ mkdir src $ cd src $ touch index.html main.js $ mkdir keyboard $ cd keyboard $ touch keyboard.js keyboard.css
Electron App
We have created four files. Lets fill these files with the neccessary code. We will start with main.js which is basically something like a launch instruction for electron.
const { app, BrowserWindow } = require('electron') function createWindow () { let win = new BrowserWindow({ // Size of app window width: 1024, height: 600, // Kiosk "true" runs app on fullscreen without obstructions. kiosk: true, webPreferences: { nodeIntegration: true } }) // Load file win.loadFile('src/index.html') // Line below enables DevTools win.webContents.openDevTools() } app.on('ready', createWindow)
Okay, electron will now know what to do on startup. Lets continue by adding our html structure to the index.html. We will import the Google Material Icons, create an input field, add some styles to it and write a little function that disables our user to deselect the input.
<!DOCTYPE html> <html> <head> <link rel="stylesheet" href="keyboard/keyboard.css"> <link href="https://fonts.googleapis.com/icon?family=Material+Icons"rel="stylesheet"> <meta charset="UTF-8"> <title>Electron Kiosk</title> <style media="screen"> body{ background-color: black; } .use-keyboard-input { font-family: sans-serif; background-color: white; color: black; font-size: 80px; width: 80%; padding: 20px 27px 12px; border: 2px solid white; box-sizing: border-box; border-radius: 4px; outline: none; display: block; margin: 70px auto 0; -webkit-user-select: none; } </style> </head> <body> <input id="disable-select" class="use-keyboard-input" type="text" placeholder="Your Name" onblur="this.focus()" autofocus /> <!-- Disable deselection of input --> <script> var inp = document.getElementById('disable-select'); inp.addEventListener('select', function() { this.selectionStart = this.selectionEnd; }, false); </script> </body> </html>
Add the Keyboard
Neat! Basically, when we run this app on a machine with a keyboard, we are set. But we don’t want to achieve that here. The kiosk app should be able to run by itself with just a touchscreen as an input option. So we’re going to follow the dcode tutorial and create a custom keyboard using vanilla javascript and some CSS. Let’s fill the keyboard/keyboard.css file with content so we don’t have to worry about that for the time being.
.keyboard{ position: fixed; left:0; bottom: 0; width: 100%; padding: 5px 0; background-color: #e2e2e2; user-select: none; transition: bottom 0.4s; } .keyboard__keys{ text-align: center; } .keyboard__key { font-family: sans-serif; height: 70px; width: 7%; margin: 3px; border-radius: 4px; border: none; background: white; color: black; font-size: 1.2rem; outline: none; cursor: pointer; display: inline-flex; align-items: center; justify-content: center; vertical-align: top; padding: 0; -webkit-tap-highlight-color: transparent; position: relative; } .keyboard__key--wide{ width: 23%; max-width: 120px; } .keyboard__key--extrawide{ width: 50%; max-width: 500px; } .keyboard__key--activatable::after{ content: ''; top: 10px; right: 10px; position: absolute; width: 8px; height: 8px; background: rgba(0,0,0,0.4); border-radius: 50%; } .keyboard__key--active::after{ background: #08ff00; } .keyboard__key--dark{ background: black; color: white; } .keyboard__key:active{ background-color: rgba(255, 255, 255, 0.12); }
You can of course adjust the styles later to suit your needs. We are now going to create the actual keyboard elements. In a nutshell, we will create an array with all the keys needed in order to subsequently render them into individual buttons. For special keys such as caps-lock, spacebar, backspace and so on, we will assign special actions and properties with the help of a switch.
const Keyboard = { elements: { main: null, keysContainer: null, keys: [] }, eventHandlers: { oninput: null, ondone: null }, properties: { value: "", capslock: false, }, init() { this.elements.main = document.createElement("div"); this.elements.keysContainer = document.createElement("div"); this.elements.main.classList.add("keyboard"); this.elements.keysContainer.classList.add("keyboard__keys"); this.elements.keysContainer.appendChild(this._createKeys()); this.elements.keys = this.elements.keysContainer.querySelectorAll(".keyboard__key"); this.elements.main.appendChild(this.elements.keysContainer); document.body.appendChild(this.elements.main); document.querySelectorAll(".use-keyboard-input").forEach(element => { element.addEventListener("focus", () => { this.open(element.value, currentValue => { element.value = currentValue; }) }); }); }, _createKeys(){ const fragment = document.createDocumentFragment(); // This array will determine your keyboard layout (e.g. qwerty, abcdef, etc.) const keyLayout = [ "q", "w", "e", "r", "t", "z", "u", "i", "o", "p", "ü", "backspace", "a", "s", "d", "f", "g", "h", "j", "k", "l", "ö", "ä", "caps", "y", "x", "c", "v", "b", "n", "m", "done", "space" ]; // Simplify icon implementation const createIconHTML = (icon_name) => { return `<i class="material-icons">${icon_name}</i>`; }; // Create keys from array keyLayout.forEach(key => { const keyElement = document.createElement("button"); const insertLineBreak = ["backspace", "ä", "done"].indexOf(key) !== -1; keyElement.setAttribute("type", "button"); keyElement.classList.add("keyboard__key"); // We will treat special keys with special properties via a switch switch(key) { case "backspace": keyElement.classList.add("keyboard__key--wide"); keyElement.innerHTML = createIconHTML("backspace"); keyElement.addEventListener("click", () => { this.properties.value = this.properties.value.substring(0, this.properties.value.length - 1); this._triggerEvent("oninput"); }); break; case "caps": keyElement.classList.add("keyboard__key--wide", "keyboard__key--activatable"); keyElement.innerHTML = createIconHTML("keyboard_capslock"); keyElement.addEventListener("click", () => { this.toggleCapsLock(); keyElement.classList.toggle("keyboard__key--active", this.properties.capsLock); }); break; case "enter": keyElement.classList.add("keyboard__key--wide"); keyElement.innerHTML = createIconHTML("keyboard_return"); keyElement.addEventListener("click", () => { this.properties.value += "\n"; this._triggerEvent("oninput"); }); break; case "space": keyElement.classList.add("keyboard__key--extrawide"); keyElement.innerHTML = createIconHTML("space_bar"); keyElement.addEventListener("click", () => { this.properties.value += " "; this._triggerEvent("oninput"); }); break; case "done": keyElement.classList.add("keyboard__key--wide", "keyboard__key--dark"); // Set an appropriate icon for your "done" action keyElement.innerHTML = createIconHTML("print"); keyElement.addEventListener("click", () => { this.close(); this._triggerEvent("onclose"); }); break; default: keyElement.textContent = key.toLowerCase(); keyElement.addEventListener("click", () => { this.properties.value += this.properties.capsLock ? key.toUpperCase() : key.toLowerCase(); this._triggerEvent("oninput"); }); break; } fragment.appendChild(keyElement); if (insertLineBreak) { fragment.appendChild(document.createElement("br")); } }); return fragment; }, _triggerEvent(handlerName) { if (typeof this.eventHandlers[handlerName] == "function") { this.eventHandlers[handlerName](this.properties.value); } }, toggleCapsLock(){ this.properties.capsLock = !this.properties.capsLock; for (const key of this.elements.keys) { if (key.childElementCount === 0) { key.textContent = this.properties.capsLock ? key.textContent.toUpperCase() : key.textContent.toLowerCase(); } } }, open(initialValue, oninput, onclose) { this.properties.value = initialValue || ""; this.eventHandlers.oninput = oninput; this.eventHandlers.onclose = onclose; this.elements.main.classList.remove("keyboard--hidden"); }, close() { this.properties.value = ""; this.eventHandlers.oninput = oninput; this.eventHandlers.onclose = onclose; document.querySelectorAll(".use-keyboard-input").forEach(element => { element.value = ""; }); } }; // Load Keyboard when ready window.addEventListener("DOMContentLoaded", function() { Keyboard.init(); });
Almost done. As a last step, we will have to import the keyboard.js script into our index.html. We will do this by adding the following line before the </body> tag.
<script src="keyboard/keyboard.js"></script>
Done!
Lets run it.
# Only on RPI export DISPLAY=:0 # start app npm start
electron app The finished interface
Credits
Scripts and Graphics by Leo Mühlfeld. Keyboard idea by Dcode. Using Google Material Icons.
|
__label__pos
| 0.978127 |
in Eloquent
Laravel Custom Casts
One of the new features in Laravel 7 is the creation of custom eloquent casts.
Previously Laravel has come with a set of basic casts such as - integer, real, float, double, decimal:, string, boolean, object, array, collection, date, datetime, and timestamp.
/**
* The attributes that should be cast.
*
* @var array
*/
protected $casts = [
'is_admin' => 'boolean',
];
These provide the majority of use cases for allowing you to change the value of the attribute on the way into the database and on the way out.
Alternatively, if you want to change the value of the attributes you can use mutator getter and setter methods. When eloquent attempts to fill the model it will use these mutator attributes to change the value of the attributes on the way in and out of the database.
/**
* Get the user's first name.
*
* @param string $value
* @return void
*/
public function getFirstNameAttribute()
{
return $this->attributes['first_name'];
}
/**
* Set the user's first name.
*
* @param string $value
* @return void
*/
public function setFirstNameAttribute($value)
{
$this->attributes['first_name'] = strtolower($value);
}
The downside of this approach is that it populates the model class which can grow larger and harder to manage. It also makes it harder to reuse any of the logic in these mutators. For example if you have an address column on multiple models and want to share the mutation across these multiple models there is no Laravel native way of doing this.
Custom Casts
This new feature allows you to abstract these mutations into a cast class which gives you ability to reuse these casts on multiple columns and models in your application.
To create a custom cast you must create a new class which implements Illuminate\Contracts\Database\Eloquent\CastsAttributes and use this in the $cast property.
/**
* The attributes that should be cast.
*
* @var array
*/
protected $casts = [
'is_admin' => IsAdmin::class,
];
Eloquent will check if there's a custom cast and change the value using this when storing and getting the values from the database.
To demo this let's create a new custom cast that will save the date time as a UTC timezone rather than the application timezone and get the values from the database in the application timezone.
First create a new class that implements the CastsAttributes.
<?php
namespace CustomCast;
use Illuminate\Contracts\Database\Eloquent\CastsAttributes;
class UtcDateTime implements CastsAttributes
{
/**
* @param \Illuminate\Database\Eloquent\Model $model
* @param string $key
* @param mixed $value
* @param array $attributes
*
* @return Carbon|mixed
*/
public function get($model, string $key, $value, array $attributes)
{
}
/**
* @param \Illuminate\Database\Eloquent\Model $model
* @param string $key
* @param mixed $value
* @param array $attributes
*
* @return array|Carbon|string
*/
public function set($model, string $key, $value, array $attributes)
{
}
}
The CastsAttributes requires two methods get and set.
Set is used when saving the model in the database we can take the date value and convert it to UTC.
return $value->copy()->setTimezone('UTC');
The Get method is used when retrieving the value from the database this is when we need to convert the date to the application timezone.
return $value->copy()->setTimezone(config('app.timezone'));
Full Custom Cast
|
__label__pos
| 0.561183 |
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@albertsun
Created August 21, 2011 05:44
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Python port of WordPress's wpautop filter
import re
from django import template
from django.utils.functional import allow_lazy
from django.template.defaultfilters import stringfilter
from django.utils.safestring import mark_safe, SafeData
from django.utils.encoding import force_unicode
from django.utils.html import escape
from django.utils.text import normalize_newlines
register = template.Library()
def linebreaks_wp(pee, autoescape=False):
"""Straight up port of http://codex.wordpress.org/Function_Reference/wpautop"""
if (pee.strip() == ""):
return ""
pee = normalize_newlines(pee)
pee = pee + "\n"
pee = re.sub(r'<br />\s*<br />', "\n\n", pee)
allblocks = r'(?:table|thead|tfoot|caption|col|colgroup|tbody|tr|td|th|div|dl|dd|dt|ul|ol|li|pre|select|option|form|map|area|blockquote|address|math|style|input|p|h[1-6]|hr|fieldset|legend|section|article|aside|hgroup|header|footer|nav|figure|figcaption|details|menu|summary)'
pee = re.sub(r'(<' + allblocks + '[^>]*>)', lambda m: "\n"+m.group(1) if m.group(1) else "\n", pee)
pee = re.sub(r'(</' + allblocks + '>)', lambda m: m.group(1)+"\n\n" if m.group(1) else "\n\n", pee)
#pee = pee.replace("\r\n", "\n")
#pee = pee.replace("\r", "\n") #these taken care of by normalize_newlines
if (pee.find("<object") != -1):
pee = re.sub(r'\s*<param([^>]*)>\s*', lambda m: "<param%s>" % (m.group(1) if m.group(1) else "", ), pee) # no pee inside object/embed
pee = re.sub(r'\s*</embed>\s*', '</embed>', pee)
pee = re.sub(r"\n\n+", "\n\n", pee) # take care of duplicates
pees = re.split(r'\n\s*\n', pee) # since PHP has a PREG_SPLIT_NO_EMPTY, may need to go through and drop any empty strings
#pees = [p for p in pees if p]
pee = "".join(["<p>%s</p>\n" % tinkle.strip('\n') for tinkle in pees])
pee = re.sub(r'<p>\s*</p>', '', pee) #under certain strange conditions it could create a P of entirely whitespace
pee = re.sub(r'<p>([^<]+)</(div|address|form)>', lambda m: "<p>%s</p></%s>" % ((lambda x: x.group(1) if x.group(1) else "")(m), (lambda x: x.group(2) if x.group(2) else "")(m), ), pee)
pee = re.sub(r'<p>\s*(</?' + allblocks + r'[^>]*>)\s*</p>', lambda m: m.group(1) if m.group(1) else "", pee) # don't pee all over a tag
pee = re.sub(r"<p>(<li.+?)</p>", lambda m: m.group(1) if m.group(1) else "", pee) # problem with nested lists
pee = re.sub(r'<p><blockquote([^>]*)>', lambda m: "<blockquote%s><p>" % (m.group(1) if m.group(1) else "",), pee, flags=re.IGNORECASE)
pee = pee.replace('</blockquote></p>', '</p></blockquote>')
pee = re.sub(r'<p>\s*(</?' + allblocks + r'[^>]*>)', lambda m: m.group(1) if m.group(1) else "", pee)
pee = re.sub(r'(</?' + allblocks + '[^>]*>)\s*</p>', lambda m: m.group(1) if m.group(1) else "", pee)
def _autop_newline_preservation_helper(matches):
return matches.group(0).replace("\n", "<WPPreserveNewline />")
pee = re.sub(r'<(script|style).*?</\1>', _autop_newline_preservation_helper, pee, flags=re.DOTALL)
pee = re.sub(r'(?<!<br />)\s*\n', "<br />\n", pee) # make line breaks
pee = pee.replace('<WPPreserveNewline />', "\n")
pee = re.sub(r'(</?' + allblocks + '[^>]*>)\s*<br />', lambda m: m.group(1) if m.group(1) else "", pee)
pee = re.sub(r'<br />(\s*</?(?:p|li|div|dl|dd|dt|th|pre|td|ul|ol)[^>]*>)', lambda m: m.group(1) if m.group(1) else "", pee)
if (pee.find('<pre') != -1):
def clean_pre(m):
if m.group(1) and m.group(2):
text = m.group(2)
text = text.replace('<br />', '')
text = text.replace('<p>', "\n")
text = text.replace('</p>', '')
text = m.group(1)+escape(text)+"</pre>"
else:
text = m.group(0)
text = text.replace('<br />', '')
text = text.replace('<p>', "\n")
text = text.replace('</p>', '')
return text
pee = re.sub('(?is)(<pre[^>]*>)(.*?)</pre>', clean_pre, pee)
pee = re.sub( r"\n</p>$", '</p>', pee)
return pee
linebreaks_wp = allow_lazy(linebreaks_wp, unicode)
@register.filter("linebreaks_wp")
@stringfilter
def linebreaks_wp_filter(value, autoescape=None):
"""Straight up port of http://codex.wordpress.org/Function_Reference/wpautop"""
autoescape = autoescape and not isinstance(value, SafeData)
return mark_safe(linebreaks_wp(value, autoescape))
linebreaks_wp_filter.is_safe = True
linebreaks_wp_filter.needs_autoescape = True
linebreaks_wp = stringfilter(linebreaks_wp)
@sebbcn
Copy link
sebbcn commented Jul 23, 2014
This gist saved my day. Thanks!
@howmp
Copy link
howmp commented Mar 29, 2017
ths for share
@nouroddini
Copy link
thank you
@frankyhung93
Copy link
This also saved my daY!! You are a hero in doing this!
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|
__label__pos
| 0.826367 |
final关键字
1 final数据
有时数据的恒定不变是很有用的，比如：
1、一个永不改变的编译时常量
2、一个在运行时被初始化的值，而你不希望它被改变。
对于编译期常量这种情况，编译器可以将该常量值代入任何可能用到它的计算式中，也就是说，可以在编译时执行计算式，这减轻了一些运行时的负担。在Java中，这类常量必须是基本数据类型，并且以final表示，在对这个常量定义的时候，必须对其进行赋值。
一个既是static又是final的域只占据一段不能被改变的存储空间。
对于基本类型，final使数值恒定不变；而对于对象引用，final使引用恒定不变。一旦引用被初始化指向一个对象，就无法再把它改为指向其他对象。然而，对象其自身却是可以被修改的，java并未提供使任何对象恒定不变的途径。
根据惯例，既是static又是fina的域（即编辑期常量），将用大表述，并使用下划线分割各个单词。例如：VALUE_TWO
2 final参数
java允许在参数列表中以声明的方式将参数指明为final。这意味着你无法在方法中更改参数引用所向的对象。
class Gizmo{
public void spin(){
}
}
public class FinalArguments {
void with(final Gizmo g){
//! g = new Gizmo(); // Illegal --g is finall
}
void wittOur( Gizmo g){
g = new Gizmo(); // ok --g not finall
g.spin();
}
void f(final int i){
// i++; //不能被改变，因为是final
}
int g(final int i){
return i+1;
}
3.final方法
使用final方法的原因有两个。第一个原因是把方法锁定，以防任何继承类修改它的含义。这是处于设计的考虑：想要确保在继承中使方法行为保持不变，并且不会被覆盖。过去建议使用final方法的第二个原因是效率。
final 和private关键字
类中所有的private方法都隐式地指定为final的。由于无法取用private方法，所以也就无法覆盖它。
class WithFinals{
private final void f(){
System.out.println("WithFinals.f()");
}
private void g(){
System.out.println("WithFinals.g()");
}
}
class OverridingPrivate extends WithFinals{
private final void f(){
System.out.println("OverridingPrivate.f()");
}
private void g(){
System.out.println("OverridingPrivate.g()");
}
}
class OverridingPrivate2 extends OverridingPrivate{
public final void f(){
System.out.println("OverridingPrivate2.f()");
}
public void g(){
System.out.println("OverridingPrivate2.g()");
}
}
public class FinalOverridingIlluion {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
OverridingPrivate2 op2 = new OverridingPrivate2();
op2.f();
op2.g();
OverridingPrivate op = op2;
//不能call 以下方法
// op.f();
// op.g();
//同理
WithFinals wf = op2;
// wf.f();
// wf.g();
}
}
3 final类
当将某个类的整体定义为final时，就表明你不打算继承该类，而且也不允许别人这样做。
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|
__label__pos
| 0.838801 |
1
$\begingroup$
What are the formulas to calculate the 4 half-planes that define the camera's view volume?
The inputs should be the camera's world matrix, focal length (and maybe sensor size?) and anything else I overlooked. I am not interested in the clipping start/end, but extra credit if you include them.
I plan to use this to calculate if an object would be visible to the camera, (which is slightly harder since the origin could be off-camera, but polygons could still be on-camera, but I can fudge that).
$\endgroup$
• 1
$\begingroup$ You should cull the objects with bounding-spheres to avoid the origin problem, its fast. Search for frustum culling, this question is more for Game development stack exchange than blender.. $\endgroup$ – Jaroslav Jerryno Novotny Mar 31 '15 at 17:04
• $\begingroup$ It is not for game. I want to add more objects (part of a lattice) to the scene, but not in places where they will never be rendered. I could easily add 100,000 objects and only have 10,000 actually show up on camera, so I'd rather just add only the ones that will appear on camera. $\endgroup$ – Mutant Bob Mar 31 '15 at 20:46
1
$\begingroup$
After a couple of quick experiments I determined that for a square camera the following coordinates (expressed in the camera's local coordinate system) would appear in the corners of the image:
x = y = sensor_width/lens /2
[±x, ±y, -1]
For a rectangular image, whichever dimension is larger becomes sensor_width/lens/2, and the smaller dimension is proportionally adjusted.
To define the half-planes in the camera's coordinate system, it's enough to calculate the cross products of the vectors pointing at the vertices of each edge, so
lr = [ x,-y,-1]
ur = [ x, y,-1]
ll = [-x,-y,-1]
ul = [-x, y,-1]
n1 = | lr × ll |
n2 = | ll × ul |
n3 = | ul × ur |
n4 = | ur × lr |
We normalize the vectors to length 1 so that we can use them in distance calculations later on.
When you want to determine if a particular coordinate c is in the camera's view cone convert it to camera local coordinates using
M = cam.matrix_world.inverted()
c2 = M c
Now that we have c2 (in the camera's coordinate system) we can compute the dot product between it and the various half-plane normals.
zi = ni ∙ c2
If all those zis are >=0 then the point is in the camera's view cone. If the original coordinate is for an object, it's useful to incorporate a fudge factor like the radius of the object's bounding sphere (centered on the coordinate) and make sure that zi >= -fudge .
And this is the python class based on all that math:
class CameraCone:
def __init__(self, matrix, sensor_width, lens, resolution_x, resolution_y):
self.matrix = matrix.inverted()
self.sensor_width = sensor_width
self.lens = lens
w = 0.5* sensor_width / lens
if resolution_x> resolution_y:
x = w
y = w*resolution_y/resolution_x
else:
x = w*resolution_x/resolution_y
y = w
lr = Vector([x,-y,-1])
ur = Vector([x,y,-1])
ll = Vector([-x,-y,-1])
ul = Vector([-x,y,-1])
self.half_plane_normals = [
lr.cross(ll).normalized(),
ll.cross(ul).normalized(),
ul.cross(ur).normalized(),
ur.cross(lr).normalized()
]
def from_camera(cam, scn):
return CameraCone(cam.matrix_world, cam.data.sensor_width, cam.data.lens, scn.render.resolution_x, scn.render.resolution_y)
def isVisible(self, loc, fudge=0):
loc2 = self.matrix * loc
for norm in self.half_plane_normals:
z2 = loc2.dot(norm)
if z2 < -fudge:
return False
return True
$\endgroup$
• $\begingroup$ this is great ! $\endgroup$ – Chebhou Apr 1 '15 at 19:44
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|
__label__pos
| 0.881817 |
Certainly! Here is an example code that demonstrates the usage of the `win32file.ReadDirectoryChangesW` function in Python, along with an explanation of each step:
python
import win32file
import time
# Define the directory to be monitored
directory_to_monitor = "C:\example_directory"
# Define the buffer size for reading changes
buffer_size = 8192
# Define the list of desired change notifications
change_notifications = (
win32file.FILE_NOTIFY_CHANGE_FILE_NAME |
win32file.FILE_NOTIFY_CHANGE_DIR_NAME |
win32file.FILE_NOTIFY_CHANGE_ATTRIBUTES |
win32file.FILE_NOTIFY_CHANGE_SIZE |
win32file.FILE_NOTIFY_CHANGE_LAST_WRITE |
win32file.FILE_NOTIFY_CHANGE_SECURITY
)
# Create a handle for monitoring changes in the directory
directory_handle = win32file.CreateFile(
directory_to_monitor,
win32file.FILE_LIST_DIRECTORY,
win32file.FILE_SHARE_READ | win32file.FILE_SHARE_WRITE | win32file.FILE_SHARE_DELETE,
None,
win32file.OPEN_EXISTING,
win32file.FILE_FLAG_BACKUP_SEMANTICS,
None
)
# Create a dictionary to map the event codes to the corresponding names
event_names = {
win32file.FILE_ACTION_ADDED: "Added",
win32file.FILE_ACTION_REMOVED: "Removed",
win32file.FILE_ACTION_MODIFIED: "Modified",
win32file.FILE_ACTION_RENAMED_OLD_NAME: "Renamed from",
win32file.FILE_ACTION_RENAMED_NEW_NAME: "Renamed to"
}
# Start monitoring the directory for changes
while True:
# Read the changes in the directory
results = win32file.ReadDirectoryChangesW(
directory_handle,
buffer_size,
True,
change_notifications,
None,
None
)
# Process the results
for action, filename in results:
# Get the event name based on the action code
event_name = event_names.get(action, "Unknown")
# Print the event name and the corresponding filename
print(f"{event_name}: {filename}")
# Wait for a short period before reading the changes again
time.sleep(1)
Explanation of the code:
1. Import the necessary modules: `win32file` for file-related operations and `time` for waiting.
2. Define the directory that needs to be monitored. This should be the full path to the directory.
3. Define the buffer size for reading changes. This determines the maximum number of bytes to be read at a time.
4. Define the list of desired change notifications to be tracked. Here, we include various types of changes such as file/directory name changes, attribute changes, size changes, write changes, and security changes.
5. Create a handle for monitoring changes in the directory using the `win32file.CreateFile` function. This function opens a handle to the directory specified in `directory_to_monitor`.
6. Create a dictionary `event_names` to map the event codes to their corresponding names. This will be used for printing the event names in a human-readable format.
7. Start an infinite loop to continuously monitor the directory for changes.
8. Use the `win32file.ReadDirectoryChangesW` function to read the changes in the directory. This function takes the directory handle, buffer size, boolean flag for monitoring subdirectories as well, the desired change notifications, and optional filter parameters. It returns a list of `(action, filename)` tuples representing the detected changes.
9. Process the results obtained from `win32file.ReadDirectoryChangesW`. For each `(action, filename)` tuple, get the corresponding event name using the `event_names` dictionary and print it along with the filename.
10. Wait for a short period (1 second in this example) before reading the changes again. This helps to avoid continuous polling and reduce resource usage.
By executing the above code, you can monitor a directory for file system changes and print corresponding events whenever a change occurs in the specified directory. The code prints events like file added, file removed, file modified, file renamed from and file renamed to.
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__label__pos
| 0.997673 |
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refer to ORLite for method description
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1 parent 90bbce7 commit 3541a79dfe98bab427f78f2f1a47b38394888b8e @jquelin committed Mar 12, 2012
Showing with 20 additions and 187 deletions.
1. +20 −187 lib/ORDB/CPAN/Mageia.pm
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207 lib/ORDB/CPAN/Mageia.pm
@@ -11,196 +11,24 @@ use ORLite::Mirror {
};
-
-# -- methods autogenerated by orlite
-
-=method my $string = ORDB::CPAN::Mageia->dsn;
-
-The C<dsn> accessor returns the dbi connection string used to connect to
-the SQLite database as a string.
-
-
-=method my $handle = ORDB::CPAN::Mageia->dbh;
-
-To reliably prevent potential SQLite deadlocks resulting from multiple
-connections in a single process, each L<ORLite> package will only ever
-maintain a single connection to the database.
-
-During a transaction, this will be the same (cached) database handle.
-
-Although in most situations you should not need a direct DBI connection
-handle, the C<dbh> method provides a method for getting a direct
-connection in a way that is compatible with ORLite's connection
-management.
-
-Please note that these connections should be short-lived, you should
-never hold onto a connection beyond the immediate scope.
-
-The transaction system in L<ORLite> is specifically designed so that
-code using the database should never have to know whether or not it is
-in a transation.
-
-Because of this, you should B<never> call the -E<gt>disconnect method on
-the database handles yourself, as the handle may be that of a currently
-running transaction.
-
-Further, you should do your own transaction management on a handle
-provided by the <dbh> method.
-
-In cases where there are extreme needs, and you B<absolutely> have to
-violate these connection handling rules, you should create your own
-completely manual DBI-E<gt>connect call to the database, using the
-connect string provided by the C<dsn> method.
-
-The C<dbh> method returns a L<DBI::db> object, or throws an exception on
-error.
-
-
-=method ORDB::CPAN::Mageia->begin;
-
-The C<begin> method indicates the start of a transaction.
-
-In the same way that L<ORLite> allows only a single connection, likewise
-it allows only a single application-wide transaction.
-
-No indication is given as to whether you are currently in a transaction
-or not, all code should be written neutrally so that it works either way
-or doesn't need to care.
-
-Returns true or throws an exception on error.
-
-
-=method ORDB::CPAN::Mageia->commit;
-
-The C<commit> method commits the current transaction. If called outside
-of a current transaction, it is accepted and treated as a null
-operation.
-
-Once the commit has been completed, the database connection falls back
-into auto-commit state. If you wish to immediately start another
-transaction, you will need to issue a separate -E<gt>begin call.
-
-Returns true or throws an exception on error.
-
-
-=method ORDB::CPAN::Mageia->rollback;
-
-The C<rollback> method rolls back the current transaction. If called outside
-of a current transaction, it is accepted and treated as a null operation.
-
-Once the rollback has been completed, the database connection falls back
-into auto-commit state. If you wish to immediately start another
-transaction, you will need to issue a separate -E<gt>begin call.
-
-If a transaction exists at END-time as the process exits, it will be
-automatically rolled back.
-
-Returns true or throws an exception on error.
-
-
-=method ORDB::CPAN::Mageia->do(...);
-
- ORDB::CPAN::Mageia->do(
- insert into table (foo, bar) values (?, ?)', {},
- $foo_value,
- $bar_value,
- );
-
-The C<do> method is a direct wrapper around the equivalent L<DBI>
-method, but applied to the appropriate locally-provided connection or
-transaction.
-
-It takes the same parameters and has the same return values and error
-behaviour.
-
-
-=method ORDB::CPAN::Mageia->selectall_arrayref(...);
-
-The C<selectall_arrayref> method is a direct wrapper around the
-equivalent L<DBI> method, but applied to the appropriate locally-
-provided connection or transaction.
-
-It takes the same parameters and has the same return values and error
-behaviour.
-
-
-=method ORDB::CPAN::Mageia->selectall_hashref(...);
-
-The C<selectall_hashref> method is a direct wrapper around the
-equivalent L<DBI> method, but applied to the appropriate locally-
-provided connection or transaction.
-
-It takes the same parameters and has the same return values and error
-behaviour.
-
-
-=method ORDB::CPAN::Mageia->selectcol_arrayref(...);
-
-The C<selectcol_arrayref> method is a direct wrapper around the
-equivalent L<DBI> method, but applied to the appropriate locally-
-provided connection or transaction.
-
-It takes the same parameters and has the same return values and error
-behaviour.
-
-
-=method ORDB::CPAN::Mageia->selectrow_array(...);
-
-The C<selectrow_array> method is a direct wrapper around the equivalent
-L<DBI> method, but applied to the appropriate locally-provided
-connection or transaction.
-
-It takes the same parameters and has the same return values and error
-behaviour.
-
-
-=method ORDB::CPAN::Mageia->selectrow_arrayref(...);
-
-The C<selectrow_arrayref> method is a direct wrapper around the
-equivalent L<DBI> method, but applied to the appropriate locally-
-provided connection or transaction.
-
-It takes the same parameters and has the same return values and error
-behaviour.
-
-
-=method ORDB::CPAN::Mageia->selectrow_hashref(...);
-
-The C<selectrow_hashref> method is a direct wrapper around the
-equivalent L<DBI> method, but applied to the appropriate locally-
-provided connection or transaction.
-
-It takes the same parameters and has the same return values and error
-behaviour.
-
-
-=method ORDB::CPAN::Mageia->prepare(...);
-
-The C<prepare> method is a direct wrapper around the equivalent L<DBI>
-method, but applied to the appropriate locally-provided connection or
-transaction
-
-It takes the same parameters and has the same return values and error
-behaviour.
-
-In general though, you should try to avoid the use of your own prepared
-statements if possible, although this is only a recommendation and by no
-means prohibited.
-
-
-=method ORDB::CPAN::Mageia->pragma(...);
-
- # Get the user_version for the schema
- my $version = ORDB::CPAN::Mageia->pragma('user_version');
-
-The C<pragma> method provides a convenient method for fetching a pragma
-for a datase. See the SQLite documentation for more details.
-
-=cut
-
1;
__END__
+=for Pod::Coverage
+ dsn
+ dbh
+ connect(ed)?
+ begin
+ do
+ iterate
+ orlite
+ pragma
+ prepare
+ rollback(_begin)?
+ select(all|col|row)_.*
+ sqlite
+
+
=head1 SYNOPSIS
use ORDB::CPAN::Mageia;
@@ -222,6 +50,11 @@ what you want with the data itself.
Check the F<examples> directory for some ideas on how to use it.
+=head1 METHODS
+
+Refere to L<ORLite> module, section B<ROOT PACKAGE METHODS>.
+
+
=head1 SEE ALSO
You can find more information on this module at:
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// point.cpp #include using std::ostream; #include "Point.h" ostream & operator<<( ostream & out, const Point & r) { out << '(' << r.getRow() << ',' << r.getColumn() << ')'; return out; } Point::Point (void) { setRow(0).setColumn(0); // use of function chaining } Point::Point (int rowV, int columnV) { setRow(rowV).setColumn(columnV); // use of function chaining } Point::Point (const Point & old) { setRow(old.getRow()).setColumn(old.getColumn()); // use of function chaining } Point::~Point(void) { } int Point::getRow(void) const { return row; } int Point::getColumn(void) const { return column; } Point & Point::setRow(int a) { row = a; return *this; // return alias to invoking instance } // allows for chaining member functions Point & Point::setColumn(int column) { (*this).column = column; // Some programmers pick the same name for the return *this; // parameter as the instance field } // Use (*this).column to refer to the instance field const Point & Point::operator=(const Point & r) { if ( this == & r ) return *this; // for function chaining row = r.row; column = r.column; return *this; } const Point & Point::print(ostream & w) const { w <<'['<
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How to Lock a Folder on SharePoint
Sharing and managing files are essential for many businesses and organizations. Cloud storage platforms like SharePoint make collaboration and access to important documents easier. Security and control of sensitive information are key concerns. Here, we’ll explore how to lock a folder on SharePoint.
Navigate to the desired folder on your SharePoint site. Click “Files” and select “Properties”. Set permissions for the folder. Choose users or groups who can access it. Set read-only or edit rights. Customize access by setting expiration dates or allowing specific actions.
SharePoint allows granular control over individual files in locked folders. Even if someone has access to the overall folder, they may be restricted from opening or modifying certain files.
Locking folders provides security and helps maintain regulatory compliance. By following these steps, you can confidently protect your organization’s files and control who can access them.
Understanding SharePoint and Folder Security
SharePoint is great for collaboration and storing documents. It also has folder security to keep sensitive info safe. Understanding how to lock a folder is important.
Permissions can be assigned to users or groups. This lets you control who can view, edit, or delete folder content.
Versioning is another way to lock a folder. It tracks changes and lets you revert back to earlier versions.
Encryption with IRM is also an option. It protects documents even if they are downloaded or shared outside of SharePoint.
Pro Tip: Review and update folder settings often. This will keep docs secure and in line with security policies.
Steps to Lock a Folder on SharePoint
1. Access SharePoint: Open a web browser & go to the SharePoint site where the folder is.
2. Navigate to the Folder: Click on the folder you want to lock. Its contents will be displayed.
3. Open Folder Settings: Click on the “Library” or “Document Library” tab. Then, choose “Library Settings” or “Document Library Settings” from the drop-down menu.
4. Enable Folder Locking: Under the “Permissions and Management” section, click on “Permissions for this document library”. On the permissions page, select the suitable permission level to lock the folder. You can either restrict access to specific people or groups, or deny access to everyone except yourself.
Once you complete these steps, your folder will be locked & only accessible to those with the correct permissions. Remember to review & update folder permissions regularly to ensure security.
Pro Tip: Create multiple permission levels on your SharePoint site for different user groups, to make sure only authorized individuals have access to sensitive folders.
Best Practices for Folder Locking on SharePoint
Ensuring your folders on SharePoint are secure requires the best practices. These guidelines help protect your sensitive info from unauthorised access. To help you, here’s a 4-step guide:
1. Set Permissions: Assign appropriate privileges to users and groups. Give access only to those who require it and limit access for others. This way you can manage who can view or edit folder contents.
2. Unique Security Groups: Create security groups with pre-defined roles instead of assigning permissions directly to individuals. You can easily manage rights across many folders by adding or removing users.
3. Version Control: Enable version control to track changes made by different users. You can audit and revert back to previous versions if needed.
4. Review and Update Permissions: As your organisation changes, so do the requirements for accessing folders. Regularly review and adjust permissions accordingly. Remove any unneeded users or groups. Make sure authorised individuals have access.
Locking a folder on SharePoint isn’t enough. It’s an extra layer of protection but not a guarantee. Encrypt sensitive files and educate users about security best practices.
This covers key aspects of folder locking on SharePoint. By following these guidelines, you can safeguard data while enabling authorised personnel to collaborate effectively.
An example of folder locking on SharePoint is when an employee mistakenly deleted a crucial document in a shared folder. Luckily, version control was on, so a past version was recovered without disruption. It shows the importance of implementing folder locking best practices to avoid data loss and minimise the effects of human error.
Troubleshooting Common Issues
Got troubles lockin’ a folder on SharePoint? Here’s what ya need to know!
1. Check yer permissions. Make sure ya got the right access level!
2. Disable document versionin’ or make sure ya try to lock a major version.
3. Active workflows can get in the way. Complete or terminate ’em before ya try to lock.
4. Don’t forget ’bout metadata! Locking the folder won’t lock the metadata. Lock ’em columns sep’rately.
Follow these tips and ya’ll be able to troubleshoot yer folder lockin’ issues on SharePoint like a pro!
Conclusion
1. To lock a folder on SharePoint, follow the steps mentioned. It’s key to secure data and stop unauthorized access.
2. Use permissions settings in SharePoint to limit who can view or edit certain folders. This ensures sensitive info stays safe.
SharePoint also has advanced security features like version history and auditing. This lets you track changes made to the folder and makes sure everyone is accountable.
Pro Tip: Check and update folder permissions regularly. This will help keep a secure framework for SharePoint folders.
Frequently Asked Questions
FAQs:
Q1: How do I lock a folder on SharePoint?
A1: To lock a folder on SharePoint, follow these steps: 1. Open the SharePoint site and navigate to the document library where the folder is located. 2. Select the folder you want to lock. 3. Click on the “…” ellipsis button in the toolbar. 4. Choose “Manage Access” from the dropdown menu. 5. In the access control panel, click on the “Advanced” link. 6. Locate the section titled “Folder Permissions” and click on the “Stop Inheriting Permissions” button. 7. Confirm the action by clicking “OK.” 8. Select the specific users or groups you want to grant access to the folder, or remove their access entirely. 9. Click “Save” to apply the changes and lock the folder.
Q2: Can I password-protect a folder on SharePoint?
A2: No, SharePoint does not provide a built-in feature to password-protect folders. However, you can control access permissions to the folder by granting or revoking user permissions. This allows you to restrict who can view, edit, or delete the contents of the folder.
Q3: Is there a way to temporarily lock a folder on SharePoint for editing?
A3: Yes, you can use the “Check Out” feature in SharePoint to temporarily lock a folder for editing. When a folder is checked out, other users can only view it but cannot make any changes until it is checked back in. This allows for exclusive editing rights and prevents simultaneous conflicting updates.
Q4: How can I unlock a folder that has been accidentally locked on SharePoint?
A4: If a folder has been accidentally locked on SharePoint, follow these steps to unlock it: 1. Open the SharePoint site and navigate to the document library. 2. Select the locked folder. 3. Click on the “…” ellipsis button in the toolbar. 4. Choose “Manage Access” from the dropdown menu. 5. In the access control panel, click on the “Advanced” link. 6. Locate the “Folder Permissions” section and click on the “Stop Inheriting Permissions” button if necessary. 7. Grant appropriate access permissions to the desired users or groups. 8. Click “Save” to apply the changes and unlock the folder.
Q5: Can I prevent others from moving or renaming a locked folder on SharePoint?
A5: Yes, you can prevent others from moving or renaming a locked folder on SharePoint by adjusting the folder’s permission settings. By assigning appropriate permissions, you can restrict users’ ability to modify folder properties, move it to a different location, or rename it. Take caution while granting such permissions to ensure the right level of access control.
Q6: Is it possible to set an expiration date for a locked folder on SharePoint?
A6: No, SharePoint does not provide a direct way to set an expiration date for locked folders. However, you can manage folder permissions and regularly review and modify access rights to ensure appropriate control over the folder’s usage. Regularly auditing and maintaining permissions can help maintain security and compliance.
Take control of your workflows today
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Implement moving of snapped features together with the snap line
• Loading branch information
mhugent committed Feb 20, 2013
1 parent 717918d commit 9aa865e0a038cbf41864f230fe61c398cf2dabf8
Showing with 141 additions and 20 deletions.
1. +2 −0 src/app/composer/qgscomposer.h
2. +1 −0 src/app/composer/qgscomposerhtmlwidget.cpp
3. +1 −0 src/app/composer/qgscomposerlabelwidget.cpp
4. +1 −0 src/app/composer/qgscomposerlegendwidget.cpp
5. +1 −0 src/app/composer/qgscomposermapwidget.cpp
6. +1 −0 src/app/composer/qgscomposerpicturewidget.cpp
7. +1 −0 src/app/composer/qgscomposerscalebarwidget.cpp
8. +1 −0 src/app/qgisapp.cpp
9. +1 −0 src/core/composer/qgsaddremoveitemcommand.cpp
10. +10 −9 src/core/composer/qgsatlascomposition.cpp
11. +1 −0 src/core/composer/qgscomposerarrow.cpp
12. +2 −0 src/core/composer/qgscomposerarrow.h
13. +1 −0 src/core/composer/qgscomposerframe.cpp
14. +2 −3 src/core/composer/qgscomposeritem.h
15. +1 −0 src/core/composer/qgscomposerlabel.cpp
16. +1 −0 src/core/composer/qgscomposerlabel.h
17. +1 −0 src/core/composer/qgscomposerlegend.cpp
18. +1 −0 src/core/composer/qgscomposermap.cpp
19. +1 −0 src/core/composer/qgscomposermap.h
20. +1 −0 src/core/composer/qgscomposermultiframe.cpp
21. +1 −0 src/core/composer/qgscomposerpicture.cpp
22. +2 −0 src/core/composer/qgscomposerpicture.h
23. +1 −0 src/core/composer/qgscomposerscalebar.cpp
24. +1 −0 src/core/composer/qgscomposerscalebar.h
25. +2 −0 src/core/composer/qgscomposershape.h
26. +1 −0 src/core/composer/qgscomposertable.h
27. +54 −5 src/core/composer/qgscomposition.cpp
28. +5 −2 src/core/composer/qgscomposition.h
29. +1 −0 src/core/composer/qgspaperitem.cpp
30. +38 −1 src/gui/qgscomposerruler.cpp
31. +3 −0 src/gui/qgscomposerruler.h
@@ -24,6 +24,8 @@
class QgisApp;
class QgsComposerArrow;
class QgsComposerFrame;
class QgsComposerHtml;
class QgsComposerLabel;
class QgsComposerLegend;
class QgsComposerPicture;
@@ -17,6 +17,7 @@
#include "qgscomposeritemwidget.h"
#include "qgscomposermultiframecommand.h"
#include "qgscomposerhtml.h"
#include "qgscomposition.h"
#include <QFileDialog>
#include <QSettings>
@@ -18,6 +18,7 @@
#include "qgscomposerlabelwidget.h"
#include "qgscomposerlabel.h"
#include "qgscomposeritemwidget.h"
#include "qgscomposition.h"
#include "qgsexpressionbuilderdialog.h"
#include <QColorDialog>
@@ -22,6 +22,7 @@
#include "qgscomposerlegendlayersdialog.h"
#include "qgscomposeritemwidget.h"
#include "qgscomposermap.h"
#include "qgscomposition.h"
#include <QFontDialog>
#include <QColorDialog>
@@ -17,6 +17,7 @@
#include "qgscomposermapwidget.h"
#include "qgscomposeritemwidget.h"
#include "qgscomposition.h"
#include "qgsmaprenderer.h"
#include "qgsstylev2.h"
#include "qgssymbolv2.h"
@@ -20,6 +20,7 @@
#include "qgscomposermap.h"
#include "qgscomposerpicture.h"
#include "qgscomposeritemwidget.h"
#include "qgscomposition.h"
#include <QDoubleValidator>
#include <QFileDialog>
#include <QFileInfo>
@@ -18,6 +18,7 @@
#include "qgscomposeritemwidget.h"
#include "qgscomposermap.h"
#include "qgscomposerscalebar.h"
#include "qgscomposition.h"
#include <QColorDialog>
#include <QFontDialog>
#include <QWidget>
@@ -69,6 +69,7 @@
#include <qgsnetworkaccessmanager.h>
#include <qgsapplication.h>
#include <qgscomposition.h>
#include <QNetworkReply>
#include <QNetworkProxy>
@@ -17,6 +17,7 @@
#include "qgsaddremoveitemcommand.h"
#include "qgscomposeritem.h"
#include "qgscomposition.h"
QgsAddRemoveItemCommand::QgsAddRemoveItemCommand( State s, QgsComposerItem* item, QgsComposition* c, const QString& text, QUndoCommand* parent ):
QUndoCommand( text, parent ), mItem( item ), mComposition( c ), mState( s ), mFirstRun( true )
@@ -19,6 +19,7 @@
#include "qgsatlascomposition.h"
#include "qgsvectorlayer.h"
#include "qgscomposermap.h"
#include "qgscomposition.h"
#include "qgsvectordataprovider.h"
#include "qgsexpression.h"
#include "qgsgeometry.h"
@@ -49,7 +50,7 @@ void QgsAtlasComposition::setCoverageLayer( QgsVectorLayer* layer )
mCoverageLayer = layer;
// update the number of features
QgsExpression::setSpecialColumn( "$numfeatures", QVariant( (int)mFeatureIds.size() ) );
QgsExpression::setSpecialColumn( "$numfeatures", QVariant(( int )mFeatureIds.size() ) );
}
void QgsAtlasComposition::beginRender()
@@ -213,18 +214,18 @@ void QgsAtlasComposition::prepareForFeature( size_t featureI )
// geometry height is too big
if ( geom_ratio < map_ratio )
{
// extent the bbox's width
double adj_width = ( map_ratio * geom_rect.height() - geom_rect.width() ) / 2.0;
xa1 -= adj_width;
xa2 += adj_width;
// extent the bbox's width
double adj_width = ( map_ratio * geom_rect.height() - geom_rect.width() ) / 2.0;
xa1 -= adj_width;
xa2 += adj_width;
}
// geometry width is too big
else if ( geom_ratio > map_ratio )
{
// extent the bbox's height
double adj_height = (geom_rect.width() / map_ratio - geom_rect.height() ) / 2.0;
ya1 -= adj_height;
ya2 += adj_height;
// extent the bbox's height
double adj_height = ( geom_rect.width() / map_ratio - geom_rect.height() ) / 2.0;
ya1 -= adj_height;
ya2 += adj_height;
}
new_extent = QgsRectangle( xa1, ya1, xa2, ya2 );
@@ -16,6 +16,7 @@
***************************************************************************/
#include "qgscomposerarrow.h"
#include "qgscomposition.h"
#include <QPainter>
#include <QSvgRenderer>
@@ -19,6 +19,8 @@
#define QGSCOMPOSERARROW_H
#include "qgscomposeritem.h"
#include <QBrush>
#include <QPen>
/**An item that draws an arrow between to points*/
class CORE_EXPORT QgsComposerArrow: public QgsComposerItem
@@ -15,6 +15,7 @@
#include "qgscomposerframe.h"
#include "qgscomposermultiframe.h"
#include "qgscomposition.h"
QgsComposerFrame::QgsComposerFrame( QgsComposition* c, QgsComposerMultiFrame* mf, qreal x, qreal y, qreal width, qreal height )
: QgsComposerItem( x, y, width, height, c )
@@ -17,17 +17,16 @@
#ifndef QGSCOMPOSERITEM_H
#define QGSCOMPOSERITEM_H
#include "qgscomposition.h"
#include "qgscomposeritemcommand.h"
#include <QGraphicsRectItem>
#include <QObject>
class QgsComposition;
class QWidget;
class QDomDocument;
class QDomElement;
class QGraphicsLineItem;
class QqsComposition;
/** \ingroup MapComposer
* A item that forms part of a map composition.
*/
@@ -16,6 +16,7 @@
***************************************************************************/
#include "qgscomposerlabel.h"
#include "qgscomposition.h"
#include "qgsexpression.h"
#include <QDate>
#include <QDomElement>
@@ -18,6 +18,7 @@
#define QGSCOMPOSERLABEL_H
#include "qgscomposeritem.h"
#include <QFont>
class QgsVectorLayer;
class QgsFeature;
@@ -19,6 +19,7 @@
#include "qgscomposerlegend.h"
#include "qgscomposerlegenditem.h"
#include "qgscomposermap.h"
#include "qgscomposition.h"
#include "qgslogger.h"
#include "qgsmaplayer.h"
#include "qgsmaplayerregistry.h"
@@ -16,6 +16,7 @@
***************************************************************************/
#include "qgscomposermap.h"
#include "qgscomposition.h"
#include "qgscoordinatetransform.h"
#include "qgslogger.h"
#include "qgsmaprenderer.h"
@@ -20,6 +20,7 @@
//#include "ui_qgscomposermapbase.h"
#include "qgscomposeritem.h"
#include "qgsrectangle.h"
#include <QFont>
#include <QGraphicsRectItem>
class QgsComposition;
@@ -15,6 +15,7 @@
#include "qgscomposermultiframe.h"
#include "qgscomposerframe.h"
#include "qgscomposition.h"
QgsComposerMultiFrame::QgsComposerMultiFrame( QgsComposition* c, bool createUndoCommands ): mComposition( c ), mResizeMode( UseExistingFrames ), mCreateUndoCommands( createUndoCommands )
{
@@ -17,6 +17,7 @@
#include "qgscomposerpicture.h"
#include "qgscomposermap.h"
#include "qgscomposition.h"
#include "qgsproject.h"
#include <QDomDocument>
#include <QDomElement>
@@ -22,6 +22,8 @@
#include <QImage>
#include <QSvgRenderer>
class QgsComposerMap;
/** \ingroup MapComposer
* A composer class that displays svg files or raster format (jpg, png, ...)
* */
@@ -16,6 +16,7 @@
#include "qgscomposerscalebar.h"
#include "qgscomposermap.h"
#include "qgscomposition.h"
#include "qgsdistancearea.h"
#include "qgsscalebarstyle.h"
#include "qgsdoubleboxscalebarstyle.h"
@@ -17,6 +17,7 @@
#define QGSCOMPOSERSCALEBAR_H
#include "qgscomposeritem.h"
#include <QFont>
#include <QPen>
#include <QColor>
@@ -19,6 +19,8 @@
#define QGSCOMPOSERSHAPE_H
#include "qgscomposeritem.h"
#include <QBrush>
#include <QPen>
/**A composer items that draws common shapes (ellipse, triangle, rectangle)*/
class CORE_EXPORT QgsComposerShape: public QgsComposerItem
@@ -19,6 +19,7 @@
#define QGSCOMPOSERTABLE_H
#include "qgscomposeritem.h"
#include "qgscomposition.h"
#include "qgsfeature.h"
#include <QSet>
@@ -17,7 +17,6 @@
#include <stdexcept>
#include "qgscomposition.h"
#include "qgscomposeritem.h"
#include "qgscomposerarrow.h"
#include "qgscomposerframe.h"
#include "qgscomposerhtml.h"
@@ -1077,25 +1076,28 @@ void QgsComposition::removeSnapLine( QGraphicsLineItem* line )
delete line;
}
QGraphicsLineItem* QgsComposition::nearestSnapLine( bool horizontal, double x, double y, double tolerance )
QGraphicsLineItem* QgsComposition::nearestSnapLine( bool horizontal, double x, double y, double tolerance,
QList< QPair< QgsComposerItem*, QgsComposerItem::ItemPositionMode> >& snappedItems )
{
bool xDirection = doubleNear( y, 0.0 );
double minSqrDist = DBL_MAX;
QGraphicsLineItem* item = 0;
double currentXCoord = 0;
double currentYCoord = 0;
double currentSqrDist = 0;
double sqrTolerance = tolerance * tolerance;
snappedItems.clear();
QList< QGraphicsLineItem* >::const_iterator it = mSnapLines.constBegin();
for ( ; it != mSnapLines.constEnd(); ++it )
{
if ( horizontal )
bool itemHorizontal = doubleNear(( *it )->line().y2() - ( *it )->line().y1(), 0 );
if ( horizontal && itemHorizontal )
{
currentYCoord = ( *it )->line().y1();
currentSqrDist = ( y - currentYCoord ) * ( y - currentYCoord );
}
else
else if ( !itemHorizontal )
{
currentXCoord = ( *it )->line().x1();
currentSqrDist = ( x - currentXCoord ) * ( x - currentXCoord );
@@ -1108,6 +1110,53 @@ QGraphicsLineItem* QgsComposition::nearestSnapLine( bool horizontal, double x, d
}
}
double itemTolerance = 0.0000001;
if ( item )
{
//go through all the items to find items snapped to this snap line
QList<QGraphicsItem *> itemList = items();
QList<QGraphicsItem *>::iterator itemIt = itemList.begin();
for ( ; itemIt != itemList.end(); ++itemIt )
{
QgsComposerItem* currentItem = dynamic_cast<QgsComposerItem*>( *itemIt );
if ( !currentItem || currentItem->type() == QgsComposerItem::ComposerPaper )
{
continue;
}
if ( horizontal )
{
if ( doubleNear( currentYCoord, currentItem->transform().dy() + currentItem->rect().top(), itemTolerance ) )
{
snappedItems.append( qMakePair( currentItem, QgsComposerItem::UpperMiddle ) );
}
else if ( doubleNear( currentYCoord, currentItem->transform().dy() + currentItem->rect().center().y(), itemTolerance ) )
{
snappedItems.append( qMakePair( currentItem, QgsComposerItem::Middle ) );
}
else if ( doubleNear( currentYCoord, currentItem->transform().dy() + currentItem->rect().bottom(), itemTolerance ) )
{
snappedItems.append( qMakePair( currentItem, QgsComposerItem::LowerMiddle ) );
}
}
else
{
if ( doubleNear( currentXCoord, currentItem->transform().dx(), itemTolerance ) )
{
snappedItems.append( qMakePair( currentItem, QgsComposerItem::MiddleLeft ) );
}
else if ( doubleNear( currentXCoord, currentItem->transform().dx() + currentItem->rect().center().x(), itemTolerance ) )
{
snappedItems.append( qMakePair( currentItem, QgsComposerItem::Middle ) );
}
else if ( doubleNear( currentXCoord, currentItem->transform().dx() + currentItem->rect().width(), itemTolerance ) )
{
snappedItems.append( qMakePair( currentItem, QgsComposerItem::MiddleRight ) );
}
}
}
}
return item;
}
@@ -16,11 +16,14 @@
#ifndef QGSCOMPOSITION_H
#define QGSCOMPOSITION_H
#include "qgscomposeritem.h"
#include <memory>
#include <QDomDocument>
#include <QGraphicsScene>
#include <QLinkedList>
#include <QList>
#include <QPair>
#include <QSet>
#include <QUndoStack>
#include <QPrinter>
@@ -30,8 +33,8 @@
#include "qgscomposeritemcommand.h"
#include "qgsatlascomposition.h"
class QgsComposerFrame;
class QgsComposerItem;
class QgsComposerMap;
class QgsPaperItem;
class QGraphicsRectItem;
@@ -264,7 +267,7 @@ class CORE_EXPORT QgsComposition: public QGraphicsScene
/**Remove custom snap line (and delete the object)*/
void removeSnapLine( QGraphicsLineItem* line );
/**Get nearest snap line*/
QGraphicsLineItem* nearestSnapLine( bool horizontal, double x, double y, double tolerance );
QGraphicsLineItem* nearestSnapLine( bool horizontal, double x, double y, double tolerance, QList< QPair< QgsComposerItem*, QgsComposerItem::ItemPositionMode > >& snappedItems );
/**Allocates new item command and saves initial state in it
@param item target item
@@ -16,6 +16,7 @@
***************************************************************************/
#include "qgspaperitem.h"
#include "qgscomposition.h"
#include <QPainter>
QgsPaperItem::QgsPaperItem( QgsComposition* c ): QgsComposerItem( c, false )
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__label__pos
| 0.977549 |
Your First Plugin (Windows)
Windows only
It is presumed you already have the necessary tools installed and are ready to go. If you are not there yet, see Installing Tools (Windows).
Barebones plugin
We will use the RhinoCommon Plugin for Rhino 3D (C#) project template to create a new general purpose plugin. The project template generates the code for a functioning plugin. Follow these steps to build the plugin.
Plugin Template
1. Launch Visual Studio and navigate to File > New > Project….
2. From the Create a new project dialog, select the RhinoCommon Plugin for Rhino 3D (C#) template from the list of installed templates and click Next.
New Project Template
3. Type the project name as shown below. You can enter a different name if you want. The template uses the project name when it creates files and classes. If you enter a different name, your files and classes will have a name different from that of the files and classes mentioned in this tutorial. Don’t forget to choose a location to store the project. When finished, click Create.
New Project Configure
4. Upon clicking Create, the New Rhino C++ Plugin dialog will appear. By default, the template will create a General Utility plugin.
Plugin Settings
5. The New RhinoCommon .NET Plugin dialog allows you to modify a number of settings used by the template when generating the plugin source code:
1. Plugin name: Modify this field if you want to change the name of the plugin’s class name.
2. Command class name:: Modify this field if you want to change the name of the plugin’s initial command class name.
3. Plugin type: Select the type of plugin that you want the template to create.
4. Target Version: Select the target Rhino version.
5. Wndows UI: If you are planning on using Windows Forms or WPF for user interface, instead of Eto, then check the approprate box.
6. Rhino location: Modify this field if the path to Rhino.exe is found in a different location than what is shown.
6. For this tutorial, just accept the default settings. Click the Finish button, and the template begins to generate your plugin project’s folders, files, and classes. When the template is finished, look through the plugin project using Visual Studio’s Solution Explorer
Plugin Anatomy
Use the Solution Explorer to expand the Solution (.sln) so that it looks like this.
Plugin Anatomy
1. HelloRhinoCommon: The plugin project (.csproj), which has the same name as its parent solution. The project that was created for us by the project template we just used.
2. Dependencies: Contains references to both the .NET Framework 4.8 and .NET 7.0 assemblies required by the plugin. The project obtains RhinoCommon dependencies via NuGet.
3. Properties: Contains the AssemblyInfo.cs source file. This file contains the meta-data, such as author and copyright, that appears in Rhino’s Plugin Manager.
4. Embedded Resources: Contains icons, bitmaps, and other non-code resources you want embedded in your plugin.
5. HelloRhinoCommonCommand.cs: The initial plugin command, which inherits from Rhino.Commands.Command.
6. HelloRhinoCommonPlugin.cs: The plugin class, which inherits from Rhino.Plugins.Plugin.
Testing
1. From Visual Studio, navigate to Debug > Start Debugging. You can also press F5, or click the Debug button on Visual Studio’s toolbar. This will load Rhino.
2. From within Rhino, navigate to Tools > Options. Navigate to the Plugins page under Rhino Options and install your plugin.
Rhino Options
3. Once your plugin is loaded, close the options dialog and run your HelloRhinoCommonCommand command.
4. You have finished creating your first plugin!
Adding Additional Commands
Rhino plugins can contain any number of commands. Commands are created by inheriting a new class from Rhino.Commands.Command.
Note, Command classes must return a unique command name. If you try to use a command name that is already in use, then your command will not work.
To add a new Rhino command to your plugin project, right-click on the project, in Visual Studio’s Solution Explorer, and click Add > New Item…. From the Add New Item dialog, select Empty RhinoCommon Command for Rhino 3D (C++), specify the name of the command, and click Add.
Rhino Command
Example
The following example code demonstrates a simple command class that essentially does nothing:
using Rhino;
using Rhino.Commands;
using Rhino.Geometry;
using Rhino.Input;
using Rhino.Input.Custom;
namespace HelloRhinoCommon
{
public class HelloRhinoCommonCommand : Command
{
public HelloRhinoCommonCommand()
{
// Rhino only creates one instance of each command class defined in a
// plug-in, so it is safe to store a refence in a static property.
Instance = this;
}
///<summary>The only instance of this command.</summary>
public static HelloRhinoCommonCommand Instance { get; private set; }
///<returns>The command name as it appears on the Rhino command line.</returns>
public override string EnglishName => "HelloRhinoCommonCommand";
protected override Result RunCommand(RhinoDoc doc, RunMode mode)
{
// TODO: start here modifying the behaviour of your command.
// ---
RhinoApp.WriteLine("The {0} command will add a line right now.", EnglishName);
Point3d pt0;
using (GetPoint getPointAction = new GetPoint())
{
getPointAction.SetCommandPrompt("Please select the start point");
if (getPointAction.Get() != GetResult.Point)
{
RhinoApp.WriteLine("No start point was selected.");
return getPointAction.CommandResult();
}
pt0 = getPointAction.Point();
}
Point3d pt1;
using (GetPoint getPointAction = new GetPoint())
{
getPointAction.SetCommandPrompt("Please select the end point");
getPointAction.SetBasePoint(pt0, true);
getPointAction.DynamicDraw +=
(sender, e) => e.Display.DrawLine(pt0, e.CurrentPoint, System.Drawing.Color.DarkRed);
if (getPointAction.Get() != GetResult.Point)
{
RhinoApp.WriteLine("No end point was selected.");
return getPointAction.CommandResult();
}
pt1 = getPointAction.Point();
}
doc.Objects.AddLine(pt0, pt1);
doc.Views.Redraw();
RhinoApp.WriteLine("The {0} command added one line to the document.", EnglishName);
// ---
return Result.Success;
}
}
}
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-module (demos_state).
-include_lib ("nitrogen_core/include/wf.hrl").
-compile(export_all).
main() -> #template { file="./templates/demos46.html" }.
title() -> "Session State and Page State".
headline() -> "Session State and Page State".
left() ->
[
"
<p>
The first counter to the right is stored in session. If you reload
the current page, or open a new tab in your browser and
navigate to this window, the count is persisted. (It will
disappear once the session times out.)
<p>
The second counter is stored in page state. It exists only for
postbacks on the current page, and its value disappears when
you close the page.
",
linecount:render()
].
right() ->
Elements = [
#p{},
#p{},
#span { text="Counter stored in session state: " }, #span { id=sessionStateCountSpan },
#p {},
#span { text="Counter stored in page state: " }, #span { id=pageStateCountSpan },
#p {},
#button { text="Increment Counters", postback=increment }
],
% Update the elements with their values...
update_elements(),
Elements.
update_elements() ->
% Update the sessionStateCountSpan element.
SessionStateCount = wf:coalesce([wf:session(count), 1]),
wf:set(sessionStateCountSpan, SessionStateCount),
% Update the pageStateCountSpan element...
PageStateCount = wf:coalesce([wf:state(count), 1]),
wf:set(pageStateCountSpan, PageStateCount).
event(increment) ->
SessionCount = wf:coalesce([wf:session(count), 1]),
StateCount = wf:coalesce([wf:state(count), 1]),
wf:session(count, SessionCount + 1),
wf:state(count, StateCount + 1),
update_elements(),
ok.
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27
$\begingroup$
I'm wondering what information might be leaked from the ecryptfs filesystem. This is what Ubuntu uses if you check the box for "encrypted home directory" when using the desktop installer, so is probably quite widely used. Key characteristics of it:
• each file is encrypted individually and stored in the underlying filesystem
• each file is padded in size to be a multiple of 4096 bytes, with a minimum of 12288 (except for directories and soft links)
• file and directory names are encrypted
• the directory structure is maintained
(Note I haven't found a spec about the above, this is worked out from observing my own filesystem - it's stored in /home/.ecryptfs/USERNAME/.Private if you want to examine your own).
So assuming you can't break the encryption keys then you can't examine the contents of the files. However there is still some information left to examine, and just as traffic analysis can deduce useful information from encrypted communications data, I'm wondering how much someone might be able to work out from the directory structure and approximate file sizes.
Certainly you could work out which directories and files contained music, video and photographs from file size. You might even be able to work out what music and videos existed. You could probably work out some of the applications in use due to their pattern of config/cache directories - firefox vs chrome etc.
Is there anything else? Is there a standard analysis of what could be deduced? Does anything else spring to mind?
(I must admit I assumed there was no padding of file sizes when I started writing this question - I'm reassured that there is).
$\endgroup$
26
$\begingroup$
(Disclosure: I'm the author of the functionality that you're asking about (good question!).)
Ubuntu's Encrypted Home Directory feature uses eCryptfs as the filesystem encryption technology. eCryptfs is a layered filesystem built directly into the Linux kernel. It mounts one directory on top of another. The top directory is really just a "virtual" mountpoint. Applications (and humans) can operate within that directory and read and write data without needing to know or be bothered by the encryption that's happening underneath. The lower directory is where the actual encrypted files are stored on disk.
This approach has several advantages. Unlike dmcrypt or full disk encryption, you don't have to pre-allocate a fixed amount of space dedicated to encryption. You can also limit what gets encrypted a bit more to the information that's truly unique to you (improving overall system performance and power consumption). There is some privilege separation between users, with each user having their own unique mount point and encryption keys. And this particular feature is hooked into PAM, so that your directory is mounted automatically when you login, and unmounted when you logout. Also, each and every file is encrypted with a unique, randomly generated key called the 'fek' (which is stored in the header of the file, and wrapped with the MOUNT passphrase). What this means is that two cleartext files that are binary equivalent encrypt to two completely different ciphertexts!
On the flip side, there are a few things that you should be aware of -- now to the meat of your question!
• The upper and lower file structure is pretty much identical, and some file names might be deduced (based on the default Ubuntu home directory skeleton)
• File permissions, file ownerships, and file timestamps are not encrypted (so files with weird permissions, like 0123 might stand out)
• Encrypted filenames limit the upper cleartext filename to about 160 characters (as the filename encryption requires some padding)
• Swap should absolutely be encrypted, if you're using Ubuntu Encrypted Home, as anything in memory can be swapped to disk at any time (and certainly is, if you hibernate a system)
• When the filesystem is actively mounted, only Unix run time Discretionary Access Controls protect you from other users on the system (note that the home directory is permission 0700)
• When the filesystem is actively mounted, eCryptfs does NOT protect you from the root user
• Unless you move your ~/.ecryptfs/wrapped-passphrase off the local system and onto removable media (like a usb stick or flash disk), your LOGIN passphrase is the weak point of the encryption
Now, all that said, I still believe that Ubuntu's Encrypted Home delivers an outstanding balance of security and usability. It's trivial to setup, and with a good login password, it provides extremely strong protection of all of your data in $HOME against off line attacks. In other words, if someone physically steals your laptop, boots a live CD and starts digging around your $HOME/.Private encrypted data, they might glean some information about your filenames, directory structure, and timestamps. But to obtain the contents of any particular file, they will need one of:
1. your LOGIN passphrase and your wrapped-passphrase file
2. the cleartext, 128-bit long, random MOUNT passphrase (stored inside of the wrapped-passphrase file)
3. enough time to brute force the 128-bit key in 2.
4. flaws in AES256
For more information, I've written magazine articles and a running series of blog posts on eCryptfs.
$\endgroup$
• $\begingroup$ Is the only big difference between eCryptFS and EncFS that EncFS is userspace with all that entails, and requires users reserve another directory elsewhere for the encrypted files? $\endgroup$ – Jeff Burdges Jan 17 '12 at 20:13
• 1
$\begingroup$ The combination of filesize and directory structure leakage looks quite problematic to me. You can guess the contents of many directories that contain known data. Self created, unpublished content on the other hand should be mostly secure. $\endgroup$ – CodesInChaos Jan 18 '12 at 12:20
• $\begingroup$ The primary difference between eCryptfs and EncFS is that eCryptfs is an in-kernel filesystem and uses the in-kernel keyring and in-kernel crypto algorithms, and EncFS is user space filesystem that uses FUSE. $\endgroup$ – Dustin Kirkland Jan 19 '12 at 2:03
• $\begingroup$ @DustinKirkland: To obtain the contents of any particular file without knowing your login passphrase, the minimum you need is: the wrapped-passphrase file and enough time to brute force your login passphrase - they just try each login passphrase in turn until they get a plaintext they can verify - whether that be the mount passphrase, or trying a file considered likely to be ASCII text and verifying the bytes are all ASCII. You don't need to brute force the random mount passphrase. $\endgroup$ – Hamish Downer Feb 18 '12 at 21:37
• $\begingroup$ @HamishDowner, if you have the wrapped-passphrase, that's correct. Note that you may not necessarily have the wrapped-passphrase. I store mine on a removable sd card or usb key. $\endgroup$ – Dustin Kirkland Feb 18 '12 at 22:25
5
$\begingroup$
eCryptfs information leakage can occur through various channels. The most serious and common leakage point has been the swap. As mentioned, Ubuntu now encrypts that, but I am told that hibernate is broken with that enabled. Other distros don't necessarily go out of their way to make sure swap is encrypted when eCryptfs is used.
eCryptfs makes no special effort to prevent key proliferation in memory. You can see how bad that problem is by running eCryptfs in a VM, saving state, and searching for your key material in the memory image. Storing your key on a USB drive won't help you much against any user (such as root) that has access to process/kernel memory. Without additional kernel hardening and/or MAC, eCryptfs is totally ineffective against a malicious root user. I also won't rehash the cold boot or DMA attacks that nearly every crypto system for general-purpose computers is susceptible to.
As others have mentioned, applications can write sensitive data anywhere, including places under /tmp or /var. Trying to pin that down on a per-app basis is intractable.
You can certainly use profiling and machine learning techniques to deduce information about the type of data being written and the applications writing the data. For instance, I've successfully applied a kNN model with the features being only number of eCryptfs reads and writes over epochs of time. If/when eCryptfs works on NFS/SMB, that will be a leak. Other features that are more readily observable, such as the approximate file sizes, the approximate file name lengths, and the directory structure, can reveal what type of data you're storing. For example, I would be able to trivially determine whether you had the source code for Tor or TrueCrypt on your box, since the number of files/directory structure for that is very low-entropy.
The CBC attacks in the presentation that Ninefingers referred to don't apply to eCryptfs or BitLocker, which both have 4096-byte CBC extents and non-predictable IVs. I have looked over the XTS spec, and I don't see how it is any more secure than BitLocker with AES-CBC and the Elephant diffuser.
Despite eCryptfs' weaknesses, it's better than nothing, and the ease of eCryptfs deployment makes it much more likely that people will encrypt rather than not encrypt. That said, if you want just about the best protection you can get for the confidentiality of your data-at-rest on a physical drive in your box, I recommend deploying FVE using Win7+BitLocker+TPM rather than per-file encryption using Linux+eCryptfs.
(edit: Someone told me I should state my creds on posts like this. I designed/implemented eCryptfs' crypto, and I was a senior dev on the Microsoft BitLocker team for a couple of years.)
$\endgroup$
2
$\begingroup$
So I answered this on security SE, then quickly realised I'd totally misread the question and explained everything you already know.
The question in my mind can be summarised succinctly by - does encrypting data on a per-file basis as opposed to a whole disk basis add any risk to the cryptographic security of the whole (negating for a moment the fact that if an application writes to /tmp... we know that and that problem is true of all partially encrypted systems).
I am going to say no - in fact the opposite. Whole disk encryption under CBC can be a problem. I make this assertion on the basis that whilst you can deduce information about a file from its size and therefore roughly guess contents, including delimiters such as magic numbers, known patterns, paddings etc, CBC mode is designed precisely to negate the repetition-of-key-schedule problem. Specifically, taking AES as an example, your key undergoes key expansion to form a key schedule, a longer piece of data used in the cipher. If you choose a piece of data as long as this schedule and repeat it X times then encrypt it, you should see X amounts of the same ciphertext. This property is what makes ECB problematic as the data set grows in size.
CBC mode does not have that problem to the same extent - the previous ciphertext is xor'd with the next plaintext block before encryption, meaning the plaintext does not repeat in line with the key schedule any more.
It does however have some problems. This presentation is all about disk encryption challenges and features several problems with CBC when applied to a full disk. Of note is the birthday paradox conclusion - that after a certain size ($2^{b/2}$ where $b$ is the size of the blocks) by the pigeonhole principle you run out of unique combinations and bytes begin to repeat, leaking information. There is, therefore, an upper limit to which CBC is viable, depending on configuration.
Encrypting on a per-file basis using CBC where the files themselves don't reach these values is therefore probably more secure. Modern full disk encryption techniques look at other methods such as XTS which aim to solve such problems as well as solve the encrypt-in-parallel problem (namely, you can't) with CBC.
$\endgroup$
• $\begingroup$ Actually, the pidgeon hole principle does only apply after $2^b$ blocks - the much lower $2^{b/2}$ limit comes from the birthday paradoxon. (Though for AES this still are $2^{64}$ blocks, i.e. 295 Exabytes, if I didn't miscalculate. This is about one tenth of the estimated global amount of data in 2012, and way more than any one file system can handle.) $\endgroup$ – Paŭlo Ebermann Feb 17 '12 at 19:32
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|
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| 0.552155 |
Serial.print()
Descripción
Enviar datos vía comunicacion serial.
Sintaxis
Serial.print(Value);
Parámetros
Value: Variable el cual se desea enviar por comunicacion serial pueden ser String, int, float, char…
Ejemplos
String Saludo = "hola";
int Numerico = 2;
float flotante = 3.0;
void setup() {
Serial.begin(9600);
}
void loop() {
Serial.print(Saludo);
delay(1000);
Serial.print(Numerico);
delay(1000);
Serial.print(flotante);
delay(1000);
}
Interfaz de comunicacion Serial
Comunicación serial
Uso del Serial.print()
En caso que quieras que cada vez que envies un dato ocurra un salto de linea, solo debes agregar «ln» al Serial.print() de esta formo Serial.println().
String Saludo = "hola";
int Numerico = 2;
float flotante = 3.0;
void setup() {
Serial.begin(9600);
}
void loop() {
Serial.println(Saludo);
delay(1000);
Serial.println(Numerico);
delay(1000);
Serial.println(flotante);
delay(1000);
}
Uso de Serial.println()
Uso de Serial.println()
|
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Take the 2-minute tour ×
MathOverflow is a question and answer site for professional mathematicians. It's 100% free, no registration required.
(1) $\pi(n)$, the number of primes at most $n$, is asymptotic to $n / \ln n$.
(2) In the Erdős-Rényi random graph model, $p = \ln n / n$ is a sharp threshold for the connectedness of the graph $G(n,p)$ on $n$ vertices with edge-probability $p$.
Is there any connection between these two, or is the ratio $n / \ln n$ natural enough to arise in several unrelated circumstances by happenstance?
(I ask as neither an expert in random graphs nor in number theory.)
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2
It'd pretty natural, I have no reason to expect a connection. – Charles Sep 18 '11 at 22:31
@Charles: I thought perhaps that was a pun :-). You are likely correct, but it would be more interesting if there were a connection. However, desiring will not make it so. – Joseph O'Rourke Sep 18 '11 at 23:21
1
I imagine the relationship is much like the one offered in this answer mathoverflow.net/questions/53122/mathematical-urban-legends/… . Gerhard "Ask Me About Symbolic Relationships" Paseman, 2011.09.18 – Gerhard Paseman Sep 18 '11 at 23:29
1 Answer 1
up vote 11 down vote accepted
I'd lean towards "coincidence", for a number of reasons:
1. $\pi(n)$ is a cardinality, whereas $p$ is a density; one is comparing apples and oranges. The density of the primes is $1/\log n$, which is quite different from $\log n/n$. (It is true that the average number of divisors $\tau(n)$ of a natural number $n$ is $\log n$, which at first glance seems to match the average degree of a Erdos-Renyi graph of density $\log n/n$, but $\tau(n)$ is very irregularly distributed (its variance is comparable to $\log^3 n$, for instance), in contrast to the Erdos-Renyi degree which obeys a central limit theorem, so this does not seem to be a good match.)
2. For Erdos-Renyi graphs there is a second threshold at 1/n, which is where the giant component begins to emerge. There doesn't seem to be anything analogous for primes.
3. In an Erdos-Renyi graph, n is fixed, and all vertices are given equal weight. For the primes, it is much more natural to work on all the natural numbers at once, and give each natural number n a different weight ($1/n^s$ being a particularly good choice). This pulls the numerology of the two settings even further apart.
Note that there certainly are useful probabilistic models of the primes, such as the Cramer model. However, there appears to be little relation between the Cramer model and the Erdos-Renyi model, other than that they are both random models with a density parameter that involves a logarithm in either the numerator or denominator.
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|
__label__pos
| 0.784724 |
Mohit Goyal
Introduction
When working with sensitive or confidential information in Google Docs, it’s important to take steps to protect your documents from unauthorized access. One of the most effective ways to secure your documents is by password protecting them. Password protection provides an additional layer of security, preventing unauthorized users from viewing, editing, or sharing your documents. In this article, we will explore different methods for password protecting your Google Docs, including using Google’s built-in encryption, setting up two-factor authentication, and using third-party add-ons. By the end of this article, you will have a better understanding of the different options available to protect your Google Docs and be able to select the best method for your needs.
Setting Up Two-Factor Authentication
Two-factor authentication (2FA) is a security feature that adds an extra layer of protection to your Google account, making it more difficult for unauthorized users to gain access to your account. With 2FA enabled, you will need to provide a verification code, in addition to your password, to log in to your Google account.
Here’s how to set up two-factor authentication for your Google account:
1. Go to the Google Account security page (https://myaccount.google.com/security).
2. Click on “2-Step Verification” and then click on “Get started.”
3. Enter your Google account password and click on “Next.”
4. Follow the on-screen instructions to choose a second step for verification. This could be through a text message, a phone call, an authenticator app, or a security key.
5. Once you have selected your preferred verification method, click on “Turn on.”
With 2FA enabled, you will be prompted to enter a verification code every time you log in to your Google account. This provides an additional layer of security, making it much more difficult for unauthorized users to gain access to your account and your Google Docs.
Using Google’s Built-in Encryption
Google provides a built-in encryption feature that allows you to password protect your Google Docs with a passphrase. The encryption feature is available on Google Docs, Sheets, and Slides, and can be a great option if you want to keep your documents secure without relying on any third-party add-ons.
Here’s how to encrypt your Google Docs with a password:
1. Open the Google Doc you want to encrypt.
2. Click on “File” in the top left corner, and then click on “Protect Document” and then “Encrypt Document.”
3. Enter a strong password that you will remember, and confirm the password by typing it again.
4. Click on “Set Password” to enable encryption.
From now on, every time someone tries to access the document, they will be prompted to enter the password you set up. Without the correct password, the document will remain encrypted and inaccessible.
It’s important to remember that this encryption only applies to the specific document you have encrypted. If you want to encrypt multiple documents, you will need to repeat the process for each document. Additionally, if you forget the password, there is no way to recover it, so it’s crucial to keep it in a safe place.
Using Third-Party Add-Ons
In addition to Google’s built-in encryption, there are several third-party add-ons that you can use to password protect your Google Docs. These add-ons provide additional security features and functionality, such as setting different levels of access and permissions for different users.
Here are some of the most popular third-party add-ons for password protecting your Google Docs:
1. DocSecrets: This add-on allows you to encrypt and password protect sensitive data within your Google Docs.
2. Power Tools: Power Tools is a suite of productivity tools that includes a password protection feature for Google Docs.
3. EasyLock: EasyLock provides advanced security features, including password protection, access control, and user permissions.
4. SecureDocs: SecureDocs is a secure document management platform that provides password protection, file-level encryption, and other security features.
To use a third-party add-on, you will first need to install it from the Google Workspace Marketplace. Once the add-on is installed, you can access it from the add-ons menu within your Google Doc. Each add-on will have its own set of instructions for setting up password protection, so be sure to read the documentation carefully.
It’s important to keep in mind that third-party add-ons may come with additional costs or subscription fees, and not all add-ons are created equal. Be sure to do your research before selecting an add-on to ensure that it meets your needs and provides the necessary level of security.
Password Protect Your Google Docs?
You can password protect your Google Docs file by following these steps:
1. Open the Google Docs file you want to password protect.
2. Click on “File” in the top left corner of the screen.
3. Select “Protect Document” from the drop-down menu.
4. In the pop-up window, click on the “Set a Password” option.
5. Enter a password in the “Set Password” field and click “Set.”
6. Confirm the password by entering it again in the “Confirm Password” field and click “Set.”
Once you have set a password, anyone who wants to access the document will need to enter the correct password to view or edit it. Keep in mind that this method only protects the file from unauthorized access within the Google account, and it does not provide full encryption of the document.
Conclusion
In conclusion, password protecting your Google Docs is an essential step to ensure that your sensitive information stays secure. Google provides built-in encryption and two-factor authentication features that can help you protect your documents from unauthorized access. Additionally, third-party add-ons provide advanced security features that can be customized to meet your specific needs.
When selecting a password protection method, it’s important to consider your security requirements and the level of access you want to provide to different users. You should also keep in mind the potential costs and subscription fees associated with third-party add-ons.
By following the steps outlined in this article, you can take the necessary precautions to secure your Google Docs and keep your confidential information safe.
|
__label__pos
| 0.956455 |
win-pvdrivers
view xenvbd_scsiport/xenvbd.c @ 1051:ca993d6b5539
fix regression in xenvbd for >4GB memory
author James Harper <[email protected]>
date Tue May 21 16:09:35 2013 +1000 (2013-05-21)
parents 4de2eb034713
children df3ee58e8b4f
line source
1 /*
2 PV Drivers for Windows Xen HVM Domains
3 Copyright (C) 2007 James Harper
5 This program is free software; you can redistribute it and/or
6 modify it under the terms of the GNU General Public License
7 as published by the Free Software Foundation; either version 2
8 of the License, or (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 */
20 #define INITGUID
22 #include "xenvbd.h"
24 #pragma warning(disable: 4127)
26 /* Not really necessary but keeps PREfast happy */
27 DRIVER_INITIALIZE DriverEntry;
28 static IO_WORKITEM_ROUTINE XenVbd_DisconnectWorkItem;
30 static VOID XenVbd_ProcessSrbList(PXENVBD_DEVICE_DATA xvdd);
31 static BOOLEAN XenVbd_ResetBus(PXENVBD_DEVICE_DATA xvdd, ULONG PathId);
32 static VOID XenVbd_CompleteDisconnect(PXENVBD_DEVICE_DATA xvdd);
34 static BOOLEAN dump_mode = FALSE;
35 #define DUMP_MODE_ERROR_LIMIT 64
36 static ULONG dump_mode_errors = 0;
38 #define StorPortAcquireSpinLock(...) {}
39 #define StorPortReleaseSpinLock(...) {}
41 static ULONG
42 SxxxPortGetSystemAddress(PVOID device_extension, PSCSI_REQUEST_BLOCK srb, PVOID *system_address) {
43 UNREFERENCED_PARAMETER(device_extension);
44 *system_address = (PUCHAR)srb->DataBuffer;
45 return STATUS_SUCCESS;
46 }
48 static PHYSICAL_ADDRESS
49 SxxxPortGetPhysicalAddress(PVOID device_extension, PSCSI_REQUEST_BLOCK srb, PVOID virtual_address, ULONG *length) {
50 UNREFERENCED_PARAMETER(device_extension);
51 UNREFERENCED_PARAMETER(srb);
52 UNREFERENCED_PARAMETER(length);
53 return MmGetPhysicalAddress(virtual_address);
54 }
56 #define SxxxPortNotification(NotificationType, DeviceExtension, ...) XenVbd_Notification##NotificationType(DeviceExtension, __VA_ARGS__)
58 static VOID
59 XenVbd_NotificationRequestComplete(PXENVBD_DEVICE_DATA xvdd, PSCSI_REQUEST_BLOCK srb) {
60 PXENVBD_SCSIPORT_DATA xvsd = (PXENVBD_SCSIPORT_DATA)xvdd->xvsd;
61 srb_list_entry_t *srb_entry = srb->SrbExtension;
62 if (srb_entry->outstanding_requests != 0) {
63 FUNCTION_MSG("srb outstanding_requests = %d\n", srb_entry->outstanding_requests);
64 }
65 xvsd->outstanding--;
66 ScsiPortNotification(RequestComplete, xvsd, srb);
67 }
69 VOID
70 XenVbd_NotificationNextLuRequest(PXENVBD_DEVICE_DATA xvdd, UCHAR PathId, UCHAR TargetId, UCHAR Lun) {
71 ScsiPortNotification(NextLuRequest, xvdd->xvsd, PathId, TargetId, Lun);
72 }
74 VOID
75 XenVbd_NotificationNextRequest(PXENVBD_DEVICE_DATA xvdd) {
76 ScsiPortNotification(NextRequest, xvdd->xvsd);
77 }
80 VOID
81 XenVbd_NotificationBusChangeDetected(PXENVBD_DEVICE_DATA xvdd, UCHAR PathId) {
82 ScsiPortNotification(BusChangeDetected, xvdd->xvsd, PathId);
83 }
85 #include "..\xenvbd_common\common_miniport.h"
88 /* called in non-dump mode */
89 static ULONG
90 XenVbd_HwScsiFindAdapter(PVOID DeviceExtension, PVOID HwContext, PVOID BusInformation, PCHAR ArgumentString, PPORT_CONFIGURATION_INFORMATION ConfigInfo, PBOOLEAN Again) {
91 PXENVBD_SCSIPORT_DATA xvsd = (PXENVBD_SCSIPORT_DATA)DeviceExtension;
92 PXENVBD_DEVICE_DATA xvdd;
93 PACCESS_RANGE access_range;
95 UNREFERENCED_PARAMETER(HwContext);
96 UNREFERENCED_PARAMETER(BusInformation);
97 UNREFERENCED_PARAMETER(ArgumentString);
99 FUNCTION_ENTER();
100 FUNCTION_MSG("IRQL = %d\n", KeGetCurrentIrql());
101 FUNCTION_MSG("xvsd = %p\n", xvsd);
103 if (ConfigInfo->NumberOfAccessRanges != 1) {
104 FUNCTION_MSG("NumberOfAccessRanges wrong\n");
105 FUNCTION_EXIT();
106 return SP_RETURN_BAD_CONFIG;
107 }
108 if (XnGetVersion() != 1) {
109 FUNCTION_MSG("Wrong XnGetVersion\n");
110 FUNCTION_EXIT();
111 return SP_RETURN_BAD_CONFIG;
112 }
113 RtlZeroMemory(xvsd, FIELD_OFFSET(XENVBD_SCSIPORT_DATA, aligned_buffer_data));
115 access_range = &((*(ConfigInfo->AccessRanges))[0]);
117 if (!dump_mode) {
118 xvdd = (PXENVBD_DEVICE_DATA)(ULONG_PTR)access_range->RangeStart.QuadPart;
119 xvsd->xvdd = xvdd;
120 xvdd->xvsd = xvsd;
121 xvdd->aligned_buffer = (PVOID)((ULONG_PTR)((PUCHAR)xvsd->aligned_buffer_data + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1));
122 } else {
123 /* make a copy of xvdd and use that copy */
124 xvdd = (PXENVBD_DEVICE_DATA)xvsd->aligned_buffer_data;
125 memcpy(xvdd, (PVOID)(ULONG_PTR)access_range->RangeStart.QuadPart, sizeof(XENVBD_DEVICE_DATA));
126 /* make sure original xvdd is set to DISCONNECTED or resume will not work */
127 ((PXENVBD_DEVICE_DATA)(ULONG_PTR)access_range->RangeStart.QuadPart)->device_state = DEVICE_STATE_DISCONNECTED;
128 xvsd->xvdd = xvdd;
129 xvdd->xvsd = xvsd;
130 xvdd->aligned_buffer = (PVOID)((ULONG_PTR)((PUCHAR)xvsd->aligned_buffer_data + sizeof(XENVBD_DEVICE_DATA) + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1));
131 if (xvsd->xvdd->device_state != DEVICE_STATE_ACTIVE) {
132 /* if we are not connected to the ring when we start dump mode then there is nothing we can do */
133 FUNCTION_MSG("Cannot connect backend in dump mode - state = %d\n", xvsd->xvdd->device_state);
134 return SP_RETURN_ERROR;
135 }
136 }
137 FUNCTION_MSG("aligned_buffer_data = %p\n", xvsd->aligned_buffer_data);
138 FUNCTION_MSG("aligned_buffer = %p\n", xvdd->aligned_buffer);
140 InitializeListHead(&xvdd->srb_list);
141 xvdd->aligned_buffer_in_use = FALSE;
142 /* align the buffer to PAGE_SIZE */
144 ConfigInfo->MaximumTransferLength = 4 * 1024 * 1024; //BLKIF_MAX_SEGMENTS_PER_REQUEST * PAGE_SIZE;
145 ConfigInfo->NumberOfPhysicalBreaks = ConfigInfo->MaximumTransferLength >> PAGE_SHIFT; //BLKIF_MAX_SEGMENTS_PER_REQUEST - 1;
146 FUNCTION_MSG("ConfigInfo->MaximumTransferLength = %d\n", ConfigInfo->MaximumTransferLength);
147 FUNCTION_MSG("ConfigInfo->NumberOfPhysicalBreaks = %d\n", ConfigInfo->NumberOfPhysicalBreaks);
148 if (!dump_mode) {
149 xvdd->aligned_buffer_size = BLKIF_MAX_SEGMENTS_PER_REQUEST * PAGE_SIZE;
150 } else {
151 xvdd->aligned_buffer_size = DUMP_MODE_UNALIGNED_PAGES * PAGE_SIZE;
152 }
154 FUNCTION_MSG("MultipleRequestPerLu = %d\n", ConfigInfo->MultipleRequestPerLu);
155 FUNCTION_MSG("TaggedQueuing = %d\n", ConfigInfo->TaggedQueuing);
156 FUNCTION_MSG("AutoRequestSense = %d\n", ConfigInfo->AutoRequestSense);
157 ConfigInfo->CachesData = FALSE;
158 ConfigInfo->MapBuffers = TRUE;
159 ConfigInfo->AlignmentMask = 0;
160 ConfigInfo->NumberOfBuses = 1;
161 ConfigInfo->InitiatorBusId[0] = 1;
162 ConfigInfo->MaximumNumberOfLogicalUnits = 1;
163 ConfigInfo->MaximumNumberOfTargets = 2;
164 FUNCTION_MSG("MapBuffers = %d\n", ConfigInfo->MapBuffers);
165 FUNCTION_MSG("NeedPhysicalAddresses = %d\n", ConfigInfo->NeedPhysicalAddresses);
166 if (ConfigInfo->Dma64BitAddresses == SCSI_DMA64_SYSTEM_SUPPORTED) {
167 FUNCTION_MSG("Dma64BitAddresses supported\n");
168 ConfigInfo->Dma64BitAddresses = SCSI_DMA64_MINIPORT_SUPPORTED;
169 ConfigInfo->ScatterGather = TRUE;
170 ConfigInfo->Master = TRUE;
171 } else {
172 FUNCTION_MSG("Dma64BitAddresses not supported\n");
173 ConfigInfo->ScatterGather = FALSE;
174 ConfigInfo->Master = FALSE;
175 }
176 *Again = FALSE;
178 FUNCTION_EXIT();
180 return SP_RETURN_FOUND;
181 }
183 /* Called at PASSIVE_LEVEL for non-dump mode */
184 static BOOLEAN
185 XenVbd_HwScsiInitialize(PVOID DeviceExtension) {
186 PXENVBD_SCSIPORT_DATA xvsd = (PXENVBD_SCSIPORT_DATA)DeviceExtension;
187 PXENVBD_DEVICE_DATA xvdd = (PXENVBD_DEVICE_DATA)xvsd->xvdd;
188 ULONG i;
190 FUNCTION_ENTER();
191 FUNCTION_MSG("IRQL = %d\n", KeGetCurrentIrql());
192 FUNCTION_MSG("dump_mode = %d\n", dump_mode);
194 xvdd->shadow_free = 0;
195 memset(xvdd->shadows, 0, sizeof(blkif_shadow_t) * SHADOW_ENTRIES);
196 for (i = 0; i < SHADOW_ENTRIES; i++) {
197 xvdd->shadows[i].req.id = i;
198 /* make sure leftover real requests's are never confused with dump mode requests */
199 if (dump_mode)
200 xvdd->shadows[i].req.id |= SHADOW_ID_DUMP_FLAG;
201 put_shadow_on_freelist(xvdd, &xvdd->shadows[i]);
202 }
204 if (!dump_mode) {
205 /* nothing */
206 } else {
207 xvdd->grant_tag = (ULONG)'DUMP';
208 }
210 FUNCTION_EXIT();
212 return TRUE;
213 }
215 /* this is only used during hiber and dump */
216 static BOOLEAN
217 XenVbd_HwScsiInterrupt(PVOID DeviceExtension)
218 {
219 PXENVBD_SCSIPORT_DATA xvsd = DeviceExtension;
220 XenVbd_HandleEvent(xvsd->xvdd);
221 //SxxxPortNotification(NextLuRequest, xvdd, 0, 0, 0);
222 return TRUE;
223 }
225 static BOOLEAN
226 XenVbd_HwScsiResetBus(PVOID DeviceExtension, ULONG PathId)
227 {
228 PXENVBD_SCSIPORT_DATA xvsd = DeviceExtension;
229 return XenVbd_ResetBus(xvsd->xvdd, PathId);
230 }
232 static VOID
233 XenVbd_CompleteDisconnect(PXENVBD_DEVICE_DATA xvdd) {
234 PXENVBD_SCSIPORT_DATA xvsd = (PXENVBD_SCSIPORT_DATA)xvdd->xvsd;
235 PSCSI_REQUEST_BLOCK srb;
237 if (xvsd->stop_srb) {
238 srb = xvsd->stop_srb;
239 xvsd->stop_srb = NULL;
240 ScsiPortNotification(RequestComplete, xvsd, srb);
241 }
242 }
244 static BOOLEAN
245 XenVbd_HwScsiStartIo(PVOID DeviceExtension, PSCSI_REQUEST_BLOCK srb) {
246 PXENVBD_SCSIPORT_DATA xvsd = DeviceExtension;
247 PXENVBD_DEVICE_DATA xvdd = (PXENVBD_DEVICE_DATA)xvsd->xvdd;
248 PSRB_IO_CONTROL sic;
250 if ((LONG)xvsd->outstanding < 0) {
251 FUNCTION_MSG("HwScsiStartIo outstanding = %d\n", xvsd->outstanding);
252 }
253 if (srb->PathId != 0 || srb->TargetId != 0 || srb->Lun != 0) {
254 FUNCTION_MSG("HwScsiStartIo (Out of bounds - PathId = %d, TargetId = %d, Lun = %d)\n", srb->PathId, srb->TargetId, srb->Lun);
255 srb->SrbStatus = SRB_STATUS_NO_DEVICE;
256 ScsiPortNotification(RequestComplete, xvsd, srb);
257 } else if (srb->Function == SRB_FUNCTION_IO_CONTROL && memcmp(((PSRB_IO_CONTROL)srb->DataBuffer)->Signature, XENVBD_CONTROL_SIG, 8) == 0) {
258 sic = srb->DataBuffer;
259 switch(sic->ControlCode) {
260 case XENVBD_CONTROL_EVENT:
261 srb->SrbStatus = SRB_STATUS_SUCCESS;
262 ScsiPortNotification(RequestComplete, xvsd, srb);
263 break;
264 case XENVBD_CONTROL_STOP:
265 if (xvdd->shadow_free == SHADOW_ENTRIES) {
266 srb->SrbStatus = SRB_STATUS_SUCCESS;
267 ScsiPortNotification(RequestComplete, xvsd, srb);
268 FUNCTION_MSG("CONTROL_STOP done\n");
269 } else {
270 xvsd->stop_srb = srb;
271 FUNCTION_MSG("CONTROL_STOP pended\n");
272 }
273 break;
274 case XENVBD_CONTROL_START:
275 // we might need to reload a few things here...
276 ScsiPortNotification(RequestComplete, xvsd, srb);
277 break;
278 default:
279 FUNCTION_MSG("XENVBD_CONTROL_%d\n", sic->ControlCode);
280 srb->SrbStatus = SRB_STATUS_ERROR;
281 ScsiPortNotification(RequestComplete, xvsd, srb);
282 break;
283 }
284 } else if (xvdd->device_state == DEVICE_STATE_INACTIVE) {
285 FUNCTION_MSG("HwScsiStartIo Inactive Device (in StartIo)\n");
286 srb->SrbStatus = SRB_STATUS_NO_DEVICE;
287 ScsiPortNotification(RequestComplete, xvsd, srb);
288 } else {
289 xvsd->outstanding++;
290 XenVbd_PutSrbOnList(xvdd, srb);
291 }
292 /* HandleEvent also puts queued SRB's on the ring */
293 XenVbd_HandleEvent(xvdd);
294 /* need 2 spare slots - 1 for EVENT and 1 for STOP/START */
295 if (xvsd->outstanding < 30) {
296 ScsiPortNotification(NextLuRequest, xvsd, 0, 0, 0);
297 } else {
298 ScsiPortNotification(NextRequest, xvsd);
299 }
300 return TRUE;
301 }
303 static SCSI_ADAPTER_CONTROL_STATUS
304 XenVbd_HwScsiAdapterControl(PVOID DeviceExtension, SCSI_ADAPTER_CONTROL_TYPE ControlType, PVOID Parameters) {
305 PXENVBD_SCSIPORT_DATA xvsd = DeviceExtension;
306 PXENVBD_DEVICE_DATA xvdd = (PXENVBD_DEVICE_DATA)xvsd->xvdd;
307 SCSI_ADAPTER_CONTROL_STATUS Status = ScsiAdapterControlSuccess;
308 PSCSI_SUPPORTED_CONTROL_TYPE_LIST SupportedControlTypeList;
310 FUNCTION_ENTER();
311 FUNCTION_MSG("IRQL = %d\n", KeGetCurrentIrql());
312 FUNCTION_MSG("xvsd = %p\n", xvsd);
314 switch (ControlType) {
315 case ScsiQuerySupportedControlTypes:
316 SupportedControlTypeList = (PSCSI_SUPPORTED_CONTROL_TYPE_LIST)Parameters;
317 FUNCTION_MSG("ScsiQuerySupportedControlTypes (Max = %d)\n", SupportedControlTypeList->MaxControlType);
318 SupportedControlTypeList->SupportedTypeList[ScsiQuerySupportedControlTypes] = TRUE;
319 SupportedControlTypeList->SupportedTypeList[ScsiStopAdapter] = TRUE;
320 SupportedControlTypeList->SupportedTypeList[ScsiRestartAdapter] = TRUE;
321 break;
322 case ScsiStopAdapter:
323 FUNCTION_MSG("ScsiStopAdapter\n");
324 if (xvdd->device_state == DEVICE_STATE_INACTIVE) {
325 FUNCTION_MSG("inactive - nothing to do\n");
326 break;
327 }
328 XN_ASSERT(IsListEmpty(&xvdd->srb_list));
329 XN_ASSERT(xvdd->shadow_free == SHADOW_ENTRIES);
330 break;
331 case ScsiRestartAdapter:
332 FUNCTION_MSG("ScsiRestartAdapter\n");
333 if (xvdd->device_state == DEVICE_STATE_INACTIVE) {
334 FUNCTION_MSG("inactive - nothing to do\n");
335 break;
336 }
337 /* increase the tag every time we stop/start to track where the gref's came from */
338 xvdd->grant_tag++;
339 break;
340 case ScsiSetBootConfig:
341 FUNCTION_MSG("ScsiSetBootConfig\n");
342 break;
343 case ScsiSetRunningConfig:
344 FUNCTION_MSG("ScsiSetRunningConfig\n");
345 break;
346 default:
347 FUNCTION_MSG("UNKNOWN\n");
348 break;
349 }
351 FUNCTION_EXIT();
353 return Status;
354 }
356 NTSTATUS
357 DriverEntry(PDRIVER_OBJECT DriverObject, PUNICODE_STRING RegistryPath) {
358 ULONG status;
359 HW_INITIALIZATION_DATA HwInitializationData;
361 /* RegistryPath == NULL when we are invoked as a crash dump driver */
362 if (!RegistryPath) {
363 dump_mode = TRUE;
364 XnPrintDump();
365 }
367 FUNCTION_ENTER();
368 FUNCTION_MSG("IRQL = %d\n", KeGetCurrentIrql());
369 FUNCTION_MSG("DriverObject = %p, RegistryPath = %p\n", DriverObject, RegistryPath);
371 RtlZeroMemory(&HwInitializationData, sizeof(HW_INITIALIZATION_DATA));
372 HwInitializationData.HwInitializationDataSize = sizeof(HW_INITIALIZATION_DATA);
373 HwInitializationData.AdapterInterfaceType = PNPBus; /* not Internal */
374 HwInitializationData.SrbExtensionSize = sizeof(srb_list_entry_t);
375 HwInitializationData.NumberOfAccessRanges = 1;
376 HwInitializationData.MapBuffers = TRUE;
377 HwInitializationData.NeedPhysicalAddresses = FALSE;
378 HwInitializationData.TaggedQueuing = TRUE;
379 HwInitializationData.AutoRequestSense = TRUE;
380 HwInitializationData.MultipleRequestPerLu = TRUE;
381 HwInitializationData.ReceiveEvent = FALSE;
382 HwInitializationData.HwInitialize = XenVbd_HwScsiInitialize;
383 HwInitializationData.HwStartIo = XenVbd_HwScsiStartIo;
384 HwInitializationData.HwFindAdapter = XenVbd_HwScsiFindAdapter;
385 HwInitializationData.HwResetBus = XenVbd_HwScsiResetBus;
386 HwInitializationData.HwAdapterControl = XenVbd_HwScsiAdapterControl;
387 if (!dump_mode) {
388 HwInitializationData.DeviceExtensionSize = FIELD_OFFSET(XENVBD_SCSIPORT_DATA, aligned_buffer_data) + UNALIGNED_BUFFER_DATA_SIZE;
389 } else {
390 HwInitializationData.HwInterrupt = XenVbd_HwScsiInterrupt;
391 HwInitializationData.DeviceExtensionSize = FIELD_OFFSET(XENVBD_SCSIPORT_DATA, aligned_buffer_data) + sizeof(XENVBD_DEVICE_DATA) + UNALIGNED_BUFFER_DATA_SIZE_DUMP_MODE;
392 }
393 status = ScsiPortInitialize(DriverObject, RegistryPath, &HwInitializationData, NULL);
395 if(!NT_SUCCESS(status)) {
396 FUNCTION_MSG("ScsiPortInitialize failed with status 0x%08x\n", status);
397 }
399 FUNCTION_EXIT();
401 return status;
402 }
|
__label__pos
| 0.995094 |
I have recently installed LMDE (Linux Mint Debian Edition) onto my laptop but I can't isntall anything because it can't find the sources. I'm assuming I need to edit the /etc/apt/sources.list file but I'm not sure. And if so I don't know in what way I should edit the file.
Recommended Answers
If it's a clean install, you should already have your default sources set to go.
I would check the basics:
Do you have intenet connectivity? Try pinging 4.2.2.1.
Do you have working DNS? Try pinging www.google.com, does it resolve?
What does apt-get update return?
Jump to Post
All 4 Replies
If it's a clean install, you should already have your default sources set to go.
I would check the basics:
Do you have intenet connectivity? Try pinging 4.2.2.1.
Do you have working DNS? Try pinging www.google.com, does it resolve?
What does apt-get update return?
The internet connection was always working fine. Don't know why but now it's working. Go figure.
They've chagned the site. How do I mark solved?
How do I mark solved?
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Addition and Subtraction of two numbers
Addition and subtraction
Students can scan the QR code to start!
Session Overview
First exercises with additions and subtractions: having to choose the right numbers or operations
15 min
• Agility with addition and subtraction.
• Understanding the importance of the order of operations.
• Positive and negative numbers.
• Having done the introduction to Polyup
Getting students ready
1. Students should go to https://m.polyup.com/MJ7MXAF/
2. Students should go to polyup.com on their computer, tablet or smartphone.
• They should click on the play button to access the Polyup environment.
• If they have an account, they can sign in with their username or email, if not, they should create a student account.
• Students should click on Poly at the bottom and enter the following code: MJ7MXAF
Starting the session
1. The teacher should put the introductory video in front of the class.
1. Students should follow the actions of the video
2. Students should open the next chip and try to find the solution
1. The teacher should show the solution in the board after 5 min approximately.
3. Students should open the second chip and try to find the solution.
1. The teacher should show the solution in the board after 5 min approximately.
4. The rest of the chips should be solved by the students on their own, either in class or at home.
** To know more about how to assign machines (the session) as homework on google classroom visit the following article
.
• Find the session solutions on the Teacher’s Manual!
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Countdown to a certain Date?
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• 7 posts
• Hello everyone,
I'd like to make a screen which simply shows todays date and system time, counting down to a certain, specified date.
Lets say i wanna count from June 1st to June 15th, displayed as simple text in days/hours/minutes/seconds. It's important to have it count down, as i want to show how many days/hours/minutes/seconds are left until this specific date.
Is that even possible with construct 3?
Now i get how a normal countdown works but i couldn't understand, how can i specify a certain date in a variable and then get the difference to the time right now (while the code is running), which i need in order to set the countdown.
If anyone can help me out, i would be extremly thankful.
• Works great!
I am curious if you can break the formulas down a bit.
I am not to familiar with Java Script input.
Set unixDate
Browser.ExecJS("new Date('" & textDate & "').getTime() / 1000")
Please tell what the formula is doing.
I can only assume it is translating textDate into Unix.
If so is it the date only or does it include the time?
Why divide by 1000?
set difference
int(unixDate-(unixtime/1000))
Why divide by 1000?
• JS code converts date (textDate) into Unix Epoch Time - number of seconds that have elapsed since January 1, 1970
"/1000" because that JS function returns milliseconds, and we need seconds.
unixtime is a C3 expression, it returns current system time in unix format, also in milliseconds.
• Thanks for the example.
Set unixDate
Browser.ExecJS("new Date('" & textDate & "').getTime() / 1000")
[/code:315j3yd3]
If unixdate is a C3 system expression, why do you use js?
• Try Construct 3
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• unixtime can only return current time. So to convert any date/time in the future you need to use some external function or addon.
Rex's "date" addon can also convert to unix time.
EDIT:
Actually, you don't need to use C3 expression and can calculate the remaining number of seconds directly in JS:
Set difference to: Browser.ExecJS("(new Date('" & textDate & "').getTime() - new Date().getTime()) / 1000")
• Here you go:
https://www.dropbox.com/s/zui1jyusc43ky ... e.c3p?dl=0
Hi and sorry to bother you with this old topic but do you know how to do this but online?If I use system date people will hack the countdown for a specific action in my app XD
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DEBIAN STRETCH KURULUM NOTLARI ============================== Kurulum, Netinstall CD'si ile yapılacak. Temel sistemin kurulması ------------------------ __Select a language__: English __Select your location__: other -> Asia -> Turkey __Configure locales__: United States en_US.UTF-8 __Additional locales__: tr_TR.UTF-8 __System Locale__: en_US.UTF-8 __Select a keyboard layout__: PC-style -> Turkish (Q layout) __Configure the network__: Özel bi durum olmadıkça DHCP kulan __DNS__: ``` 208.67.222.222 208.67.220.220 8.8.8.8 8.8.4.4 ``` __Configure the clock (time zone)__: Europe/Istanbul __Partitition disks__: Manual __Partition table__: gpt #### örnek bölümlendirme 1 ``` / 500 MB sda1 (bootable) /usr 5 GB sda2 (~3 GB) /var 5 GB sda3 (~2 GB) /tmp 500 MB sda4 (tmpfs yapılabilir) swap 1 GB sda5 (hibernate için ~RAM) /home X GB sda6 ``` #### örnek bölümlendirme 2 ``` /boot 100 MB sda1 (bootable) crypto X GB sda2 (mount to /) ``` SSD disk kullanılıyor ve TRIM desteği varsa ext4 partitionlarda discard özelliği aktif hale getirilecek. Bütün partitionlarda noatime özelliği aktif olsun. Kurulum sonrası ilk ayarlar --------------------------- #### /etc/apt/apt.conf.d/80recommends ``` APT::Install-Recommends "0"; APT::Install-Suggests "0"; ``` #### /etc/apt/sources.list ``` deb http://ftp2.de.debian.org/debian/ stretch main non-free contrib deb-src http://ftp2.de.debian.org/debian/ stretch main non-free contrib deb http://security.debian.org/debian-security stretch/updates main contrib non-free deb-src http://security.debian.org/debian-security stretch/updates main contrib non-free ``` #### Multimedia deposu kullanilacaksa... ``` deb http://www.deb-multimedia.org stretch main non-free deb-src http://www.deb-multimedia.org stretch main non-free ``` #### x2go kullanılacaksa... ``` deb http://packages.x2go.org/debian stretch main ``` #### riot.im kurulacaksa... ``` deb https://riot.im/packages/debian/ stable main ``` #### Ring kurulacaksa... ``` deb https://dl.ring.cx/ring-nightly/debian_9/ ring main ``` #### Anahtar yüklemeleri ###### Multimedia ```bash apt install deb-multimedia-keyring apt update ``` ###### x2go ```bash apt-get install x2go-keyring apt update ``` ###### riot.im ```bash wget -qNP /tmp/ https://riot.im/packages/debian/repo-key.asc apt-key add /tmp/repo-key.asc apt update ``` ###### Ring ```bash apt install apt-transport-https dirmngr apt-key adv --keyserver pgp.mit.edu --recv-keys \ A295D773307D25A33AE72F2F64CD5FA175348F84 apt update ``` #### Güncelleme ```bash apt update && \ apt -dy dist-upgrade && \ apt autoclean && \ apt dist-upgrade && \ apt autoremove --purge ``` #### İlk aşamada yüklenecek paketler ```bash apt install zsh tmux git vim-nox autojump bridge-utils apt install dbus libpam-systemd (container içine kurulumlarda gerekebilir) ``` #### Default paketlerden silinecekler ```bash apt purge installation-report reportbug nano apt purge tasksel tasksel-data task-english os-prober rm -rf /var/lib/os-prober # autoremove ile silinmemesi icin bu komut gerekli. apt install openssh-server apt autoremove --purge ``` #### Grub ayarları Grub için parola iki kere girilecek, görüntü gelmeyecek. ```bash grub-mkpasswd-pbkdf2 >>/etc/grub.d/01_password ``` ###### /etc/grub.d/01_password ``` #!/bin/sh # parola grub-mkpasswd-pbkdf2 komutu ile üretiliyor cat </dev/null | head -10 } update_hosts(){ HOSTS=`cat < /tmp/mplayer.pipe" bind[mplayer_mute] = Pause program[mplayer_vol_l] = sh -c "echo 'volume -1' > /tmp/mplayer.pipe" bind[mplayer_vol_l] = XF86AudioLowerVolume program[mplayer_vol_r] = sh -c "echo 'volume +1' > /tmp/mplayer.pipe" bind[mplayer_vol_r] = XF86AudioRaiseVolume ``` #### ~/bin/ ###### capture_screen Ekran görüntüsünü alıp SimpleHTTPServer ile web'ten yayınlar. Pencere yöneticisi için kısayol oluşturulsun. ``` #!/bin/bash mkdir -p /tmp/screenshot scrot /tmp/screenshot/screenshot.png echo '' > /tmp/screenshot/index.html x-terminal-emulator -vb +sb -fg NavajoWhite1 -bg black -cr yellow \ -fn "-misc-fixed-medium-r-normal--18-120-100-100-c-90-iso10646-1" \ -T "Capture Screen" -e /bin/bash -c \ "/sbin/ifconfig eth | grep 'inet addr:' | cut -d: -f2 | cut -d' ' -f1; \ echo -e '\n\n'; \ cd /tmp/screenshot && python -m SimpleHTTPServer 9999" ``` ###### zargan.py Kod deposundan kopyalanacak. #### Firefox ###### preferences * General -> When Firefox starts: Show a blank page * General -> Home page: https://emrah.com/ * General -> Language -> Choose -> Turkish (add, move down) * General -> Language -> Check your spelling as you type: false * General -> Downloads -> Always ask you where to save files: true * General -> Firefox Updates -> Automatically update search engines: False * General -> Network Proxy -> Settings ``` Manual Proxy Configuration SOCKS Host: localhost SOCKS Port: 28080 SOCKS Type: SOCKS v5 No Proxy for: localhost, 127.0.0.1, 192.168.0.0/16, 172.16.0.0/12, 10.0.0.0/8 Proxy DNS when using SOCKS v5: true ``` * Search -> Default Search Engine: DuckDuckGo * Privacy & Security -> Forms & Passwords -> Remember logins and passwords for websites: False * Privacy & Security -> History -> Never Remeber History * Privacy & Security -> Tracking Protection -> Always * Privacy & Security -> Block dangerous downloads: False * Privacy & Security -> Certificates -> View Certificates -> Authorities -> Delete or Distrust ``` E-Tuğra (silinecek) TUBITAK (silinecek) TURKTRUST (silinecek) ``` Bu işlem sonrasında otorite, listede kalacak ama güvenilir olduğunu belirten OK işareti kalkacak. ###### about:config * __browser.cache.disk.enable__: false * __browser.sessionstore.interval__: 60000 * __network.prefetch-next__: false * __intl.charset.fallback.utf8_for_file__: true ###### Add-ons * Tridactyl * Adblock Plus * NoScript Security Suite by Giorgio Maone * Markdown Viewer Webext ###### Diğer * Noscript whitelist temizlenir. * Bir kere boş tab açılıp Tridactyl için izin verilir. * Noscript izni verilecek sitelere bir kere girilir. * duckduckgo * demo siteler * player (dash, hls) * egroupware * github, ycombinator, wttr.in, debian, pypi * bankalar, yemeksepeti * digital ocean * radyolar ###### second profile __second__ adlı profili oluştur. ```bash firefox-esr -no-remote -ProfileManager ``` ```bash cd ~/.mozilla/firefox DEFAULT=$(ls | grep .default) SECOND=$(ls | grep .second) rm -rf $SECOND cp -arp $DEFAULT $SECOND ``` #### bitlbee ###### /etc/bitlbee/bitlbee.conf ``` DaemonInterface = 127.0.0.1 AuthMode = Closed AuthPassword = md5:... ``` ###### md5 değerini bulmak için ```bash bitlbee -x hash parola1 ``` ```bash /etc/init.d/bitlbee restart ``` #### weechat Ayarların default değerlerle oluşması için weechat-curses bir kere başlatılır. ###### ~/.weechat/weechat.conf ``` item_time_format = "%a, %d %b %Y %H:%M" ``` ###### ~/.weechat/logger.conf ``` auto_log = off ``` ###### ~/.weechat/irc.conf ``` [server_default] nicks = "emrah,emrah_,emrah__" realname = "emrah" username = "emrah" [server] freenode.addresses = "chat.freenode.net/7000" freenode.ssl = on freenode.ssl_dhkey_size = 512 freenode.password = "parola" freenode.autoconnect = on freenode.autoreconnect = on freenode.autoreconnect_delay = 10 freenode.nicks = "emrah,emrah_,emrah__" freenode.username = "emrah" freenode.realname = "emrah" freenode.autojoin = "#gnu,#debian" freenode.autorejoin = on freenode.autorejoin_delay = 1 bitlbee_loc.addresses = "127.0.0.1/6667" bitlbee_loc.ssl = off bitlbee_loc.password = "parola1" bitlbee_loc.autoconnect = on bitlbee_loc.autoreconnect = on bitlbee_loc.autoreconnect_delay = 10 bitlbee_loc.nicks = "emrah,emrah_,emrah__" bitlbee_loc.username = "emrah" bitlbee_loc.realname = "emrah" bitlbee_loc.command = "/msg nickserv identify parola2" bitlbee_loc.autorejoin = on bitlbee_loc.autorejoin_delay = 1 ``` ###### bitlbee hesabının açılması ``` register parola2 set charset utf-8 # gtalk account add jabber [email protected] account gtalk set ssl true account gtalk set server talk.google.com account gtalk set port 5223 account gtalk set password "parola_gtalk" account gtalk on ```
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HP Officejet 6812 Wireless Setup
123-hp-com-banner
HP Officejet 6812 Wireless Setup
PRINT FROM A WIRELESS-CAPABLE COMPUTER
Without connecting to a wireless network, one can print wirelessly with the use of HP wireless direct in their HP Officejet 6812 printer.
How to print from a wireless-capable computer (Windows)?
1. Ensure that the HP Wireless Direct option is switched on.
2. Now, the Wi-Fi connection on your printer needs to be switched on.
3. From your computer, connect to a new network as you usually do.
4. Choose the wireless network you would to connect to.
5. When prompted, enter the security code for the network.
6. If your printer uses the network through an USB connection, then do the following.
1. Based on the operating system you use, do the following,
1. Windows 8: Start – – > app bar – – > All Apps – – > Printer Name – – > Utilities.
2. Windows 7, Windows Vista and Windows XP: Start – – > All Programs – – > HP – – > Printer Folder.
2. Choose Printer Setup & Software and then tap on Connect a new printer.
3. Select Wireless option in the Connection Option dialog box. From the list displayed, choose the HP printer software.
4. Now, follow the on-screen instructions to complete the process.
7. Print the document that you need to.
How to print from a wireless-capable computer (OS X)?
1. Ensure that your HP wireless direct is switched on.
2. Switch on AirPort.
3. On clicking the AirPort icon, select the HP wireless direct name which is listed as HP-Print-**-OfficejetXXXX.)
4. Add your HP printer.
1. Under the System Preferences section, choose Print & Fax or Print & Scan, depending on the operating system you use.
2. Select the + (plus) symbol on the left hand corner where the printers are listed.
3. Tap on the printer you want to use and then click Add.
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Cyber Pickpocketers want your Passwords
Updated April, 2019: This article was originally written in Nov., 2011. We thought it was just as important today, so spruced it up with some current examples.
How is a pickpocketer like an online hacker?
Offline it may happen like this: Someone accidentally bumps into you and, the next thing you know, your wallet is missing.
Online you may not even know it is happening, but if someone does find out your password (for your website, your email account, your Facebook account or worse…), they can cause lots of damage:
• They could steal your money or personal, private information
• They could pull down your website, put up bad code (that collects your visitor's info), or send your visitors to an inappropriate site
• They could email annoying spam to all your contacts (friends, family, business associates) disguised as your email address
Whatever they do, the result is similar to being mugged or pickpocketed: You may be left scared, waiting for them to come back and wondering, Why me?
Typically, hackers (like muggers and pickpocketers) aren't after you personally, though try telling that to someone who has just encountered one. It probably has nothing to do with you…other than you were the easiest target around them at that moment.
Are you making yourself an easy target? Are you doing any of the following:
• Using the same password everywhere
• Using a common word, like your dog's name, for your password
You probably thought it was just easier to use the same password everywhere. Nowadays, we have to remember so many passwords. It just makes sense to make it easy on ourselves, right? Well, not with cyber pickpocketers (better known as Hackers) around.
Let's look at what is known about how some of these Hackers work (there are a lot of other ways, but these are two of the more common types):
1. The Repeat Offender: Let's say you use that same password everywhere. A hacker figures it out in one place, do you think he/she is going to stop there? It doesn't matter how obscure the word is, if you use that password everywhere and someone figures it out in one place, they have then figured it out for all your accounts. And think about it this way:
• If they have access to your email account, they probably have access to more info about you than they need
• Just getting into your Facebook account could eventually lead them to where you bank, and they are banking on you using that same password everywhere
• Do yourself a favor, if you do nothing else right now, make your bank password really secure… now!
• AND AS A BUSINESS OWNER: Do your customers/clients’ a favor – make sure their info is safe, by creating unique, secure passwords for your site and email address (wherever they share info with you!)
2. The Dictionary Thief: These guys aren't stealing dictionaries, but they are making an educated guess you are using a common name or a word found in the dictionary. These guys/gals have done their research, they also know the most common words people use as passwords. Here are a few (not in any particular order) of The Worst Passwords Of 2018 according to Forbes.
• 123456
• password
• 123456789
• 12345678
• monkey
• sunshine
• princess
• iloveyou
If you are using any of these most commonly used passwords, PLEASE change them immediately.
Those dictionary thieves create computer programs to run a script that goes through every common word and name. The computer script does the work for them, they just let the program run – any time of day or night – until it finds the password that gets them logged in!
Again, in most cases, they aren't going after you personally, they are just looking for an easy password to gain access. So, with a little work you can save yourself a lot of trouble!
These are just two of many examples! I'm not trying to make you feel helpless, it's the opposite, I want you to take control. Maybe I am trying to scare you a little…though just enough to make you take action!
So, what actions can make you more secure right now?
I'll make suggestions in a moment, but first want to state that a quick and easy thing to do is get 1Password and start using this powerful tool immediately! I highly recommend it to create and manage all your passwords. I have been using it myself since April of 2010 and can't believe I ever existed without it.
I love their video, because it shows you how easy it is to use:
There are a ton of reasons I use it, but the top ones are:
• You create 1 Master Password to log into this password management tool (don't get confused, this is the password to unlock 1Password). Think of it like an apartment manager being able to unlock any door, even though all the individual doors have their own keys. This means you only have to remember your Master Password to get access to all your other really long, secure passwords
• It has a password generator tool built-in, so you can easily make a strong password that automatically gets saved in this software
• It is encrypted, so it keeps everything secure
• It has a browser add-on: If you are online and need to log in to any online site (Facebook, Gmail, your bank, anything…) you just click the 1P icon and it fills in the password for you!
What are the best practices for creating user names and passwords?
Below are a few of the top ones I like to share with my clients, but there are always more things you can do:
• Create unique user names and passwords for each account (DO NOT use the same user name and password on everything from your email account to your bank account! This is critical and can't be stressed enough!)
• Keep passwords in a secure place, like a tool specifically encrypted for password storage.
• This helps you to not have to remember multiple passwords, because it remembers them for you, then protects the various ones you have created.
• Either use a password generating tool (included in 1Password) or make sure the password contains a mixture of upper and lower case letters, numbers and special characters. Do not use a common word that is in the dictionary and then throw in a # or two at the end. Break up the letters with characters and #, the longer the better.
Here is an example of a secure password: 992t2S#92M9!C7yb4nb9D7h4&dRm7^zEjs8Ws3QQ
(I know, you are thinking, “Who can remember that!?” Don't worry, 1Password will make it so you don't have to remember this password, just one master one!)
• Do not provide your passwords to others – even your staff. If you have to give someone a password, create separate ones for each staff member or intern who might be helping you out. That way, should they leave, you can delete that password and create a new one for the person who is taking over. And, did I mention, you can manage them all within 1Password.
OK, I'm not saying this is the only password tool out there. I used to use a free one, but it didn't have as many features. I'd rather you use one of those than have you keep using the same common word as your password for everything! However, the reason I fell in love with 1Password was because it is so simple to use. It can also sync across multiple devices, which are all encrypted with the same level of security as financial institutions use.
So, now you have no excuse not to have a secure password.
Please do take this seriously and change your passwords to something more secure now, before the cyber pickpocketer happens upon your website (with access to your confidential info and or your clients' personal data), email account, Facebook account or worse (anywhere with your credit card info)!
Keep it secure! And, if any of your accounts should get hacked, change the password immediately, along with any other accounts that share it!
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