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ckpts/universal/global_step40/zero/10.mlp.dense_h_to_4h.weight/exp_avg.pt

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ckpts/universal/global_step40/zero/10.mlp.dense_h_to_4h.weight/fp32.pt

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ckpts/universal/global_step40/zero/12.attention.dense.weight/exp_avg.pt

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ckpts/universal/global_step40/zero/12.attention.dense.weight/fp32.pt

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ckpts/universal/global_step40/zero/14.post_attention_layernorm.weight/exp_avg.pt

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ckpts/universal/global_step40/zero/14.post_attention_layernorm.weight/exp_avg_sq.pt

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ckpts/universal/global_step40/zero/14.post_attention_layernorm.weight/fp32.pt

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ckpts/universal/global_step40/zero/9.attention.dense.weight/exp_avg.pt

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ckpts/universal/global_step40/zero/9.attention.dense.weight/fp32.pt

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venv/lib/python3.10/site-packages/numpy/lib/tests/test__datasource.py

@@ -0,0 +1,350 @@
+import os
+import pytest
+from tempfile import mkdtemp, mkstemp, NamedTemporaryFile
+from shutil import rmtree
+
+import numpy.lib._datasource as datasource
+from numpy.testing import assert_, assert_equal, assert_raises
+
+import urllib.request as urllib_request
+from urllib.parse import urlparse
+from urllib.error import URLError
+
+
+def urlopen_stub(url, data=None):
+    '''Stub to replace urlopen for testing.'''
+    if url == valid_httpurl():
+        tmpfile = NamedTemporaryFile(prefix='urltmp_')
+        return tmpfile
+    else:
+        raise URLError('Name or service not known')
+
+# setup and teardown
+old_urlopen = None
+
+
+def setup_module():
+    global old_urlopen
+
+    old_urlopen = urllib_request.urlopen
+    urllib_request.urlopen = urlopen_stub
+
+
+def teardown_module():
+    urllib_request.urlopen = old_urlopen
+
+# A valid website for more robust testing
+http_path = 'http://www.google.com/'
+http_file = 'index.html'
+
+http_fakepath = 'http://fake.abc.web/site/'
+http_fakefile = 'fake.txt'
+
+malicious_files = ['/etc/shadow', '../../shadow',
+                   '..\\system.dat', 'c:\\windows\\system.dat']
+
+magic_line = b'three is the magic number'
+
+
+# Utility functions used by many tests
+def valid_textfile(filedir):
+    # Generate and return a valid temporary file.
+    fd, path = mkstemp(suffix='.txt', prefix='dstmp_', dir=filedir, text=True)
+    os.close(fd)
+    return path
+
+
+def invalid_textfile(filedir):
+    # Generate and return an invalid filename.
+    fd, path = mkstemp(suffix='.txt', prefix='dstmp_', dir=filedir)
+    os.close(fd)
+    os.remove(path)
+    return path
+
+
+def valid_httpurl():
+    return http_path+http_file
+
+
+def invalid_httpurl():
+    return http_fakepath+http_fakefile
+
+
+def valid_baseurl():
+    return http_path
+
+
+def invalid_baseurl():
+    return http_fakepath
+
+
+def valid_httpfile():
+    return http_file
+
+
+def invalid_httpfile():
+    return http_fakefile
+
+
+class TestDataSourceOpen:
+    def setup_method(self):
+        self.tmpdir = mkdtemp()
+        self.ds = datasource.DataSource(self.tmpdir)
+
+    def teardown_method(self):
+        rmtree(self.tmpdir)
+        del self.ds
+
+    def test_ValidHTTP(self):
+        fh = self.ds.open(valid_httpurl())
+        assert_(fh)
+        fh.close()
+
+    def test_InvalidHTTP(self):
+        url = invalid_httpurl()
+        assert_raises(OSError, self.ds.open, url)
+        try:
+            self.ds.open(url)
+        except OSError as e:
+            # Regression test for bug fixed in r4342.
+            assert_(e.errno is None)
+
+    def test_InvalidHTTPCacheURLError(self):
+        assert_raises(URLError, self.ds._cache, invalid_httpurl())
+
+    def test_ValidFile(self):
+        local_file = valid_textfile(self.tmpdir)
+        fh = self.ds.open(local_file)
+        assert_(fh)
+        fh.close()
+
+    def test_InvalidFile(self):
+        invalid_file = invalid_textfile(self.tmpdir)
+        assert_raises(OSError, self.ds.open, invalid_file)
+
+    def test_ValidGzipFile(self):
+        try:
+            import gzip
+        except ImportError:
+            # We don't have the gzip capabilities to test.
+            pytest.skip()
+        # Test datasource's internal file_opener for Gzip files.
+        filepath = os.path.join(self.tmpdir, 'foobar.txt.gz')
+        fp = gzip.open(filepath, 'w')
+        fp.write(magic_line)
+        fp.close()
+        fp = self.ds.open(filepath)
+        result = fp.readline()
+        fp.close()
+        assert_equal(magic_line, result)
+
+    def test_ValidBz2File(self):
+        try:
+            import bz2
+        except ImportError:
+            # We don't have the bz2 capabilities to test.
+            pytest.skip()
+        # Test datasource's internal file_opener for BZip2 files.
+        filepath = os.path.join(self.tmpdir, 'foobar.txt.bz2')
+        fp = bz2.BZ2File(filepath, 'w')
+        fp.write(magic_line)
+        fp.close()
+        fp = self.ds.open(filepath)
+        result = fp.readline()
+        fp.close()
+        assert_equal(magic_line, result)
+
+
+class TestDataSourceExists:
+    def setup_method(self):
+        self.tmpdir = mkdtemp()
+        self.ds = datasource.DataSource(self.tmpdir)
+
+    def teardown_method(self):
+        rmtree(self.tmpdir)
+        del self.ds
+
+    def test_ValidHTTP(self):
+        assert_(self.ds.exists(valid_httpurl()))
+
+    def test_InvalidHTTP(self):
+        assert_equal(self.ds.exists(invalid_httpurl()), False)
+
+    def test_ValidFile(self):
+        # Test valid file in destpath
+        tmpfile = valid_textfile(self.tmpdir)
+        assert_(self.ds.exists(tmpfile))
+        # Test valid local file not in destpath
+        localdir = mkdtemp()
+        tmpfile = valid_textfile(localdir)
+        assert_(self.ds.exists(tmpfile))
+        rmtree(localdir)
+
+    def test_InvalidFile(self):
+        tmpfile = invalid_textfile(self.tmpdir)
+        assert_equal(self.ds.exists(tmpfile), False)
+
+
+class TestDataSourceAbspath:
+    def setup_method(self):
+        self.tmpdir = os.path.abspath(mkdtemp())
+        self.ds = datasource.DataSource(self.tmpdir)
+
+    def teardown_method(self):
+        rmtree(self.tmpdir)
+        del self.ds
+
+    def test_ValidHTTP(self):
+        scheme, netloc, upath, pms, qry, frg = urlparse(valid_httpurl())
+        local_path = os.path.join(self.tmpdir, netloc,
+                                  upath.strip(os.sep).strip('/'))
+        assert_equal(local_path, self.ds.abspath(valid_httpurl()))
+
+    def test_ValidFile(self):
+        tmpfile = valid_textfile(self.tmpdir)
+        tmpfilename = os.path.split(tmpfile)[-1]
+        # Test with filename only
+        assert_equal(tmpfile, self.ds.abspath(tmpfilename))
+        # Test filename with complete path
+        assert_equal(tmpfile, self.ds.abspath(tmpfile))
+
+    def test_InvalidHTTP(self):
+        scheme, netloc, upath, pms, qry, frg = urlparse(invalid_httpurl())
+        invalidhttp = os.path.join(self.tmpdir, netloc,
+                                   upath.strip(os.sep).strip('/'))
+        assert_(invalidhttp != self.ds.abspath(valid_httpurl()))
+
+    def test_InvalidFile(self):
+        invalidfile = valid_textfile(self.tmpdir)
+        tmpfile = valid_textfile(self.tmpdir)
+        tmpfilename = os.path.split(tmpfile)[-1]
+        # Test with filename only
+        assert_(invalidfile != self.ds.abspath(tmpfilename))
+        # Test filename with complete path
+        assert_(invalidfile != self.ds.abspath(tmpfile))
+
+    def test_sandboxing(self):
+        tmpfile = valid_textfile(self.tmpdir)
+        tmpfilename = os.path.split(tmpfile)[-1]
+
+        tmp_path = lambda x: os.path.abspath(self.ds.abspath(x))
+
+        assert_(tmp_path(valid_httpurl()).startswith(self.tmpdir))
+        assert_(tmp_path(invalid_httpurl()).startswith(self.tmpdir))
+        assert_(tmp_path(tmpfile).startswith(self.tmpdir))
+        assert_(tmp_path(tmpfilename).startswith(self.tmpdir))
+        for fn in malicious_files:
+            assert_(tmp_path(http_path+fn).startswith(self.tmpdir))
+            assert_(tmp_path(fn).startswith(self.tmpdir))
+
+    def test_windows_os_sep(self):
+        orig_os_sep = os.sep
+        try:
+            os.sep = '\\'
+            self.test_ValidHTTP()
+            self.test_ValidFile()
+            self.test_InvalidHTTP()
+            self.test_InvalidFile()
+            self.test_sandboxing()
+        finally:
+            os.sep = orig_os_sep
+
+
+class TestRepositoryAbspath:
+    def setup_method(self):
+        self.tmpdir = os.path.abspath(mkdtemp())
+        self.repos = datasource.Repository(valid_baseurl(), self.tmpdir)
+
+    def teardown_method(self):
+        rmtree(self.tmpdir)
+        del self.repos
+
+    def test_ValidHTTP(self):
+        scheme, netloc, upath, pms, qry, frg = urlparse(valid_httpurl())
+        local_path = os.path.join(self.repos._destpath, netloc,
+                                  upath.strip(os.sep).strip('/'))
+        filepath = self.repos.abspath(valid_httpfile())
+        assert_equal(local_path, filepath)
+
+    def test_sandboxing(self):
+        tmp_path = lambda x: os.path.abspath(self.repos.abspath(x))
+        assert_(tmp_path(valid_httpfile()).startswith(self.tmpdir))
+        for fn in malicious_files:
+            assert_(tmp_path(http_path+fn).startswith(self.tmpdir))
+            assert_(tmp_path(fn).startswith(self.tmpdir))
+
+    def test_windows_os_sep(self):
+        orig_os_sep = os.sep
+        try:
+            os.sep = '\\'
+            self.test_ValidHTTP()
+            self.test_sandboxing()
+        finally:
+            os.sep = orig_os_sep
+
+
+class TestRepositoryExists:
+    def setup_method(self):
+        self.tmpdir = mkdtemp()
+        self.repos = datasource.Repository(valid_baseurl(), self.tmpdir)
+
+    def teardown_method(self):
+        rmtree(self.tmpdir)
+        del self.repos
+
+    def test_ValidFile(self):
+        # Create local temp file
+        tmpfile = valid_textfile(self.tmpdir)
+        assert_(self.repos.exists(tmpfile))
+
+    def test_InvalidFile(self):
+        tmpfile = invalid_textfile(self.tmpdir)
+        assert_equal(self.repos.exists(tmpfile), False)
+
+    def test_RemoveHTTPFile(self):
+        assert_(self.repos.exists(valid_httpurl()))
+
+    def test_CachedHTTPFile(self):
+        localfile = valid_httpurl()
+        # Create a locally cached temp file with an URL based
+        # directory structure.  This is similar to what Repository.open
+        # would do.
+        scheme, netloc, upath, pms, qry, frg = urlparse(localfile)
+        local_path = os.path.join(self.repos._destpath, netloc)
+        os.mkdir(local_path, 0o0700)
+        tmpfile = valid_textfile(local_path)
+        assert_(self.repos.exists(tmpfile))
+
+
+class TestOpenFunc:
+    def setup_method(self):
+        self.tmpdir = mkdtemp()
+
+    def teardown_method(self):
+        rmtree(self.tmpdir)
+
+    def test_DataSourceOpen(self):
+        local_file = valid_textfile(self.tmpdir)
+        # Test case where destpath is passed in
+        fp = datasource.open(local_file, destpath=self.tmpdir)
+        assert_(fp)
+        fp.close()
+        # Test case where default destpath is used
+        fp = datasource.open(local_file)
+        assert_(fp)
+        fp.close()
+
+def test_del_attr_handling():
+    # DataSource __del__ can be called
+    # even if __init__ fails when the
+    # Exception object is caught by the
+    # caller as happens in refguide_check
+    # is_deprecated() function
+
+    ds = datasource.DataSource()
+    # simulate failed __init__ by removing key attribute
+    # produced within __init__ and expected by __del__
+    del ds._istmpdest
+    # should not raise an AttributeError if __del__
+    # gracefully handles failed __init__:
+    ds.__del__()

venv/lib/python3.10/site-packages/numpy/lib/tests/test__iotools.py

@@ -0,0 +1,353 @@
+import time
+from datetime import date
+
+import numpy as np
+from numpy.testing import (
+    assert_, assert_equal, assert_allclose, assert_raises,
+    )
+from numpy.lib._iotools import (
+    LineSplitter, NameValidator, StringConverter,
+    has_nested_fields, easy_dtype, flatten_dtype
+    )
+
+
+class TestLineSplitter:
+    "Tests the LineSplitter class."
+
+    def test_no_delimiter(self):
+        "Test LineSplitter w/o delimiter"
+        strg = " 1 2 3 4  5 # test"
+        test = LineSplitter()(strg)
+        assert_equal(test, ['1', '2', '3', '4', '5'])
+        test = LineSplitter('')(strg)
+        assert_equal(test, ['1', '2', '3', '4', '5'])
+
+    def test_space_delimiter(self):
+        "Test space delimiter"
+        strg = " 1 2 3 4  5 # test"
+        test = LineSplitter(' ')(strg)
+        assert_equal(test, ['1', '2', '3', '4', '', '5'])
+        test = LineSplitter('  ')(strg)
+        assert_equal(test, ['1 2 3 4', '5'])
+
+    def test_tab_delimiter(self):
+        "Test tab delimiter"
+        strg = " 1\t 2\t 3\t 4\t 5  6"
+        test = LineSplitter('\t')(strg)
+        assert_equal(test, ['1', '2', '3', '4', '5  6'])
+        strg = " 1  2\t 3  4\t 5  6"
+        test = LineSplitter('\t')(strg)
+        assert_equal(test, ['1  2', '3  4', '5  6'])
+
+    def test_other_delimiter(self):
+        "Test LineSplitter on delimiter"
+        strg = "1,2,3,4,,5"
+        test = LineSplitter(',')(strg)
+        assert_equal(test, ['1', '2', '3', '4', '', '5'])
+        #
+        strg = " 1,2,3,4,,5 # test"
+        test = LineSplitter(',')(strg)
+        assert_equal(test, ['1', '2', '3', '4', '', '5'])
+
+        # gh-11028 bytes comment/delimiters should get encoded
+        strg = b" 1,2,3,4,,5 % test"
+        test = LineSplitter(delimiter=b',', comments=b'%')(strg)
+        assert_equal(test, ['1', '2', '3', '4', '', '5'])
+
+    def test_constant_fixed_width(self):
+        "Test LineSplitter w/ fixed-width fields"
+        strg = "  1  2  3  4     5   # test"
+        test = LineSplitter(3)(strg)
+        assert_equal(test, ['1', '2', '3', '4', '', '5', ''])
+        #
+        strg = "  1     3  4  5  6# test"
+        test = LineSplitter(20)(strg)
+        assert_equal(test, ['1     3  4  5  6'])
+        #
+        strg = "  1     3  4  5  6# test"
+        test = LineSplitter(30)(strg)
+        assert_equal(test, ['1     3  4  5  6'])
+
+    def test_variable_fixed_width(self):
+        strg = "  1     3  4  5  6# test"
+        test = LineSplitter((3, 6, 6, 3))(strg)
+        assert_equal(test, ['1', '3', '4  5', '6'])
+        #
+        strg = "  1     3  4  5  6# test"
+        test = LineSplitter((6, 6, 9))(strg)
+        assert_equal(test, ['1', '3  4', '5  6'])
+
+# -----------------------------------------------------------------------------
+
+
+class TestNameValidator:
+
+    def test_case_sensitivity(self):
+        "Test case sensitivity"
+        names = ['A', 'a', 'b', 'c']
+        test = NameValidator().validate(names)
+        assert_equal(test, ['A', 'a', 'b', 'c'])
+        test = NameValidator(case_sensitive=False).validate(names)
+        assert_equal(test, ['A', 'A_1', 'B', 'C'])
+        test = NameValidator(case_sensitive='upper').validate(names)
+        assert_equal(test, ['A', 'A_1', 'B', 'C'])
+        test = NameValidator(case_sensitive='lower').validate(names)
+        assert_equal(test, ['a', 'a_1', 'b', 'c'])
+
+        # check exceptions
+        assert_raises(ValueError, NameValidator, case_sensitive='foobar')
+
+    def test_excludelist(self):
+        "Test excludelist"
+        names = ['dates', 'data', 'Other Data', 'mask']
+        validator = NameValidator(excludelist=['dates', 'data', 'mask'])
+        test = validator.validate(names)
+        assert_equal(test, ['dates_', 'data_', 'Other_Data', 'mask_'])
+
+    def test_missing_names(self):
+        "Test validate missing names"
+        namelist = ('a', 'b', 'c')
+        validator = NameValidator()
+        assert_equal(validator(namelist), ['a', 'b', 'c'])
+        namelist = ('', 'b', 'c')
+        assert_equal(validator(namelist), ['f0', 'b', 'c'])
+        namelist = ('a', 'b', '')
+        assert_equal(validator(namelist), ['a', 'b', 'f0'])
+        namelist = ('', 'f0', '')
+        assert_equal(validator(namelist), ['f1', 'f0', 'f2'])
+
+    def test_validate_nb_names(self):
+        "Test validate nb names"
+        namelist = ('a', 'b', 'c')
+        validator = NameValidator()
+        assert_equal(validator(namelist, nbfields=1), ('a',))
+        assert_equal(validator(namelist, nbfields=5, defaultfmt="g%i"),
+                     ['a', 'b', 'c', 'g0', 'g1'])
+
+    def test_validate_wo_names(self):
+        "Test validate no names"
+        namelist = None
+        validator = NameValidator()
+        assert_(validator(namelist) is None)
+        assert_equal(validator(namelist, nbfields=3), ['f0', 'f1', 'f2'])
+
+# -----------------------------------------------------------------------------
+
+
+def _bytes_to_date(s):
+    return date(*time.strptime(s, "%Y-%m-%d")[:3])
+
+
+class TestStringConverter:
+    "Test StringConverter"
+
+    def test_creation(self):
+        "Test creation of a StringConverter"
+        converter = StringConverter(int, -99999)
+        assert_equal(converter._status, 1)
+        assert_equal(converter.default, -99999)
+
+    def test_upgrade(self):
+        "Tests the upgrade method."
+
+        converter = StringConverter()
+        assert_equal(converter._status, 0)
+
+        # test int
+        assert_equal(converter.upgrade('0'), 0)
+        assert_equal(converter._status, 1)
+
+        # On systems where long defaults to 32-bit, the statuses will be
+        # offset by one, so we check for this here.
+        import numpy.core.numeric as nx
+        status_offset = int(nx.dtype(nx.int_).itemsize < nx.dtype(nx.int64).itemsize)
+
+        # test int > 2**32
+        assert_equal(converter.upgrade('17179869184'), 17179869184)
+        assert_equal(converter._status, 1 + status_offset)
+
+        # test float
+        assert_allclose(converter.upgrade('0.'), 0.0)
+        assert_equal(converter._status, 2 + status_offset)
+
+        # test complex
+        assert_equal(converter.upgrade('0j'), complex('0j'))
+        assert_equal(converter._status, 3 + status_offset)
+
+        # test str
+        # note that the longdouble type has been skipped, so the
+        # _status increases by 2. Everything should succeed with
+        # unicode conversion (8).
+        for s in ['a', b'a']:
+            res = converter.upgrade(s)
+            assert_(type(res) is str)
+            assert_equal(res, 'a')
+            assert_equal(converter._status, 8 + status_offset)
+
+    def test_missing(self):
+        "Tests the use of missing values."
+        converter = StringConverter(missing_values=('missing',
+                                                    'missed'))
+        converter.upgrade('0')
+        assert_equal(converter('0'), 0)
+        assert_equal(converter(''), converter.default)
+        assert_equal(converter('missing'), converter.default)
+        assert_equal(converter('missed'), converter.default)
+        try:
+            converter('miss')
+        except ValueError:
+            pass
+
+    def test_upgrademapper(self):
+        "Tests updatemapper"
+        dateparser = _bytes_to_date
+        _original_mapper = StringConverter._mapper[:]
+        try:
+            StringConverter.upgrade_mapper(dateparser, date(2000, 1, 1))
+            convert = StringConverter(dateparser, date(2000, 1, 1))
+            test = convert('2001-01-01')
+            assert_equal(test, date(2001, 1, 1))
+            test = convert('2009-01-01')
+            assert_equal(test, date(2009, 1, 1))
+            test = convert('')
+            assert_equal(test, date(2000, 1, 1))
+        finally:
+            StringConverter._mapper = _original_mapper
+
+    def test_string_to_object(self):
+        "Make sure that string-to-object functions are properly recognized"
+        old_mapper = StringConverter._mapper[:]  # copy of list
+        conv = StringConverter(_bytes_to_date)
+        assert_equal(conv._mapper, old_mapper)
+        assert_(hasattr(conv, 'default'))
+
+    def test_keep_default(self):
+        "Make sure we don't lose an explicit default"
+        converter = StringConverter(None, missing_values='',
+                                    default=-999)
+        converter.upgrade('3.14159265')
+        assert_equal(converter.default, -999)
+        assert_equal(converter.type, np.dtype(float))
+        #
+        converter = StringConverter(
+            None, missing_values='', default=0)
+        converter.upgrade('3.14159265')
+        assert_equal(converter.default, 0)
+        assert_equal(converter.type, np.dtype(float))
+
+    def test_keep_default_zero(self):
+        "Check that we don't lose a default of 0"
+        converter = StringConverter(int, default=0,
+                                    missing_values="N/A")
+        assert_equal(converter.default, 0)
+
+    def test_keep_missing_values(self):
+        "Check that we're not losing missing values"
+        converter = StringConverter(int, default=0,
+                                    missing_values="N/A")
+        assert_equal(
+            converter.missing_values, {'', 'N/A'})
+
+    def test_int64_dtype(self):
+        "Check that int64 integer types can be specified"
+        converter = StringConverter(np.int64, default=0)
+        val = "-9223372036854775807"
+        assert_(converter(val) == -9223372036854775807)
+        val = "9223372036854775807"
+        assert_(converter(val) == 9223372036854775807)
+
+    def test_uint64_dtype(self):
+        "Check that uint64 integer types can be specified"
+        converter = StringConverter(np.uint64, default=0)
+        val = "9223372043271415339"
+        assert_(converter(val) == 9223372043271415339)
+
+
+class TestMiscFunctions:
+
+    def test_has_nested_dtype(self):
+        "Test has_nested_dtype"
+        ndtype = np.dtype(float)
+        assert_equal(has_nested_fields(ndtype), False)
+        ndtype = np.dtype([('A', '|S3'), ('B', float)])
+        assert_equal(has_nested_fields(ndtype), False)
+        ndtype = np.dtype([('A', int), ('B', [('BA', float), ('BB', '|S1')])])
+        assert_equal(has_nested_fields(ndtype), True)
+
+    def test_easy_dtype(self):
+        "Test ndtype on dtypes"
+        # Simple case
+        ndtype = float
+        assert_equal(easy_dtype(ndtype), np.dtype(float))
+        # As string w/o names
+        ndtype = "i4, f8"
+        assert_equal(easy_dtype(ndtype),
+                     np.dtype([('f0', "i4"), ('f1', "f8")]))
+        # As string w/o names but different default format
+        assert_equal(easy_dtype(ndtype, defaultfmt="field_%03i"),
+                     np.dtype([('field_000', "i4"), ('field_001', "f8")]))
+        # As string w/ names
+        ndtype = "i4, f8"
+        assert_equal(easy_dtype(ndtype, names="a, b"),
+                     np.dtype([('a', "i4"), ('b', "f8")]))
+        # As string w/ names (too many)
+        ndtype = "i4, f8"
+        assert_equal(easy_dtype(ndtype, names="a, b, c"),
+                     np.dtype([('a', "i4"), ('b', "f8")]))
+        # As string w/ names (not enough)
+        ndtype = "i4, f8"
+        assert_equal(easy_dtype(ndtype, names=", b"),
+                     np.dtype([('f0', "i4"), ('b', "f8")]))
+        # ... (with different default format)
+        assert_equal(easy_dtype(ndtype, names="a", defaultfmt="f%02i"),
+                     np.dtype([('a', "i4"), ('f00', "f8")]))
+        # As list of tuples w/o names
+        ndtype = [('A', int), ('B', float)]
+        assert_equal(easy_dtype(ndtype), np.dtype([('A', int), ('B', float)]))
+        # As list of tuples w/ names
+        assert_equal(easy_dtype(ndtype, names="a,b"),
+                     np.dtype([('a', int), ('b', float)]))
+        # As list of tuples w/ not enough names
+        assert_equal(easy_dtype(ndtype, names="a"),
+                     np.dtype([('a', int), ('f0', float)]))
+        # As list of tuples w/ too many names
+        assert_equal(easy_dtype(ndtype, names="a,b,c"),
+                     np.dtype([('a', int), ('b', float)]))
+        # As list of types w/o names
+        ndtype = (int, float, float)
+        assert_equal(easy_dtype(ndtype),
+                     np.dtype([('f0', int), ('f1', float), ('f2', float)]))
+        # As list of types w names
+        ndtype = (int, float, float)
+        assert_equal(easy_dtype(ndtype, names="a, b, c"),
+                     np.dtype([('a', int), ('b', float), ('c', float)]))
+        # As simple dtype w/ names
+        ndtype = np.dtype(float)
+        assert_equal(easy_dtype(ndtype, names="a, b, c"),
+                     np.dtype([(_, float) for _ in ('a', 'b', 'c')]))
+        # As simple dtype w/o names (but multiple fields)
+        ndtype = np.dtype(float)
+        assert_equal(
+            easy_dtype(ndtype, names=['', '', ''], defaultfmt="f%02i"),
+            np.dtype([(_, float) for _ in ('f00', 'f01', 'f02')]))
+
+    def test_flatten_dtype(self):
+        "Testing flatten_dtype"
+        # Standard dtype
+        dt = np.dtype([("a", "f8"), ("b", "f8")])
+        dt_flat = flatten_dtype(dt)
+        assert_equal(dt_flat, [float, float])
+        # Recursive dtype
+        dt = np.dtype([("a", [("aa", '|S1'), ("ab", '|S2')]), ("b", int)])
+        dt_flat = flatten_dtype(dt)
+        assert_equal(dt_flat, [np.dtype('|S1'), np.dtype('|S2'), int])
+        # dtype with shaped fields
+        dt = np.dtype([("a", (float, 2)), ("b", (int, 3))])
+        dt_flat = flatten_dtype(dt)
+        assert_equal(dt_flat, [float, int])
+        dt_flat = flatten_dtype(dt, True)
+        assert_equal(dt_flat, [float] * 2 + [int] * 3)
+        # dtype w/ titles
+        dt = np.dtype([(("a", "A"), "f8"), (("b", "B"), "f8")])
+        dt_flat = flatten_dtype(dt)
+        assert_equal(dt_flat, [float, float])

venv/lib/python3.10/site-packages/numpy/lib/tests/test_arraysetops.py

@@ -0,0 +1,944 @@
+"""Test functions for 1D array set operations.
+
+"""
+import numpy as np
+
+from numpy.testing import (assert_array_equal, assert_equal,
+                           assert_raises, assert_raises_regex)
+from numpy.lib.arraysetops import (
+    ediff1d, intersect1d, setxor1d, union1d, setdiff1d, unique, in1d, isin
+    )
+import pytest
+
+
+class TestSetOps:
+
+    def test_intersect1d(self):
+        # unique inputs
+        a = np.array([5, 7, 1, 2])
+        b = np.array([2, 4, 3, 1, 5])
+
+        ec = np.array([1, 2, 5])
+        c = intersect1d(a, b, assume_unique=True)
+        assert_array_equal(c, ec)
+
+        # non-unique inputs
+        a = np.array([5, 5, 7, 1, 2])
+        b = np.array([2, 1, 4, 3, 3, 1, 5])
+
+        ed = np.array([1, 2, 5])
+        c = intersect1d(a, b)
+        assert_array_equal(c, ed)
+        assert_array_equal([], intersect1d([], []))
+
+    def test_intersect1d_array_like(self):
+        # See gh-11772
+        class Test:
+            def __array__(self):
+                return np.arange(3)
+
+        a = Test()
+        res = intersect1d(a, a)
+        assert_array_equal(res, a)
+        res = intersect1d([1, 2, 3], [1, 2, 3])
+        assert_array_equal(res, [1, 2, 3])
+
+    def test_intersect1d_indices(self):
+        # unique inputs
+        a = np.array([1, 2, 3, 4])
+        b = np.array([2, 1, 4, 6])
+        c, i1, i2 = intersect1d(a, b, assume_unique=True, return_indices=True)
+        ee = np.array([1, 2, 4])
+        assert_array_equal(c, ee)
+        assert_array_equal(a[i1], ee)
+        assert_array_equal(b[i2], ee)
+
+        # non-unique inputs
+        a = np.array([1, 2, 2, 3, 4, 3, 2])
+        b = np.array([1, 8, 4, 2, 2, 3, 2, 3])
+        c, i1, i2 = intersect1d(a, b, return_indices=True)
+        ef = np.array([1, 2, 3, 4])
+        assert_array_equal(c, ef)
+        assert_array_equal(a[i1], ef)
+        assert_array_equal(b[i2], ef)
+
+        # non1d, unique inputs
+        a = np.array([[2, 4, 5, 6], [7, 8, 1, 15]])
+        b = np.array([[3, 2, 7, 6], [10, 12, 8, 9]])
+        c, i1, i2 = intersect1d(a, b, assume_unique=True, return_indices=True)
+        ui1 = np.unravel_index(i1, a.shape)
+        ui2 = np.unravel_index(i2, b.shape)
+        ea = np.array([2, 6, 7, 8])
+        assert_array_equal(ea, a[ui1])
+        assert_array_equal(ea, b[ui2])
+
+        # non1d, not assumed to be uniqueinputs
+        a = np.array([[2, 4, 5, 6, 6], [4, 7, 8, 7, 2]])
+        b = np.array([[3, 2, 7, 7], [10, 12, 8, 7]])
+        c, i1, i2 = intersect1d(a, b, return_indices=True)
+        ui1 = np.unravel_index(i1, a.shape)
+        ui2 = np.unravel_index(i2, b.shape)
+        ea = np.array([2, 7, 8])
+        assert_array_equal(ea, a[ui1])
+        assert_array_equal(ea, b[ui2])
+
+    def test_setxor1d(self):
+        a = np.array([5, 7, 1, 2])
+        b = np.array([2, 4, 3, 1, 5])
+
+        ec = np.array([3, 4, 7])
+        c = setxor1d(a, b)
+        assert_array_equal(c, ec)
+
+        a = np.array([1, 2, 3])
+        b = np.array([6, 5, 4])
+
+        ec = np.array([1, 2, 3, 4, 5, 6])
+        c = setxor1d(a, b)
+        assert_array_equal(c, ec)
+
+        a = np.array([1, 8, 2, 3])
+        b = np.array([6, 5, 4, 8])
+
+        ec = np.array([1, 2, 3, 4, 5, 6])
+        c = setxor1d(a, b)
+        assert_array_equal(c, ec)
+
+        assert_array_equal([], setxor1d([], []))
+
+    def test_ediff1d(self):
+        zero_elem = np.array([])
+        one_elem = np.array([1])
+        two_elem = np.array([1, 2])
+
+        assert_array_equal([], ediff1d(zero_elem))
+        assert_array_equal([0], ediff1d(zero_elem, to_begin=0))
+        assert_array_equal([0], ediff1d(zero_elem, to_end=0))
+        assert_array_equal([-1, 0], ediff1d(zero_elem, to_begin=-1, to_end=0))
+        assert_array_equal([], ediff1d(one_elem))
+        assert_array_equal([1], ediff1d(two_elem))
+        assert_array_equal([7, 1, 9], ediff1d(two_elem, to_begin=7, to_end=9))
+        assert_array_equal([5, 6, 1, 7, 8],
+                           ediff1d(two_elem, to_begin=[5, 6], to_end=[7, 8]))
+        assert_array_equal([1, 9], ediff1d(two_elem, to_end=9))
+        assert_array_equal([1, 7, 8], ediff1d(two_elem, to_end=[7, 8]))
+        assert_array_equal([7, 1], ediff1d(two_elem, to_begin=7))
+        assert_array_equal([5, 6, 1], ediff1d(two_elem, to_begin=[5, 6]))
+
+    @pytest.mark.parametrize("ary, prepend, append, expected", [
+        # should fail because trying to cast
+        # np.nan standard floating point value
+        # into an integer array:
+        (np.array([1, 2, 3], dtype=np.int64),
+         None,
+         np.nan,
+         'to_end'),
+        # should fail because attempting
+        # to downcast to int type:
+        (np.array([1, 2, 3], dtype=np.int64),
+         np.array([5, 7, 2], dtype=np.float32),
+         None,
+         'to_begin'),
+        # should fail because attempting to cast
+        # two special floating point values
+        # to integers (on both sides of ary),
+        # `to_begin` is in the error message as the impl checks this first:
+        (np.array([1., 3., 9.], dtype=np.int8),
+         np.nan,
+         np.nan,
+         'to_begin'),
+         ])
+    def test_ediff1d_forbidden_type_casts(self, ary, prepend, append, expected):
+        # verify resolution of gh-11490
+
+        # specifically, raise an appropriate
+        # Exception when attempting to append or
+        # prepend with an incompatible type
+        msg = 'dtype of `{}` must be compatible'.format(expected)
+        with assert_raises_regex(TypeError, msg):
+            ediff1d(ary=ary,
+                    to_end=append,
+                    to_begin=prepend)
+
+    @pytest.mark.parametrize(
+        "ary,prepend,append,expected",
+        [
+         (np.array([1, 2, 3], dtype=np.int16),
+          2**16,  # will be cast to int16 under same kind rule.
+          2**16 + 4,
+          np.array([0, 1, 1, 4], dtype=np.int16)),
+         (np.array([1, 2, 3], dtype=np.float32),
+          np.array([5], dtype=np.float64),
+          None,
+          np.array([5, 1, 1], dtype=np.float32)),
+         (np.array([1, 2, 3], dtype=np.int32),
+          0,
+          0,
+          np.array([0, 1, 1, 0], dtype=np.int32)),
+         (np.array([1, 2, 3], dtype=np.int64),
+          3,
+          -9,
+          np.array([3, 1, 1, -9], dtype=np.int64)),
+        ]
+    )
+    def test_ediff1d_scalar_handling(self,
+                                     ary,
+                                     prepend,
+                                     append,
+                                     expected):
+        # maintain backwards-compatibility
+        # of scalar prepend / append behavior
+        # in ediff1d following fix for gh-11490
+        actual = np.ediff1d(ary=ary,
+                            to_end=append,
+                            to_begin=prepend)
+        assert_equal(actual, expected)
+        assert actual.dtype == expected.dtype
+
+    @pytest.mark.parametrize("kind", [None, "sort", "table"])
+    def test_isin(self, kind):
+        # the tests for in1d cover most of isin's behavior
+        # if in1d is removed, would need to change those tests to test
+        # isin instead.
+        def _isin_slow(a, b):
+            b = np.asarray(b).flatten().tolist()
+            return a in b
+        isin_slow = np.vectorize(_isin_slow, otypes=[bool], excluded={1})
+
+        def assert_isin_equal(a, b):
+            x = isin(a, b, kind=kind)
+            y = isin_slow(a, b)
+            assert_array_equal(x, y)
+
+        # multidimensional arrays in both arguments
+        a = np.arange(24).reshape([2, 3, 4])
+        b = np.array([[10, 20, 30], [0, 1, 3], [11, 22, 33]])
+        assert_isin_equal(a, b)
+
+        # array-likes as both arguments
+        c = [(9, 8), (7, 6)]
+        d = (9, 7)
+        assert_isin_equal(c, d)
+
+        # zero-d array:
+        f = np.array(3)
+        assert_isin_equal(f, b)
+        assert_isin_equal(a, f)
+        assert_isin_equal(f, f)
+
+        # scalar:
+        assert_isin_equal(5, b)
+        assert_isin_equal(a, 6)
+        assert_isin_equal(5, 6)
+
+        # empty array-like:
+        if kind != "table":
+            # An empty list will become float64,
+            # which is invalid for kind="table"
+            x = []
+            assert_isin_equal(x, b)
+            assert_isin_equal(a, x)
+            assert_isin_equal(x, x)
+
+        # empty array with various types:
+        for dtype in [bool, np.int64, np.float64]:
+            if kind == "table" and dtype == np.float64:
+                continue
+
+            if dtype in {np.int64, np.float64}:
+                ar = np.array([10, 20, 30], dtype=dtype)
+            elif dtype in {bool}:
+                ar = np.array([True, False, False])
+
+            empty_array = np.array([], dtype=dtype)
+
+            assert_isin_equal(empty_array, ar)
+            assert_isin_equal(ar, empty_array)
+            assert_isin_equal(empty_array, empty_array)
+
+    @pytest.mark.parametrize("kind", [None, "sort", "table"])
+    def test_in1d(self, kind):
+        # we use two different sizes for the b array here to test the
+        # two different paths in in1d().
+        for mult in (1, 10):
+            # One check without np.array to make sure lists are handled correct
+            a = [5, 7, 1, 2]
+            b = [2, 4, 3, 1, 5] * mult
+            ec = np.array([True, False, True, True])
+            c = in1d(a, b, assume_unique=True, kind=kind)
+            assert_array_equal(c, ec)
+
+            a[0] = 8
+            ec = np.array([False, False, True, True])
+            c = in1d(a, b, assume_unique=True, kind=kind)
+            assert_array_equal(c, ec)
+
+            a[0], a[3] = 4, 8
+            ec = np.array([True, False, True, False])
+            c = in1d(a, b, assume_unique=True, kind=kind)
+            assert_array_equal(c, ec)
+
+            a = np.array([5, 4, 5, 3, 4, 4, 3, 4, 3, 5, 2, 1, 5, 5])
+            b = [2, 3, 4] * mult
+            ec = [False, True, False, True, True, True, True, True, True,
+                  False, True, False, False, False]
+            c = in1d(a, b, kind=kind)
+            assert_array_equal(c, ec)
+
+            b = b + [5, 5, 4] * mult
+            ec = [True, True, True, True, True, True, True, True, True, True,
+                  True, False, True, True]
+            c = in1d(a, b, kind=kind)
+            assert_array_equal(c, ec)
+
+            a = np.array([5, 7, 1, 2])
+            b = np.array([2, 4, 3, 1, 5] * mult)
+            ec = np.array([True, False, True, True])
+            c = in1d(a, b, kind=kind)
+            assert_array_equal(c, ec)
+
+            a = np.array([5, 7, 1, 1, 2])
+            b = np.array([2, 4, 3, 3, 1, 5] * mult)
+            ec = np.array([True, False, True, True, True])
+            c = in1d(a, b, kind=kind)
+            assert_array_equal(c, ec)
+
+            a = np.array([5, 5])
+            b = np.array([2, 2] * mult)
+            ec = np.array([False, False])
+            c = in1d(a, b, kind=kind)
+            assert_array_equal(c, ec)
+
+        a = np.array([5])
+        b = np.array([2])
+        ec = np.array([False])
+        c = in1d(a, b, kind=kind)
+        assert_array_equal(c, ec)
+
+        if kind in {None, "sort"}:
+            assert_array_equal(in1d([], [], kind=kind), [])
+
+    def test_in1d_char_array(self):
+        a = np.array(['a', 'b', 'c', 'd', 'e', 'c', 'e', 'b'])
+        b = np.array(['a', 'c'])
+
+        ec = np.array([True, False, True, False, False, True, False, False])
+        c = in1d(a, b)
+
+        assert_array_equal(c, ec)
+
+    @pytest.mark.parametrize("kind", [None, "sort", "table"])
+    def test_in1d_invert(self, kind):
+        "Test in1d's invert parameter"
+        # We use two different sizes for the b array here to test the
+        # two different paths in in1d().
+        for mult in (1, 10):
+            a = np.array([5, 4, 5, 3, 4, 4, 3, 4, 3, 5, 2, 1, 5, 5])
+            b = [2, 3, 4] * mult
+            assert_array_equal(np.invert(in1d(a, b, kind=kind)),
+                               in1d(a, b, invert=True, kind=kind))
+
+        # float:
+        if kind in {None, "sort"}:
+            for mult in (1, 10):
+                a = np.array([5, 4, 5, 3, 4, 4, 3, 4, 3, 5, 2, 1, 5, 5],
+                            dtype=np.float32)
+                b = [2, 3, 4] * mult
+                b = np.array(b, dtype=np.float32)
+                assert_array_equal(np.invert(in1d(a, b, kind=kind)),
+                                   in1d(a, b, invert=True, kind=kind))
+
+    @pytest.mark.parametrize("kind", [None, "sort", "table"])
+    def test_in1d_ravel(self, kind):
+        # Test that in1d ravels its input arrays. This is not documented
+        # behavior however. The test is to ensure consistentency.
+        a = np.arange(6).reshape(2, 3)
+        b = np.arange(3, 9).reshape(3, 2)
+        long_b = np.arange(3, 63).reshape(30, 2)
+        ec = np.array([False, False, False, True, True, True])
+
+        assert_array_equal(in1d(a, b, assume_unique=True, kind=kind),
+                           ec)
+        assert_array_equal(in1d(a, b, assume_unique=False,
+                                kind=kind),
+                           ec)
+        assert_array_equal(in1d(a, long_b, assume_unique=True,
+                                kind=kind),
+                           ec)
+        assert_array_equal(in1d(a, long_b, assume_unique=False,
+                                kind=kind),
+                           ec)
+
+    def test_in1d_hit_alternate_algorithm(self):
+        """Hit the standard isin code with integers"""
+        # Need extreme range to hit standard code
+        # This hits it without the use of kind='table'
+        a = np.array([5, 4, 5, 3, 4, 4, 1e9], dtype=np.int64)
+        b = np.array([2, 3, 4, 1e9], dtype=np.int64)
+        expected = np.array([0, 1, 0, 1, 1, 1, 1], dtype=bool)
+        assert_array_equal(expected, in1d(a, b))
+        assert_array_equal(np.invert(expected), in1d(a, b, invert=True))
+
+        a = np.array([5, 7, 1, 2], dtype=np.int64)
+        b = np.array([2, 4, 3, 1, 5, 1e9], dtype=np.int64)
+        ec = np.array([True, False, True, True])
+        c = in1d(a, b, assume_unique=True)
+        assert_array_equal(c, ec)
+
+    @pytest.mark.parametrize("kind", [None, "sort", "table"])
+    def test_in1d_boolean(self, kind):
+        """Test that in1d works for boolean input"""
+        a = np.array([True, False])
+        b = np.array([False, False, False])
+        expected = np.array([False, True])
+        assert_array_equal(expected,
+                           in1d(a, b, kind=kind))
+        assert_array_equal(np.invert(expected),
+                           in1d(a, b, invert=True, kind=kind))
+
+    @pytest.mark.parametrize("kind", [None, "sort"])
+    def test_in1d_timedelta(self, kind):
+        """Test that in1d works for timedelta input"""
+        rstate = np.random.RandomState(0)
+        a = rstate.randint(0, 100, size=10)
+        b = rstate.randint(0, 100, size=10)
+        truth = in1d(a, b)
+        a_timedelta = a.astype("timedelta64[s]")
+        b_timedelta = b.astype("timedelta64[s]")
+        assert_array_equal(truth, in1d(a_timedelta, b_timedelta, kind=kind))
+
+    def test_in1d_table_timedelta_fails(self):
+        a = np.array([0, 1, 2], dtype="timedelta64[s]")
+        b = a
+        # Make sure it raises a value error:
+        with pytest.raises(ValueError):
+            in1d(a, b, kind="table")
+
+    @pytest.mark.parametrize(
+        "dtype1,dtype2",
+        [
+            (np.int8, np.int16),
+            (np.int16, np.int8),
+            (np.uint8, np.uint16),
+            (np.uint16, np.uint8),
+            (np.uint8, np.int16),
+            (np.int16, np.uint8),
+        ]
+    )
+    @pytest.mark.parametrize("kind", [None, "sort", "table"])
+    def test_in1d_mixed_dtype(self, dtype1, dtype2, kind):
+        """Test that in1d works as expected for mixed dtype input."""
+        is_dtype2_signed = np.issubdtype(dtype2, np.signedinteger)
+        ar1 = np.array([0, 0, 1, 1], dtype=dtype1)
+
+        if is_dtype2_signed:
+            ar2 = np.array([-128, 0, 127], dtype=dtype2)
+        else:
+            ar2 = np.array([127, 0, 255], dtype=dtype2)
+
+        expected = np.array([True, True, False, False])
+
+        expect_failure = kind == "table" and any((
+            dtype1 == np.int8 and dtype2 == np.int16,
+            dtype1 == np.int16 and dtype2 == np.int8
+        ))
+
+        if expect_failure:
+            with pytest.raises(RuntimeError, match="exceed the maximum"):
+                in1d(ar1, ar2, kind=kind)
+        else:
+            assert_array_equal(in1d(ar1, ar2, kind=kind), expected)
+
+    @pytest.mark.parametrize("kind", [None, "sort", "table"])
+    def test_in1d_mixed_boolean(self, kind):
+        """Test that in1d works as expected for bool/int input."""
+        for dtype in np.typecodes["AllInteger"]:
+            a = np.array([True, False, False], dtype=bool)
+            b = np.array([0, 0, 0, 0], dtype=dtype)
+            expected = np.array([False, True, True], dtype=bool)
+            assert_array_equal(in1d(a, b, kind=kind), expected)
+
+            a, b = b, a
+            expected = np.array([True, True, True, True], dtype=bool)
+            assert_array_equal(in1d(a, b, kind=kind), expected)
+
+    def test_in1d_first_array_is_object(self):
+        ar1 = [None]
+        ar2 = np.array([1]*10)
+        expected = np.array([False])
+        result = np.in1d(ar1, ar2)
+        assert_array_equal(result, expected)
+
+    def test_in1d_second_array_is_object(self):
+        ar1 = 1
+        ar2 = np.array([None]*10)
+        expected = np.array([False])
+        result = np.in1d(ar1, ar2)
+        assert_array_equal(result, expected)
+
+    def test_in1d_both_arrays_are_object(self):
+        ar1 = [None]
+        ar2 = np.array([None]*10)
+        expected = np.array([True])
+        result = np.in1d(ar1, ar2)
+        assert_array_equal(result, expected)
+
+    def test_in1d_both_arrays_have_structured_dtype(self):
+        # Test arrays of a structured data type containing an integer field
+        # and a field of dtype `object` allowing for arbitrary Python objects
+        dt = np.dtype([('field1', int), ('field2', object)])
+        ar1 = np.array([(1, None)], dtype=dt)
+        ar2 = np.array([(1, None)]*10, dtype=dt)
+        expected = np.array([True])
+        result = np.in1d(ar1, ar2)
+        assert_array_equal(result, expected)
+
+    def test_in1d_with_arrays_containing_tuples(self):
+        ar1 = np.array([(1,), 2], dtype=object)
+        ar2 = np.array([(1,), 2], dtype=object)
+        expected = np.array([True, True])
+        result = np.in1d(ar1, ar2)
+        assert_array_equal(result, expected)
+        result = np.in1d(ar1, ar2, invert=True)
+        assert_array_equal(result, np.invert(expected))
+
+        # An integer is added at the end of the array to make sure
+        # that the array builder will create the array with tuples
+        # and after it's created the integer is removed.
+        # There's a bug in the array constructor that doesn't handle
+        # tuples properly and adding the integer fixes that.
+        ar1 = np.array([(1,), (2, 1), 1], dtype=object)
+        ar1 = ar1[:-1]
+        ar2 = np.array([(1,), (2, 1), 1], dtype=object)
+        ar2 = ar2[:-1]
+        expected = np.array([True, True])
+        result = np.in1d(ar1, ar2)
+        assert_array_equal(result, expected)
+        result = np.in1d(ar1, ar2, invert=True)
+        assert_array_equal(result, np.invert(expected))
+
+        ar1 = np.array([(1,), (2, 3), 1], dtype=object)
+        ar1 = ar1[:-1]
+        ar2 = np.array([(1,), 2], dtype=object)
+        expected = np.array([True, False])
+        result = np.in1d(ar1, ar2)
+        assert_array_equal(result, expected)
+        result = np.in1d(ar1, ar2, invert=True)
+        assert_array_equal(result, np.invert(expected))
+
+    def test_in1d_errors(self):
+        """Test that in1d raises expected errors."""
+
+        # Error 1: `kind` is not one of 'sort' 'table' or None.
+        ar1 = np.array([1, 2, 3, 4, 5])
+        ar2 = np.array([2, 4, 6, 8, 10])
+        assert_raises(ValueError, in1d, ar1, ar2, kind='quicksort')
+
+        # Error 2: `kind="table"` does not work for non-integral arrays.
+        obj_ar1 = np.array([1, 'a', 3, 'b', 5], dtype=object)
+        obj_ar2 = np.array([1, 'a', 3, 'b', 5], dtype=object)
+        assert_raises(ValueError, in1d, obj_ar1, obj_ar2, kind='table')
+
+        for dtype in [np.int32, np.int64]:
+            ar1 = np.array([-1, 2, 3, 4, 5], dtype=dtype)
+            # The range of this array will overflow:
+            overflow_ar2 = np.array([-1, np.iinfo(dtype).max], dtype=dtype)
+
+            # Error 3: `kind="table"` will trigger a runtime error
+            #  if there is an integer overflow expected when computing the
+            #  range of ar2
+            assert_raises(
+                RuntimeError,
+                in1d, ar1, overflow_ar2, kind='table'
+            )
+
+            # Non-error: `kind=None` will *not* trigger a runtime error
+            #  if there is an integer overflow, it will switch to
+            #  the `sort` algorithm.
+            result = np.in1d(ar1, overflow_ar2, kind=None)
+            assert_array_equal(result, [True] + [False] * 4)
+            result = np.in1d(ar1, overflow_ar2, kind='sort')
+            assert_array_equal(result, [True] + [False] * 4)
+
+    def test_union1d(self):
+        a = np.array([5, 4, 7, 1, 2])
+        b = np.array([2, 4, 3, 3, 2, 1, 5])
+
+        ec = np.array([1, 2, 3, 4, 5, 7])
+        c = union1d(a, b)
+        assert_array_equal(c, ec)
+
+        # Tests gh-10340, arguments to union1d should be
+        # flattened if they are not already 1D
+        x = np.array([[0, 1, 2], [3, 4, 5]])
+        y = np.array([0, 1, 2, 3, 4])
+        ez = np.array([0, 1, 2, 3, 4, 5])
+        z = union1d(x, y)
+        assert_array_equal(z, ez)
+
+        assert_array_equal([], union1d([], []))
+
+    def test_setdiff1d(self):
+        a = np.array([6, 5, 4, 7, 1, 2, 7, 4])
+        b = np.array([2, 4, 3, 3, 2, 1, 5])
+
+        ec = np.array([6, 7])
+        c = setdiff1d(a, b)
+        assert_array_equal(c, ec)
+
+        a = np.arange(21)
+        b = np.arange(19)
+        ec = np.array([19, 20])
+        c = setdiff1d(a, b)
+        assert_array_equal(c, ec)
+
+        assert_array_equal([], setdiff1d([], []))
+        a = np.array((), np.uint32)
+        assert_equal(setdiff1d(a, []).dtype, np.uint32)
+
+    def test_setdiff1d_unique(self):
+        a = np.array([3, 2, 1])
+        b = np.array([7, 5, 2])
+        expected = np.array([3, 1])
+        actual = setdiff1d(a, b, assume_unique=True)
+        assert_equal(actual, expected)
+
+    def test_setdiff1d_char_array(self):
+        a = np.array(['a', 'b', 'c'])
+        b = np.array(['a', 'b', 's'])
+        assert_array_equal(setdiff1d(a, b), np.array(['c']))
+
+    def test_manyways(self):
+        a = np.array([5, 7, 1, 2, 8])
+        b = np.array([9, 8, 2, 4, 3, 1, 5])
+
+        c1 = setxor1d(a, b)
+        aux1 = intersect1d(a, b)
+        aux2 = union1d(a, b)
+        c2 = setdiff1d(aux2, aux1)
+        assert_array_equal(c1, c2)
+
+
+class TestUnique:
+
+    def test_unique_1d(self):
+
+        def check_all(a, b, i1, i2, c, dt):
+            base_msg = 'check {0} failed for type {1}'
+
+            msg = base_msg.format('values', dt)
+            v = unique(a)
+            assert_array_equal(v, b, msg)
+
+            msg = base_msg.format('return_index', dt)
+            v, j = unique(a, True, False, False)
+            assert_array_equal(v, b, msg)
+            assert_array_equal(j, i1, msg)
+
+            msg = base_msg.format('return_inverse', dt)
+            v, j = unique(a, False, True, False)
+            assert_array_equal(v, b, msg)
+            assert_array_equal(j, i2, msg)
+
+            msg = base_msg.format('return_counts', dt)
+            v, j = unique(a, False, False, True)
+            assert_array_equal(v, b, msg)
+            assert_array_equal(j, c, msg)
+
+            msg = base_msg.format('return_index and return_inverse', dt)
+            v, j1, j2 = unique(a, True, True, False)
+            assert_array_equal(v, b, msg)
+            assert_array_equal(j1, i1, msg)
+            assert_array_equal(j2, i2, msg)
+
+            msg = base_msg.format('return_index and return_counts', dt)
+            v, j1, j2 = unique(a, True, False, True)
+            assert_array_equal(v, b, msg)
+            assert_array_equal(j1, i1, msg)
+            assert_array_equal(j2, c, msg)
+
+            msg = base_msg.format('return_inverse and return_counts', dt)
+            v, j1, j2 = unique(a, False, True, True)
+            assert_array_equal(v, b, msg)
+            assert_array_equal(j1, i2, msg)
+            assert_array_equal(j2, c, msg)
+
+            msg = base_msg.format(('return_index, return_inverse '
+                                   'and return_counts'), dt)
+            v, j1, j2, j3 = unique(a, True, True, True)
+            assert_array_equal(v, b, msg)
+            assert_array_equal(j1, i1, msg)
+            assert_array_equal(j2, i2, msg)
+            assert_array_equal(j3, c, msg)
+
+        a = [5, 7, 1, 2, 1, 5, 7]*10
+        b = [1, 2, 5, 7]
+        i1 = [2, 3, 0, 1]
+        i2 = [2, 3, 0, 1, 0, 2, 3]*10
+        c = np.multiply([2, 1, 2, 2], 10)
+
+        # test for numeric arrays
+        types = []
+        types.extend(np.typecodes['AllInteger'])
+        types.extend(np.typecodes['AllFloat'])
+        types.append('datetime64[D]')
+        types.append('timedelta64[D]')
+        for dt in types:
+            aa = np.array(a, dt)
+            bb = np.array(b, dt)
+            check_all(aa, bb, i1, i2, c, dt)
+
+        # test for object arrays
+        dt = 'O'
+        aa = np.empty(len(a), dt)
+        aa[:] = a
+        bb = np.empty(len(b), dt)
+        bb[:] = b
+        check_all(aa, bb, i1, i2, c, dt)
+
+        # test for structured arrays
+        dt = [('', 'i'), ('', 'i')]
+        aa = np.array(list(zip(a, a)), dt)
+        bb = np.array(list(zip(b, b)), dt)
+        check_all(aa, bb, i1, i2, c, dt)
+
+        # test for ticket #2799
+        aa = [1. + 0.j, 1 - 1.j, 1]
+        assert_array_equal(np.unique(aa), [1. - 1.j, 1. + 0.j])
+
+        # test for ticket #4785
+        a = [(1, 2), (1, 2), (2, 3)]
+        unq = [1, 2, 3]
+        inv = [0, 1, 0, 1, 1, 2]
+        a1 = unique(a)
+        assert_array_equal(a1, unq)
+        a2, a2_inv = unique(a, return_inverse=True)
+        assert_array_equal(a2, unq)
+        assert_array_equal(a2_inv, inv)
+
+        # test for chararrays with return_inverse (gh-5099)
+        a = np.chararray(5)
+        a[...] = ''
+        a2, a2_inv = np.unique(a, return_inverse=True)
+        assert_array_equal(a2_inv, np.zeros(5))
+
+        # test for ticket #9137
+        a = []
+        a1_idx = np.unique(a, return_index=True)[1]
+        a2_inv = np.unique(a, return_inverse=True)[1]
+        a3_idx, a3_inv = np.unique(a, return_index=True,
+                                   return_inverse=True)[1:]
+        assert_equal(a1_idx.dtype, np.intp)
+        assert_equal(a2_inv.dtype, np.intp)
+        assert_equal(a3_idx.dtype, np.intp)
+        assert_equal(a3_inv.dtype, np.intp)
+
+        # test for ticket 2111 - float
+        a = [2.0, np.nan, 1.0, np.nan]
+        ua = [1.0, 2.0, np.nan]
+        ua_idx = [2, 0, 1]
+        ua_inv = [1, 2, 0, 2]
+        ua_cnt = [1, 1, 2]
+        assert_equal(np.unique(a), ua)
+        assert_equal(np.unique(a, return_index=True), (ua, ua_idx))
+        assert_equal(np.unique(a, return_inverse=True), (ua, ua_inv))
+        assert_equal(np.unique(a, return_counts=True), (ua, ua_cnt))
+
+        # test for ticket 2111 - complex
+        a = [2.0-1j, np.nan, 1.0+1j, complex(0.0, np.nan), complex(1.0, np.nan)]
+        ua = [1.0+1j, 2.0-1j, complex(0.0, np.nan)]
+        ua_idx = [2, 0, 3]
+        ua_inv = [1, 2, 0, 2, 2]
+        ua_cnt = [1, 1, 3]
+        assert_equal(np.unique(a), ua)
+        assert_equal(np.unique(a, return_index=True), (ua, ua_idx))
+        assert_equal(np.unique(a, return_inverse=True), (ua, ua_inv))
+        assert_equal(np.unique(a, return_counts=True), (ua, ua_cnt))
+
+        # test for ticket 2111 - datetime64
+        nat = np.datetime64('nat')
+        a = [np.datetime64('2020-12-26'), nat, np.datetime64('2020-12-24'), nat]
+        ua = [np.datetime64('2020-12-24'), np.datetime64('2020-12-26'), nat]
+        ua_idx = [2, 0, 1]
+        ua_inv = [1, 2, 0, 2]
+        ua_cnt = [1, 1, 2]
+        assert_equal(np.unique(a), ua)
+        assert_equal(np.unique(a, return_index=True), (ua, ua_idx))
+        assert_equal(np.unique(a, return_inverse=True), (ua, ua_inv))
+        assert_equal(np.unique(a, return_counts=True), (ua, ua_cnt))
+
+        # test for ticket 2111 - timedelta
+        nat = np.timedelta64('nat')
+        a = [np.timedelta64(1, 'D'), nat, np.timedelta64(1, 'h'), nat]
+        ua = [np.timedelta64(1, 'h'), np.timedelta64(1, 'D'), nat]
+        ua_idx = [2, 0, 1]
+        ua_inv = [1, 2, 0, 2]
+        ua_cnt = [1, 1, 2]
+        assert_equal(np.unique(a), ua)
+        assert_equal(np.unique(a, return_index=True), (ua, ua_idx))
+        assert_equal(np.unique(a, return_inverse=True), (ua, ua_inv))
+        assert_equal(np.unique(a, return_counts=True), (ua, ua_cnt))
+
+        # test for gh-19300
+        all_nans = [np.nan] * 4
+        ua = [np.nan]
+        ua_idx = [0]
+        ua_inv = [0, 0, 0, 0]
+        ua_cnt = [4]
+        assert_equal(np.unique(all_nans), ua)
+        assert_equal(np.unique(all_nans, return_index=True), (ua, ua_idx))
+        assert_equal(np.unique(all_nans, return_inverse=True), (ua, ua_inv))
+        assert_equal(np.unique(all_nans, return_counts=True), (ua, ua_cnt))
+
+    def test_unique_axis_errors(self):
+        assert_raises(TypeError, self._run_axis_tests, object)
+        assert_raises(TypeError, self._run_axis_tests,
+                      [('a', int), ('b', object)])
+
+        assert_raises(np.AxisError, unique, np.arange(10), axis=2)
+        assert_raises(np.AxisError, unique, np.arange(10), axis=-2)
+
+    def test_unique_axis_list(self):
+        msg = "Unique failed on list of lists"
+        inp = [[0, 1, 0], [0, 1, 0]]
+        inp_arr = np.asarray(inp)
+        assert_array_equal(unique(inp, axis=0), unique(inp_arr, axis=0), msg)
+        assert_array_equal(unique(inp, axis=1), unique(inp_arr, axis=1), msg)
+
+    def test_unique_axis(self):
+        types = []
+        types.extend(np.typecodes['AllInteger'])
+        types.extend(np.typecodes['AllFloat'])
+        types.append('datetime64[D]')
+        types.append('timedelta64[D]')
+        types.append([('a', int), ('b', int)])
+        types.append([('a', int), ('b', float)])
+
+        for dtype in types:
+            self._run_axis_tests(dtype)
+
+        msg = 'Non-bitwise-equal booleans test failed'
+        data = np.arange(10, dtype=np.uint8).reshape(-1, 2).view(bool)
+        result = np.array([[False, True], [True, True]], dtype=bool)
+        assert_array_equal(unique(data, axis=0), result, msg)
+
+        msg = 'Negative zero equality test failed'
+        data = np.array([[-0.0, 0.0], [0.0, -0.0], [-0.0, 0.0], [0.0, -0.0]])
+        result = np.array([[-0.0, 0.0]])
+        assert_array_equal(unique(data, axis=0), result, msg)
+
+    @pytest.mark.parametrize("axis", [0, -1])
+    def test_unique_1d_with_axis(self, axis):
+        x = np.array([4, 3, 2, 3, 2, 1, 2, 2])
+        uniq = unique(x, axis=axis)
+        assert_array_equal(uniq, [1, 2, 3, 4])
+
+    def test_unique_axis_zeros(self):
+        # issue 15559
+        single_zero = np.empty(shape=(2, 0), dtype=np.int8)
+        uniq, idx, inv, cnt = unique(single_zero, axis=0, return_index=True,
+                                     return_inverse=True, return_counts=True)
+
+        # there's 1 element of shape (0,) along axis 0
+        assert_equal(uniq.dtype, single_zero.dtype)
+        assert_array_equal(uniq, np.empty(shape=(1, 0)))
+        assert_array_equal(idx, np.array([0]))
+        assert_array_equal(inv, np.array([0, 0]))
+        assert_array_equal(cnt, np.array([2]))
+
+        # there's 0 elements of shape (2,) along axis 1
+        uniq, idx, inv, cnt = unique(single_zero, axis=1, return_index=True,
+                                     return_inverse=True, return_counts=True)
+
+        assert_equal(uniq.dtype, single_zero.dtype)
+        assert_array_equal(uniq, np.empty(shape=(2, 0)))
+        assert_array_equal(idx, np.array([]))
+        assert_array_equal(inv, np.array([]))
+        assert_array_equal(cnt, np.array([]))
+
+        # test a "complicated" shape
+        shape = (0, 2, 0, 3, 0, 4, 0)
+        multiple_zeros = np.empty(shape=shape)
+        for axis in range(len(shape)):
+            expected_shape = list(shape)
+            if shape[axis] == 0:
+                expected_shape[axis] = 0
+            else:
+                expected_shape[axis] = 1
+
+            assert_array_equal(unique(multiple_zeros, axis=axis),
+                               np.empty(shape=expected_shape))
+
+    def test_unique_masked(self):
+        # issue 8664
+        x = np.array([64, 0, 1, 2, 3, 63, 63, 0, 0, 0, 1, 2, 0, 63, 0],
+                     dtype='uint8')
+        y = np.ma.masked_equal(x, 0)
+
+        v = np.unique(y)
+        v2, i, c = np.unique(y, return_index=True, return_counts=True)
+
+        msg = 'Unique returned different results when asked for index'
+        assert_array_equal(v.data, v2.data, msg)
+        assert_array_equal(v.mask, v2.mask, msg)
+
+    def test_unique_sort_order_with_axis(self):
+        # These tests fail if sorting along axis is done by treating subarrays
+        # as unsigned byte strings.  See gh-10495.
+        fmt = "sort order incorrect for integer type '%s'"
+        for dt in 'bhilq':
+            a = np.array([[-1], [0]], dt)
+            b = np.unique(a, axis=0)
+            assert_array_equal(a, b, fmt % dt)
+
+    def _run_axis_tests(self, dtype):
+        data = np.array([[0, 1, 0, 0],
+                         [1, 0, 0, 0],
+                         [0, 1, 0, 0],
+                         [1, 0, 0, 0]]).astype(dtype)
+
+        msg = 'Unique with 1d array and axis=0 failed'
+        result = np.array([0, 1])
+        assert_array_equal(unique(data), result.astype(dtype), msg)
+
+        msg = 'Unique with 2d array and axis=0 failed'
+        result = np.array([[0, 1, 0, 0], [1, 0, 0, 0]])
+        assert_array_equal(unique(data, axis=0), result.astype(dtype), msg)
+
+        msg = 'Unique with 2d array and axis=1 failed'
+        result = np.array([[0, 0, 1], [0, 1, 0], [0, 0, 1], [0, 1, 0]])
+        assert_array_equal(unique(data, axis=1), result.astype(dtype), msg)
+
+        msg = 'Unique with 3d array and axis=2 failed'
+        data3d = np.array([[[1, 1],
+                            [1, 0]],
+                           [[0, 1],
+                            [0, 0]]]).astype(dtype)
+        result = np.take(data3d, [1, 0], axis=2)
+        assert_array_equal(unique(data3d, axis=2), result, msg)
+
+        uniq, idx, inv, cnt = unique(data, axis=0, return_index=True,
+                                     return_inverse=True, return_counts=True)
+        msg = "Unique's return_index=True failed with axis=0"
+        assert_array_equal(data[idx], uniq, msg)
+        msg = "Unique's return_inverse=True failed with axis=0"
+        assert_array_equal(uniq[inv], data)
+        msg = "Unique's return_counts=True failed with axis=0"
+        assert_array_equal(cnt, np.array([2, 2]), msg)
+
+        uniq, idx, inv, cnt = unique(data, axis=1, return_index=True,
+                                     return_inverse=True, return_counts=True)
+        msg = "Unique's return_index=True failed with axis=1"
+        assert_array_equal(data[:, idx], uniq)
+        msg = "Unique's return_inverse=True failed with axis=1"
+        assert_array_equal(uniq[:, inv], data)
+        msg = "Unique's return_counts=True failed with axis=1"
+        assert_array_equal(cnt, np.array([2, 1, 1]), msg)
+
+    def test_unique_nanequals(self):
+        # issue 20326
+        a = np.array([1, 1, np.nan, np.nan, np.nan])
+        unq = np.unique(a)
+        not_unq = np.unique(a, equal_nan=False)
+        assert_array_equal(unq, np.array([1, np.nan]))
+        assert_array_equal(not_unq, np.array([1, np.nan, np.nan, np.nan]))

venv/lib/python3.10/site-packages/numpy/lib/tests/test_arrayterator.py

@@ -0,0 +1,46 @@
+from operator import mul
+from functools import reduce
+
+import numpy as np
+from numpy.random import randint
+from numpy.lib import Arrayterator
+from numpy.testing import assert_
+
+
+def test():
+    np.random.seed(np.arange(10))
+
+    # Create a random array
+    ndims = randint(5)+1
+    shape = tuple(randint(10)+1 for dim in range(ndims))
+    els = reduce(mul, shape)
+    a = np.arange(els)
+    a.shape = shape
+
+    buf_size = randint(2*els)
+    b = Arrayterator(a, buf_size)
+
+    # Check that each block has at most ``buf_size`` elements
+    for block in b:
+        assert_(len(block.flat) <= (buf_size or els))
+
+    # Check that all elements are iterated correctly
+    assert_(list(b.flat) == list(a.flat))
+
+    # Slice arrayterator
+    start = [randint(dim) for dim in shape]
+    stop = [randint(dim)+1 for dim in shape]
+    step = [randint(dim)+1 for dim in shape]
+    slice_ = tuple(slice(*t) for t in zip(start, stop, step))
+    c = b[slice_]
+    d = a[slice_]
+
+    # Check that each block has at most ``buf_size`` elements
+    for block in c:
+        assert_(len(block.flat) <= (buf_size or els))
+
+    # Check that the arrayterator is sliced correctly
+    assert_(np.all(c.__array__() == d))
+
+    # Check that all elements are iterated correctly
+    assert_(list(c.flat) == list(d.flat))

venv/lib/python3.10/site-packages/numpy/lib/tests/test_recfunctions.py

@@ -0,0 +1,1043 @@
+import pytest
+
+import numpy as np
+import numpy.ma as ma
+from numpy.ma.mrecords import MaskedRecords
+from numpy.ma.testutils import assert_equal
+from numpy.testing import assert_, assert_raises
+from numpy.lib.recfunctions import (
+    drop_fields, rename_fields, get_fieldstructure, recursive_fill_fields,
+    find_duplicates, merge_arrays, append_fields, stack_arrays, join_by,
+    repack_fields, unstructured_to_structured, structured_to_unstructured,
+    apply_along_fields, require_fields, assign_fields_by_name)
+get_fieldspec = np.lib.recfunctions._get_fieldspec
+get_names = np.lib.recfunctions.get_names
+get_names_flat = np.lib.recfunctions.get_names_flat
+zip_descr = np.lib.recfunctions._zip_descr
+zip_dtype = np.lib.recfunctions._zip_dtype
+
+
+class TestRecFunctions:
+    # Misc tests
+
+    def setup_method(self):
+        x = np.array([1, 2, ])
+        y = np.array([10, 20, 30])
+        z = np.array([('A', 1.), ('B', 2.)],
+                     dtype=[('A', '|S3'), ('B', float)])
+        w = np.array([(1, (2, 3.0)), (4, (5, 6.0))],
+                     dtype=[('a', int), ('b', [('ba', float), ('bb', int)])])
+        self.data = (w, x, y, z)
+
+    def test_zip_descr(self):
+        # Test zip_descr
+        (w, x, y, z) = self.data
+
+        # Std array
+        test = zip_descr((x, x), flatten=True)
+        assert_equal(test,
+                     np.dtype([('', int), ('', int)]))
+        test = zip_descr((x, x), flatten=False)
+        assert_equal(test,
+                     np.dtype([('', int), ('', int)]))
+
+        # Std & flexible-dtype
+        test = zip_descr((x, z), flatten=True)
+        assert_equal(test,
+                     np.dtype([('', int), ('A', '|S3'), ('B', float)]))
+        test = zip_descr((x, z), flatten=False)
+        assert_equal(test,
+                     np.dtype([('', int),
+                               ('', [('A', '|S3'), ('B', float)])]))
+
+        # Standard & nested dtype
+        test = zip_descr((x, w), flatten=True)
+        assert_equal(test,
+                     np.dtype([('', int),
+                               ('a', int),
+                               ('ba', float), ('bb', int)]))
+        test = zip_descr((x, w), flatten=False)
+        assert_equal(test,
+                     np.dtype([('', int),
+                               ('', [('a', int),
+                                     ('b', [('ba', float), ('bb', int)])])]))
+
+    def test_drop_fields(self):
+        # Test drop_fields
+        a = np.array([(1, (2, 3.0)), (4, (5, 6.0))],
+                     dtype=[('a', int), ('b', [('ba', float), ('bb', int)])])
+
+        # A basic field
+        test = drop_fields(a, 'a')
+        control = np.array([((2, 3.0),), ((5, 6.0),)],
+                           dtype=[('b', [('ba', float), ('bb', int)])])
+        assert_equal(test, control)
+
+        # Another basic field (but nesting two fields)
+        test = drop_fields(a, 'b')
+        control = np.array([(1,), (4,)], dtype=[('a', int)])
+        assert_equal(test, control)
+
+        # A nested sub-field
+        test = drop_fields(a, ['ba', ])
+        control = np.array([(1, (3.0,)), (4, (6.0,))],
+                           dtype=[('a', int), ('b', [('bb', int)])])
+        assert_equal(test, control)
+
+        # All the nested sub-field from a field: zap that field
+        test = drop_fields(a, ['ba', 'bb'])
+        control = np.array([(1,), (4,)], dtype=[('a', int)])
+        assert_equal(test, control)
+
+        # dropping all fields results in an array with no fields
+        test = drop_fields(a, ['a', 'b'])
+        control = np.array([(), ()], dtype=[])
+        assert_equal(test, control)
+
+    def test_rename_fields(self):
+        # Test rename fields
+        a = np.array([(1, (2, [3.0, 30.])), (4, (5, [6.0, 60.]))],
+                     dtype=[('a', int),
+                            ('b', [('ba', float), ('bb', (float, 2))])])
+        test = rename_fields(a, {'a': 'A', 'bb': 'BB'})
+        newdtype = [('A', int), ('b', [('ba', float), ('BB', (float, 2))])]
+        control = a.view(newdtype)
+        assert_equal(test.dtype, newdtype)
+        assert_equal(test, control)
+
+    def test_get_names(self):
+        # Test get_names
+        ndtype = np.dtype([('A', '|S3'), ('B', float)])
+        test = get_names(ndtype)
+        assert_equal(test, ('A', 'B'))
+
+        ndtype = np.dtype([('a', int), ('b', [('ba', float), ('bb', int)])])
+        test = get_names(ndtype)
+        assert_equal(test, ('a', ('b', ('ba', 'bb'))))
+
+        ndtype = np.dtype([('a', int), ('b', [])])
+        test = get_names(ndtype)
+        assert_equal(test, ('a', ('b', ())))
+
+        ndtype = np.dtype([])
+        test = get_names(ndtype)
+        assert_equal(test, ())
+
+    def test_get_names_flat(self):
+        # Test get_names_flat
+        ndtype = np.dtype([('A', '|S3'), ('B', float)])
+        test = get_names_flat(ndtype)
+        assert_equal(test, ('A', 'B'))
+
+        ndtype = np.dtype([('a', int), ('b', [('ba', float), ('bb', int)])])
+        test = get_names_flat(ndtype)
+        assert_equal(test, ('a', 'b', 'ba', 'bb'))
+
+        ndtype = np.dtype([('a', int), ('b', [])])
+        test = get_names_flat(ndtype)
+        assert_equal(test, ('a', 'b'))
+
+        ndtype = np.dtype([])
+        test = get_names_flat(ndtype)
+        assert_equal(test, ())
+
+    def test_get_fieldstructure(self):
+        # Test get_fieldstructure
+
+        # No nested fields
+        ndtype = np.dtype([('A', '|S3'), ('B', float)])
+        test = get_fieldstructure(ndtype)
+        assert_equal(test, {'A': [], 'B': []})
+
+        # One 1-nested field
+        ndtype = np.dtype([('A', int), ('B', [('BA', float), ('BB', '|S1')])])
+        test = get_fieldstructure(ndtype)
+        assert_equal(test, {'A': [], 'B': [], 'BA': ['B', ], 'BB': ['B']})
+
+        # One 2-nested fields
+        ndtype = np.dtype([('A', int),
+                           ('B', [('BA', int),
+                                  ('BB', [('BBA', int), ('BBB', int)])])])
+        test = get_fieldstructure(ndtype)
+        control = {'A': [], 'B': [], 'BA': ['B'], 'BB': ['B'],
+                   'BBA': ['B', 'BB'], 'BBB': ['B', 'BB']}
+        assert_equal(test, control)
+
+        # 0 fields
+        ndtype = np.dtype([])
+        test = get_fieldstructure(ndtype)
+        assert_equal(test, {})
+
+    def test_find_duplicates(self):
+        # Test find_duplicates
+        a = ma.array([(2, (2., 'B')), (1, (2., 'B')), (2, (2., 'B')),
+                      (1, (1., 'B')), (2, (2., 'B')), (2, (2., 'C'))],
+                     mask=[(0, (0, 0)), (0, (0, 0)), (0, (0, 0)),
+                           (0, (0, 0)), (1, (0, 0)), (0, (1, 0))],
+                     dtype=[('A', int), ('B', [('BA', float), ('BB', '|S1')])])
+
+        test = find_duplicates(a, ignoremask=False, return_index=True)
+        control = [0, 2]
+        assert_equal(sorted(test[-1]), control)
+        assert_equal(test[0], a[test[-1]])
+
+        test = find_duplicates(a, key='A', return_index=True)
+        control = [0, 1, 2, 3, 5]
+        assert_equal(sorted(test[-1]), control)
+        assert_equal(test[0], a[test[-1]])
+
+        test = find_duplicates(a, key='B', return_index=True)
+        control = [0, 1, 2, 4]
+        assert_equal(sorted(test[-1]), control)
+        assert_equal(test[0], a[test[-1]])
+
+        test = find_duplicates(a, key='BA', return_index=True)
+        control = [0, 1, 2, 4]
+        assert_equal(sorted(test[-1]), control)
+        assert_equal(test[0], a[test[-1]])
+
+        test = find_duplicates(a, key='BB', return_index=True)
+        control = [0, 1, 2, 3, 4]
+        assert_equal(sorted(test[-1]), control)
+        assert_equal(test[0], a[test[-1]])
+
+    def test_find_duplicates_ignoremask(self):
+        # Test the ignoremask option of find_duplicates
+        ndtype = [('a', int)]
+        a = ma.array([1, 1, 1, 2, 2, 3, 3],
+                     mask=[0, 0, 1, 0, 0, 0, 1]).view(ndtype)
+        test = find_duplicates(a, ignoremask=True, return_index=True)
+        control = [0, 1, 3, 4]
+        assert_equal(sorted(test[-1]), control)
+        assert_equal(test[0], a[test[-1]])
+
+        test = find_duplicates(a, ignoremask=False, return_index=True)
+        control = [0, 1, 2, 3, 4, 6]
+        assert_equal(sorted(test[-1]), control)
+        assert_equal(test[0], a[test[-1]])
+
+    def test_repack_fields(self):
+        dt = np.dtype('u1,f4,i8', align=True)
+        a = np.zeros(2, dtype=dt)
+
+        assert_equal(repack_fields(dt), np.dtype('u1,f4,i8'))
+        assert_equal(repack_fields(a).itemsize, 13)
+        assert_equal(repack_fields(repack_fields(dt), align=True), dt)
+
+        # make sure type is preserved
+        dt = np.dtype((np.record, dt))
+        assert_(repack_fields(dt).type is np.record)
+
+    def test_structured_to_unstructured(self, tmp_path):
+        a = np.zeros(4, dtype=[('a', 'i4'), ('b', 'f4,u2'), ('c', 'f4', 2)])
+        out = structured_to_unstructured(a)
+        assert_equal(out, np.zeros((4,5), dtype='f8'))
+
+        b = np.array([(1, 2, 5), (4, 5, 7), (7, 8 ,11), (10, 11, 12)],
+                     dtype=[('x', 'i4'), ('y', 'f4'), ('z', 'f8')])
+        out = np.mean(structured_to_unstructured(b[['x', 'z']]), axis=-1)
+        assert_equal(out, np.array([ 3. ,  5.5,  9. , 11. ]))
+        out = np.mean(structured_to_unstructured(b[['x']]), axis=-1)
+        assert_equal(out, np.array([ 1. ,  4. ,  7. , 10. ]))
+
+        c = np.arange(20).reshape((4,5))
+        out = unstructured_to_structured(c, a.dtype)
+        want = np.array([( 0, ( 1.,  2), [ 3.,  4.]),
+                         ( 5, ( 6.,  7), [ 8.,  9.]),
+                         (10, (11., 12), [13., 14.]),
+                         (15, (16., 17), [18., 19.])],
+                     dtype=[('a', 'i4'),
+                            ('b', [('f0', 'f4'), ('f1', 'u2')]),
+                            ('c', 'f4', (2,))])
+        assert_equal(out, want)
+
+        d = np.array([(1, 2, 5), (4, 5, 7), (7, 8 ,11), (10, 11, 12)],
+                     dtype=[('x', 'i4'), ('y', 'f4'), ('z', 'f8')])
+        assert_equal(apply_along_fields(np.mean, d),
+                     np.array([ 8.0/3,  16.0/3,  26.0/3, 11. ]))
+        assert_equal(apply_along_fields(np.mean, d[['x', 'z']]),
+                     np.array([ 3. ,  5.5,  9. , 11. ]))
+
+        # check that for uniform field dtypes we get a view, not a copy:
+        d = np.array([(1, 2, 5), (4, 5, 7), (7, 8 ,11), (10, 11, 12)],
+                     dtype=[('x', 'i4'), ('y', 'i4'), ('z', 'i4')])
+        dd = structured_to_unstructured(d)
+        ddd = unstructured_to_structured(dd, d.dtype)
+        assert_(np.shares_memory(dd, d))
+        assert_(np.shares_memory(ddd, d))
+
+        # check that reversing the order of attributes works
+        dd_attrib_rev = structured_to_unstructured(d[['z', 'x']])
+        assert_equal(dd_attrib_rev, [[5, 1], [7, 4], [11, 7], [12, 10]])
+        assert_(np.shares_memory(dd_attrib_rev, d))
+
+        # including uniform fields with subarrays unpacked
+        d = np.array([(1, [2,  3], [[ 4,  5], [ 6,  7]]),
+                      (8, [9, 10], [[11, 12], [13, 14]])],
+                     dtype=[('x0', 'i4'), ('x1', ('i4', 2)),
+                            ('x2', ('i4', (2, 2)))])
+        dd = structured_to_unstructured(d)
+        ddd = unstructured_to_structured(dd, d.dtype)
+        assert_(np.shares_memory(dd, d))
+        assert_(np.shares_memory(ddd, d))
+
+        # check that reversing with sub-arrays works as expected
+        d_rev = d[::-1]
+        dd_rev = structured_to_unstructured(d_rev)
+        assert_equal(dd_rev, [[8, 9, 10, 11, 12, 13, 14],
+                              [1, 2, 3, 4, 5, 6, 7]])
+
+        # check that sub-arrays keep the order of their values
+        d_attrib_rev = d[['x2', 'x1', 'x0']]
+        dd_attrib_rev = structured_to_unstructured(d_attrib_rev)
+        assert_equal(dd_attrib_rev, [[4, 5, 6, 7, 2, 3, 1],
+                                     [11, 12, 13, 14, 9, 10, 8]])
+
+        # with ignored field at the end
+        d = np.array([(1, [2,  3], [[4, 5], [6, 7]], 32),
+                      (8, [9, 10], [[11, 12], [13, 14]], 64)],
+                     dtype=[('x0', 'i4'), ('x1', ('i4', 2)),
+                            ('x2', ('i4', (2, 2))), ('ignored', 'u1')])
+        dd = structured_to_unstructured(d[['x0', 'x1', 'x2']])
+        assert_(np.shares_memory(dd, d))
+        assert_equal(dd, [[1, 2, 3, 4, 5, 6, 7],
+                          [8, 9, 10, 11, 12, 13, 14]])
+
+        # test that nested fields with identical names don't break anything
+        point = np.dtype([('x', int), ('y', int)])
+        triangle = np.dtype([('a', point), ('b', point), ('c', point)])
+        arr = np.zeros(10, triangle)
+        res = structured_to_unstructured(arr, dtype=int)
+        assert_equal(res, np.zeros((10, 6), dtype=int))
+
+
+        # test nested combinations of subarrays and structured arrays, gh-13333
+        def subarray(dt, shape):
+            return np.dtype((dt, shape))
+
+        def structured(*dts):
+            return np.dtype([('x{}'.format(i), dt) for i, dt in enumerate(dts)])
+
+        def inspect(dt, dtype=None):
+            arr = np.zeros((), dt)
+            ret = structured_to_unstructured(arr, dtype=dtype)
+            backarr = unstructured_to_structured(ret, dt)
+            return ret.shape, ret.dtype, backarr.dtype
+
+        dt = structured(subarray(structured(np.int32, np.int32), 3))
+        assert_equal(inspect(dt), ((6,), np.int32, dt))
+
+        dt = structured(subarray(subarray(np.int32, 2), 2))
+        assert_equal(inspect(dt), ((4,), np.int32, dt))
+
+        dt = structured(np.int32)
+        assert_equal(inspect(dt), ((1,), np.int32, dt))
+
+        dt = structured(np.int32, subarray(subarray(np.int32, 2), 2))
+        assert_equal(inspect(dt), ((5,), np.int32, dt))
+
+        dt = structured()
+        assert_raises(ValueError, structured_to_unstructured, np.zeros(3, dt))
+
+        # these currently don't work, but we may make it work in the future
+        assert_raises(NotImplementedError, structured_to_unstructured,
+                                           np.zeros(3, dt), dtype=np.int32)
+        assert_raises(NotImplementedError, unstructured_to_structured,
+                                           np.zeros((3,0), dtype=np.int32))
+
+        # test supported ndarray subclasses
+        d_plain = np.array([(1, 2), (3, 4)], dtype=[('a', 'i4'), ('b', 'i4')])
+        dd_expected = structured_to_unstructured(d_plain, copy=True)
+
+        # recarray
+        d = d_plain.view(np.recarray)
+
+        dd = structured_to_unstructured(d, copy=False)
+        ddd = structured_to_unstructured(d, copy=True)
+        assert_(np.shares_memory(d, dd))
+        assert_(type(dd) is np.recarray)
+        assert_(type(ddd) is np.recarray)
+        assert_equal(dd, dd_expected)
+        assert_equal(ddd, dd_expected)
+
+        # memmap
+        d = np.memmap(tmp_path / 'memmap',
+                      mode='w+',
+                      dtype=d_plain.dtype,
+                      shape=d_plain.shape)
+        d[:] = d_plain
+        dd = structured_to_unstructured(d, copy=False)
+        ddd = structured_to_unstructured(d, copy=True)
+        assert_(np.shares_memory(d, dd))
+        assert_(type(dd) is np.memmap)
+        assert_(type(ddd) is np.memmap)
+        assert_equal(dd, dd_expected)
+        assert_equal(ddd, dd_expected)
+
+    def test_unstructured_to_structured(self):
+        # test if dtype is the args of np.dtype
+        a = np.zeros((20, 2))
+        test_dtype_args = [('x', float), ('y', float)]
+        test_dtype = np.dtype(test_dtype_args)
+        field1 = unstructured_to_structured(a, dtype=test_dtype_args)  # now
+        field2 = unstructured_to_structured(a, dtype=test_dtype)  # before
+        assert_equal(field1, field2)
+
+    def test_field_assignment_by_name(self):
+        a = np.ones(2, dtype=[('a', 'i4'), ('b', 'f8'), ('c', 'u1')])
+        newdt = [('b', 'f4'), ('c', 'u1')]
+
+        assert_equal(require_fields(a, newdt), np.ones(2, newdt))
+
+        b = np.array([(1,2), (3,4)], dtype=newdt)
+        assign_fields_by_name(a, b, zero_unassigned=False)
+        assert_equal(a, np.array([(1,1,2),(1,3,4)], dtype=a.dtype))
+        assign_fields_by_name(a, b)
+        assert_equal(a, np.array([(0,1,2),(0,3,4)], dtype=a.dtype))
+
+        # test nested fields
+        a = np.ones(2, dtype=[('a', [('b', 'f8'), ('c', 'u1')])])
+        newdt = [('a', [('c', 'u1')])]
+        assert_equal(require_fields(a, newdt), np.ones(2, newdt))
+        b = np.array([((2,),), ((3,),)], dtype=newdt)
+        assign_fields_by_name(a, b, zero_unassigned=False)
+        assert_equal(a, np.array([((1,2),), ((1,3),)], dtype=a.dtype))
+        assign_fields_by_name(a, b)
+        assert_equal(a, np.array([((0,2),), ((0,3),)], dtype=a.dtype))
+
+        # test unstructured code path for 0d arrays
+        a, b = np.array(3), np.array(0)
+        assign_fields_by_name(b, a)
+        assert_equal(b[()], 3)
+
+
+class TestRecursiveFillFields:
+    # Test recursive_fill_fields.
+    def test_simple_flexible(self):
+        # Test recursive_fill_fields on flexible-array
+        a = np.array([(1, 10.), (2, 20.)], dtype=[('A', int), ('B', float)])
+        b = np.zeros((3,), dtype=a.dtype)
+        test = recursive_fill_fields(a, b)
+        control = np.array([(1, 10.), (2, 20.), (0, 0.)],
+                           dtype=[('A', int), ('B', float)])
+        assert_equal(test, control)
+
+    def test_masked_flexible(self):
+        # Test recursive_fill_fields on masked flexible-array
+        a = ma.array([(1, 10.), (2, 20.)], mask=[(0, 1), (1, 0)],
+                     dtype=[('A', int), ('B', float)])
+        b = ma.zeros((3,), dtype=a.dtype)
+        test = recursive_fill_fields(a, b)
+        control = ma.array([(1, 10.), (2, 20.), (0, 0.)],
+                           mask=[(0, 1), (1, 0), (0, 0)],
+                           dtype=[('A', int), ('B', float)])
+        assert_equal(test, control)
+
+
+class TestMergeArrays:
+    # Test merge_arrays
+
+    def setup_method(self):
+        x = np.array([1, 2, ])
+        y = np.array([10, 20, 30])
+        z = np.array(
+            [('A', 1.), ('B', 2.)], dtype=[('A', '|S3'), ('B', float)])
+        w = np.array(
+            [(1, (2, 3.0, ())), (4, (5, 6.0, ()))],
+            dtype=[('a', int), ('b', [('ba', float), ('bb', int), ('bc', [])])])
+        self.data = (w, x, y, z)
+
+    def test_solo(self):
+        # Test merge_arrays on a single array.
+        (_, x, _, z) = self.data
+
+        test = merge_arrays(x)
+        control = np.array([(1,), (2,)], dtype=[('f0', int)])
+        assert_equal(test, control)
+        test = merge_arrays((x,))
+        assert_equal(test, control)
+
+        test = merge_arrays(z, flatten=False)
+        assert_equal(test, z)
+        test = merge_arrays(z, flatten=True)
+        assert_equal(test, z)
+
+    def test_solo_w_flatten(self):
+        # Test merge_arrays on a single array w & w/o flattening
+        w = self.data[0]
+        test = merge_arrays(w, flatten=False)
+        assert_equal(test, w)
+
+        test = merge_arrays(w, flatten=True)
+        control = np.array([(1, 2, 3.0), (4, 5, 6.0)],
+                           dtype=[('a', int), ('ba', float), ('bb', int)])
+        assert_equal(test, control)
+
+    def test_standard(self):
+        # Test standard & standard
+        # Test merge arrays
+        (_, x, y, _) = self.data
+        test = merge_arrays((x, y), usemask=False)
+        control = np.array([(1, 10), (2, 20), (-1, 30)],
+                           dtype=[('f0', int), ('f1', int)])
+        assert_equal(test, control)
+
+        test = merge_arrays((x, y), usemask=True)
+        control = ma.array([(1, 10), (2, 20), (-1, 30)],
+                           mask=[(0, 0), (0, 0), (1, 0)],
+                           dtype=[('f0', int), ('f1', int)])
+        assert_equal(test, control)
+        assert_equal(test.mask, control.mask)
+
+    def test_flatten(self):
+        # Test standard & flexible
+        (_, x, _, z) = self.data
+        test = merge_arrays((x, z), flatten=True)
+        control = np.array([(1, 'A', 1.), (2, 'B', 2.)],
+                           dtype=[('f0', int), ('A', '|S3'), ('B', float)])
+        assert_equal(test, control)
+
+        test = merge_arrays((x, z), flatten=False)
+        control = np.array([(1, ('A', 1.)), (2, ('B', 2.))],
+                           dtype=[('f0', int),
+                                  ('f1', [('A', '|S3'), ('B', float)])])
+        assert_equal(test, control)
+
+    def test_flatten_wflexible(self):
+        # Test flatten standard & nested
+        (w, x, _, _) = self.data
+        test = merge_arrays((x, w), flatten=True)
+        control = np.array([(1, 1, 2, 3.0), (2, 4, 5, 6.0)],
+                           dtype=[('f0', int),
+                                  ('a', int), ('ba', float), ('bb', int)])
+        assert_equal(test, control)
+
+        test = merge_arrays((x, w), flatten=False)
+        controldtype = [('f0', int),
+                                ('f1', [('a', int),
+                                        ('b', [('ba', float), ('bb', int), ('bc', [])])])]
+        control = np.array([(1., (1, (2, 3.0, ()))), (2, (4, (5, 6.0, ())))],
+                           dtype=controldtype)
+        assert_equal(test, control)
+
+    def test_wmasked_arrays(self):
+        # Test merge_arrays masked arrays
+        (_, x, _, _) = self.data
+        mx = ma.array([1, 2, 3], mask=[1, 0, 0])
+        test = merge_arrays((x, mx), usemask=True)
+        control = ma.array([(1, 1), (2, 2), (-1, 3)],
+                           mask=[(0, 1), (0, 0), (1, 0)],
+                           dtype=[('f0', int), ('f1', int)])
+        assert_equal(test, control)
+        test = merge_arrays((x, mx), usemask=True, asrecarray=True)
+        assert_equal(test, control)
+        assert_(isinstance(test, MaskedRecords))
+
+    def test_w_singlefield(self):
+        # Test single field
+        test = merge_arrays((np.array([1, 2]).view([('a', int)]),
+                             np.array([10., 20., 30.])),)
+        control = ma.array([(1, 10.), (2, 20.), (-1, 30.)],
+                           mask=[(0, 0), (0, 0), (1, 0)],
+                           dtype=[('a', int), ('f1', float)])
+        assert_equal(test, control)
+
+    def test_w_shorter_flex(self):
+        # Test merge_arrays w/ a shorter flexndarray.
+        z = self.data[-1]
+
+        # Fixme, this test looks incomplete and broken
+        #test = merge_arrays((z, np.array([10, 20, 30]).view([('C', int)])))
+        #control = np.array([('A', 1., 10), ('B', 2., 20), ('-1', -1, 20)],
+        #                   dtype=[('A', '|S3'), ('B', float), ('C', int)])
+        #assert_equal(test, control)
+
+        # Hack to avoid pyflakes warnings about unused variables
+        merge_arrays((z, np.array([10, 20, 30]).view([('C', int)])))
+        np.array([('A', 1., 10), ('B', 2., 20), ('-1', -1, 20)],
+                 dtype=[('A', '|S3'), ('B', float), ('C', int)])
+
+    def test_singlerecord(self):
+        (_, x, y, z) = self.data
+        test = merge_arrays((x[0], y[0], z[0]), usemask=False)
+        control = np.array([(1, 10, ('A', 1))],
+                           dtype=[('f0', int),
+                                  ('f1', int),
+                                  ('f2', [('A', '|S3'), ('B', float)])])
+        assert_equal(test, control)
+
+
+class TestAppendFields:
+    # Test append_fields
+
+    def setup_method(self):
+        x = np.array([1, 2, ])
+        y = np.array([10, 20, 30])
+        z = np.array(
+            [('A', 1.), ('B', 2.)], dtype=[('A', '|S3'), ('B', float)])
+        w = np.array([(1, (2, 3.0)), (4, (5, 6.0))],
+                     dtype=[('a', int), ('b', [('ba', float), ('bb', int)])])
+        self.data = (w, x, y, z)
+
+    def test_append_single(self):
+        # Test simple case
+        (_, x, _, _) = self.data
+        test = append_fields(x, 'A', data=[10, 20, 30])
+        control = ma.array([(1, 10), (2, 20), (-1, 30)],
+                           mask=[(0, 0), (0, 0), (1, 0)],
+                           dtype=[('f0', int), ('A', int)],)
+        assert_equal(test, control)
+
+    def test_append_double(self):
+        # Test simple case
+        (_, x, _, _) = self.data
+        test = append_fields(x, ('A', 'B'), data=[[10, 20, 30], [100, 200]])
+        control = ma.array([(1, 10, 100), (2, 20, 200), (-1, 30, -1)],
+                           mask=[(0, 0, 0), (0, 0, 0), (1, 0, 1)],
+                           dtype=[('f0', int), ('A', int), ('B', int)],)
+        assert_equal(test, control)
+
+    def test_append_on_flex(self):
+        # Test append_fields on flexible type arrays
+        z = self.data[-1]
+        test = append_fields(z, 'C', data=[10, 20, 30])
+        control = ma.array([('A', 1., 10), ('B', 2., 20), (-1, -1., 30)],
+                           mask=[(0, 0, 0), (0, 0, 0), (1, 1, 0)],
+                           dtype=[('A', '|S3'), ('B', float), ('C', int)],)
+        assert_equal(test, control)
+
+    def test_append_on_nested(self):
+        # Test append_fields on nested fields
+        w = self.data[0]
+        test = append_fields(w, 'C', data=[10, 20, 30])
+        control = ma.array([(1, (2, 3.0), 10),
+                            (4, (5, 6.0), 20),
+                            (-1, (-1, -1.), 30)],
+                           mask=[(
+                               0, (0, 0), 0), (0, (0, 0), 0), (1, (1, 1), 0)],
+                           dtype=[('a', int),
+                                  ('b', [('ba', float), ('bb', int)]),
+                                  ('C', int)],)
+        assert_equal(test, control)
+
+
+class TestStackArrays:
+    # Test stack_arrays
+    def setup_method(self):
+        x = np.array([1, 2, ])
+        y = np.array([10, 20, 30])
+        z = np.array(
+            [('A', 1.), ('B', 2.)], dtype=[('A', '|S3'), ('B', float)])
+        w = np.array([(1, (2, 3.0)), (4, (5, 6.0))],
+                     dtype=[('a', int), ('b', [('ba', float), ('bb', int)])])
+        self.data = (w, x, y, z)
+
+    def test_solo(self):
+        # Test stack_arrays on single arrays
+        (_, x, _, _) = self.data
+        test = stack_arrays((x,))
+        assert_equal(test, x)
+        assert_(test is x)
+
+        test = stack_arrays(x)
+        assert_equal(test, x)
+        assert_(test is x)
+
+    def test_unnamed_fields(self):
+        # Tests combinations of arrays w/o named fields
+        (_, x, y, _) = self.data
+
+        test = stack_arrays((x, x), usemask=False)
+        control = np.array([1, 2, 1, 2])
+        assert_equal(test, control)
+
+        test = stack_arrays((x, y), usemask=False)
+        control = np.array([1, 2, 10, 20, 30])
+        assert_equal(test, control)
+
+        test = stack_arrays((y, x), usemask=False)
+        control = np.array([10, 20, 30, 1, 2])
+        assert_equal(test, control)
+
+    def test_unnamed_and_named_fields(self):
+        # Test combination of arrays w/ & w/o named fields
+        (_, x, _, z) = self.data
+
+        test = stack_arrays((x, z))
+        control = ma.array([(1, -1, -1), (2, -1, -1),
+                            (-1, 'A', 1), (-1, 'B', 2)],
+                           mask=[(0, 1, 1), (0, 1, 1),
+                                 (1, 0, 0), (1, 0, 0)],
+                           dtype=[('f0', int), ('A', '|S3'), ('B', float)])
+        assert_equal(test, control)
+        assert_equal(test.mask, control.mask)
+
+        test = stack_arrays((z, x))
+        control = ma.array([('A', 1, -1), ('B', 2, -1),
+                            (-1, -1, 1), (-1, -1, 2), ],
+                           mask=[(0, 0, 1), (0, 0, 1),
+                                 (1, 1, 0), (1, 1, 0)],
+                           dtype=[('A', '|S3'), ('B', float), ('f2', int)])
+        assert_equal(test, control)
+        assert_equal(test.mask, control.mask)
+
+        test = stack_arrays((z, z, x))
+        control = ma.array([('A', 1, -1), ('B', 2, -1),
+                            ('A', 1, -1), ('B', 2, -1),
+                            (-1, -1, 1), (-1, -1, 2), ],
+                           mask=[(0, 0, 1), (0, 0, 1),
+                                 (0, 0, 1), (0, 0, 1),
+                                 (1, 1, 0), (1, 1, 0)],
+                           dtype=[('A', '|S3'), ('B', float), ('f2', int)])
+        assert_equal(test, control)
+
+    def test_matching_named_fields(self):
+        # Test combination of arrays w/ matching field names
+        (_, x, _, z) = self.data
+        zz = np.array([('a', 10., 100.), ('b', 20., 200.), ('c', 30., 300.)],
+                      dtype=[('A', '|S3'), ('B', float), ('C', float)])
+        test = stack_arrays((z, zz))
+        control = ma.array([('A', 1, -1), ('B', 2, -1),
+                            (
+                                'a', 10., 100.), ('b', 20., 200.), ('c', 30., 300.)],
+                           dtype=[('A', '|S3'), ('B', float), ('C', float)],
+                           mask=[(0, 0, 1), (0, 0, 1),
+                                 (0, 0, 0), (0, 0, 0), (0, 0, 0)])
+        assert_equal(test, control)
+        assert_equal(test.mask, control.mask)
+
+        test = stack_arrays((z, zz, x))
+        ndtype = [('A', '|S3'), ('B', float), ('C', float), ('f3', int)]
+        control = ma.array([('A', 1, -1, -1), ('B', 2, -1, -1),
+                            ('a', 10., 100., -1), ('b', 20., 200., -1),
+                            ('c', 30., 300., -1),
+                            (-1, -1, -1, 1), (-1, -1, -1, 2)],
+                           dtype=ndtype,
+                           mask=[(0, 0, 1, 1), (0, 0, 1, 1),
+                                 (0, 0, 0, 1), (0, 0, 0, 1), (0, 0, 0, 1),
+                                 (1, 1, 1, 0), (1, 1, 1, 0)])
+        assert_equal(test, control)
+        assert_equal(test.mask, control.mask)
+
+    def test_defaults(self):
+        # Test defaults: no exception raised if keys of defaults are not fields.
+        (_, _, _, z) = self.data
+        zz = np.array([('a', 10., 100.), ('b', 20., 200.), ('c', 30., 300.)],
+                      dtype=[('A', '|S3'), ('B', float), ('C', float)])
+        defaults = {'A': '???', 'B': -999., 'C': -9999., 'D': -99999.}
+        test = stack_arrays((z, zz), defaults=defaults)
+        control = ma.array([('A', 1, -9999.), ('B', 2, -9999.),
+                            (
+                                'a', 10., 100.), ('b', 20., 200.), ('c', 30., 300.)],
+                           dtype=[('A', '|S3'), ('B', float), ('C', float)],
+                           mask=[(0, 0, 1), (0, 0, 1),
+                                 (0, 0, 0), (0, 0, 0), (0, 0, 0)])
+        assert_equal(test, control)
+        assert_equal(test.data, control.data)
+        assert_equal(test.mask, control.mask)
+
+    def test_autoconversion(self):
+        # Tests autoconversion
+        adtype = [('A', int), ('B', bool), ('C', float)]
+        a = ma.array([(1, 2, 3)], mask=[(0, 1, 0)], dtype=adtype)
+        bdtype = [('A', int), ('B', float), ('C', float)]
+        b = ma.array([(4, 5, 6)], dtype=bdtype)
+        control = ma.array([(1, 2, 3), (4, 5, 6)], mask=[(0, 1, 0), (0, 0, 0)],
+                           dtype=bdtype)
+        test = stack_arrays((a, b), autoconvert=True)
+        assert_equal(test, control)
+        assert_equal(test.mask, control.mask)
+        with assert_raises(TypeError):
+            stack_arrays((a, b), autoconvert=False)
+
+    def test_checktitles(self):
+        # Test using titles in the field names
+        adtype = [(('a', 'A'), int), (('b', 'B'), bool), (('c', 'C'), float)]
+        a = ma.array([(1, 2, 3)], mask=[(0, 1, 0)], dtype=adtype)
+        bdtype = [(('a', 'A'), int), (('b', 'B'), bool), (('c', 'C'), float)]
+        b = ma.array([(4, 5, 6)], dtype=bdtype)
+        test = stack_arrays((a, b))
+        control = ma.array([(1, 2, 3), (4, 5, 6)], mask=[(0, 1, 0), (0, 0, 0)],
+                           dtype=bdtype)
+        assert_equal(test, control)
+        assert_equal(test.mask, control.mask)
+
+    def test_subdtype(self):
+        z = np.array([
+            ('A', 1), ('B', 2)
+        ], dtype=[('A', '|S3'), ('B', float, (1,))])
+        zz = np.array([
+            ('a', [10.], 100.), ('b', [20.], 200.), ('c', [30.], 300.)
+        ], dtype=[('A', '|S3'), ('B', float, (1,)), ('C', float)])
+
+        res = stack_arrays((z, zz))
+        expected = ma.array(
+            data=[
+                (b'A', [1.0], 0),
+                (b'B', [2.0], 0),
+                (b'a', [10.0], 100.0),
+                (b'b', [20.0], 200.0),
+                (b'c', [30.0], 300.0)],
+            mask=[
+                (False, [False],  True),
+                (False, [False],  True),
+                (False, [False], False),
+                (False, [False], False),
+                (False, [False], False)
+            ],
+            dtype=zz.dtype
+        )
+        assert_equal(res.dtype, expected.dtype)
+        assert_equal(res, expected)
+        assert_equal(res.mask, expected.mask)
+
+
+class TestJoinBy:
+    def setup_method(self):
+        self.a = np.array(list(zip(np.arange(10), np.arange(50, 60),
+                                   np.arange(100, 110))),
+                          dtype=[('a', int), ('b', int), ('c', int)])
+        self.b = np.array(list(zip(np.arange(5, 15), np.arange(65, 75),
+                                   np.arange(100, 110))),
+                          dtype=[('a', int), ('b', int), ('d', int)])
+
+    def test_inner_join(self):
+        # Basic test of join_by
+        a, b = self.a, self.b
+
+        test = join_by('a', a, b, jointype='inner')
+        control = np.array([(5, 55, 65, 105, 100), (6, 56, 66, 106, 101),
+                            (7, 57, 67, 107, 102), (8, 58, 68, 108, 103),
+                            (9, 59, 69, 109, 104)],
+                           dtype=[('a', int), ('b1', int), ('b2', int),
+                                  ('c', int), ('d', int)])
+        assert_equal(test, control)
+
+    def test_join(self):
+        a, b = self.a, self.b
+
+        # Fixme, this test is broken
+        #test = join_by(('a', 'b'), a, b)
+        #control = np.array([(5, 55, 105, 100), (6, 56, 106, 101),
+        #                    (7, 57, 107, 102), (8, 58, 108, 103),
+        #                    (9, 59, 109, 104)],
+        #                   dtype=[('a', int), ('b', int),
+        #                          ('c', int), ('d', int)])
+        #assert_equal(test, control)
+
+        # Hack to avoid pyflakes unused variable warnings
+        join_by(('a', 'b'), a, b)
+        np.array([(5, 55, 105, 100), (6, 56, 106, 101),
+                  (7, 57, 107, 102), (8, 58, 108, 103),
+                  (9, 59, 109, 104)],
+                  dtype=[('a', int), ('b', int),
+                         ('c', int), ('d', int)])
+
+    def test_join_subdtype(self):
+        # tests the bug in https://stackoverflow.com/q/44769632/102441
+        foo = np.array([(1,)],
+                       dtype=[('key', int)])
+        bar = np.array([(1, np.array([1,2,3]))],
+                       dtype=[('key', int), ('value', 'uint16', 3)])
+        res = join_by('key', foo, bar)
+        assert_equal(res, bar.view(ma.MaskedArray))
+
+    def test_outer_join(self):
+        a, b = self.a, self.b
+
+        test = join_by(('a', 'b'), a, b, 'outer')
+        control = ma.array([(0, 50, 100, -1), (1, 51, 101, -1),
+                            (2, 52, 102, -1), (3, 53, 103, -1),
+                            (4, 54, 104, -1), (5, 55, 105, -1),
+                            (5, 65, -1, 100), (6, 56, 106, -1),
+                            (6, 66, -1, 101), (7, 57, 107, -1),
+                            (7, 67, -1, 102), (8, 58, 108, -1),
+                            (8, 68, -1, 103), (9, 59, 109, -1),
+                            (9, 69, -1, 104), (10, 70, -1, 105),
+                            (11, 71, -1, 106), (12, 72, -1, 107),
+                            (13, 73, -1, 108), (14, 74, -1, 109)],
+                           mask=[(0, 0, 0, 1), (0, 0, 0, 1),
+                                 (0, 0, 0, 1), (0, 0, 0, 1),
+                                 (0, 0, 0, 1), (0, 0, 0, 1),
+                                 (0, 0, 1, 0), (0, 0, 0, 1),
+                                 (0, 0, 1, 0), (0, 0, 0, 1),
+                                 (0, 0, 1, 0), (0, 0, 0, 1),
+                                 (0, 0, 1, 0), (0, 0, 0, 1),
+                                 (0, 0, 1, 0), (0, 0, 1, 0),
+                                 (0, 0, 1, 0), (0, 0, 1, 0),
+                                 (0, 0, 1, 0), (0, 0, 1, 0)],
+                           dtype=[('a', int), ('b', int),
+                                  ('c', int), ('d', int)])
+        assert_equal(test, control)
+
+    def test_leftouter_join(self):
+        a, b = self.a, self.b
+
+        test = join_by(('a', 'b'), a, b, 'leftouter')
+        control = ma.array([(0, 50, 100, -1), (1, 51, 101, -1),
+                            (2, 52, 102, -1), (3, 53, 103, -1),
+                            (4, 54, 104, -1), (5, 55, 105, -1),
+                            (6, 56, 106, -1), (7, 57, 107, -1),
+                            (8, 58, 108, -1), (9, 59, 109, -1)],
+                           mask=[(0, 0, 0, 1), (0, 0, 0, 1),
+                                 (0, 0, 0, 1), (0, 0, 0, 1),
+                                 (0, 0, 0, 1), (0, 0, 0, 1),
+                                 (0, 0, 0, 1), (0, 0, 0, 1),
+                                 (0, 0, 0, 1), (0, 0, 0, 1)],
+                           dtype=[('a', int), ('b', int), ('c', int), ('d', int)])
+        assert_equal(test, control)
+
+    def test_different_field_order(self):
+        # gh-8940
+        a = np.zeros(3, dtype=[('a', 'i4'), ('b', 'f4'), ('c', 'u1')])
+        b = np.ones(3, dtype=[('c', 'u1'), ('b', 'f4'), ('a', 'i4')])
+        # this should not give a FutureWarning:
+        j = join_by(['c', 'b'], a, b, jointype='inner', usemask=False)
+        assert_equal(j.dtype.names, ['b', 'c', 'a1', 'a2'])
+
+    def test_duplicate_keys(self):
+        a = np.zeros(3, dtype=[('a', 'i4'), ('b', 'f4'), ('c', 'u1')])
+        b = np.ones(3, dtype=[('c', 'u1'), ('b', 'f4'), ('a', 'i4')])
+        assert_raises(ValueError, join_by, ['a', 'b', 'b'], a, b)
+
+    def test_same_name_different_dtypes_key(self):
+        a_dtype = np.dtype([('key', 'S5'), ('value', '<f4')])
+        b_dtype = np.dtype([('key', 'S10'), ('value', '<f4')])
+        expected_dtype = np.dtype([
+            ('key', 'S10'), ('value1', '<f4'), ('value2', '<f4')])
+
+        a = np.array([('Sarah',  8.0), ('John', 6.0)], dtype=a_dtype)
+        b = np.array([('Sarah', 10.0), ('John', 7.0)], dtype=b_dtype)
+        res = join_by('key', a, b)
+
+        assert_equal(res.dtype, expected_dtype)
+
+    def test_same_name_different_dtypes(self):
+        # gh-9338
+        a_dtype = np.dtype([('key', 'S10'), ('value', '<f4')])
+        b_dtype = np.dtype([('key', 'S10'), ('value', '<f8')])
+        expected_dtype = np.dtype([
+            ('key', '|S10'), ('value1', '<f4'), ('value2', '<f8')])
+
+        a = np.array([('Sarah',  8.0), ('John', 6.0)], dtype=a_dtype)
+        b = np.array([('Sarah', 10.0), ('John', 7.0)], dtype=b_dtype)
+        res = join_by('key', a, b)
+
+        assert_equal(res.dtype, expected_dtype)
+
+    def test_subarray_key(self):
+        a_dtype = np.dtype([('pos', int, 3), ('f', '<f4')])
+        a = np.array([([1, 1, 1], np.pi), ([1, 2, 3], 0.0)], dtype=a_dtype)
+
+        b_dtype = np.dtype([('pos', int, 3), ('g', '<f4')])
+        b = np.array([([1, 1, 1], 3), ([3, 2, 1], 0.0)], dtype=b_dtype)
+
+        expected_dtype = np.dtype([('pos', int, 3), ('f', '<f4'), ('g', '<f4')])
+        expected = np.array([([1, 1, 1], np.pi, 3)], dtype=expected_dtype)
+
+        res = join_by('pos', a, b)
+        assert_equal(res.dtype, expected_dtype)
+        assert_equal(res, expected)
+
+    def test_padded_dtype(self):
+        dt = np.dtype('i1,f4', align=True)
+        dt.names = ('k', 'v')
+        assert_(len(dt.descr), 3)  # padding field is inserted
+
+        a = np.array([(1, 3), (3, 2)], dt)
+        b = np.array([(1, 1), (2, 2)], dt)
+        res = join_by('k', a, b)
+
+        # no padding fields remain
+        expected_dtype = np.dtype([
+            ('k', 'i1'), ('v1', 'f4'), ('v2', 'f4')
+        ])
+
+        assert_equal(res.dtype, expected_dtype)
+
+
+class TestJoinBy2:
+    @classmethod
+    def setup_method(cls):
+        cls.a = np.array(list(zip(np.arange(10), np.arange(50, 60),
+                                  np.arange(100, 110))),
+                         dtype=[('a', int), ('b', int), ('c', int)])
+        cls.b = np.array(list(zip(np.arange(10), np.arange(65, 75),
+                                  np.arange(100, 110))),
+                         dtype=[('a', int), ('b', int), ('d', int)])
+
+    def test_no_r1postfix(self):
+        # Basic test of join_by no_r1postfix
+        a, b = self.a, self.b
+
+        test = join_by(
+            'a', a, b, r1postfix='', r2postfix='2', jointype='inner')
+        control = np.array([(0, 50, 65, 100, 100), (1, 51, 66, 101, 101),
+                            (2, 52, 67, 102, 102), (3, 53, 68, 103, 103),
+                            (4, 54, 69, 104, 104), (5, 55, 70, 105, 105),
+                            (6, 56, 71, 106, 106), (7, 57, 72, 107, 107),
+                            (8, 58, 73, 108, 108), (9, 59, 74, 109, 109)],
+                           dtype=[('a', int), ('b', int), ('b2', int),
+                                  ('c', int), ('d', int)])
+        assert_equal(test, control)
+
+    def test_no_postfix(self):
+        assert_raises(ValueError, join_by, 'a', self.a, self.b,
+                      r1postfix='', r2postfix='')
+
+    def test_no_r2postfix(self):
+        # Basic test of join_by no_r2postfix
+        a, b = self.a, self.b
+
+        test = join_by(
+            'a', a, b, r1postfix='1', r2postfix='', jointype='inner')
+        control = np.array([(0, 50, 65, 100, 100), (1, 51, 66, 101, 101),
+                            (2, 52, 67, 102, 102), (3, 53, 68, 103, 103),
+                            (4, 54, 69, 104, 104), (5, 55, 70, 105, 105),
+                            (6, 56, 71, 106, 106), (7, 57, 72, 107, 107),
+                            (8, 58, 73, 108, 108), (9, 59, 74, 109, 109)],
+                           dtype=[('a', int), ('b1', int), ('b', int),
+                                  ('c', int), ('d', int)])
+        assert_equal(test, control)
+
+    def test_two_keys_two_vars(self):
+        a = np.array(list(zip(np.tile([10, 11], 5), np.repeat(np.arange(5), 2),
+                              np.arange(50, 60), np.arange(10, 20))),
+                     dtype=[('k', int), ('a', int), ('b', int), ('c', int)])
+
+        b = np.array(list(zip(np.tile([10, 11], 5), np.repeat(np.arange(5), 2),
+                              np.arange(65, 75), np.arange(0, 10))),
+                     dtype=[('k', int), ('a', int), ('b', int), ('c', int)])
+
+        control = np.array([(10, 0, 50, 65, 10, 0), (11, 0, 51, 66, 11, 1),
+                            (10, 1, 52, 67, 12, 2), (11, 1, 53, 68, 13, 3),
+                            (10, 2, 54, 69, 14, 4), (11, 2, 55, 70, 15, 5),
+                            (10, 3, 56, 71, 16, 6), (11, 3, 57, 72, 17, 7),
+                            (10, 4, 58, 73, 18, 8), (11, 4, 59, 74, 19, 9)],
+                           dtype=[('k', int), ('a', int), ('b1', int),
+                                  ('b2', int), ('c1', int), ('c2', int)])
+        test = join_by(
+            ['a', 'k'], a, b, r1postfix='1', r2postfix='2', jointype='inner')
+        assert_equal(test.dtype, control.dtype)
+        assert_equal(test, control)
+
+class TestAppendFieldsObj:
+    """
+    Test append_fields with arrays containing objects
+    """
+    # https://github.com/numpy/numpy/issues/2346
+
+    def setup_method(self):
+        from datetime import date
+        self.data = dict(obj=date(2000, 1, 1))
+
+    def test_append_to_objects(self):
+        "Test append_fields when the base array contains objects"
+        obj = self.data['obj']
+        x = np.array([(obj, 1.), (obj, 2.)],
+                      dtype=[('A', object), ('B', float)])
+        y = np.array([10, 20], dtype=int)
+        test = append_fields(x, 'C', data=y, usemask=False)
+        control = np.array([(obj, 1.0, 10), (obj, 2.0, 20)],
+                           dtype=[('A', object), ('B', float), ('C', int)])
+        assert_equal(test, control)

venv/lib/python3.10/site-packages/numpy/lib/tests/test_stride_tricks.py

@@ -0,0 +1,645 @@
+import numpy as np
+from numpy.core._rational_tests import rational
+from numpy.testing import (
+    assert_equal, assert_array_equal, assert_raises, assert_,
+    assert_raises_regex, assert_warns,
+    )
+from numpy.lib.stride_tricks import (
+    as_strided, broadcast_arrays, _broadcast_shape, broadcast_to,
+    broadcast_shapes, sliding_window_view,
+    )
+import pytest
+
+
+def assert_shapes_correct(input_shapes, expected_shape):
+    # Broadcast a list of arrays with the given input shapes and check the
+    # common output shape.
+
+    inarrays = [np.zeros(s) for s in input_shapes]
+    outarrays = broadcast_arrays(*inarrays)
+    outshapes = [a.shape for a in outarrays]
+    expected = [expected_shape] * len(inarrays)
+    assert_equal(outshapes, expected)
+
+
+def assert_incompatible_shapes_raise(input_shapes):
+    # Broadcast a list of arrays with the given (incompatible) input shapes
+    # and check that they raise a ValueError.
+
+    inarrays = [np.zeros(s) for s in input_shapes]
+    assert_raises(ValueError, broadcast_arrays, *inarrays)
+
+
+def assert_same_as_ufunc(shape0, shape1, transposed=False, flipped=False):
+    # Broadcast two shapes against each other and check that the data layout
+    # is the same as if a ufunc did the broadcasting.
+
+    x0 = np.zeros(shape0, dtype=int)
+    # Note that multiply.reduce's identity element is 1.0, so when shape1==(),
+    # this gives the desired n==1.
+    n = int(np.multiply.reduce(shape1))
+    x1 = np.arange(n).reshape(shape1)
+    if transposed:
+        x0 = x0.T
+        x1 = x1.T
+    if flipped:
+        x0 = x0[::-1]
+        x1 = x1[::-1]
+    # Use the add ufunc to do the broadcasting. Since we're adding 0s to x1, the
+    # result should be exactly the same as the broadcasted view of x1.
+    y = x0 + x1
+    b0, b1 = broadcast_arrays(x0, x1)
+    assert_array_equal(y, b1)
+
+
+def test_same():
+    x = np.arange(10)
+    y = np.arange(10)
+    bx, by = broadcast_arrays(x, y)
+    assert_array_equal(x, bx)
+    assert_array_equal(y, by)
+
+def test_broadcast_kwargs():
+    # ensure that a TypeError is appropriately raised when
+    # np.broadcast_arrays() is called with any keyword
+    # argument other than 'subok'
+    x = np.arange(10)
+    y = np.arange(10)
+
+    with assert_raises_regex(TypeError, 'got an unexpected keyword'):
+        broadcast_arrays(x, y, dtype='float64')
+
+
+def test_one_off():
+    x = np.array([[1, 2, 3]])
+    y = np.array([[1], [2], [3]])
+    bx, by = broadcast_arrays(x, y)
+    bx0 = np.array([[1, 2, 3], [1, 2, 3], [1, 2, 3]])
+    by0 = bx0.T
+    assert_array_equal(bx0, bx)
+    assert_array_equal(by0, by)
+
+
+def test_same_input_shapes():
+    # Check that the final shape is just the input shape.
+
+    data = [
+        (),
+        (1,),
+        (3,),
+        (0, 1),
+        (0, 3),
+        (1, 0),
+        (3, 0),
+        (1, 3),
+        (3, 1),
+        (3, 3),
+    ]
+    for shape in data:
+        input_shapes = [shape]
+        # Single input.
+        assert_shapes_correct(input_shapes, shape)
+        # Double input.
+        input_shapes2 = [shape, shape]
+        assert_shapes_correct(input_shapes2, shape)
+        # Triple input.
+        input_shapes3 = [shape, shape, shape]
+        assert_shapes_correct(input_shapes3, shape)
+
+
+def test_two_compatible_by_ones_input_shapes():
+    # Check that two different input shapes of the same length, but some have
+    # ones, broadcast to the correct shape.
+
+    data = [
+        [[(1,), (3,)], (3,)],
+        [[(1, 3), (3, 3)], (3, 3)],
+        [[(3, 1), (3, 3)], (3, 3)],
+        [[(1, 3), (3, 1)], (3, 3)],
+        [[(1, 1), (3, 3)], (3, 3)],
+        [[(1, 1), (1, 3)], (1, 3)],
+        [[(1, 1), (3, 1)], (3, 1)],
+        [[(1, 0), (0, 0)], (0, 0)],
+        [[(0, 1), (0, 0)], (0, 0)],
+        [[(1, 0), (0, 1)], (0, 0)],
+        [[(1, 1), (0, 0)], (0, 0)],
+        [[(1, 1), (1, 0)], (1, 0)],
+        [[(1, 1), (0, 1)], (0, 1)],
+    ]
+    for input_shapes, expected_shape in data:
+        assert_shapes_correct(input_shapes, expected_shape)
+        # Reverse the input shapes since broadcasting should be symmetric.
+        assert_shapes_correct(input_shapes[::-1], expected_shape)
+
+
+def test_two_compatible_by_prepending_ones_input_shapes():
+    # Check that two different input shapes (of different lengths) broadcast
+    # to the correct shape.
+
+    data = [
+        [[(), (3,)], (3,)],
+        [[(3,), (3, 3)], (3, 3)],
+        [[(3,), (3, 1)], (3, 3)],
+        [[(1,), (3, 3)], (3, 3)],
+        [[(), (3, 3)], (3, 3)],
+        [[(1, 1), (3,)], (1, 3)],
+        [[(1,), (3, 1)], (3, 1)],
+        [[(1,), (1, 3)], (1, 3)],
+        [[(), (1, 3)], (1, 3)],
+        [[(), (3, 1)], (3, 1)],
+        [[(), (0,)], (0,)],
+        [[(0,), (0, 0)], (0, 0)],
+        [[(0,), (0, 1)], (0, 0)],
+        [[(1,), (0, 0)], (0, 0)],
+        [[(), (0, 0)], (0, 0)],
+        [[(1, 1), (0,)], (1, 0)],
+        [[(1,), (0, 1)], (0, 1)],
+        [[(1,), (1, 0)], (1, 0)],
+        [[(), (1, 0)], (1, 0)],
+        [[(), (0, 1)], (0, 1)],
+    ]
+    for input_shapes, expected_shape in data:
+        assert_shapes_correct(input_shapes, expected_shape)
+        # Reverse the input shapes since broadcasting should be symmetric.
+        assert_shapes_correct(input_shapes[::-1], expected_shape)
+
+
+def test_incompatible_shapes_raise_valueerror():
+    # Check that a ValueError is raised for incompatible shapes.
+
+    data = [
+        [(3,), (4,)],
+        [(2, 3), (2,)],
+        [(3,), (3,), (4,)],
+        [(1, 3, 4), (2, 3, 3)],
+    ]
+    for input_shapes in data:
+        assert_incompatible_shapes_raise(input_shapes)
+        # Reverse the input shapes since broadcasting should be symmetric.
+        assert_incompatible_shapes_raise(input_shapes[::-1])
+
+
+def test_same_as_ufunc():
+    # Check that the data layout is the same as if a ufunc did the operation.
+
+    data = [
+        [[(1,), (3,)], (3,)],
+        [[(1, 3), (3, 3)], (3, 3)],
+        [[(3, 1), (3, 3)], (3, 3)],
+        [[(1, 3), (3, 1)], (3, 3)],
+        [[(1, 1), (3, 3)], (3, 3)],
+        [[(1, 1), (1, 3)], (1, 3)],
+        [[(1, 1), (3, 1)], (3, 1)],
+        [[(1, 0), (0, 0)], (0, 0)],
+        [[(0, 1), (0, 0)], (0, 0)],
+        [[(1, 0), (0, 1)], (0, 0)],
+        [[(1, 1), (0, 0)], (0, 0)],
+        [[(1, 1), (1, 0)], (1, 0)],
+        [[(1, 1), (0, 1)], (0, 1)],
+        [[(), (3,)], (3,)],
+        [[(3,), (3, 3)], (3, 3)],
+        [[(3,), (3, 1)], (3, 3)],
+        [[(1,), (3, 3)], (3, 3)],
+        [[(), (3, 3)], (3, 3)],
+        [[(1, 1), (3,)], (1, 3)],
+        [[(1,), (3, 1)], (3, 1)],
+        [[(1,), (1, 3)], (1, 3)],
+        [[(), (1, 3)], (1, 3)],
+        [[(), (3, 1)], (3, 1)],
+        [[(), (0,)], (0,)],
+        [[(0,), (0, 0)], (0, 0)],
+        [[(0,), (0, 1)], (0, 0)],
+        [[(1,), (0, 0)], (0, 0)],
+        [[(), (0, 0)], (0, 0)],
+        [[(1, 1), (0,)], (1, 0)],
+        [[(1,), (0, 1)], (0, 1)],
+        [[(1,), (1, 0)], (1, 0)],
+        [[(), (1, 0)], (1, 0)],
+        [[(), (0, 1)], (0, 1)],
+    ]
+    for input_shapes, expected_shape in data:
+        assert_same_as_ufunc(input_shapes[0], input_shapes[1],
+                             "Shapes: %s %s" % (input_shapes[0], input_shapes[1]))
+        # Reverse the input shapes since broadcasting should be symmetric.
+        assert_same_as_ufunc(input_shapes[1], input_shapes[0])
+        # Try them transposed, too.
+        assert_same_as_ufunc(input_shapes[0], input_shapes[1], True)
+        # ... and flipped for non-rank-0 inputs in order to test negative
+        # strides.
+        if () not in input_shapes:
+            assert_same_as_ufunc(input_shapes[0], input_shapes[1], False, True)
+            assert_same_as_ufunc(input_shapes[0], input_shapes[1], True, True)
+
+
+def test_broadcast_to_succeeds():
+    data = [
+        [np.array(0), (0,), np.array(0)],
+        [np.array(0), (1,), np.zeros(1)],
+        [np.array(0), (3,), np.zeros(3)],
+        [np.ones(1), (1,), np.ones(1)],
+        [np.ones(1), (2,), np.ones(2)],
+        [np.ones(1), (1, 2, 3), np.ones((1, 2, 3))],
+        [np.arange(3), (3,), np.arange(3)],
+        [np.arange(3), (1, 3), np.arange(3).reshape(1, -1)],
+        [np.arange(3), (2, 3), np.array([[0, 1, 2], [0, 1, 2]])],
+        # test if shape is not a tuple
+        [np.ones(0), 0, np.ones(0)],
+        [np.ones(1), 1, np.ones(1)],
+        [np.ones(1), 2, np.ones(2)],
+        # these cases with size 0 are strange, but they reproduce the behavior
+        # of broadcasting with ufuncs (see test_same_as_ufunc above)
+        [np.ones(1), (0,), np.ones(0)],
+        [np.ones((1, 2)), (0, 2), np.ones((0, 2))],
+        [np.ones((2, 1)), (2, 0), np.ones((2, 0))],
+    ]
+    for input_array, shape, expected in data:
+        actual = broadcast_to(input_array, shape)
+        assert_array_equal(expected, actual)
+
+
+def test_broadcast_to_raises():
+    data = [
+        [(0,), ()],
+        [(1,), ()],
+        [(3,), ()],
+        [(3,), (1,)],
+        [(3,), (2,)],
+        [(3,), (4,)],
+        [(1, 2), (2, 1)],
+        [(1, 1), (1,)],
+        [(1,), -1],
+        [(1,), (-1,)],
+        [(1, 2), (-1, 2)],
+    ]
+    for orig_shape, target_shape in data:
+        arr = np.zeros(orig_shape)
+        assert_raises(ValueError, lambda: broadcast_to(arr, target_shape))
+
+
+def test_broadcast_shape():
+    # tests internal _broadcast_shape
+    # _broadcast_shape is already exercised indirectly by broadcast_arrays
+    # _broadcast_shape is also exercised by the public broadcast_shapes function
+    assert_equal(_broadcast_shape(), ())
+    assert_equal(_broadcast_shape([1, 2]), (2,))
+    assert_equal(_broadcast_shape(np.ones((1, 1))), (1, 1))
+    assert_equal(_broadcast_shape(np.ones((1, 1)), np.ones((3, 4))), (3, 4))
+    assert_equal(_broadcast_shape(*([np.ones((1, 2))] * 32)), (1, 2))
+    assert_equal(_broadcast_shape(*([np.ones((1, 2))] * 100)), (1, 2))
+
+    # regression tests for gh-5862
+    assert_equal(_broadcast_shape(*([np.ones(2)] * 32 + [1])), (2,))
+    bad_args = [np.ones(2)] * 32 + [np.ones(3)] * 32
+    assert_raises(ValueError, lambda: _broadcast_shape(*bad_args))
+
+
+def test_broadcast_shapes_succeeds():
+    # tests public broadcast_shapes
+    data = [
+        [[], ()],
+        [[()], ()],
+        [[(7,)], (7,)],
+        [[(1, 2), (2,)], (1, 2)],
+        [[(1, 1)], (1, 1)],
+        [[(1, 1), (3, 4)], (3, 4)],
+        [[(6, 7), (5, 6, 1), (7,), (5, 1, 7)], (5, 6, 7)],
+        [[(5, 6, 1)], (5, 6, 1)],
+        [[(1, 3), (3, 1)], (3, 3)],
+        [[(1, 0), (0, 0)], (0, 0)],
+        [[(0, 1), (0, 0)], (0, 0)],
+        [[(1, 0), (0, 1)], (0, 0)],
+        [[(1, 1), (0, 0)], (0, 0)],
+        [[(1, 1), (1, 0)], (1, 0)],
+        [[(1, 1), (0, 1)], (0, 1)],
+        [[(), (0,)], (0,)],
+        [[(0,), (0, 0)], (0, 0)],
+        [[(0,), (0, 1)], (0, 0)],
+        [[(1,), (0, 0)], (0, 0)],
+        [[(), (0, 0)], (0, 0)],
+        [[(1, 1), (0,)], (1, 0)],
+        [[(1,), (0, 1)], (0, 1)],
+        [[(1,), (1, 0)], (1, 0)],
+        [[(), (1, 0)], (1, 0)],
+        [[(), (0, 1)], (0, 1)],
+        [[(1,), (3,)], (3,)],
+        [[2, (3, 2)], (3, 2)],
+    ]
+    for input_shapes, target_shape in data:
+        assert_equal(broadcast_shapes(*input_shapes), target_shape)
+
+    assert_equal(broadcast_shapes(*([(1, 2)] * 32)), (1, 2))
+    assert_equal(broadcast_shapes(*([(1, 2)] * 100)), (1, 2))
+
+    # regression tests for gh-5862
+    assert_equal(broadcast_shapes(*([(2,)] * 32)), (2,))
+
+
+def test_broadcast_shapes_raises():
+    # tests public broadcast_shapes
+    data = [
+        [(3,), (4,)],
+        [(2, 3), (2,)],
+        [(3,), (3,), (4,)],
+        [(1, 3, 4), (2, 3, 3)],
+        [(1, 2), (3,1), (3,2), (10, 5)],
+        [2, (2, 3)],
+    ]
+    for input_shapes in data:
+        assert_raises(ValueError, lambda: broadcast_shapes(*input_shapes))
+
+    bad_args = [(2,)] * 32 + [(3,)] * 32
+    assert_raises(ValueError, lambda: broadcast_shapes(*bad_args))
+
+
+def test_as_strided():
+    a = np.array([None])
+    a_view = as_strided(a)
+    expected = np.array([None])
+    assert_array_equal(a_view, np.array([None]))
+
+    a = np.array([1, 2, 3, 4])
+    a_view = as_strided(a, shape=(2,), strides=(2 * a.itemsize,))
+    expected = np.array([1, 3])
+    assert_array_equal(a_view, expected)
+
+    a = np.array([1, 2, 3, 4])
+    a_view = as_strided(a, shape=(3, 4), strides=(0, 1 * a.itemsize))
+    expected = np.array([[1, 2, 3, 4], [1, 2, 3, 4], [1, 2, 3, 4]])
+    assert_array_equal(a_view, expected)
+
+    # Regression test for gh-5081
+    dt = np.dtype([('num', 'i4'), ('obj', 'O')])
+    a = np.empty((4,), dtype=dt)
+    a['num'] = np.arange(1, 5)
+    a_view = as_strided(a, shape=(3, 4), strides=(0, a.itemsize))
+    expected_num = [[1, 2, 3, 4]] * 3
+    expected_obj = [[None]*4]*3
+    assert_equal(a_view.dtype, dt)
+    assert_array_equal(expected_num, a_view['num'])
+    assert_array_equal(expected_obj, a_view['obj'])
+
+    # Make sure that void types without fields are kept unchanged
+    a = np.empty((4,), dtype='V4')
+    a_view = as_strided(a, shape=(3, 4), strides=(0, a.itemsize))
+    assert_equal(a.dtype, a_view.dtype)
+
+    # Make sure that the only type that could fail is properly handled
+    dt = np.dtype({'names': [''], 'formats': ['V4']})
+    a = np.empty((4,), dtype=dt)
+    a_view = as_strided(a, shape=(3, 4), strides=(0, a.itemsize))
+    assert_equal(a.dtype, a_view.dtype)
+
+    # Custom dtypes should not be lost (gh-9161)
+    r = [rational(i) for i in range(4)]
+    a = np.array(r, dtype=rational)
+    a_view = as_strided(a, shape=(3, 4), strides=(0, a.itemsize))
+    assert_equal(a.dtype, a_view.dtype)
+    assert_array_equal([r] * 3, a_view)
+
+
+class TestSlidingWindowView:
+    def test_1d(self):
+        arr = np.arange(5)
+        arr_view = sliding_window_view(arr, 2)
+        expected = np.array([[0, 1],
+                             [1, 2],
+                             [2, 3],
+                             [3, 4]])
+        assert_array_equal(arr_view, expected)
+
+    def test_2d(self):
+        i, j = np.ogrid[:3, :4]
+        arr = 10*i + j
+        shape = (2, 2)
+        arr_view = sliding_window_view(arr, shape)
+        expected = np.array([[[[0, 1], [10, 11]],
+                              [[1, 2], [11, 12]],
+                              [[2, 3], [12, 13]]],
+                             [[[10, 11], [20, 21]],
+                              [[11, 12], [21, 22]],
+                              [[12, 13], [22, 23]]]])
+        assert_array_equal(arr_view, expected)
+
+    def test_2d_with_axis(self):
+        i, j = np.ogrid[:3, :4]
+        arr = 10*i + j
+        arr_view = sliding_window_view(arr, 3, 0)
+        expected = np.array([[[0, 10, 20],
+                              [1, 11, 21],
+                              [2, 12, 22],
+                              [3, 13, 23]]])
+        assert_array_equal(arr_view, expected)
+
+    def test_2d_repeated_axis(self):
+        i, j = np.ogrid[:3, :4]
+        arr = 10*i + j
+        arr_view = sliding_window_view(arr, (2, 3), (1, 1))
+        expected = np.array([[[[0, 1, 2],
+                               [1, 2, 3]]],
+                             [[[10, 11, 12],
+                               [11, 12, 13]]],
+                             [[[20, 21, 22],
+                               [21, 22, 23]]]])
+        assert_array_equal(arr_view, expected)
+
+    def test_2d_without_axis(self):
+        i, j = np.ogrid[:4, :4]
+        arr = 10*i + j
+        shape = (2, 3)
+        arr_view = sliding_window_view(arr, shape)
+        expected = np.array([[[[0, 1, 2], [10, 11, 12]],
+                              [[1, 2, 3], [11, 12, 13]]],
+                             [[[10, 11, 12], [20, 21, 22]],
+                              [[11, 12, 13], [21, 22, 23]]],
+                             [[[20, 21, 22], [30, 31, 32]],
+                              [[21, 22, 23], [31, 32, 33]]]])
+        assert_array_equal(arr_view, expected)
+
+    def test_errors(self):
+        i, j = np.ogrid[:4, :4]
+        arr = 10*i + j
+        with pytest.raises(ValueError, match='cannot contain negative values'):
+            sliding_window_view(arr, (-1, 3))
+        with pytest.raises(
+                ValueError,
+                match='must provide window_shape for all dimensions of `x`'):
+            sliding_window_view(arr, (1,))
+        with pytest.raises(
+                ValueError,
+                match='Must provide matching length window_shape and axis'):
+            sliding_window_view(arr, (1, 3, 4), axis=(0, 1))
+        with pytest.raises(
+                ValueError,
+                match='window shape cannot be larger than input array'):
+            sliding_window_view(arr, (5, 5))
+
+    def test_writeable(self):
+        arr = np.arange(5)
+        view = sliding_window_view(arr, 2, writeable=False)
+        assert_(not view.flags.writeable)
+        with pytest.raises(
+                ValueError,
+                match='assignment destination is read-only'):
+            view[0, 0] = 3
+        view = sliding_window_view(arr, 2, writeable=True)
+        assert_(view.flags.writeable)
+        view[0, 1] = 3
+        assert_array_equal(arr, np.array([0, 3, 2, 3, 4]))
+
+    def test_subok(self):
+        class MyArray(np.ndarray):
+            pass
+
+        arr = np.arange(5).view(MyArray)
+        assert_(not isinstance(sliding_window_view(arr, 2,
+                                                   subok=False),
+                               MyArray))
+        assert_(isinstance(sliding_window_view(arr, 2, subok=True), MyArray))
+        # Default behavior
+        assert_(not isinstance(sliding_window_view(arr, 2), MyArray))
+
+
+def as_strided_writeable():
+    arr = np.ones(10)
+    view = as_strided(arr, writeable=False)
+    assert_(not view.flags.writeable)
+
+    # Check that writeable also is fine:
+    view = as_strided(arr, writeable=True)
+    assert_(view.flags.writeable)
+    view[...] = 3
+    assert_array_equal(arr, np.full_like(arr, 3))
+
+    # Test that things do not break down for readonly:
+    arr.flags.writeable = False
+    view = as_strided(arr, writeable=False)
+    view = as_strided(arr, writeable=True)
+    assert_(not view.flags.writeable)
+
+
+class VerySimpleSubClass(np.ndarray):
+    def __new__(cls, *args, **kwargs):
+        return np.array(*args, subok=True, **kwargs).view(cls)
+
+
+class SimpleSubClass(VerySimpleSubClass):
+    def __new__(cls, *args, **kwargs):
+        self = np.array(*args, subok=True, **kwargs).view(cls)
+        self.info = 'simple'
+        return self
+
+    def __array_finalize__(self, obj):
+        self.info = getattr(obj, 'info', '') + ' finalized'
+
+
+def test_subclasses():
+    # test that subclass is preserved only if subok=True
+    a = VerySimpleSubClass([1, 2, 3, 4])
+    assert_(type(a) is VerySimpleSubClass)
+    a_view = as_strided(a, shape=(2,), strides=(2 * a.itemsize,))
+    assert_(type(a_view) is np.ndarray)
+    a_view = as_strided(a, shape=(2,), strides=(2 * a.itemsize,), subok=True)
+    assert_(type(a_view) is VerySimpleSubClass)
+    # test that if a subclass has __array_finalize__, it is used
+    a = SimpleSubClass([1, 2, 3, 4])
+    a_view = as_strided(a, shape=(2,), strides=(2 * a.itemsize,), subok=True)
+    assert_(type(a_view) is SimpleSubClass)
+    assert_(a_view.info == 'simple finalized')
+
+    # similar tests for broadcast_arrays
+    b = np.arange(len(a)).reshape(-1, 1)
+    a_view, b_view = broadcast_arrays(a, b)
+    assert_(type(a_view) is np.ndarray)
+    assert_(type(b_view) is np.ndarray)
+    assert_(a_view.shape == b_view.shape)
+    a_view, b_view = broadcast_arrays(a, b, subok=True)
+    assert_(type(a_view) is SimpleSubClass)
+    assert_(a_view.info == 'simple finalized')
+    assert_(type(b_view) is np.ndarray)
+    assert_(a_view.shape == b_view.shape)
+
+    # and for broadcast_to
+    shape = (2, 4)
+    a_view = broadcast_to(a, shape)
+    assert_(type(a_view) is np.ndarray)
+    assert_(a_view.shape == shape)
+    a_view = broadcast_to(a, shape, subok=True)
+    assert_(type(a_view) is SimpleSubClass)
+    assert_(a_view.info == 'simple finalized')
+    assert_(a_view.shape == shape)
+
+
+def test_writeable():
+    # broadcast_to should return a readonly array
+    original = np.array([1, 2, 3])
+    result = broadcast_to(original, (2, 3))
+    assert_equal(result.flags.writeable, False)
+    assert_raises(ValueError, result.__setitem__, slice(None), 0)
+
+    # but the result of broadcast_arrays needs to be writeable, to
+    # preserve backwards compatibility
+    for is_broadcast, results in [(False, broadcast_arrays(original,)),
+                                  (True, broadcast_arrays(0, original))]:
+        for result in results:
+            # This will change to False in a future version
+            if is_broadcast:
+                with assert_warns(FutureWarning):
+                    assert_equal(result.flags.writeable, True)
+                with assert_warns(DeprecationWarning):
+                    result[:] = 0
+                # Warning not emitted, writing to the array resets it
+                assert_equal(result.flags.writeable, True)
+            else:
+                # No warning:
+                assert_equal(result.flags.writeable, True)
+
+    for results in [broadcast_arrays(original),
+                    broadcast_arrays(0, original)]:
+        for result in results:
+            # resets the warn_on_write DeprecationWarning
+            result.flags.writeable = True
+            # check: no warning emitted
+            assert_equal(result.flags.writeable, True)
+            result[:] = 0
+
+    # keep readonly input readonly
+    original.flags.writeable = False
+    _, result = broadcast_arrays(0, original)
+    assert_equal(result.flags.writeable, False)
+
+    # regression test for GH6491
+    shape = (2,)
+    strides = [0]
+    tricky_array = as_strided(np.array(0), shape, strides)
+    other = np.zeros((1,))
+    first, second = broadcast_arrays(tricky_array, other)
+    assert_(first.shape == second.shape)
+
+
+def test_writeable_memoryview():
+    # The result of broadcast_arrays exports as a non-writeable memoryview
+    # because otherwise there is no good way to opt in to the new behaviour
+    # (i.e. you would need to set writeable to False explicitly).
+    # See gh-13929.
+    original = np.array([1, 2, 3])
+
+    for is_broadcast, results in [(False, broadcast_arrays(original,)),
+                                  (True, broadcast_arrays(0, original))]:
+        for result in results:
+            # This will change to False in a future version
+            if is_broadcast:
+                # memoryview(result, writable=True) will give warning but cannot
+                # be tested using the python API.
+                assert memoryview(result).readonly
+            else:
+                assert not memoryview(result).readonly
+
+
+def test_reference_types():
+    input_array = np.array('a', dtype=object)
+    expected = np.array(['a'] * 3, dtype=object)
+    actual = broadcast_to(input_array, (3,))
+    assert_array_equal(expected, actual)
+
+    actual, _ = broadcast_arrays(input_array, np.ones(3))
+    assert_array_equal(expected, actual)

venv/lib/python3.10/site-packages/numpy/lib/tests/test_twodim_base.py

@@ -0,0 +1,541 @@
+"""Test functions for matrix module
+
+"""
+from numpy.testing import (
+    assert_equal, assert_array_equal, assert_array_max_ulp,
+    assert_array_almost_equal, assert_raises, assert_
+)
+from numpy import (
+    arange, add, fliplr, flipud, zeros, ones, eye, array, diag, histogram2d,
+    tri, mask_indices, triu_indices, triu_indices_from, tril_indices,
+    tril_indices_from, vander,
+)
+import numpy as np
+
+import pytest
+
+
+def get_mat(n):
+    data = arange(n)
+    data = add.outer(data, data)
+    return data
+
+
+class TestEye:
+    def test_basic(self):
+        assert_equal(eye(4),
+                     array([[1, 0, 0, 0],
+                            [0, 1, 0, 0],
+                            [0, 0, 1, 0],
+                            [0, 0, 0, 1]]))
+
+        assert_equal(eye(4, dtype='f'),
+                     array([[1, 0, 0, 0],
+                            [0, 1, 0, 0],
+                            [0, 0, 1, 0],
+                            [0, 0, 0, 1]], 'f'))
+
+        assert_equal(eye(3) == 1,
+                     eye(3, dtype=bool))
+
+    def test_uint64(self):
+        # Regression test for gh-9982
+        assert_equal(eye(np.uint64(2), dtype=int), array([[1, 0], [0, 1]]))
+        assert_equal(eye(np.uint64(2), M=np.uint64(4), k=np.uint64(1)),
+                     array([[0, 1, 0, 0], [0, 0, 1, 0]]))
+
+    def test_diag(self):
+        assert_equal(eye(4, k=1),
+                     array([[0, 1, 0, 0],
+                            [0, 0, 1, 0],
+                            [0, 0, 0, 1],
+                            [0, 0, 0, 0]]))
+
+        assert_equal(eye(4, k=-1),
+                     array([[0, 0, 0, 0],
+                            [1, 0, 0, 0],
+                            [0, 1, 0, 0],
+                            [0, 0, 1, 0]]))
+
+    def test_2d(self):
+        assert_equal(eye(4, 3),
+                     array([[1, 0, 0],
+                            [0, 1, 0],
+                            [0, 0, 1],
+                            [0, 0, 0]]))
+
+        assert_equal(eye(3, 4),
+                     array([[1, 0, 0, 0],
+                            [0, 1, 0, 0],
+                            [0, 0, 1, 0]]))
+
+    def test_diag2d(self):
+        assert_equal(eye(3, 4, k=2),
+                     array([[0, 0, 1, 0],
+                            [0, 0, 0, 1],
+                            [0, 0, 0, 0]]))
+
+        assert_equal(eye(4, 3, k=-2),
+                     array([[0, 0, 0],
+                            [0, 0, 0],
+                            [1, 0, 0],
+                            [0, 1, 0]]))
+
+    def test_eye_bounds(self):
+        assert_equal(eye(2, 2, 1), [[0, 1], [0, 0]])
+        assert_equal(eye(2, 2, -1), [[0, 0], [1, 0]])
+        assert_equal(eye(2, 2, 2), [[0, 0], [0, 0]])
+        assert_equal(eye(2, 2, -2), [[0, 0], [0, 0]])
+        assert_equal(eye(3, 2, 2), [[0, 0], [0, 0], [0, 0]])
+        assert_equal(eye(3, 2, 1), [[0, 1], [0, 0], [0, 0]])
+        assert_equal(eye(3, 2, -1), [[0, 0], [1, 0], [0, 1]])
+        assert_equal(eye(3, 2, -2), [[0, 0], [0, 0], [1, 0]])
+        assert_equal(eye(3, 2, -3), [[0, 0], [0, 0], [0, 0]])
+
+    def test_strings(self):
+        assert_equal(eye(2, 2, dtype='S3'),
+                     [[b'1', b''], [b'', b'1']])
+
+    def test_bool(self):
+        assert_equal(eye(2, 2, dtype=bool), [[True, False], [False, True]])
+
+    def test_order(self):
+        mat_c = eye(4, 3, k=-1)
+        mat_f = eye(4, 3, k=-1, order='F')
+        assert_equal(mat_c, mat_f)
+        assert mat_c.flags.c_contiguous
+        assert not mat_c.flags.f_contiguous
+        assert not mat_f.flags.c_contiguous
+        assert mat_f.flags.f_contiguous
+
+
+class TestDiag:
+    def test_vector(self):
+        vals = (100 * arange(5)).astype('l')
+        b = zeros((5, 5))
+        for k in range(5):
+            b[k, k] = vals[k]
+        assert_equal(diag(vals), b)
+        b = zeros((7, 7))
+        c = b.copy()
+        for k in range(5):
+            b[k, k + 2] = vals[k]
+            c[k + 2, k] = vals[k]
+        assert_equal(diag(vals, k=2), b)
+        assert_equal(diag(vals, k=-2), c)
+
+    def test_matrix(self, vals=None):
+        if vals is None:
+            vals = (100 * get_mat(5) + 1).astype('l')
+        b = zeros((5,))
+        for k in range(5):
+            b[k] = vals[k, k]
+        assert_equal(diag(vals), b)
+        b = b * 0
+        for k in range(3):
+            b[k] = vals[k, k + 2]
+        assert_equal(diag(vals, 2), b[:3])
+        for k in range(3):
+            b[k] = vals[k + 2, k]
+        assert_equal(diag(vals, -2), b[:3])
+
+    def test_fortran_order(self):
+        vals = array((100 * get_mat(5) + 1), order='F', dtype='l')
+        self.test_matrix(vals)
+
+    def test_diag_bounds(self):
+        A = [[1, 2], [3, 4], [5, 6]]
+        assert_equal(diag(A, k=2), [])
+        assert_equal(diag(A, k=1), [2])
+        assert_equal(diag(A, k=0), [1, 4])
+        assert_equal(diag(A, k=-1), [3, 6])
+        assert_equal(diag(A, k=-2), [5])
+        assert_equal(diag(A, k=-3), [])
+
+    def test_failure(self):
+        assert_raises(ValueError, diag, [[[1]]])
+
+
+class TestFliplr:
+    def test_basic(self):
+        assert_raises(ValueError, fliplr, ones(4))
+        a = get_mat(4)
+        b = a[:, ::-1]
+        assert_equal(fliplr(a), b)
+        a = [[0, 1, 2],
+             [3, 4, 5]]
+        b = [[2, 1, 0],
+             [5, 4, 3]]
+        assert_equal(fliplr(a), b)
+
+
+class TestFlipud:
+    def test_basic(self):
+        a = get_mat(4)
+        b = a[::-1, :]
+        assert_equal(flipud(a), b)
+        a = [[0, 1, 2],
+             [3, 4, 5]]
+        b = [[3, 4, 5],
+             [0, 1, 2]]
+        assert_equal(flipud(a), b)
+
+
+class TestHistogram2d:
+    def test_simple(self):
+        x = array(
+            [0.41702200, 0.72032449, 1.1437481e-4, 0.302332573, 0.146755891])
+        y = array(
+            [0.09233859, 0.18626021, 0.34556073, 0.39676747, 0.53881673])
+        xedges = np.linspace(0, 1, 10)
+        yedges = np.linspace(0, 1, 10)
+        H = histogram2d(x, y, (xedges, yedges))[0]
+        answer = array(
+            [[0, 0, 0, 1, 0, 0, 0, 0, 0],
+             [0, 0, 0, 0, 0, 0, 1, 0, 0],
+             [0, 0, 0, 0, 0, 0, 0, 0, 0],
+             [1, 0, 1, 0, 0, 0, 0, 0, 0],
+             [0, 1, 0, 0, 0, 0, 0, 0, 0],
+             [0, 0, 0, 0, 0, 0, 0, 0, 0],
+             [0, 0, 0, 0, 0, 0, 0, 0, 0],
+             [0, 0, 0, 0, 0, 0, 0, 0, 0],
+             [0, 0, 0, 0, 0, 0, 0, 0, 0]])
+        assert_array_equal(H.T, answer)
+        H = histogram2d(x, y, xedges)[0]
+        assert_array_equal(H.T, answer)
+        H, xedges, yedges = histogram2d(list(range(10)), list(range(10)))
+        assert_array_equal(H, eye(10, 10))
+        assert_array_equal(xedges, np.linspace(0, 9, 11))
+        assert_array_equal(yedges, np.linspace(0, 9, 11))
+
+    def test_asym(self):
+        x = array([1, 1, 2, 3, 4, 4, 4, 5])
+        y = array([1, 3, 2, 0, 1, 2, 3, 4])
+        H, xed, yed = histogram2d(
+            x, y, (6, 5), range=[[0, 6], [0, 5]], density=True)
+        answer = array(
+            [[0., 0, 0, 0, 0],
+             [0, 1, 0, 1, 0],
+             [0, 0, 1, 0, 0],
+             [1, 0, 0, 0, 0],
+             [0, 1, 1, 1, 0],
+             [0, 0, 0, 0, 1]])
+        assert_array_almost_equal(H, answer/8., 3)
+        assert_array_equal(xed, np.linspace(0, 6, 7))
+        assert_array_equal(yed, np.linspace(0, 5, 6))
+
+    def test_density(self):
+        x = array([1, 2, 3, 1, 2, 3, 1, 2, 3])
+        y = array([1, 1, 1, 2, 2, 2, 3, 3, 3])
+        H, xed, yed = histogram2d(
+            x, y, [[1, 2, 3, 5], [1, 2, 3, 5]], density=True)
+        answer = array([[1, 1, .5],
+                        [1, 1, .5],
+                        [.5, .5, .25]])/9.
+        assert_array_almost_equal(H, answer, 3)
+
+    def test_all_outliers(self):
+        r = np.random.rand(100) + 1. + 1e6  # histogramdd rounds by decimal=6
+        H, xed, yed = histogram2d(r, r, (4, 5), range=([0, 1], [0, 1]))
+        assert_array_equal(H, 0)
+
+    def test_empty(self):
+        a, edge1, edge2 = histogram2d([], [], bins=([0, 1], [0, 1]))
+        assert_array_max_ulp(a, array([[0.]]))
+
+        a, edge1, edge2 = histogram2d([], [], bins=4)
+        assert_array_max_ulp(a, np.zeros((4, 4)))
+
+    def test_binparameter_combination(self):
+        x = array(
+            [0, 0.09207008, 0.64575234, 0.12875982, 0.47390599,
+             0.59944483, 1])
+        y = array(
+            [0, 0.14344267, 0.48988575, 0.30558665, 0.44700682,
+             0.15886423, 1])
+        edges = (0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1)
+        H, xe, ye = histogram2d(x, y, (edges, 4))
+        answer = array(
+            [[2., 0., 0., 0.],
+             [0., 1., 0., 0.],
+             [0., 0., 0., 0.],
+             [0., 0., 0., 0.],
+             [0., 1., 0., 0.],
+             [1., 0., 0., 0.],
+             [0., 1., 0., 0.],
+             [0., 0., 0., 0.],
+             [0., 0., 0., 0.],
+             [0., 0., 0., 1.]])
+        assert_array_equal(H, answer)
+        assert_array_equal(ye, array([0., 0.25, 0.5, 0.75, 1]))
+        H, xe, ye = histogram2d(x, y, (4, edges))
+        answer = array(
+            [[1., 1., 0., 1., 0., 0., 0., 0., 0., 0.],
+             [0., 0., 0., 0., 1., 0., 0., 0., 0., 0.],
+             [0., 1., 0., 0., 1., 0., 0., 0., 0., 0.],
+             [0., 0., 0., 0., 0., 0., 0., 0., 0., 1.]])
+        assert_array_equal(H, answer)
+        assert_array_equal(xe, array([0., 0.25, 0.5, 0.75, 1]))
+
+    def test_dispatch(self):
+        class ShouldDispatch:
+            def __array_function__(self, function, types, args, kwargs):
+                return types, args, kwargs
+
+        xy = [1, 2]
+        s_d = ShouldDispatch()
+        r = histogram2d(s_d, xy)
+        # Cannot use assert_equal since that dispatches...
+        assert_(r == ((ShouldDispatch,), (s_d, xy), {}))
+        r = histogram2d(xy, s_d)
+        assert_(r == ((ShouldDispatch,), (xy, s_d), {}))
+        r = histogram2d(xy, xy, bins=s_d)
+        assert_(r, ((ShouldDispatch,), (xy, xy), dict(bins=s_d)))
+        r = histogram2d(xy, xy, bins=[s_d, 5])
+        assert_(r, ((ShouldDispatch,), (xy, xy), dict(bins=[s_d, 5])))
+        assert_raises(Exception, histogram2d, xy, xy, bins=[s_d])
+        r = histogram2d(xy, xy, weights=s_d)
+        assert_(r, ((ShouldDispatch,), (xy, xy), dict(weights=s_d)))
+
+    @pytest.mark.parametrize(("x_len", "y_len"), [(10, 11), (20, 19)])
+    def test_bad_length(self, x_len, y_len):
+        x, y = np.ones(x_len), np.ones(y_len)
+        with pytest.raises(ValueError,
+                           match='x and y must have the same length.'):
+            histogram2d(x, y)
+
+
+class TestTri:
+    def test_dtype(self):
+        out = array([[1, 0, 0],
+                     [1, 1, 0],
+                     [1, 1, 1]])
+        assert_array_equal(tri(3), out)
+        assert_array_equal(tri(3, dtype=bool), out.astype(bool))
+
+
+def test_tril_triu_ndim2():
+    for dtype in np.typecodes['AllFloat'] + np.typecodes['AllInteger']:
+        a = np.ones((2, 2), dtype=dtype)
+        b = np.tril(a)
+        c = np.triu(a)
+        assert_array_equal(b, [[1, 0], [1, 1]])
+        assert_array_equal(c, b.T)
+        # should return the same dtype as the original array
+        assert_equal(b.dtype, a.dtype)
+        assert_equal(c.dtype, a.dtype)
+
+
+def test_tril_triu_ndim3():
+    for dtype in np.typecodes['AllFloat'] + np.typecodes['AllInteger']:
+        a = np.array([
+            [[1, 1], [1, 1]],
+            [[1, 1], [1, 0]],
+            [[1, 1], [0, 0]],
+            ], dtype=dtype)
+        a_tril_desired = np.array([
+            [[1, 0], [1, 1]],
+            [[1, 0], [1, 0]],
+            [[1, 0], [0, 0]],
+            ], dtype=dtype)
+        a_triu_desired = np.array([
+            [[1, 1], [0, 1]],
+            [[1, 1], [0, 0]],
+            [[1, 1], [0, 0]],
+            ], dtype=dtype)
+        a_triu_observed = np.triu(a)
+        a_tril_observed = np.tril(a)
+        assert_array_equal(a_triu_observed, a_triu_desired)
+        assert_array_equal(a_tril_observed, a_tril_desired)
+        assert_equal(a_triu_observed.dtype, a.dtype)
+        assert_equal(a_tril_observed.dtype, a.dtype)
+
+
+def test_tril_triu_with_inf():
+    # Issue 4859
+    arr = np.array([[1, 1, np.inf],
+                    [1, 1, 1],
+                    [np.inf, 1, 1]])
+    out_tril = np.array([[1, 0, 0],
+                         [1, 1, 0],
+                         [np.inf, 1, 1]])
+    out_triu = out_tril.T
+    assert_array_equal(np.triu(arr), out_triu)
+    assert_array_equal(np.tril(arr), out_tril)
+
+
+def test_tril_triu_dtype():
+    # Issue 4916
+    # tril and triu should return the same dtype as input
+    for c in np.typecodes['All']:
+        if c == 'V':
+            continue
+        arr = np.zeros((3, 3), dtype=c)
+        assert_equal(np.triu(arr).dtype, arr.dtype)
+        assert_equal(np.tril(arr).dtype, arr.dtype)
+
+    # check special cases
+    arr = np.array([['2001-01-01T12:00', '2002-02-03T13:56'],
+                    ['2004-01-01T12:00', '2003-01-03T13:45']],
+                   dtype='datetime64')
+    assert_equal(np.triu(arr).dtype, arr.dtype)
+    assert_equal(np.tril(arr).dtype, arr.dtype)
+
+    arr = np.zeros((3, 3), dtype='f4,f4')
+    assert_equal(np.triu(arr).dtype, arr.dtype)
+    assert_equal(np.tril(arr).dtype, arr.dtype)
+
+
+def test_mask_indices():
+    # simple test without offset
+    iu = mask_indices(3, np.triu)
+    a = np.arange(9).reshape(3, 3)
+    assert_array_equal(a[iu], array([0, 1, 2, 4, 5, 8]))
+    # Now with an offset
+    iu1 = mask_indices(3, np.triu, 1)
+    assert_array_equal(a[iu1], array([1, 2, 5]))
+
+
+def test_tril_indices():
+    # indices without and with offset
+    il1 = tril_indices(4)
+    il2 = tril_indices(4, k=2)
+    il3 = tril_indices(4, m=5)
+    il4 = tril_indices(4, k=2, m=5)
+
+    a = np.array([[1, 2, 3, 4],
+                  [5, 6, 7, 8],
+                  [9, 10, 11, 12],
+                  [13, 14, 15, 16]])
+    b = np.arange(1, 21).reshape(4, 5)
+
+    # indexing:
+    assert_array_equal(a[il1],
+                       array([1, 5, 6, 9, 10, 11, 13, 14, 15, 16]))
+    assert_array_equal(b[il3],
+                       array([1, 6, 7, 11, 12, 13, 16, 17, 18, 19]))
+
+    # And for assigning values:
+    a[il1] = -1
+    assert_array_equal(a,
+                       array([[-1, 2, 3, 4],
+                              [-1, -1, 7, 8],
+                              [-1, -1, -1, 12],
+                              [-1, -1, -1, -1]]))
+    b[il3] = -1
+    assert_array_equal(b,
+                       array([[-1, 2, 3, 4, 5],
+                              [-1, -1, 8, 9, 10],
+                              [-1, -1, -1, 14, 15],
+                              [-1, -1, -1, -1, 20]]))
+    # These cover almost the whole array (two diagonals right of the main one):
+    a[il2] = -10
+    assert_array_equal(a,
+                       array([[-10, -10, -10, 4],
+                              [-10, -10, -10, -10],
+                              [-10, -10, -10, -10],
+                              [-10, -10, -10, -10]]))
+    b[il4] = -10
+    assert_array_equal(b,
+                       array([[-10, -10, -10, 4, 5],
+                              [-10, -10, -10, -10, 10],
+                              [-10, -10, -10, -10, -10],
+                              [-10, -10, -10, -10, -10]]))
+
+
+class TestTriuIndices:
+    def test_triu_indices(self):
+        iu1 = triu_indices(4)
+        iu2 = triu_indices(4, k=2)
+        iu3 = triu_indices(4, m=5)
+        iu4 = triu_indices(4, k=2, m=5)
+
+        a = np.array([[1, 2, 3, 4],
+                      [5, 6, 7, 8],
+                      [9, 10, 11, 12],
+                      [13, 14, 15, 16]])
+        b = np.arange(1, 21).reshape(4, 5)
+
+        # Both for indexing:
+        assert_array_equal(a[iu1],
+                           array([1, 2, 3, 4, 6, 7, 8, 11, 12, 16]))
+        assert_array_equal(b[iu3],
+                           array([1, 2, 3, 4, 5, 7, 8, 9,
+                                  10, 13, 14, 15, 19, 20]))
+
+        # And for assigning values:
+        a[iu1] = -1
+        assert_array_equal(a,
+                           array([[-1, -1, -1, -1],
+                                  [5, -1, -1, -1],
+                                  [9, 10, -1, -1],
+                                  [13, 14, 15, -1]]))
+        b[iu3] = -1
+        assert_array_equal(b,
+                           array([[-1, -1, -1, -1, -1],
+                                  [6, -1, -1, -1, -1],
+                                  [11, 12, -1, -1, -1],
+                                  [16, 17, 18, -1, -1]]))
+
+        # These cover almost the whole array (two diagonals right of the
+        # main one):
+        a[iu2] = -10
+        assert_array_equal(a,
+                           array([[-1, -1, -10, -10],
+                                  [5, -1, -1, -10],
+                                  [9, 10, -1, -1],
+                                  [13, 14, 15, -1]]))
+        b[iu4] = -10
+        assert_array_equal(b,
+                           array([[-1, -1, -10, -10, -10],
+                                  [6, -1, -1, -10, -10],
+                                  [11, 12, -1, -1, -10],
+                                  [16, 17, 18, -1, -1]]))
+
+
+class TestTrilIndicesFrom:
+    def test_exceptions(self):
+        assert_raises(ValueError, tril_indices_from, np.ones((2,)))
+        assert_raises(ValueError, tril_indices_from, np.ones((2, 2, 2)))
+        # assert_raises(ValueError, tril_indices_from, np.ones((2, 3)))
+
+
+class TestTriuIndicesFrom:
+    def test_exceptions(self):
+        assert_raises(ValueError, triu_indices_from, np.ones((2,)))
+        assert_raises(ValueError, triu_indices_from, np.ones((2, 2, 2)))
+        # assert_raises(ValueError, triu_indices_from, np.ones((2, 3)))
+
+
+class TestVander:
+    def test_basic(self):
+        c = np.array([0, 1, -2, 3])
+        v = vander(c)
+        powers = np.array([[0, 0, 0, 0, 1],
+                           [1, 1, 1, 1, 1],
+                           [16, -8, 4, -2, 1],
+                           [81, 27, 9, 3, 1]])
+        # Check default value of N:
+        assert_array_equal(v, powers[:, 1:])
+        # Check a range of N values, including 0 and 5 (greater than default)
+        m = powers.shape[1]
+        for n in range(6):
+            v = vander(c, N=n)
+            assert_array_equal(v, powers[:, m-n:m])
+
+    def test_dtypes(self):
+        c = array([11, -12, 13], dtype=np.int8)
+        v = vander(c)
+        expected = np.array([[121, 11, 1],
+                             [144, -12, 1],
+                             [169, 13, 1]])
+        assert_array_equal(v, expected)
+
+        c = array([1.0+1j, 1.0-1j])
+        v = vander(c, N=3)
+        expected = np.array([[2j, 1+1j, 1],
+                             [-2j, 1-1j, 1]])
+        # The data is floating point, but the values are small integers,
+        # so assert_array_equal *should* be safe here (rather than, say,
+        # assert_array_almost_equal).
+        assert_array_equal(v, expected)

venv/lib/python3.10/site-packages/numpy/lib/tests/test_type_check.py

@@ -0,0 +1,478 @@
+import numpy as np
+from numpy.testing import (
+    assert_, assert_equal, assert_array_equal, assert_raises
+    )
+from numpy.lib.type_check import (
+    common_type, mintypecode, isreal, iscomplex, isposinf, isneginf,
+    nan_to_num, isrealobj, iscomplexobj, asfarray, real_if_close
+    )
+
+
+def assert_all(x):
+    assert_(np.all(x), x)
+
+
+class TestCommonType:
+    def test_basic(self):
+        ai32 = np.array([[1, 2], [3, 4]], dtype=np.int32)
+        af16 = np.array([[1, 2], [3, 4]], dtype=np.float16)
+        af32 = np.array([[1, 2], [3, 4]], dtype=np.float32)
+        af64 = np.array([[1, 2], [3, 4]], dtype=np.float64)
+        acs = np.array([[1+5j, 2+6j], [3+7j, 4+8j]], dtype=np.csingle)
+        acd = np.array([[1+5j, 2+6j], [3+7j, 4+8j]], dtype=np.cdouble)
+        assert_(common_type(ai32) == np.float64)
+        assert_(common_type(af16) == np.float16)
+        assert_(common_type(af32) == np.float32)
+        assert_(common_type(af64) == np.float64)
+        assert_(common_type(acs) == np.csingle)
+        assert_(common_type(acd) == np.cdouble)
+
+
+class TestMintypecode:
+
+    def test_default_1(self):
+        for itype in '1bcsuwil':
+            assert_equal(mintypecode(itype), 'd')
+        assert_equal(mintypecode('f'), 'f')
+        assert_equal(mintypecode('d'), 'd')
+        assert_equal(mintypecode('F'), 'F')
+        assert_equal(mintypecode('D'), 'D')
+
+    def test_default_2(self):
+        for itype in '1bcsuwil':
+            assert_equal(mintypecode(itype+'f'), 'f')
+            assert_equal(mintypecode(itype+'d'), 'd')
+            assert_equal(mintypecode(itype+'F'), 'F')
+            assert_equal(mintypecode(itype+'D'), 'D')
+        assert_equal(mintypecode('ff'), 'f')
+        assert_equal(mintypecode('fd'), 'd')
+        assert_equal(mintypecode('fF'), 'F')
+        assert_equal(mintypecode('fD'), 'D')
+        assert_equal(mintypecode('df'), 'd')
+        assert_equal(mintypecode('dd'), 'd')
+        #assert_equal(mintypecode('dF',savespace=1),'F')
+        assert_equal(mintypecode('dF'), 'D')
+        assert_equal(mintypecode('dD'), 'D')
+        assert_equal(mintypecode('Ff'), 'F')
+        #assert_equal(mintypecode('Fd',savespace=1),'F')
+        assert_equal(mintypecode('Fd'), 'D')
+        assert_equal(mintypecode('FF'), 'F')
+        assert_equal(mintypecode('FD'), 'D')
+        assert_equal(mintypecode('Df'), 'D')
+        assert_equal(mintypecode('Dd'), 'D')
+        assert_equal(mintypecode('DF'), 'D')
+        assert_equal(mintypecode('DD'), 'D')
+
+    def test_default_3(self):
+        assert_equal(mintypecode('fdF'), 'D')
+        #assert_equal(mintypecode('fdF',savespace=1),'F')
+        assert_equal(mintypecode('fdD'), 'D')
+        assert_equal(mintypecode('fFD'), 'D')
+        assert_equal(mintypecode('dFD'), 'D')
+
+        assert_equal(mintypecode('ifd'), 'd')
+        assert_equal(mintypecode('ifF'), 'F')
+        assert_equal(mintypecode('ifD'), 'D')
+        assert_equal(mintypecode('idF'), 'D')
+        #assert_equal(mintypecode('idF',savespace=1),'F')
+        assert_equal(mintypecode('idD'), 'D')
+
+
+class TestIsscalar:
+
+    def test_basic(self):
+        assert_(np.isscalar(3))
+        assert_(not np.isscalar([3]))
+        assert_(not np.isscalar((3,)))
+        assert_(np.isscalar(3j))
+        assert_(np.isscalar(4.0))
+
+
+class TestReal:
+
+    def test_real(self):
+        y = np.random.rand(10,)
+        assert_array_equal(y, np.real(y))
+
+        y = np.array(1)
+        out = np.real(y)
+        assert_array_equal(y, out)
+        assert_(isinstance(out, np.ndarray))
+
+        y = 1
+        out = np.real(y)
+        assert_equal(y, out)
+        assert_(not isinstance(out, np.ndarray))
+
+    def test_cmplx(self):
+        y = np.random.rand(10,)+1j*np.random.rand(10,)
+        assert_array_equal(y.real, np.real(y))
+
+        y = np.array(1 + 1j)
+        out = np.real(y)
+        assert_array_equal(y.real, out)
+        assert_(isinstance(out, np.ndarray))
+
+        y = 1 + 1j
+        out = np.real(y)
+        assert_equal(1.0, out)
+        assert_(not isinstance(out, np.ndarray))
+
+
+class TestImag:
+
+    def test_real(self):
+        y = np.random.rand(10,)
+        assert_array_equal(0, np.imag(y))
+
+        y = np.array(1)
+        out = np.imag(y)
+        assert_array_equal(0, out)
+        assert_(isinstance(out, np.ndarray))
+
+        y = 1
+        out = np.imag(y)
+        assert_equal(0, out)
+        assert_(not isinstance(out, np.ndarray))
+
+    def test_cmplx(self):
+        y = np.random.rand(10,)+1j*np.random.rand(10,)
+        assert_array_equal(y.imag, np.imag(y))
+
+        y = np.array(1 + 1j)
+        out = np.imag(y)
+        assert_array_equal(y.imag, out)
+        assert_(isinstance(out, np.ndarray))
+
+        y = 1 + 1j
+        out = np.imag(y)
+        assert_equal(1.0, out)
+        assert_(not isinstance(out, np.ndarray))
+
+
+class TestIscomplex:
+
+    def test_fail(self):
+        z = np.array([-1, 0, 1])
+        res = iscomplex(z)
+        assert_(not np.any(res, axis=0))
+
+    def test_pass(self):
+        z = np.array([-1j, 1, 0])
+        res = iscomplex(z)
+        assert_array_equal(res, [1, 0, 0])
+
+
+class TestIsreal:
+
+    def test_pass(self):
+        z = np.array([-1, 0, 1j])
+        res = isreal(z)
+        assert_array_equal(res, [1, 1, 0])
+
+    def test_fail(self):
+        z = np.array([-1j, 1, 0])
+        res = isreal(z)
+        assert_array_equal(res, [0, 1, 1])
+
+
+class TestIscomplexobj:
+
+    def test_basic(self):
+        z = np.array([-1, 0, 1])
+        assert_(not iscomplexobj(z))
+        z = np.array([-1j, 0, -1])
+        assert_(iscomplexobj(z))
+
+    def test_scalar(self):
+        assert_(not iscomplexobj(1.0))
+        assert_(iscomplexobj(1+0j))
+
+    def test_list(self):
+        assert_(iscomplexobj([3, 1+0j, True]))
+        assert_(not iscomplexobj([3, 1, True]))
+
+    def test_duck(self):
+        class DummyComplexArray:
+            @property
+            def dtype(self):
+                return np.dtype(complex)
+        dummy = DummyComplexArray()
+        assert_(iscomplexobj(dummy))
+
+    def test_pandas_duck(self):
+        # This tests a custom np.dtype duck-typed class, such as used by pandas
+        # (pandas.core.dtypes)
+        class PdComplex(np.complex128):
+            pass
+        class PdDtype:
+            name = 'category'
+            names = None
+            type = PdComplex
+            kind = 'c'
+            str = '<c16'
+            base = np.dtype('complex128')
+        class DummyPd:
+            @property
+            def dtype(self):
+                return PdDtype
+        dummy = DummyPd()
+        assert_(iscomplexobj(dummy))
+
+    def test_custom_dtype_duck(self):
+        class MyArray(list):
+            @property
+            def dtype(self):
+                return complex
+
+        a = MyArray([1+0j, 2+0j, 3+0j])
+        assert_(iscomplexobj(a))
+
+
+class TestIsrealobj:
+    def test_basic(self):
+        z = np.array([-1, 0, 1])
+        assert_(isrealobj(z))
+        z = np.array([-1j, 0, -1])
+        assert_(not isrealobj(z))
+
+
+class TestIsnan:
+
+    def test_goodvalues(self):
+        z = np.array((-1., 0., 1.))
+        res = np.isnan(z) == 0
+        assert_all(np.all(res, axis=0))
+
+    def test_posinf(self):
+        with np.errstate(divide='ignore'):
+            assert_all(np.isnan(np.array((1.,))/0.) == 0)
+
+    def test_neginf(self):
+        with np.errstate(divide='ignore'):
+            assert_all(np.isnan(np.array((-1.,))/0.) == 0)
+
+    def test_ind(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            assert_all(np.isnan(np.array((0.,))/0.) == 1)
+
+    def test_integer(self):
+        assert_all(np.isnan(1) == 0)
+
+    def test_complex(self):
+        assert_all(np.isnan(1+1j) == 0)
+
+    def test_complex1(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            assert_all(np.isnan(np.array(0+0j)/0.) == 1)
+
+
+class TestIsfinite:
+    # Fixme, wrong place, isfinite now ufunc
+
+    def test_goodvalues(self):
+        z = np.array((-1., 0., 1.))
+        res = np.isfinite(z) == 1
+        assert_all(np.all(res, axis=0))
+
+    def test_posinf(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            assert_all(np.isfinite(np.array((1.,))/0.) == 0)
+
+    def test_neginf(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            assert_all(np.isfinite(np.array((-1.,))/0.) == 0)
+
+    def test_ind(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            assert_all(np.isfinite(np.array((0.,))/0.) == 0)
+
+    def test_integer(self):
+        assert_all(np.isfinite(1) == 1)
+
+    def test_complex(self):
+        assert_all(np.isfinite(1+1j) == 1)
+
+    def test_complex1(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            assert_all(np.isfinite(np.array(1+1j)/0.) == 0)
+
+
+class TestIsinf:
+    # Fixme, wrong place, isinf now ufunc
+
+    def test_goodvalues(self):
+        z = np.array((-1., 0., 1.))
+        res = np.isinf(z) == 0
+        assert_all(np.all(res, axis=0))
+
+    def test_posinf(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            assert_all(np.isinf(np.array((1.,))/0.) == 1)
+
+    def test_posinf_scalar(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            assert_all(np.isinf(np.array(1.,)/0.) == 1)
+
+    def test_neginf(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            assert_all(np.isinf(np.array((-1.,))/0.) == 1)
+
+    def test_neginf_scalar(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            assert_all(np.isinf(np.array(-1.)/0.) == 1)
+
+    def test_ind(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            assert_all(np.isinf(np.array((0.,))/0.) == 0)
+
+
+class TestIsposinf:
+
+    def test_generic(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            vals = isposinf(np.array((-1., 0, 1))/0.)
+        assert_(vals[0] == 0)
+        assert_(vals[1] == 0)
+        assert_(vals[2] == 1)
+
+
+class TestIsneginf:
+
+    def test_generic(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            vals = isneginf(np.array((-1., 0, 1))/0.)
+        assert_(vals[0] == 1)
+        assert_(vals[1] == 0)
+        assert_(vals[2] == 0)
+
+
+class TestNanToNum:
+
+    def test_generic(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            vals = nan_to_num(np.array((-1., 0, 1))/0.)
+        assert_all(vals[0] < -1e10) and assert_all(np.isfinite(vals[0]))
+        assert_(vals[1] == 0)
+        assert_all(vals[2] > 1e10) and assert_all(np.isfinite(vals[2]))
+        assert_equal(type(vals), np.ndarray)
+        
+        # perform the same tests but with nan, posinf and neginf keywords
+        with np.errstate(divide='ignore', invalid='ignore'):
+            vals = nan_to_num(np.array((-1., 0, 1))/0., 
+                              nan=10, posinf=20, neginf=30)
+        assert_equal(vals, [30, 10, 20])
+        assert_all(np.isfinite(vals[[0, 2]]))
+        assert_equal(type(vals), np.ndarray)
+
+        # perform the same test but in-place
+        with np.errstate(divide='ignore', invalid='ignore'):
+            vals = np.array((-1., 0, 1))/0.
+        result = nan_to_num(vals, copy=False)
+
+        assert_(result is vals)
+        assert_all(vals[0] < -1e10) and assert_all(np.isfinite(vals[0]))
+        assert_(vals[1] == 0)
+        assert_all(vals[2] > 1e10) and assert_all(np.isfinite(vals[2]))
+        assert_equal(type(vals), np.ndarray)
+        
+        # perform the same test but in-place
+        with np.errstate(divide='ignore', invalid='ignore'):
+            vals = np.array((-1., 0, 1))/0.
+        result = nan_to_num(vals, copy=False, nan=10, posinf=20, neginf=30)
+
+        assert_(result is vals)
+        assert_equal(vals, [30, 10, 20])
+        assert_all(np.isfinite(vals[[0, 2]]))
+        assert_equal(type(vals), np.ndarray)
+
+    def test_array(self):
+        vals = nan_to_num([1])
+        assert_array_equal(vals, np.array([1], int))
+        assert_equal(type(vals), np.ndarray)
+        vals = nan_to_num([1], nan=10, posinf=20, neginf=30)
+        assert_array_equal(vals, np.array([1], int))
+        assert_equal(type(vals), np.ndarray)
+
+    def test_integer(self):
+        vals = nan_to_num(1)
+        assert_all(vals == 1)
+        assert_equal(type(vals), np.int_)
+        vals = nan_to_num(1, nan=10, posinf=20, neginf=30)
+        assert_all(vals == 1)
+        assert_equal(type(vals), np.int_)
+
+    def test_float(self):
+        vals = nan_to_num(1.0)
+        assert_all(vals == 1.0)
+        assert_equal(type(vals), np.float_)
+        vals = nan_to_num(1.1, nan=10, posinf=20, neginf=30)
+        assert_all(vals == 1.1)
+        assert_equal(type(vals), np.float_)
+
+    def test_complex_good(self):
+        vals = nan_to_num(1+1j)
+        assert_all(vals == 1+1j)
+        assert_equal(type(vals), np.complex_)
+        vals = nan_to_num(1+1j, nan=10, posinf=20, neginf=30)
+        assert_all(vals == 1+1j)
+        assert_equal(type(vals), np.complex_)
+
+    def test_complex_bad(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            v = 1 + 1j
+            v += np.array(0+1.j)/0.
+        vals = nan_to_num(v)
+        # !! This is actually (unexpectedly) zero
+        assert_all(np.isfinite(vals))
+        assert_equal(type(vals), np.complex_)
+
+    def test_complex_bad2(self):
+        with np.errstate(divide='ignore', invalid='ignore'):
+            v = 1 + 1j
+            v += np.array(-1+1.j)/0.
+        vals = nan_to_num(v)
+        assert_all(np.isfinite(vals))
+        assert_equal(type(vals), np.complex_)
+        # Fixme
+        #assert_all(vals.imag > 1e10)  and assert_all(np.isfinite(vals))
+        # !! This is actually (unexpectedly) positive
+        # !! inf.  Comment out for now, and see if it
+        # !! changes
+        #assert_all(vals.real < -1e10) and assert_all(np.isfinite(vals))
+    
+    def test_do_not_rewrite_previous_keyword(self):
+        # This is done to test that when, for instance, nan=np.inf then these 
+        # values are not rewritten by posinf keyword to the posinf value.
+        with np.errstate(divide='ignore', invalid='ignore'):
+            vals = nan_to_num(np.array((-1., 0, 1))/0., nan=np.inf, posinf=999)
+        assert_all(np.isfinite(vals[[0, 2]]))
+        assert_all(vals[0] < -1e10)
+        assert_equal(vals[[1, 2]], [np.inf, 999])
+        assert_equal(type(vals), np.ndarray)
+
+
+class TestRealIfClose:
+
+    def test_basic(self):
+        a = np.random.rand(10)
+        b = real_if_close(a+1e-15j)
+        assert_all(isrealobj(b))
+        assert_array_equal(a, b)
+        b = real_if_close(a+1e-7j)
+        assert_all(iscomplexobj(b))
+        b = real_if_close(a+1e-7j, tol=1e-6)
+        assert_all(isrealobj(b))
+
+
+class TestArrayConversion:
+
+    def test_asfarray(self):
+        a = asfarray(np.array([1, 2, 3]))
+        assert_equal(a.__class__, np.ndarray)
+        assert_(np.issubdtype(a.dtype, np.floating))
+
+        # previously this would infer dtypes from arrays, unlike every single
+        # other numpy function
+        assert_raises(TypeError,
+            asfarray, np.array([1, 2, 3]), dtype=np.array(1.0))

venv/lib/python3.10/site-packages/numpy/polynomial/__init__.py

@@ -0,0 +1,185 @@
+"""
+A sub-package for efficiently dealing with polynomials.
+
+Within the documentation for this sub-package, a "finite power series,"
+i.e., a polynomial (also referred to simply as a "series") is represented
+by a 1-D numpy array of the polynomial's coefficients, ordered from lowest
+order term to highest.  For example, array([1,2,3]) represents
+``P_0 + 2*P_1 + 3*P_2``, where P_n is the n-th order basis polynomial
+applicable to the specific module in question, e.g., `polynomial` (which
+"wraps" the "standard" basis) or `chebyshev`.  For optimal performance,
+all operations on polynomials, including evaluation at an argument, are
+implemented as operations on the coefficients.  Additional (module-specific)
+information can be found in the docstring for the module of interest.
+
+This package provides *convenience classes* for each of six different kinds
+of polynomials:
+
+         ========================    ================
+         **Name**                    **Provides**
+         ========================    ================
+         `~polynomial.Polynomial`    Power series
+         `~chebyshev.Chebyshev`      Chebyshev series
+         `~legendre.Legendre`        Legendre series
+         `~laguerre.Laguerre`        Laguerre series
+         `~hermite.Hermite`          Hermite series
+         `~hermite_e.HermiteE`       HermiteE series
+         ========================    ================
+
+These *convenience classes* provide a consistent interface for creating,
+manipulating, and fitting data with polynomials of different bases.
+The convenience classes are the preferred interface for the `~numpy.polynomial`
+package, and are available from the ``numpy.polynomial`` namespace.
+This eliminates the need to navigate to the corresponding submodules, e.g.
+``np.polynomial.Polynomial`` or ``np.polynomial.Chebyshev`` instead of
+``np.polynomial.polynomial.Polynomial`` or
+``np.polynomial.chebyshev.Chebyshev``, respectively.
+The classes provide a more consistent and concise interface than the
+type-specific functions defined in the submodules for each type of polynomial.
+For example, to fit a Chebyshev polynomial with degree ``1`` to data given
+by arrays ``xdata`` and ``ydata``, the
+`~chebyshev.Chebyshev.fit` class method::
+
+    >>> from numpy.polynomial import Chebyshev
+    >>> c = Chebyshev.fit(xdata, ydata, deg=1)
+
+is preferred over the `chebyshev.chebfit` function from the
+``np.polynomial.chebyshev`` module::
+
+    >>> from numpy.polynomial.chebyshev import chebfit
+    >>> c = chebfit(xdata, ydata, deg=1)
+
+See :doc:`routines.polynomials.classes` for more details.
+
+Convenience Classes
+===================
+
+The following lists the various constants and methods common to all of
+the classes representing the various kinds of polynomials. In the following,
+the term ``Poly`` represents any one of the convenience classes (e.g.
+`~polynomial.Polynomial`, `~chebyshev.Chebyshev`, `~hermite.Hermite`, etc.)
+while the lowercase ``p`` represents an **instance** of a polynomial class.
+
+Constants
+---------
+
+- ``Poly.domain``     -- Default domain
+- ``Poly.window``     -- Default window
+- ``Poly.basis_name`` -- String used to represent the basis
+- ``Poly.maxpower``   -- Maximum value ``n`` such that ``p**n`` is allowed
+- ``Poly.nickname``   -- String used in printing
+
+Creation
+--------
+
+Methods for creating polynomial instances.
+
+- ``Poly.basis(degree)``    -- Basis polynomial of given degree
+- ``Poly.identity()``       -- ``p`` where ``p(x) = x`` for all ``x``
+- ``Poly.fit(x, y, deg)``   -- ``p`` of degree ``deg`` with coefficients
+  determined by the least-squares fit to the data ``x``, ``y``
+- ``Poly.fromroots(roots)`` -- ``p`` with specified roots
+- ``p.copy()``              -- Create a copy of ``p``
+
+Conversion
+----------
+
+Methods for converting a polynomial instance of one kind to another.
+
+- ``p.cast(Poly)``    -- Convert ``p`` to instance of kind ``Poly``
+- ``p.convert(Poly)`` -- Convert ``p`` to instance of kind ``Poly`` or map
+  between ``domain`` and ``window``
+
+Calculus
+--------
+- ``p.deriv()`` -- Take the derivative of ``p``
+- ``p.integ()`` -- Integrate ``p``
+
+Validation
+----------
+- ``Poly.has_samecoef(p1, p2)``   -- Check if coefficients match
+- ``Poly.has_samedomain(p1, p2)`` -- Check if domains match
+- ``Poly.has_sametype(p1, p2)``   -- Check if types match
+- ``Poly.has_samewindow(p1, p2)`` -- Check if windows match
+
+Misc
+----
+- ``p.linspace()`` -- Return ``x, p(x)`` at equally-spaced points in ``domain``
+- ``p.mapparms()`` -- Return the parameters for the linear mapping between
+  ``domain`` and ``window``.
+- ``p.roots()``    -- Return the roots of `p`.
+- ``p.trim()``     -- Remove trailing coefficients.
+- ``p.cutdeg(degree)`` -- Truncate p to given degree
+- ``p.truncate(size)`` -- Truncate p to given size
+
+"""
+from .polynomial import Polynomial
+from .chebyshev import Chebyshev
+from .legendre import Legendre
+from .hermite import Hermite
+from .hermite_e import HermiteE
+from .laguerre import Laguerre
+
+__all__ = [
+    "set_default_printstyle",
+    "polynomial", "Polynomial",
+    "chebyshev", "Chebyshev",
+    "legendre", "Legendre",
+    "hermite", "Hermite",
+    "hermite_e", "HermiteE",
+    "laguerre", "Laguerre",
+]
+
+
+def set_default_printstyle(style):
+    """
+    Set the default format for the string representation of polynomials.
+
+    Values for ``style`` must be valid inputs to ``__format__``, i.e. 'ascii'
+    or 'unicode'.
+
+    Parameters
+    ----------
+    style : str
+        Format string for default printing style. Must be either 'ascii' or
+        'unicode'.
+
+    Notes
+    -----
+    The default format depends on the platform: 'unicode' is used on
+    Unix-based systems and 'ascii' on Windows. This determination is based on
+    default font support for the unicode superscript and subscript ranges.
+
+    Examples
+    --------
+    >>> p = np.polynomial.Polynomial([1, 2, 3])
+    >>> c = np.polynomial.Chebyshev([1, 2, 3])
+    >>> np.polynomial.set_default_printstyle('unicode')
+    >>> print(p)
+    1.0 + 2.0·x + 3.0·x²
+    >>> print(c)
+    1.0 + 2.0·T₁(x) + 3.0·T₂(x)
+    >>> np.polynomial.set_default_printstyle('ascii')
+    >>> print(p)
+    1.0 + 2.0 x + 3.0 x**2
+    >>> print(c)
+    1.0 + 2.0 T_1(x) + 3.0 T_2(x)
+    >>> # Formatting supersedes all class/package-level defaults
+    >>> print(f"{p:unicode}")
+    1.0 + 2.0·x + 3.0·x²
+    """
+    if style not in ('unicode', 'ascii'):
+        raise ValueError(
+            f"Unsupported format string '{style}'. Valid options are 'ascii' "
+            f"and 'unicode'"
+        )
+    _use_unicode = True
+    if style == 'ascii':
+        _use_unicode = False
+    from ._polybase import ABCPolyBase
+    ABCPolyBase._use_unicode = _use_unicode
+
+
+from numpy._pytesttester import PytestTester
+test = PytestTester(__name__)
+del PytestTester

venv/lib/python3.10/site-packages/numpy/polynomial/__init__.pyi

@@ -0,0 +1,22 @@
+from numpy._pytesttester import PytestTester
+
+from numpy.polynomial import (
+    chebyshev as chebyshev,
+    hermite as hermite,
+    hermite_e as hermite_e,
+    laguerre as laguerre,
+    legendre as legendre,
+    polynomial as polynomial,
+)
+from numpy.polynomial.chebyshev import Chebyshev as Chebyshev
+from numpy.polynomial.hermite import Hermite as Hermite
+from numpy.polynomial.hermite_e import HermiteE as HermiteE
+from numpy.polynomial.laguerre import Laguerre as Laguerre
+from numpy.polynomial.legendre import Legendre as Legendre
+from numpy.polynomial.polynomial import Polynomial as Polynomial
+
+__all__: list[str]
+__path__: list[str]
+test: PytestTester
+
+def set_default_printstyle(style): ...

venv/lib/python3.10/site-packages/numpy/polynomial/_polybase.py

@@ -0,0 +1,1206 @@
+"""
+Abstract base class for the various polynomial Classes.
+
+The ABCPolyBase class provides the methods needed to implement the common API
+for the various polynomial classes. It operates as a mixin, but uses the
+abc module from the stdlib, hence it is only available for Python >= 2.6.
+
+"""
+import os
+import abc
+import numbers
+
+import numpy as np
+from . import polyutils as pu
+
+__all__ = ['ABCPolyBase']
+
+class ABCPolyBase(abc.ABC):
+    """An abstract base class for immutable series classes.
+
+    ABCPolyBase provides the standard Python numerical methods
+    '+', '-', '*', '//', '%', 'divmod', '**', and '()' along with the
+    methods listed below.
+
+    .. versionadded:: 1.9.0
+
+    Parameters
+    ----------
+    coef : array_like
+        Series coefficients in order of increasing degree, i.e.,
+        ``(1, 2, 3)`` gives ``1*P_0(x) + 2*P_1(x) + 3*P_2(x)``, where
+        ``P_i`` is the basis polynomials of degree ``i``.
+    domain : (2,) array_like, optional
+        Domain to use. The interval ``[domain[0], domain[1]]`` is mapped
+        to the interval ``[window[0], window[1]]`` by shifting and scaling.
+        The default value is the derived class domain.
+    window : (2,) array_like, optional
+        Window, see domain for its use. The default value is the
+        derived class window.
+    symbol : str, optional
+        Symbol used to represent the independent variable in string 
+        representations of the polynomial expression, e.g. for printing.
+        The symbol must be a valid Python identifier. Default value is 'x'.
+
+        .. versionadded:: 1.24
+
+    Attributes
+    ----------
+    coef : (N,) ndarray
+        Series coefficients in order of increasing degree.
+    domain : (2,) ndarray
+        Domain that is mapped to window.
+    window : (2,) ndarray
+        Window that domain is mapped to.
+    symbol : str
+        Symbol representing the independent variable.
+
+    Class Attributes
+    ----------------
+    maxpower : int
+        Maximum power allowed, i.e., the largest number ``n`` such that
+        ``p(x)**n`` is allowed. This is to limit runaway polynomial size.
+    domain : (2,) ndarray
+        Default domain of the class.
+    window : (2,) ndarray
+        Default window of the class.
+
+    """
+
+    # Not hashable
+    __hash__ = None
+
+    # Opt out of numpy ufuncs and Python ops with ndarray subclasses.
+    __array_ufunc__ = None
+
+    # Limit runaway size. T_n^m has degree n*m
+    maxpower = 100
+
+    # Unicode character mappings for improved __str__
+    _superscript_mapping = str.maketrans({
+        "0": "⁰",
+        "1": "¹",
+        "2": "²",
+        "3": "³",
+        "4": "⁴",
+        "5": "⁵",
+        "6": "⁶",
+        "7": "⁷",
+        "8": "⁸",
+        "9": "⁹"
+    })
+    _subscript_mapping = str.maketrans({
+        "0": "₀",
+        "1": "₁",
+        "2": "₂",
+        "3": "₃",
+        "4": "₄",
+        "5": "₅",
+        "6": "₆",
+        "7": "₇",
+        "8": "₈",
+        "9": "₉"
+    })
+    # Some fonts don't support full unicode character ranges necessary for
+    # the full set of superscripts and subscripts, including common/default
+    # fonts in Windows shells/terminals. Therefore, default to ascii-only
+    # printing on windows.
+    _use_unicode = not os.name == 'nt'
+
+    @property
+    def symbol(self):
+        return self._symbol
+
+    @property
+    @abc.abstractmethod
+    def domain(self):
+        pass
+
+    @property
+    @abc.abstractmethod
+    def window(self):
+        pass
+
+    @property
+    @abc.abstractmethod
+    def basis_name(self):
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    def _add(c1, c2):
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    def _sub(c1, c2):
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    def _mul(c1, c2):
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    def _div(c1, c2):
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    def _pow(c, pow, maxpower=None):
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    def _val(x, c):
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    def _int(c, m, k, lbnd, scl):
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    def _der(c, m, scl):
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    def _fit(x, y, deg, rcond, full):
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    def _line(off, scl):
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    def _roots(c):
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    def _fromroots(r):
+        pass
+
+    def has_samecoef(self, other):
+        """Check if coefficients match.
+
+        .. versionadded:: 1.6.0
+
+        Parameters
+        ----------
+        other : class instance
+            The other class must have the ``coef`` attribute.
+
+        Returns
+        -------
+        bool : boolean
+            True if the coefficients are the same, False otherwise.
+
+        """
+        if len(self.coef) != len(other.coef):
+            return False
+        elif not np.all(self.coef == other.coef):
+            return False
+        else:
+            return True
+
+    def has_samedomain(self, other):
+        """Check if domains match.
+
+        .. versionadded:: 1.6.0
+
+        Parameters
+        ----------
+        other : class instance
+            The other class must have the ``domain`` attribute.
+
+        Returns
+        -------
+        bool : boolean
+            True if the domains are the same, False otherwise.
+
+        """
+        return np.all(self.domain == other.domain)
+
+    def has_samewindow(self, other):
+        """Check if windows match.
+
+        .. versionadded:: 1.6.0
+
+        Parameters
+        ----------
+        other : class instance
+            The other class must have the ``window`` attribute.
+
+        Returns
+        -------
+        bool : boolean
+            True if the windows are the same, False otherwise.
+
+        """
+        return np.all(self.window == other.window)
+
+    def has_sametype(self, other):
+        """Check if types match.
+
+        .. versionadded:: 1.7.0
+
+        Parameters
+        ----------
+        other : object
+            Class instance.
+
+        Returns
+        -------
+        bool : boolean
+            True if other is same class as self
+
+        """
+        return isinstance(other, self.__class__)
+
+    def _get_coefficients(self, other):
+        """Interpret other as polynomial coefficients.
+
+        The `other` argument is checked to see if it is of the same
+        class as self with identical domain and window. If so,
+        return its coefficients, otherwise return `other`.
+
+        .. versionadded:: 1.9.0
+
+        Parameters
+        ----------
+        other : anything
+            Object to be checked.
+
+        Returns
+        -------
+        coef
+            The coefficients of`other` if it is a compatible instance,
+            of ABCPolyBase, otherwise `other`.
+
+        Raises
+        ------
+        TypeError
+            When `other` is an incompatible instance of ABCPolyBase.
+
+        """
+        if isinstance(other, ABCPolyBase):
+            if not isinstance(other, self.__class__):
+                raise TypeError("Polynomial types differ")
+            elif not np.all(self.domain == other.domain):
+                raise TypeError("Domains differ")
+            elif not np.all(self.window == other.window):
+                raise TypeError("Windows differ")
+            elif self.symbol != other.symbol:
+                raise ValueError("Polynomial symbols differ")
+            return other.coef
+        return other
+
+    def __init__(self, coef, domain=None, window=None, symbol='x'):
+        [coef] = pu.as_series([coef], trim=False)
+        self.coef = coef
+
+        if domain is not None:
+            [domain] = pu.as_series([domain], trim=False)
+            if len(domain) != 2:
+                raise ValueError("Domain has wrong number of elements.")
+            self.domain = domain
+
+        if window is not None:
+            [window] = pu.as_series([window], trim=False)
+            if len(window) != 2:
+                raise ValueError("Window has wrong number of elements.")
+            self.window = window
+
+        # Validation for symbol
+        try:
+            if not symbol.isidentifier():
+                raise ValueError(
+                    "Symbol string must be a valid Python identifier"
+                )
+        # If a user passes in something other than a string, the above
+        # results in an AttributeError. Catch this and raise a more
+        # informative exception
+        except AttributeError:
+            raise TypeError("Symbol must be a non-empty string")
+
+        self._symbol = symbol
+
+    def __repr__(self):
+        coef = repr(self.coef)[6:-1]
+        domain = repr(self.domain)[6:-1]
+        window = repr(self.window)[6:-1]
+        name = self.__class__.__name__
+        return (f"{name}({coef}, domain={domain}, window={window}, "
+                f"symbol='{self.symbol}')")
+
+    def __format__(self, fmt_str):
+        if fmt_str == '':
+            return self.__str__()
+        if fmt_str not in ('ascii', 'unicode'):
+            raise ValueError(
+                f"Unsupported format string '{fmt_str}' passed to "
+                f"{self.__class__}.__format__. Valid options are "
+                f"'ascii' and 'unicode'"
+            )
+        if fmt_str == 'ascii':
+            return self._generate_string(self._str_term_ascii)
+        return self._generate_string(self._str_term_unicode)
+
+    def __str__(self):
+        if self._use_unicode:
+            return self._generate_string(self._str_term_unicode)
+        return self._generate_string(self._str_term_ascii)
+
+    def _generate_string(self, term_method):
+        """
+        Generate the full string representation of the polynomial, using
+        ``term_method`` to generate each polynomial term.
+        """
+        # Get configuration for line breaks
+        linewidth = np.get_printoptions().get('linewidth', 75)
+        if linewidth < 1:
+            linewidth = 1
+        out = pu.format_float(self.coef[0])
+        for i, coef in enumerate(self.coef[1:]):
+            out += " "
+            power = str(i + 1)
+            # Polynomial coefficient
+            # The coefficient array can be an object array with elements that
+            # will raise a TypeError with >= 0 (e.g. strings or Python
+            # complex). In this case, represent the coefficient as-is.
+            try:
+                if coef >= 0:
+                    next_term = f"+ " + pu.format_float(coef, parens=True)
+                else:
+                    next_term = f"- " + pu.format_float(-coef, parens=True)
+            except TypeError:
+                next_term = f"+ {coef}"
+            # Polynomial term
+            next_term += term_method(power, self.symbol)
+            # Length of the current line with next term added
+            line_len = len(out.split('\n')[-1]) + len(next_term)
+            # If not the last term in the polynomial, it will be two
+            # characters longer due to the +/- with the next term
+            if i < len(self.coef[1:]) - 1:
+                line_len += 2
+            # Handle linebreaking
+            if line_len >= linewidth:
+                next_term = next_term.replace(" ", "\n", 1)
+            out += next_term
+        return out
+
+    @classmethod
+    def _str_term_unicode(cls, i, arg_str):
+        """
+        String representation of single polynomial term using unicode
+        characters for superscripts and subscripts.
+        """
+        if cls.basis_name is None:
+            raise NotImplementedError(
+                "Subclasses must define either a basis_name, or override "
+                "_str_term_unicode(cls, i, arg_str)"
+            )
+        return (f"·{cls.basis_name}{i.translate(cls._subscript_mapping)}"
+                f"({arg_str})")
+
+    @classmethod
+    def _str_term_ascii(cls, i, arg_str):
+        """
+        String representation of a single polynomial term using ** and _ to
+        represent superscripts and subscripts, respectively.
+        """
+        if cls.basis_name is None:
+            raise NotImplementedError(
+                "Subclasses must define either a basis_name, or override "
+                "_str_term_ascii(cls, i, arg_str)"
+            )
+        return f" {cls.basis_name}_{i}({arg_str})"
+
+    @classmethod
+    def _repr_latex_term(cls, i, arg_str, needs_parens):
+        if cls.basis_name is None:
+            raise NotImplementedError(
+                "Subclasses must define either a basis name, or override "
+                "_repr_latex_term(i, arg_str, needs_parens)")
+        # since we always add parens, we don't care if the expression needs them
+        return f"{{{cls.basis_name}}}_{{{i}}}({arg_str})"
+
+    @staticmethod
+    def _repr_latex_scalar(x, parens=False):
+        # TODO: we're stuck with disabling math formatting until we handle
+        # exponents in this function
+        return r'\text{{{}}}'.format(pu.format_float(x, parens=parens))
+
+    def _repr_latex_(self):
+        # get the scaled argument string to the basis functions
+        off, scale = self.mapparms()
+        if off == 0 and scale == 1:
+            term = self.symbol
+            needs_parens = False
+        elif scale == 1:
+            term = f"{self._repr_latex_scalar(off)} + {self.symbol}"
+            needs_parens = True
+        elif off == 0:
+            term = f"{self._repr_latex_scalar(scale)}{self.symbol}"
+            needs_parens = True
+        else:
+            term = (
+                f"{self._repr_latex_scalar(off)} + "
+                f"{self._repr_latex_scalar(scale)}{self.symbol}"
+            )
+            needs_parens = True
+
+        mute = r"\color{{LightGray}}{{{}}}".format
+
+        parts = []
+        for i, c in enumerate(self.coef):
+            # prevent duplication of + and - signs
+            if i == 0:
+                coef_str = f"{self._repr_latex_scalar(c)}"
+            elif not isinstance(c, numbers.Real):
+                coef_str = f" + ({self._repr_latex_scalar(c)})"
+            elif not np.signbit(c):
+                coef_str = f" + {self._repr_latex_scalar(c, parens=True)}"
+            else:
+                coef_str = f" - {self._repr_latex_scalar(-c, parens=True)}"
+
+            # produce the string for the term
+            term_str = self._repr_latex_term(i, term, needs_parens)
+            if term_str == '1':
+                part = coef_str
+            else:
+                part = rf"{coef_str}\,{term_str}"
+
+            if c == 0:
+                part = mute(part)
+
+            parts.append(part)
+
+        if parts:
+            body = ''.join(parts)
+        else:
+            # in case somehow there are no coefficients at all
+            body = '0'
+
+        return rf"${self.symbol} \mapsto {body}$"
+
+
+
+    # Pickle and copy
+
+    def __getstate__(self):
+        ret = self.__dict__.copy()
+        ret['coef'] = self.coef.copy()
+        ret['domain'] = self.domain.copy()
+        ret['window'] = self.window.copy()
+        ret['symbol'] = self.symbol
+        return ret
+
+    def __setstate__(self, dict):
+        self.__dict__ = dict
+
+    # Call
+
+    def __call__(self, arg):
+        off, scl = pu.mapparms(self.domain, self.window)
+        arg = off + scl*arg
+        return self._val(arg, self.coef)
+
+    def __iter__(self):
+        return iter(self.coef)
+
+    def __len__(self):
+        return len(self.coef)
+
+    # Numeric properties.
+
+    def __neg__(self):
+        return self.__class__(
+            -self.coef, self.domain, self.window, self.symbol
+        )
+
+    def __pos__(self):
+        return self
+
+    def __add__(self, other):
+        othercoef = self._get_coefficients(other)
+        try:
+            coef = self._add(self.coef, othercoef)
+        except Exception:
+            return NotImplemented
+        return self.__class__(coef, self.domain, self.window, self.symbol)
+
+    def __sub__(self, other):
+        othercoef = self._get_coefficients(other)
+        try:
+            coef = self._sub(self.coef, othercoef)
+        except Exception:
+            return NotImplemented
+        return self.__class__(coef, self.domain, self.window, self.symbol)
+
+    def __mul__(self, other):
+        othercoef = self._get_coefficients(other)
+        try:
+            coef = self._mul(self.coef, othercoef)
+        except Exception:
+            return NotImplemented
+        return self.__class__(coef, self.domain, self.window, self.symbol)
+
+    def __truediv__(self, other):
+        # there is no true divide if the rhs is not a Number, although it
+        # could return the first n elements of an infinite series.
+        # It is hard to see where n would come from, though.
+        if not isinstance(other, numbers.Number) or isinstance(other, bool):
+            raise TypeError(
+                f"unsupported types for true division: "
+                f"'{type(self)}', '{type(other)}'"
+            )
+        return self.__floordiv__(other)
+
+    def __floordiv__(self, other):
+        res = self.__divmod__(other)
+        if res is NotImplemented:
+            return res
+        return res[0]
+
+    def __mod__(self, other):
+        res = self.__divmod__(other)
+        if res is NotImplemented:
+            return res
+        return res[1]
+
+    def __divmod__(self, other):
+        othercoef = self._get_coefficients(other)
+        try:
+            quo, rem = self._div(self.coef, othercoef)
+        except ZeroDivisionError:
+            raise
+        except Exception:
+            return NotImplemented
+        quo = self.__class__(quo, self.domain, self.window, self.symbol)
+        rem = self.__class__(rem, self.domain, self.window, self.symbol)
+        return quo, rem
+
+    def __pow__(self, other):
+        coef = self._pow(self.coef, other, maxpower=self.maxpower)
+        res = self.__class__(coef, self.domain, self.window, self.symbol)
+        return res
+
+    def __radd__(self, other):
+        try:
+            coef = self._add(other, self.coef)
+        except Exception:
+            return NotImplemented
+        return self.__class__(coef, self.domain, self.window, self.symbol)
+
+    def __rsub__(self, other):
+        try:
+            coef = self._sub(other, self.coef)
+        except Exception:
+            return NotImplemented
+        return self.__class__(coef, self.domain, self.window, self.symbol)
+
+    def __rmul__(self, other):
+        try:
+            coef = self._mul(other, self.coef)
+        except Exception:
+            return NotImplemented
+        return self.__class__(coef, self.domain, self.window, self.symbol)
+
+    def __rdiv__(self, other):
+        # set to __floordiv__ /.
+        return self.__rfloordiv__(other)
+
+    def __rtruediv__(self, other):
+        # An instance of ABCPolyBase is not considered a
+        # Number.
+        return NotImplemented
+
+    def __rfloordiv__(self, other):
+        res = self.__rdivmod__(other)
+        if res is NotImplemented:
+            return res
+        return res[0]
+
+    def __rmod__(self, other):
+        res = self.__rdivmod__(other)
+        if res is NotImplemented:
+            return res
+        return res[1]
+
+    def __rdivmod__(self, other):
+        try:
+            quo, rem = self._div(other, self.coef)
+        except ZeroDivisionError:
+            raise
+        except Exception:
+            return NotImplemented
+        quo = self.__class__(quo, self.domain, self.window, self.symbol)
+        rem = self.__class__(rem, self.domain, self.window, self.symbol)
+        return quo, rem
+
+    def __eq__(self, other):
+        res = (isinstance(other, self.__class__) and
+               np.all(self.domain == other.domain) and
+               np.all(self.window == other.window) and
+               (self.coef.shape == other.coef.shape) and
+               np.all(self.coef == other.coef) and
+               (self.symbol == other.symbol))
+        return res
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    #
+    # Extra methods.
+    #
+
+    def copy(self):
+        """Return a copy.
+
+        Returns
+        -------
+        new_series : series
+            Copy of self.
+
+        """
+        return self.__class__(self.coef, self.domain, self.window, self.symbol)
+
+    def degree(self):
+        """The degree of the series.
+
+        .. versionadded:: 1.5.0
+
+        Returns
+        -------
+        degree : int
+            Degree of the series, one less than the number of coefficients.
+
+        Examples
+        --------
+
+        Create a polynomial object for ``1 + 7*x + 4*x**2``:
+
+        >>> poly = np.polynomial.Polynomial([1, 7, 4])
+        >>> print(poly)
+        1.0 + 7.0·x + 4.0·x²
+        >>> poly.degree()
+        2
+
+        Note that this method does not check for non-zero coefficients.
+        You must trim the polynomial to remove any trailing zeroes:
+
+        >>> poly = np.polynomial.Polynomial([1, 7, 0])
+        >>> print(poly)
+        1.0 + 7.0·x + 0.0·x²
+        >>> poly.degree()
+        2
+        >>> poly.trim().degree()
+        1
+
+        """
+        return len(self) - 1
+
+    def cutdeg(self, deg):
+        """Truncate series to the given degree.
+
+        Reduce the degree of the series to `deg` by discarding the
+        high order terms. If `deg` is greater than the current degree a
+        copy of the current series is returned. This can be useful in least
+        squares where the coefficients of the high degree terms may be very
+        small.
+
+        .. versionadded:: 1.5.0
+
+        Parameters
+        ----------
+        deg : non-negative int
+            The series is reduced to degree `deg` by discarding the high
+            order terms. The value of `deg` must be a non-negative integer.
+
+        Returns
+        -------
+        new_series : series
+            New instance of series with reduced degree.
+
+        """
+        return self.truncate(deg + 1)
+
+    def trim(self, tol=0):
+        """Remove trailing coefficients
+
+        Remove trailing coefficients until a coefficient is reached whose
+        absolute value greater than `tol` or the beginning of the series is
+        reached. If all the coefficients would be removed the series is set
+        to ``[0]``. A new series instance is returned with the new
+        coefficients.  The current instance remains unchanged.
+
+        Parameters
+        ----------
+        tol : non-negative number.
+            All trailing coefficients less than `tol` will be removed.
+
+        Returns
+        -------
+        new_series : series
+            New instance of series with trimmed coefficients.
+
+        """
+        coef = pu.trimcoef(self.coef, tol)
+        return self.__class__(coef, self.domain, self.window, self.symbol)
+
+    def truncate(self, size):
+        """Truncate series to length `size`.
+
+        Reduce the series to length `size` by discarding the high
+        degree terms. The value of `size` must be a positive integer. This
+        can be useful in least squares where the coefficients of the
+        high degree terms may be very small.
+
+        Parameters
+        ----------
+        size : positive int
+            The series is reduced to length `size` by discarding the high
+            degree terms. The value of `size` must be a positive integer.
+
+        Returns
+        -------
+        new_series : series
+            New instance of series with truncated coefficients.
+
+        """
+        isize = int(size)
+        if isize != size or isize < 1:
+            raise ValueError("size must be a positive integer")
+        if isize >= len(self.coef):
+            coef = self.coef
+        else:
+            coef = self.coef[:isize]
+        return self.__class__(coef, self.domain, self.window, self.symbol)
+
+    def convert(self, domain=None, kind=None, window=None):
+        """Convert series to a different kind and/or domain and/or window.
+
+        Parameters
+        ----------
+        domain : array_like, optional
+            The domain of the converted series. If the value is None,
+            the default domain of `kind` is used.
+        kind : class, optional
+            The polynomial series type class to which the current instance
+            should be converted. If kind is None, then the class of the
+            current instance is used.
+        window : array_like, optional
+            The window of the converted series. If the value is None,
+            the default window of `kind` is used.
+
+        Returns
+        -------
+        new_series : series
+            The returned class can be of different type than the current
+            instance and/or have a different domain and/or different
+            window.
+
+        Notes
+        -----
+        Conversion between domains and class types can result in
+        numerically ill defined series.
+
+        """
+        if kind is None:
+            kind = self.__class__
+        if domain is None:
+            domain = kind.domain
+        if window is None:
+            window = kind.window
+        return self(kind.identity(domain, window=window, symbol=self.symbol))
+
+    def mapparms(self):
+        """Return the mapping parameters.
+
+        The returned values define a linear map ``off + scl*x`` that is
+        applied to the input arguments before the series is evaluated. The
+        map depends on the ``domain`` and ``window``; if the current
+        ``domain`` is equal to the ``window`` the resulting map is the
+        identity.  If the coefficients of the series instance are to be
+        used by themselves outside this class, then the linear function
+        must be substituted for the ``x`` in the standard representation of
+        the base polynomials.
+
+        Returns
+        -------
+        off, scl : float or complex
+            The mapping function is defined by ``off + scl*x``.
+
+        Notes
+        -----
+        If the current domain is the interval ``[l1, r1]`` and the window
+        is ``[l2, r2]``, then the linear mapping function ``L`` is
+        defined by the equations::
+
+            L(l1) = l2
+            L(r1) = r2
+
+        """
+        return pu.mapparms(self.domain, self.window)
+
+    def integ(self, m=1, k=[], lbnd=None):
+        """Integrate.
+
+        Return a series instance that is the definite integral of the
+        current series.
+
+        Parameters
+        ----------
+        m : non-negative int
+            The number of integrations to perform.
+        k : array_like
+            Integration constants. The first constant is applied to the
+            first integration, the second to the second, and so on. The
+            list of values must less than or equal to `m` in length and any
+            missing values are set to zero.
+        lbnd : Scalar
+            The lower bound of the definite integral.
+
+        Returns
+        -------
+        new_series : series
+            A new series representing the integral. The domain is the same
+            as the domain of the integrated series.
+
+        """
+        off, scl = self.mapparms()
+        if lbnd is None:
+            lbnd = 0
+        else:
+            lbnd = off + scl*lbnd
+        coef = self._int(self.coef, m, k, lbnd, 1./scl)
+        return self.__class__(coef, self.domain, self.window, self.symbol)
+
+    def deriv(self, m=1):
+        """Differentiate.
+
+        Return a series instance of that is the derivative of the current
+        series.
+
+        Parameters
+        ----------
+        m : non-negative int
+            Find the derivative of order `m`.
+
+        Returns
+        -------
+        new_series : series
+            A new series representing the derivative. The domain is the same
+            as the domain of the differentiated series.
+
+        """
+        off, scl = self.mapparms()
+        coef = self._der(self.coef, m, scl)
+        return self.__class__(coef, self.domain, self.window, self.symbol)
+
+    def roots(self):
+        """Return the roots of the series polynomial.
+
+        Compute the roots for the series. Note that the accuracy of the
+        roots decreases the further outside the `domain` they lie.
+
+        Returns
+        -------
+        roots : ndarray
+            Array containing the roots of the series.
+
+        """
+        roots = self._roots(self.coef)
+        return pu.mapdomain(roots, self.window, self.domain)
+
+    def linspace(self, n=100, domain=None):
+        """Return x, y values at equally spaced points in domain.
+
+        Returns the x, y values at `n` linearly spaced points across the
+        domain.  Here y is the value of the polynomial at the points x. By
+        default the domain is the same as that of the series instance.
+        This method is intended mostly as a plotting aid.
+
+        .. versionadded:: 1.5.0
+
+        Parameters
+        ----------
+        n : int, optional
+            Number of point pairs to return. The default value is 100.
+        domain : {None, array_like}, optional
+            If not None, the specified domain is used instead of that of
+            the calling instance. It should be of the form ``[beg,end]``.
+            The default is None which case the class domain is used.
+
+        Returns
+        -------
+        x, y : ndarray
+            x is equal to linspace(self.domain[0], self.domain[1], n) and
+            y is the series evaluated at element of x.
+
+        """
+        if domain is None:
+            domain = self.domain
+        x = np.linspace(domain[0], domain[1], n)
+        y = self(x)
+        return x, y
+
+    @classmethod
+    def fit(cls, x, y, deg, domain=None, rcond=None, full=False, w=None,
+        window=None, symbol='x'):
+        """Least squares fit to data.
+
+        Return a series instance that is the least squares fit to the data
+        `y` sampled at `x`. The domain of the returned instance can be
+        specified and this will often result in a superior fit with less
+        chance of ill conditioning.
+
+        Parameters
+        ----------
+        x : array_like, shape (M,)
+            x-coordinates of the M sample points ``(x[i], y[i])``.
+        y : array_like, shape (M,)
+            y-coordinates of the M sample points ``(x[i], y[i])``.
+        deg : int or 1-D array_like
+            Degree(s) of the fitting polynomials. If `deg` is a single integer
+            all terms up to and including the `deg`'th term are included in the
+            fit. For NumPy versions >= 1.11.0 a list of integers specifying the
+            degrees of the terms to include may be used instead.
+        domain : {None, [beg, end], []}, optional
+            Domain to use for the returned series. If ``None``,
+            then a minimal domain that covers the points `x` is chosen.  If
+            ``[]`` the class domain is used. The default value was the
+            class domain in NumPy 1.4 and ``None`` in later versions.
+            The ``[]`` option was added in numpy 1.5.0.
+        rcond : float, optional
+            Relative condition number of the fit. Singular values smaller
+            than this relative to the largest singular value will be
+            ignored. The default value is len(x)*eps, where eps is the
+            relative precision of the float type, about 2e-16 in most
+            cases.
+        full : bool, optional
+            Switch determining nature of return value. When it is False
+            (the default) just the coefficients are returned, when True
+            diagnostic information from the singular value decomposition is
+            also returned.
+        w : array_like, shape (M,), optional
+            Weights. If not None, the weight ``w[i]`` applies to the unsquared
+            residual ``y[i] - y_hat[i]`` at ``x[i]``. Ideally the weights are
+            chosen so that the errors of the products ``w[i]*y[i]`` all have
+            the same variance.  When using inverse-variance weighting, use
+            ``w[i] = 1/sigma(y[i])``.  The default value is None.
+
+            .. versionadded:: 1.5.0
+        window : {[beg, end]}, optional
+            Window to use for the returned series. The default
+            value is the default class domain
+
+            .. versionadded:: 1.6.0
+        symbol : str, optional
+            Symbol representing the independent variable. Default is 'x'.
+
+        Returns
+        -------
+        new_series : series
+            A series that represents the least squares fit to the data and
+            has the domain and window specified in the call. If the
+            coefficients for the unscaled and unshifted basis polynomials are
+            of interest, do ``new_series.convert().coef``.
+
+        [resid, rank, sv, rcond] : list
+            These values are only returned if ``full == True``
+
+            - resid -- sum of squared residuals of the least squares fit
+            - rank -- the numerical rank of the scaled Vandermonde matrix
+            - sv -- singular values of the scaled Vandermonde matrix
+            - rcond -- value of `rcond`.
+
+            For more details, see `linalg.lstsq`.
+
+        """
+        if domain is None:
+            domain = pu.getdomain(x)
+        elif type(domain) is list and len(domain) == 0:
+            domain = cls.domain
+
+        if window is None:
+            window = cls.window
+
+        xnew = pu.mapdomain(x, domain, window)
+        res = cls._fit(xnew, y, deg, w=w, rcond=rcond, full=full)
+        if full:
+            [coef, status] = res
+            return (
+                cls(coef, domain=domain, window=window, symbol=symbol), status
+            )
+        else:
+            coef = res
+            return cls(coef, domain=domain, window=window, symbol=symbol)
+
+    @classmethod
+    def fromroots(cls, roots, domain=[], window=None, symbol='x'):
+        """Return series instance that has the specified roots.
+
+        Returns a series representing the product
+        ``(x - r[0])*(x - r[1])*...*(x - r[n-1])``, where ``r`` is a
+        list of roots.
+
+        Parameters
+        ----------
+        roots : array_like
+            List of roots.
+        domain : {[], None, array_like}, optional
+            Domain for the resulting series. If None the domain is the
+            interval from the smallest root to the largest. If [] the
+            domain is the class domain. The default is [].
+        window : {None, array_like}, optional
+            Window for the returned series. If None the class window is
+            used. The default is None.
+        symbol : str, optional
+            Symbol representing the independent variable. Default is 'x'.
+
+        Returns
+        -------
+        new_series : series
+            Series with the specified roots.
+
+        """
+        [roots] = pu.as_series([roots], trim=False)
+        if domain is None:
+            domain = pu.getdomain(roots)
+        elif type(domain) is list and len(domain) == 0:
+            domain = cls.domain
+
+        if window is None:
+            window = cls.window
+
+        deg = len(roots)
+        off, scl = pu.mapparms(domain, window)
+        rnew = off + scl*roots
+        coef = cls._fromroots(rnew) / scl**deg
+        return cls(coef, domain=domain, window=window, symbol=symbol)
+
+    @classmethod
+    def identity(cls, domain=None, window=None, symbol='x'):
+        """Identity function.
+
+        If ``p`` is the returned series, then ``p(x) == x`` for all
+        values of x.
+
+        Parameters
+        ----------
+        domain : {None, array_like}, optional
+            If given, the array must be of the form ``[beg, end]``, where
+            ``beg`` and ``end`` are the endpoints of the domain. If None is
+            given then the class domain is used. The default is None.
+        window : {None, array_like}, optional
+            If given, the resulting array must be if the form
+            ``[beg, end]``, where ``beg`` and ``end`` are the endpoints of
+            the window. If None is given then the class window is used. The
+            default is None.
+        symbol : str, optional
+            Symbol representing the independent variable. Default is 'x'.
+
+        Returns
+        -------
+        new_series : series
+             Series of representing the identity.
+
+        """
+        if domain is None:
+            domain = cls.domain
+        if window is None:
+            window = cls.window
+        off, scl = pu.mapparms(window, domain)
+        coef = cls._line(off, scl)
+        return cls(coef, domain, window, symbol)
+
+    @classmethod
+    def basis(cls, deg, domain=None, window=None, symbol='x'):
+        """Series basis polynomial of degree `deg`.
+
+        Returns the series representing the basis polynomial of degree `deg`.
+
+        .. versionadded:: 1.7.0
+
+        Parameters
+        ----------
+        deg : int
+            Degree of the basis polynomial for the series. Must be >= 0.
+        domain : {None, array_like}, optional
+            If given, the array must be of the form ``[beg, end]``, where
+            ``beg`` and ``end`` are the endpoints of the domain. If None is
+            given then the class domain is used. The default is None.
+        window : {None, array_like}, optional
+            If given, the resulting array must be if the form
+            ``[beg, end]``, where ``beg`` and ``end`` are the endpoints of
+            the window. If None is given then the class window is used. The
+            default is None.
+        symbol : str, optional
+            Symbol representing the independent variable. Default is 'x'.
+
+        Returns
+        -------
+        new_series : series
+            A series with the coefficient of the `deg` term set to one and
+            all others zero.
+
+        """
+        if domain is None:
+            domain = cls.domain
+        if window is None:
+            window = cls.window
+        ideg = int(deg)
+
+        if ideg != deg or ideg < 0:
+            raise ValueError("deg must be non-negative integer")
+        return cls([0]*ideg + [1], domain, window, symbol)
+
+    @classmethod
+    def cast(cls, series, domain=None, window=None):
+        """Convert series to series of this class.
+
+        The `series` is expected to be an instance of some polynomial
+        series of one of the types supported by by the numpy.polynomial
+        module, but could be some other class that supports the convert
+        method.
+
+        .. versionadded:: 1.7.0
+
+        Parameters
+        ----------
+        series : series
+            The series instance to be converted.
+        domain : {None, array_like}, optional
+            If given, the array must be of the form ``[beg, end]``, where
+            ``beg`` and ``end`` are the endpoints of the domain. If None is
+            given then the class domain is used. The default is None.
+        window : {None, array_like}, optional
+            If given, the resulting array must be if the form
+            ``[beg, end]``, where ``beg`` and ``end`` are the endpoints of
+            the window. If None is given then the class window is used. The
+            default is None.
+
+        Returns
+        -------
+        new_series : series
+            A series of the same kind as the calling class and equal to
+            `series` when evaluated.
+
+        See Also
+        --------
+        convert : similar instance method
+
+        """
+        if domain is None:
+            domain = cls.domain
+        if window is None:
+            window = cls.window
+        return series.convert(domain, cls, window)

venv/lib/python3.10/site-packages/numpy/polynomial/_polybase.pyi

@@ -0,0 +1,71 @@
+import abc
+from typing import Any, ClassVar
+
+__all__: list[str]
+
+class ABCPolyBase(abc.ABC):
+    __hash__: ClassVar[None]  # type: ignore[assignment]
+    __array_ufunc__: ClassVar[None]
+    maxpower: ClassVar[int]
+    coef: Any
+    @property
+    def symbol(self) -> str: ...
+    @property
+    @abc.abstractmethod
+    def domain(self): ...
+    @property
+    @abc.abstractmethod
+    def window(self): ...
+    @property
+    @abc.abstractmethod
+    def basis_name(self): ...
+    def has_samecoef(self, other): ...
+    def has_samedomain(self, other): ...
+    def has_samewindow(self, other): ...
+    def has_sametype(self, other): ...
+    def __init__(self, coef, domain=..., window=..., symbol: str = ...) -> None: ...
+    def __format__(self, fmt_str): ...
+    def __call__(self, arg): ...
+    def __iter__(self): ...
+    def __len__(self): ...
+    def __neg__(self): ...
+    def __pos__(self): ...
+    def __add__(self, other): ...
+    def __sub__(self, other): ...
+    def __mul__(self, other): ...
+    def __truediv__(self, other): ...
+    def __floordiv__(self, other): ...
+    def __mod__(self, other): ...
+    def __divmod__(self, other): ...
+    def __pow__(self, other): ...
+    def __radd__(self, other): ...
+    def __rsub__(self, other): ...
+    def __rmul__(self, other): ...
+    def __rdiv__(self, other): ...
+    def __rtruediv__(self, other): ...
+    def __rfloordiv__(self, other): ...
+    def __rmod__(self, other): ...
+    def __rdivmod__(self, other): ...
+    def __eq__(self, other): ...
+    def __ne__(self, other): ...
+    def copy(self): ...
+    def degree(self): ...
+    def cutdeg(self, deg): ...
+    def trim(self, tol=...): ...
+    def truncate(self, size): ...
+    def convert(self, domain=..., kind=..., window=...): ...
+    def mapparms(self): ...
+    def integ(self, m=..., k = ..., lbnd=...): ...
+    def deriv(self, m=...): ...
+    def roots(self): ...
+    def linspace(self, n=..., domain=...): ...
+    @classmethod
+    def fit(cls, x, y, deg, domain=..., rcond=..., full=..., w=..., window=...): ...
+    @classmethod
+    def fromroots(cls, roots, domain = ..., window=...): ...
+    @classmethod
+    def identity(cls, domain=..., window=...): ...
+    @classmethod
+    def basis(cls, deg, domain=..., window=...): ...
+    @classmethod
+    def cast(cls, series, domain=..., window=...): ...

venv/lib/python3.10/site-packages/numpy/polynomial/chebyshev.py

@@ -0,0 +1,2082 @@
+"""
+====================================================
+Chebyshev Series (:mod:`numpy.polynomial.chebyshev`)
+====================================================
+
+This module provides a number of objects (mostly functions) useful for
+dealing with Chebyshev series, including a `Chebyshev` class that
+encapsulates the usual arithmetic operations.  (General information
+on how this module represents and works with such polynomials is in the
+docstring for its "parent" sub-package, `numpy.polynomial`).
+
+Classes
+-------
+
+.. autosummary::
+   :toctree: generated/
+
+   Chebyshev
+
+
+Constants
+---------
+
+.. autosummary::
+   :toctree: generated/
+
+   chebdomain
+   chebzero
+   chebone
+   chebx
+
+Arithmetic
+----------
+
+.. autosummary::
+   :toctree: generated/
+
+   chebadd
+   chebsub
+   chebmulx
+   chebmul
+   chebdiv
+   chebpow
+   chebval
+   chebval2d
+   chebval3d
+   chebgrid2d
+   chebgrid3d
+
+Calculus
+--------
+
+.. autosummary::
+   :toctree: generated/
+
+   chebder
+   chebint
+
+Misc Functions
+--------------
+
+.. autosummary::
+   :toctree: generated/
+
+   chebfromroots
+   chebroots
+   chebvander
+   chebvander2d
+   chebvander3d
+   chebgauss
+   chebweight
+   chebcompanion
+   chebfit
+   chebpts1
+   chebpts2
+   chebtrim
+   chebline
+   cheb2poly
+   poly2cheb
+   chebinterpolate
+
+See also
+--------
+`numpy.polynomial`
+
+Notes
+-----
+The implementations of multiplication, division, integration, and
+differentiation use the algebraic identities [1]_:
+
+.. math::
+    T_n(x) = \\frac{z^n + z^{-n}}{2} \\\\
+    z\\frac{dx}{dz} = \\frac{z - z^{-1}}{2}.
+
+where
+
+.. math:: x = \\frac{z + z^{-1}}{2}.
+
+These identities allow a Chebyshev series to be expressed as a finite,
+symmetric Laurent series.  In this module, this sort of Laurent series
+is referred to as a "z-series."
+
+References
+----------
+.. [1] A. T. Benjamin, et al., "Combinatorial Trigonometry with Chebyshev
+  Polynomials," *Journal of Statistical Planning and Inference 14*, 2008
+  (https://web.archive.org/web/20080221202153/https://www.math.hmc.edu/~benjamin/papers/CombTrig.pdf, pg. 4)
+
+"""
+import numpy as np
+import numpy.linalg as la
+from numpy.core.multiarray import normalize_axis_index
+
+from . import polyutils as pu
+from ._polybase import ABCPolyBase
+
+__all__ = [
+    'chebzero', 'chebone', 'chebx', 'chebdomain', 'chebline', 'chebadd',
+    'chebsub', 'chebmulx', 'chebmul', 'chebdiv', 'chebpow', 'chebval',
+    'chebder', 'chebint', 'cheb2poly', 'poly2cheb', 'chebfromroots',
+    'chebvander', 'chebfit', 'chebtrim', 'chebroots', 'chebpts1',
+    'chebpts2', 'Chebyshev', 'chebval2d', 'chebval3d', 'chebgrid2d',
+    'chebgrid3d', 'chebvander2d', 'chebvander3d', 'chebcompanion',
+    'chebgauss', 'chebweight', 'chebinterpolate']
+
+chebtrim = pu.trimcoef
+
+#
+# A collection of functions for manipulating z-series. These are private
+# functions and do minimal error checking.
+#
+
+def _cseries_to_zseries(c):
+    """Convert Chebyshev series to z-series.
+
+    Convert a Chebyshev series to the equivalent z-series. The result is
+    never an empty array. The dtype of the return is the same as that of
+    the input. No checks are run on the arguments as this routine is for
+    internal use.
+
+    Parameters
+    ----------
+    c : 1-D ndarray
+        Chebyshev coefficients, ordered from low to high
+
+    Returns
+    -------
+    zs : 1-D ndarray
+        Odd length symmetric z-series, ordered from  low to high.
+
+    """
+    n = c.size
+    zs = np.zeros(2*n-1, dtype=c.dtype)
+    zs[n-1:] = c/2
+    return zs + zs[::-1]
+
+
+def _zseries_to_cseries(zs):
+    """Convert z-series to a Chebyshev series.
+
+    Convert a z series to the equivalent Chebyshev series. The result is
+    never an empty array. The dtype of the return is the same as that of
+    the input. No checks are run on the arguments as this routine is for
+    internal use.
+
+    Parameters
+    ----------
+    zs : 1-D ndarray
+        Odd length symmetric z-series, ordered from  low to high.
+
+    Returns
+    -------
+    c : 1-D ndarray
+        Chebyshev coefficients, ordered from  low to high.
+
+    """
+    n = (zs.size + 1)//2
+    c = zs[n-1:].copy()
+    c[1:n] *= 2
+    return c
+
+
+def _zseries_mul(z1, z2):
+    """Multiply two z-series.
+
+    Multiply two z-series to produce a z-series.
+
+    Parameters
+    ----------
+    z1, z2 : 1-D ndarray
+        The arrays must be 1-D but this is not checked.
+
+    Returns
+    -------
+    product : 1-D ndarray
+        The product z-series.
+
+    Notes
+    -----
+    This is simply convolution. If symmetric/anti-symmetric z-series are
+    denoted by S/A then the following rules apply:
+
+    S*S, A*A -> S
+    S*A, A*S -> A
+
+    """
+    return np.convolve(z1, z2)
+
+
+def _zseries_div(z1, z2):
+    """Divide the first z-series by the second.
+
+    Divide `z1` by `z2` and return the quotient and remainder as z-series.
+    Warning: this implementation only applies when both z1 and z2 have the
+    same symmetry, which is sufficient for present purposes.
+
+    Parameters
+    ----------
+    z1, z2 : 1-D ndarray
+        The arrays must be 1-D and have the same symmetry, but this is not
+        checked.
+
+    Returns
+    -------
+
+    (quotient, remainder) : 1-D ndarrays
+        Quotient and remainder as z-series.
+
+    Notes
+    -----
+    This is not the same as polynomial division on account of the desired form
+    of the remainder. If symmetric/anti-symmetric z-series are denoted by S/A
+    then the following rules apply:
+
+    S/S -> S,S
+    A/A -> S,A
+
+    The restriction to types of the same symmetry could be fixed but seems like
+    unneeded generality. There is no natural form for the remainder in the case
+    where there is no symmetry.
+
+    """
+    z1 = z1.copy()
+    z2 = z2.copy()
+    lc1 = len(z1)
+    lc2 = len(z2)
+    if lc2 == 1:
+        z1 /= z2
+        return z1, z1[:1]*0
+    elif lc1 < lc2:
+        return z1[:1]*0, z1
+    else:
+        dlen = lc1 - lc2
+        scl = z2[0]
+        z2 /= scl
+        quo = np.empty(dlen + 1, dtype=z1.dtype)
+        i = 0
+        j = dlen
+        while i < j:
+            r = z1[i]
+            quo[i] = z1[i]
+            quo[dlen - i] = r
+            tmp = r*z2
+            z1[i:i+lc2] -= tmp
+            z1[j:j+lc2] -= tmp
+            i += 1
+            j -= 1
+        r = z1[i]
+        quo[i] = r
+        tmp = r*z2
+        z1[i:i+lc2] -= tmp
+        quo /= scl
+        rem = z1[i+1:i-1+lc2].copy()
+        return quo, rem
+
+
+def _zseries_der(zs):
+    """Differentiate a z-series.
+
+    The derivative is with respect to x, not z. This is achieved using the
+    chain rule and the value of dx/dz given in the module notes.
+
+    Parameters
+    ----------
+    zs : z-series
+        The z-series to differentiate.
+
+    Returns
+    -------
+    derivative : z-series
+        The derivative
+
+    Notes
+    -----
+    The zseries for x (ns) has been multiplied by two in order to avoid
+    using floats that are incompatible with Decimal and likely other
+    specialized scalar types. This scaling has been compensated by
+    multiplying the value of zs by two also so that the two cancels in the
+    division.
+
+    """
+    n = len(zs)//2
+    ns = np.array([-1, 0, 1], dtype=zs.dtype)
+    zs *= np.arange(-n, n+1)*2
+    d, r = _zseries_div(zs, ns)
+    return d
+
+
+def _zseries_int(zs):
+    """Integrate a z-series.
+
+    The integral is with respect to x, not z. This is achieved by a change
+    of variable using dx/dz given in the module notes.
+
+    Parameters
+    ----------
+    zs : z-series
+        The z-series to integrate
+
+    Returns
+    -------
+    integral : z-series
+        The indefinite integral
+
+    Notes
+    -----
+    The zseries for x (ns) has been multiplied by two in order to avoid
+    using floats that are incompatible with Decimal and likely other
+    specialized scalar types. This scaling has been compensated by
+    dividing the resulting zs by two.
+
+    """
+    n = 1 + len(zs)//2
+    ns = np.array([-1, 0, 1], dtype=zs.dtype)
+    zs = _zseries_mul(zs, ns)
+    div = np.arange(-n, n+1)*2
+    zs[:n] /= div[:n]
+    zs[n+1:] /= div[n+1:]
+    zs[n] = 0
+    return zs
+
+#
+# Chebyshev series functions
+#
+
+
+def poly2cheb(pol):
+    """
+    Convert a polynomial to a Chebyshev series.
+
+    Convert an array representing the coefficients of a polynomial (relative
+    to the "standard" basis) ordered from lowest degree to highest, to an
+    array of the coefficients of the equivalent Chebyshev series, ordered
+    from lowest to highest degree.
+
+    Parameters
+    ----------
+    pol : array_like
+        1-D array containing the polynomial coefficients
+
+    Returns
+    -------
+    c : ndarray
+        1-D array containing the coefficients of the equivalent Chebyshev
+        series.
+
+    See Also
+    --------
+    cheb2poly
+
+    Notes
+    -----
+    The easy way to do conversions between polynomial basis sets
+    is to use the convert method of a class instance.
+
+    Examples
+    --------
+    >>> from numpy import polynomial as P
+    >>> p = P.Polynomial(range(4))
+    >>> p
+    Polynomial([0., 1., 2., 3.], domain=[-1,  1], window=[-1,  1])
+    >>> c = p.convert(kind=P.Chebyshev)
+    >>> c
+    Chebyshev([1.  , 3.25, 1.  , 0.75], domain=[-1.,  1.], window=[-1.,  1.])
+    >>> P.chebyshev.poly2cheb(range(4))
+    array([1.  , 3.25, 1.  , 0.75])
+
+    """
+    [pol] = pu.as_series([pol])
+    deg = len(pol) - 1
+    res = 0
+    for i in range(deg, -1, -1):
+        res = chebadd(chebmulx(res), pol[i])
+    return res
+
+
+def cheb2poly(c):
+    """
+    Convert a Chebyshev series to a polynomial.
+
+    Convert an array representing the coefficients of a Chebyshev series,
+    ordered from lowest degree to highest, to an array of the coefficients
+    of the equivalent polynomial (relative to the "standard" basis) ordered
+    from lowest to highest degree.
+
+    Parameters
+    ----------
+    c : array_like
+        1-D array containing the Chebyshev series coefficients, ordered
+        from lowest order term to highest.
+
+    Returns
+    -------
+    pol : ndarray
+        1-D array containing the coefficients of the equivalent polynomial
+        (relative to the "standard" basis) ordered from lowest order term
+        to highest.
+
+    See Also
+    --------
+    poly2cheb
+
+    Notes
+    -----
+    The easy way to do conversions between polynomial basis sets
+    is to use the convert method of a class instance.
+
+    Examples
+    --------
+    >>> from numpy import polynomial as P
+    >>> c = P.Chebyshev(range(4))
+    >>> c
+    Chebyshev([0., 1., 2., 3.], domain=[-1,  1], window=[-1,  1])
+    >>> p = c.convert(kind=P.Polynomial)
+    >>> p
+    Polynomial([-2., -8.,  4., 12.], domain=[-1.,  1.], window=[-1.,  1.])
+    >>> P.chebyshev.cheb2poly(range(4))
+    array([-2.,  -8.,   4.,  12.])
+
+    """
+    from .polynomial import polyadd, polysub, polymulx
+
+    [c] = pu.as_series([c])
+    n = len(c)
+    if n < 3:
+        return c
+    else:
+        c0 = c[-2]
+        c1 = c[-1]
+        # i is the current degree of c1
+        for i in range(n - 1, 1, -1):
+            tmp = c0
+            c0 = polysub(c[i - 2], c1)
+            c1 = polyadd(tmp, polymulx(c1)*2)
+        return polyadd(c0, polymulx(c1))
+
+
+#
+# These are constant arrays are of integer type so as to be compatible
+# with the widest range of other types, such as Decimal.
+#
+
+# Chebyshev default domain.
+chebdomain = np.array([-1, 1])
+
+# Chebyshev coefficients representing zero.
+chebzero = np.array([0])
+
+# Chebyshev coefficients representing one.
+chebone = np.array([1])
+
+# Chebyshev coefficients representing the identity x.
+chebx = np.array([0, 1])
+
+
+def chebline(off, scl):
+    """
+    Chebyshev series whose graph is a straight line.
+
+    Parameters
+    ----------
+    off, scl : scalars
+        The specified line is given by ``off + scl*x``.
+
+    Returns
+    -------
+    y : ndarray
+        This module's representation of the Chebyshev series for
+        ``off + scl*x``.
+
+    See Also
+    --------
+    numpy.polynomial.polynomial.polyline
+    numpy.polynomial.legendre.legline
+    numpy.polynomial.laguerre.lagline
+    numpy.polynomial.hermite.hermline
+    numpy.polynomial.hermite_e.hermeline
+
+    Examples
+    --------
+    >>> import numpy.polynomial.chebyshev as C
+    >>> C.chebline(3,2)
+    array([3, 2])
+    >>> C.chebval(-3, C.chebline(3,2)) # should be -3
+    -3.0
+
+    """
+    if scl != 0:
+        return np.array([off, scl])
+    else:
+        return np.array([off])
+
+
+def chebfromroots(roots):
+    """
+    Generate a Chebyshev series with given roots.
+
+    The function returns the coefficients of the polynomial
+
+    .. math:: p(x) = (x - r_0) * (x - r_1) * ... * (x - r_n),
+
+    in Chebyshev form, where the `r_n` are the roots specified in `roots`.
+    If a zero has multiplicity n, then it must appear in `roots` n times.
+    For instance, if 2 is a root of multiplicity three and 3 is a root of
+    multiplicity 2, then `roots` looks something like [2, 2, 2, 3, 3]. The
+    roots can appear in any order.
+
+    If the returned coefficients are `c`, then
+
+    .. math:: p(x) = c_0 + c_1 * T_1(x) + ... +  c_n * T_n(x)
+
+    The coefficient of the last term is not generally 1 for monic
+    polynomials in Chebyshev form.
+
+    Parameters
+    ----------
+    roots : array_like
+        Sequence containing the roots.
+
+    Returns
+    -------
+    out : ndarray
+        1-D array of coefficients.  If all roots are real then `out` is a
+        real array, if some of the roots are complex, then `out` is complex
+        even if all the coefficients in the result are real (see Examples
+        below).
+
+    See Also
+    --------
+    numpy.polynomial.polynomial.polyfromroots
+    numpy.polynomial.legendre.legfromroots
+    numpy.polynomial.laguerre.lagfromroots
+    numpy.polynomial.hermite.hermfromroots
+    numpy.polynomial.hermite_e.hermefromroots
+
+    Examples
+    --------
+    >>> import numpy.polynomial.chebyshev as C
+    >>> C.chebfromroots((-1,0,1)) # x^3 - x relative to the standard basis
+    array([ 0.  , -0.25,  0.  ,  0.25])
+    >>> j = complex(0,1)
+    >>> C.chebfromroots((-j,j)) # x^2 + 1 relative to the standard basis
+    array([1.5+0.j, 0. +0.j, 0.5+0.j])
+
+    """
+    return pu._fromroots(chebline, chebmul, roots)
+
+
+def chebadd(c1, c2):
+    """
+    Add one Chebyshev series to another.
+
+    Returns the sum of two Chebyshev series `c1` + `c2`.  The arguments
+    are sequences of coefficients ordered from lowest order term to
+    highest, i.e., [1,2,3] represents the series ``T_0 + 2*T_1 + 3*T_2``.
+
+    Parameters
+    ----------
+    c1, c2 : array_like
+        1-D arrays of Chebyshev series coefficients ordered from low to
+        high.
+
+    Returns
+    -------
+    out : ndarray
+        Array representing the Chebyshev series of their sum.
+
+    See Also
+    --------
+    chebsub, chebmulx, chebmul, chebdiv, chebpow
+
+    Notes
+    -----
+    Unlike multiplication, division, etc., the sum of two Chebyshev series
+    is a Chebyshev series (without having to "reproject" the result onto
+    the basis set) so addition, just like that of "standard" polynomials,
+    is simply "component-wise."
+
+    Examples
+    --------
+    >>> from numpy.polynomial import chebyshev as C
+    >>> c1 = (1,2,3)
+    >>> c2 = (3,2,1)
+    >>> C.chebadd(c1,c2)
+    array([4., 4., 4.])
+
+    """
+    return pu._add(c1, c2)
+
+
+def chebsub(c1, c2):
+    """
+    Subtract one Chebyshev series from another.
+
+    Returns the difference of two Chebyshev series `c1` - `c2`.  The
+    sequences of coefficients are from lowest order term to highest, i.e.,
+    [1,2,3] represents the series ``T_0 + 2*T_1 + 3*T_2``.
+
+    Parameters
+    ----------
+    c1, c2 : array_like
+        1-D arrays of Chebyshev series coefficients ordered from low to
+        high.
+
+    Returns
+    -------
+    out : ndarray
+        Of Chebyshev series coefficients representing their difference.
+
+    See Also
+    --------
+    chebadd, chebmulx, chebmul, chebdiv, chebpow
+
+    Notes
+    -----
+    Unlike multiplication, division, etc., the difference of two Chebyshev
+    series is a Chebyshev series (without having to "reproject" the result
+    onto the basis set) so subtraction, just like that of "standard"
+    polynomials, is simply "component-wise."
+
+    Examples
+    --------
+    >>> from numpy.polynomial import chebyshev as C
+    >>> c1 = (1,2,3)
+    >>> c2 = (3,2,1)
+    >>> C.chebsub(c1,c2)
+    array([-2.,  0.,  2.])
+    >>> C.chebsub(c2,c1) # -C.chebsub(c1,c2)
+    array([ 2.,  0., -2.])
+
+    """
+    return pu._sub(c1, c2)
+
+
+def chebmulx(c):
+    """Multiply a Chebyshev series by x.
+
+    Multiply the polynomial `c` by x, where x is the independent
+    variable.
+
+
+    Parameters
+    ----------
+    c : array_like
+        1-D array of Chebyshev series coefficients ordered from low to
+        high.
+
+    Returns
+    -------
+    out : ndarray
+        Array representing the result of the multiplication.
+
+    Notes
+    -----
+
+    .. versionadded:: 1.5.0
+
+    Examples
+    --------
+    >>> from numpy.polynomial import chebyshev as C
+    >>> C.chebmulx([1,2,3])
+    array([1. , 2.5, 1. , 1.5])
+
+    """
+    # c is a trimmed copy
+    [c] = pu.as_series([c])
+    # The zero series needs special treatment
+    if len(c) == 1 and c[0] == 0:
+        return c
+
+    prd = np.empty(len(c) + 1, dtype=c.dtype)
+    prd[0] = c[0]*0
+    prd[1] = c[0]
+    if len(c) > 1:
+        tmp = c[1:]/2
+        prd[2:] = tmp
+        prd[0:-2] += tmp
+    return prd
+
+
+def chebmul(c1, c2):
+    """
+    Multiply one Chebyshev series by another.
+
+    Returns the product of two Chebyshev series `c1` * `c2`.  The arguments
+    are sequences of coefficients, from lowest order "term" to highest,
+    e.g., [1,2,3] represents the series ``T_0 + 2*T_1 + 3*T_2``.
+
+    Parameters
+    ----------
+    c1, c2 : array_like
+        1-D arrays of Chebyshev series coefficients ordered from low to
+        high.
+
+    Returns
+    -------
+    out : ndarray
+        Of Chebyshev series coefficients representing their product.
+
+    See Also
+    --------
+    chebadd, chebsub, chebmulx, chebdiv, chebpow
+
+    Notes
+    -----
+    In general, the (polynomial) product of two C-series results in terms
+    that are not in the Chebyshev polynomial basis set.  Thus, to express
+    the product as a C-series, it is typically necessary to "reproject"
+    the product onto said basis set, which typically produces
+    "unintuitive live" (but correct) results; see Examples section below.
+
+    Examples
+    --------
+    >>> from numpy.polynomial import chebyshev as C
+    >>> c1 = (1,2,3)
+    >>> c2 = (3,2,1)
+    >>> C.chebmul(c1,c2) # multiplication requires "reprojection"
+    array([  6.5,  12. ,  12. ,   4. ,   1.5])
+
+    """
+    # c1, c2 are trimmed copies
+    [c1, c2] = pu.as_series([c1, c2])
+    z1 = _cseries_to_zseries(c1)
+    z2 = _cseries_to_zseries(c2)
+    prd = _zseries_mul(z1, z2)
+    ret = _zseries_to_cseries(prd)
+    return pu.trimseq(ret)
+
+
+def chebdiv(c1, c2):
+    """
+    Divide one Chebyshev series by another.
+
+    Returns the quotient-with-remainder of two Chebyshev series
+    `c1` / `c2`.  The arguments are sequences of coefficients from lowest
+    order "term" to highest, e.g., [1,2,3] represents the series
+    ``T_0 + 2*T_1 + 3*T_2``.
+
+    Parameters
+    ----------
+    c1, c2 : array_like
+        1-D arrays of Chebyshev series coefficients ordered from low to
+        high.
+
+    Returns
+    -------
+    [quo, rem] : ndarrays
+        Of Chebyshev series coefficients representing the quotient and
+        remainder.
+
+    See Also
+    --------
+    chebadd, chebsub, chebmulx, chebmul, chebpow
+
+    Notes
+    -----
+    In general, the (polynomial) division of one C-series by another
+    results in quotient and remainder terms that are not in the Chebyshev
+    polynomial basis set.  Thus, to express these results as C-series, it
+    is typically necessary to "reproject" the results onto said basis
+    set, which typically produces "unintuitive" (but correct) results;
+    see Examples section below.
+
+    Examples
+    --------
+    >>> from numpy.polynomial import chebyshev as C
+    >>> c1 = (1,2,3)
+    >>> c2 = (3,2,1)
+    >>> C.chebdiv(c1,c2) # quotient "intuitive," remainder not
+    (array([3.]), array([-8., -4.]))
+    >>> c2 = (0,1,2,3)
+    >>> C.chebdiv(c2,c1) # neither "intuitive"
+    (array([0., 2.]), array([-2., -4.]))
+
+    """
+    # c1, c2 are trimmed copies
+    [c1, c2] = pu.as_series([c1, c2])
+    if c2[-1] == 0:
+        raise ZeroDivisionError()
+
+    # note: this is more efficient than `pu._div(chebmul, c1, c2)`
+    lc1 = len(c1)
+    lc2 = len(c2)
+    if lc1 < lc2:
+        return c1[:1]*0, c1
+    elif lc2 == 1:
+        return c1/c2[-1], c1[:1]*0
+    else:
+        z1 = _cseries_to_zseries(c1)
+        z2 = _cseries_to_zseries(c2)
+        quo, rem = _zseries_div(z1, z2)
+        quo = pu.trimseq(_zseries_to_cseries(quo))
+        rem = pu.trimseq(_zseries_to_cseries(rem))
+        return quo, rem
+
+
+def chebpow(c, pow, maxpower=16):
+    """Raise a Chebyshev series to a power.
+
+    Returns the Chebyshev series `c` raised to the power `pow`. The
+    argument `c` is a sequence of coefficients ordered from low to high.
+    i.e., [1,2,3] is the series  ``T_0 + 2*T_1 + 3*T_2.``
+
+    Parameters
+    ----------
+    c : array_like
+        1-D array of Chebyshev series coefficients ordered from low to
+        high.
+    pow : integer
+        Power to which the series will be raised
+    maxpower : integer, optional
+        Maximum power allowed. This is mainly to limit growth of the series
+        to unmanageable size. Default is 16
+
+    Returns
+    -------
+    coef : ndarray
+        Chebyshev series of power.
+
+    See Also
+    --------
+    chebadd, chebsub, chebmulx, chebmul, chebdiv
+
+    Examples
+    --------
+    >>> from numpy.polynomial import chebyshev as C
+    >>> C.chebpow([1, 2, 3, 4], 2)
+    array([15.5, 22. , 16. , ..., 12.5, 12. ,  8. ])
+
+    """
+    # note: this is more efficient than `pu._pow(chebmul, c1, c2)`, as it
+    # avoids converting between z and c series repeatedly
+
+    # c is a trimmed copy
+    [c] = pu.as_series([c])
+    power = int(pow)
+    if power != pow or power < 0:
+        raise ValueError("Power must be a non-negative integer.")
+    elif maxpower is not None and power > maxpower:
+        raise ValueError("Power is too large")
+    elif power == 0:
+        return np.array([1], dtype=c.dtype)
+    elif power == 1:
+        return c
+    else:
+        # This can be made more efficient by using powers of two
+        # in the usual way.
+        zs = _cseries_to_zseries(c)
+        prd = zs
+        for i in range(2, power + 1):
+            prd = np.convolve(prd, zs)
+        return _zseries_to_cseries(prd)
+
+
+def chebder(c, m=1, scl=1, axis=0):
+    """
+    Differentiate a Chebyshev series.
+
+    Returns the Chebyshev series coefficients `c` differentiated `m` times
+    along `axis`.  At each iteration the result is multiplied by `scl` (the
+    scaling factor is for use in a linear change of variable). The argument
+    `c` is an array of coefficients from low to high degree along each
+    axis, e.g., [1,2,3] represents the series ``1*T_0 + 2*T_1 + 3*T_2``
+    while [[1,2],[1,2]] represents ``1*T_0(x)*T_0(y) + 1*T_1(x)*T_0(y) +
+    2*T_0(x)*T_1(y) + 2*T_1(x)*T_1(y)`` if axis=0 is ``x`` and axis=1 is
+    ``y``.
+
+    Parameters
+    ----------
+    c : array_like
+        Array of Chebyshev series coefficients. If c is multidimensional
+        the different axis correspond to different variables with the
+        degree in each axis given by the corresponding index.
+    m : int, optional
+        Number of derivatives taken, must be non-negative. (Default: 1)
+    scl : scalar, optional
+        Each differentiation is multiplied by `scl`.  The end result is
+        multiplication by ``scl**m``.  This is for use in a linear change of
+        variable. (Default: 1)
+    axis : int, optional
+        Axis over which the derivative is taken. (Default: 0).
+
+        .. versionadded:: 1.7.0
+
+    Returns
+    -------
+    der : ndarray
+        Chebyshev series of the derivative.
+
+    See Also
+    --------
+    chebint
+
+    Notes
+    -----
+    In general, the result of differentiating a C-series needs to be
+    "reprojected" onto the C-series basis set. Thus, typically, the
+    result of this function is "unintuitive," albeit correct; see Examples
+    section below.
+
+    Examples
+    --------
+    >>> from numpy.polynomial import chebyshev as C
+    >>> c = (1,2,3,4)
+    >>> C.chebder(c)
+    array([14., 12., 24.])
+    >>> C.chebder(c,3)
+    array([96.])
+    >>> C.chebder(c,scl=-1)
+    array([-14., -12., -24.])
+    >>> C.chebder(c,2,-1)
+    array([12.,  96.])
+
+    """
+    c = np.array(c, ndmin=1, copy=True)
+    if c.dtype.char in '?bBhHiIlLqQpP':
+        c = c.astype(np.double)
+    cnt = pu._deprecate_as_int(m, "the order of derivation")
+    iaxis = pu._deprecate_as_int(axis, "the axis")
+    if cnt < 0:
+        raise ValueError("The order of derivation must be non-negative")
+    iaxis = normalize_axis_index(iaxis, c.ndim)
+
+    if cnt == 0:
+        return c
+
+    c = np.moveaxis(c, iaxis, 0)
+    n = len(c)
+    if cnt >= n:
+        c = c[:1]*0
+    else:
+        for i in range(cnt):
+            n = n - 1
+            c *= scl
+            der = np.empty((n,) + c.shape[1:], dtype=c.dtype)
+            for j in range(n, 2, -1):
+                der[j - 1] = (2*j)*c[j]
+                c[j - 2] += (j*c[j])/(j - 2)
+            if n > 1:
+                der[1] = 4*c[2]
+            der[0] = c[1]
+            c = der
+    c = np.moveaxis(c, 0, iaxis)
+    return c
+
+
+def chebint(c, m=1, k=[], lbnd=0, scl=1, axis=0):
+    """
+    Integrate a Chebyshev series.
+
+    Returns the Chebyshev series coefficients `c` integrated `m` times from
+    `lbnd` along `axis`. At each iteration the resulting series is
+    **multiplied** by `scl` and an integration constant, `k`, is added.
+    The scaling factor is for use in a linear change of variable.  ("Buyer
+    beware": note that, depending on what one is doing, one may want `scl`
+    to be the reciprocal of what one might expect; for more information,
+    see the Notes section below.)  The argument `c` is an array of
+    coefficients from low to high degree along each axis, e.g., [1,2,3]
+    represents the series ``T_0 + 2*T_1 + 3*T_2`` while [[1,2],[1,2]]
+    represents ``1*T_0(x)*T_0(y) + 1*T_1(x)*T_0(y) + 2*T_0(x)*T_1(y) +
+    2*T_1(x)*T_1(y)`` if axis=0 is ``x`` and axis=1 is ``y``.
+
+    Parameters
+    ----------
+    c : array_like
+        Array of Chebyshev series coefficients. If c is multidimensional
+        the different axis correspond to different variables with the
+        degree in each axis given by the corresponding index.
+    m : int, optional
+        Order of integration, must be positive. (Default: 1)
+    k : {[], list, scalar}, optional
+        Integration constant(s).  The value of the first integral at zero
+        is the first value in the list, the value of the second integral
+        at zero is the second value, etc.  If ``k == []`` (the default),
+        all constants are set to zero.  If ``m == 1``, a single scalar can
+        be given instead of a list.
+    lbnd : scalar, optional
+        The lower bound of the integral. (Default: 0)
+    scl : scalar, optional
+        Following each integration the result is *multiplied* by `scl`
+        before the integration constant is added. (Default: 1)
+    axis : int, optional
+        Axis over which the integral is taken. (Default: 0).
+
+        .. versionadded:: 1.7.0
+
+    Returns
+    -------
+    S : ndarray
+        C-series coefficients of the integral.
+
+    Raises
+    ------
+    ValueError
+        If ``m < 1``, ``len(k) > m``, ``np.ndim(lbnd) != 0``, or
+        ``np.ndim(scl) != 0``.
+
+    See Also
+    --------
+    chebder
+
+    Notes
+    -----
+    Note that the result of each integration is *multiplied* by `scl`.
+    Why is this important to note?  Say one is making a linear change of
+    variable :math:`u = ax + b` in an integral relative to `x`.  Then
+    :math:`dx = du/a`, so one will need to set `scl` equal to
+    :math:`1/a`- perhaps not what one would have first thought.
+
+    Also note that, in general, the result of integrating a C-series needs
+    to be "reprojected" onto the C-series basis set.  Thus, typically,
+    the result of this function is "unintuitive," albeit correct; see
+    Examples section below.
+
+    Examples
+    --------
+    >>> from numpy.polynomial import chebyshev as C
+    >>> c = (1,2,3)
+    >>> C.chebint(c)
+    array([ 0.5, -0.5,  0.5,  0.5])
+    >>> C.chebint(c,3)
+    array([ 0.03125   , -0.1875    ,  0.04166667, -0.05208333,  0.01041667, # may vary
+        0.00625   ])
+    >>> C.chebint(c, k=3)
+    array([ 3.5, -0.5,  0.5,  0.5])
+    >>> C.chebint(c,lbnd=-2)
+    array([ 8.5, -0.5,  0.5,  0.5])
+    >>> C.chebint(c,scl=-2)
+    array([-1.,  1., -1., -1.])
+
+    """
+    c = np.array(c, ndmin=1, copy=True)
+    if c.dtype.char in '?bBhHiIlLqQpP':
+        c = c.astype(np.double)
+    if not np.iterable(k):
+        k = [k]
+    cnt = pu._deprecate_as_int(m, "the order of integration")
+    iaxis = pu._deprecate_as_int(axis, "the axis")
+    if cnt < 0:
+        raise ValueError("The order of integration must be non-negative")
+    if len(k) > cnt:
+        raise ValueError("Too many integration constants")
+    if np.ndim(lbnd) != 0:
+        raise ValueError("lbnd must be a scalar.")
+    if np.ndim(scl) != 0:
+        raise ValueError("scl must be a scalar.")
+    iaxis = normalize_axis_index(iaxis, c.ndim)
+
+    if cnt == 0:
+        return c
+
+    c = np.moveaxis(c, iaxis, 0)
+    k = list(k) + [0]*(cnt - len(k))
+    for i in range(cnt):
+        n = len(c)
+        c *= scl
+        if n == 1 and np.all(c[0] == 0):
+            c[0] += k[i]
+        else:
+            tmp = np.empty((n + 1,) + c.shape[1:], dtype=c.dtype)
+            tmp[0] = c[0]*0
+            tmp[1] = c[0]
+            if n > 1:
+                tmp[2] = c[1]/4
+            for j in range(2, n):
+                tmp[j + 1] = c[j]/(2*(j + 1))
+                tmp[j - 1] -= c[j]/(2*(j - 1))
+            tmp[0] += k[i] - chebval(lbnd, tmp)
+            c = tmp
+    c = np.moveaxis(c, 0, iaxis)
+    return c
+
+
+def chebval(x, c, tensor=True):
+    """
+    Evaluate a Chebyshev series at points x.
+
+    If `c` is of length `n + 1`, this function returns the value:
+
+    .. math:: p(x) = c_0 * T_0(x) + c_1 * T_1(x) + ... + c_n * T_n(x)
+
+    The parameter `x` is converted to an array only if it is a tuple or a
+    list, otherwise it is treated as a scalar. In either case, either `x`
+    or its elements must support multiplication and addition both with
+    themselves and with the elements of `c`.
+
+    If `c` is a 1-D array, then `p(x)` will have the same shape as `x`.  If
+    `c` is multidimensional, then the shape of the result depends on the
+    value of `tensor`. If `tensor` is true the shape will be c.shape[1:] +
+    x.shape. If `tensor` is false the shape will be c.shape[1:]. Note that
+    scalars have shape (,).
+
+    Trailing zeros in the coefficients will be used in the evaluation, so
+    they should be avoided if efficiency is a concern.
+
+    Parameters
+    ----------
+    x : array_like, compatible object
+        If `x` is a list or tuple, it is converted to an ndarray, otherwise
+        it is left unchanged and treated as a scalar. In either case, `x`
+        or its elements must support addition and multiplication with
+        themselves and with the elements of `c`.
+    c : array_like
+        Array of coefficients ordered so that the coefficients for terms of
+        degree n are contained in c[n]. If `c` is multidimensional the
+        remaining indices enumerate multiple polynomials. In the two
+        dimensional case the coefficients may be thought of as stored in
+        the columns of `c`.
+    tensor : boolean, optional
+        If True, the shape of the coefficient array is extended with ones
+        on the right, one for each dimension of `x`. Scalars have dimension 0
+        for this action. The result is that every column of coefficients in
+        `c` is evaluated for every element of `x`. If False, `x` is broadcast
+        over the columns of `c` for the evaluation.  This keyword is useful
+        when `c` is multidimensional. The default value is True.
+
+        .. versionadded:: 1.7.0
+
+    Returns
+    -------
+    values : ndarray, algebra_like
+        The shape of the return value is described above.
+
+    See Also
+    --------
+    chebval2d, chebgrid2d, chebval3d, chebgrid3d
+
+    Notes
+    -----
+    The evaluation uses Clenshaw recursion, aka synthetic division.
+
+    """
+    c = np.array(c, ndmin=1, copy=True)
+    if c.dtype.char in '?bBhHiIlLqQpP':
+        c = c.astype(np.double)
+    if isinstance(x, (tuple, list)):
+        x = np.asarray(x)
+    if isinstance(x, np.ndarray) and tensor:
+        c = c.reshape(c.shape + (1,)*x.ndim)
+
+    if len(c) == 1:
+        c0 = c[0]
+        c1 = 0
+    elif len(c) == 2:
+        c0 = c[0]
+        c1 = c[1]
+    else:
+        x2 = 2*x
+        c0 = c[-2]
+        c1 = c[-1]
+        for i in range(3, len(c) + 1):
+            tmp = c0
+            c0 = c[-i] - c1
+            c1 = tmp + c1*x2
+    return c0 + c1*x
+
+
+def chebval2d(x, y, c):
+    """
+    Evaluate a 2-D Chebyshev series at points (x, y).
+
+    This function returns the values:
+
+    .. math:: p(x,y) = \\sum_{i,j} c_{i,j} * T_i(x) * T_j(y)
+
+    The parameters `x` and `y` are converted to arrays only if they are
+    tuples or a lists, otherwise they are treated as a scalars and they
+    must have the same shape after conversion. In either case, either `x`
+    and `y` or their elements must support multiplication and addition both
+    with themselves and with the elements of `c`.
+
+    If `c` is a 1-D array a one is implicitly appended to its shape to make
+    it 2-D. The shape of the result will be c.shape[2:] + x.shape.
+
+    Parameters
+    ----------
+    x, y : array_like, compatible objects
+        The two dimensional series is evaluated at the points `(x, y)`,
+        where `x` and `y` must have the same shape. If `x` or `y` is a list
+        or tuple, it is first converted to an ndarray, otherwise it is left
+        unchanged and if it isn't an ndarray it is treated as a scalar.
+    c : array_like
+        Array of coefficients ordered so that the coefficient of the term
+        of multi-degree i,j is contained in ``c[i,j]``. If `c` has
+        dimension greater than 2 the remaining indices enumerate multiple
+        sets of coefficients.
+
+    Returns
+    -------
+    values : ndarray, compatible object
+        The values of the two dimensional Chebyshev series at points formed
+        from pairs of corresponding values from `x` and `y`.
+
+    See Also
+    --------
+    chebval, chebgrid2d, chebval3d, chebgrid3d
+
+    Notes
+    -----
+
+    .. versionadded:: 1.7.0
+
+    """
+    return pu._valnd(chebval, c, x, y)
+
+
+def chebgrid2d(x, y, c):
+    """
+    Evaluate a 2-D Chebyshev series on the Cartesian product of x and y.
+
+    This function returns the values:
+
+    .. math:: p(a,b) = \\sum_{i,j} c_{i,j} * T_i(a) * T_j(b),
+
+    where the points `(a, b)` consist of all pairs formed by taking
+    `a` from `x` and `b` from `y`. The resulting points form a grid with
+    `x` in the first dimension and `y` in the second.
+
+    The parameters `x` and `y` are converted to arrays only if they are
+    tuples or a lists, otherwise they are treated as a scalars. In either
+    case, either `x` and `y` or their elements must support multiplication
+    and addition both with themselves and with the elements of `c`.
+
+    If `c` has fewer than two dimensions, ones are implicitly appended to
+    its shape to make it 2-D. The shape of the result will be c.shape[2:] +
+    x.shape + y.shape.
+
+    Parameters
+    ----------
+    x, y : array_like, compatible objects
+        The two dimensional series is evaluated at the points in the
+        Cartesian product of `x` and `y`.  If `x` or `y` is a list or
+        tuple, it is first converted to an ndarray, otherwise it is left
+        unchanged and, if it isn't an ndarray, it is treated as a scalar.
+    c : array_like
+        Array of coefficients ordered so that the coefficient of the term of
+        multi-degree i,j is contained in `c[i,j]`. If `c` has dimension
+        greater than two the remaining indices enumerate multiple sets of
+        coefficients.
+
+    Returns
+    -------
+    values : ndarray, compatible object
+        The values of the two dimensional Chebyshev series at points in the
+        Cartesian product of `x` and `y`.
+
+    See Also
+    --------
+    chebval, chebval2d, chebval3d, chebgrid3d
+
+    Notes
+    -----
+
+    .. versionadded:: 1.7.0
+
+    """
+    return pu._gridnd(chebval, c, x, y)
+
+
+def chebval3d(x, y, z, c):
+    """
+    Evaluate a 3-D Chebyshev series at points (x, y, z).
+
+    This function returns the values:
+
+    .. math:: p(x,y,z) = \\sum_{i,j,k} c_{i,j,k} * T_i(x) * T_j(y) * T_k(z)
+
+    The parameters `x`, `y`, and `z` are converted to arrays only if
+    they are tuples or a lists, otherwise they are treated as a scalars and
+    they must have the same shape after conversion. In either case, either
+    `x`, `y`, and `z` or their elements must support multiplication and
+    addition both with themselves and with the elements of `c`.
+
+    If `c` has fewer than 3 dimensions, ones are implicitly appended to its
+    shape to make it 3-D. The shape of the result will be c.shape[3:] +
+    x.shape.
+
+    Parameters
+    ----------
+    x, y, z : array_like, compatible object
+        The three dimensional series is evaluated at the points
+        `(x, y, z)`, where `x`, `y`, and `z` must have the same shape.  If
+        any of `x`, `y`, or `z` is a list or tuple, it is first converted
+        to an ndarray, otherwise it is left unchanged and if it isn't an
+        ndarray it is  treated as a scalar.
+    c : array_like
+        Array of coefficients ordered so that the coefficient of the term of
+        multi-degree i,j,k is contained in ``c[i,j,k]``. If `c` has dimension
+        greater than 3 the remaining indices enumerate multiple sets of
+        coefficients.
+
+    Returns
+    -------
+    values : ndarray, compatible object
+        The values of the multidimensional polynomial on points formed with
+        triples of corresponding values from `x`, `y`, and `z`.
+
+    See Also
+    --------
+    chebval, chebval2d, chebgrid2d, chebgrid3d
+
+    Notes
+    -----
+
+    .. versionadded:: 1.7.0
+
+    """
+    return pu._valnd(chebval, c, x, y, z)
+
+
+def chebgrid3d(x, y, z, c):
+    """
+    Evaluate a 3-D Chebyshev series on the Cartesian product of x, y, and z.
+
+    This function returns the values:
+
+    .. math:: p(a,b,c) = \\sum_{i,j,k} c_{i,j,k} * T_i(a) * T_j(b) * T_k(c)
+
+    where the points `(a, b, c)` consist of all triples formed by taking
+    `a` from `x`, `b` from `y`, and `c` from `z`. The resulting points form
+    a grid with `x` in the first dimension, `y` in the second, and `z` in
+    the third.
+
+    The parameters `x`, `y`, and `z` are converted to arrays only if they
+    are tuples or a lists, otherwise they are treated as a scalars. In
+    either case, either `x`, `y`, and `z` or their elements must support
+    multiplication and addition both with themselves and with the elements
+    of `c`.
+
+    If `c` has fewer than three dimensions, ones are implicitly appended to
+    its shape to make it 3-D. The shape of the result will be c.shape[3:] +
+    x.shape + y.shape + z.shape.
+
+    Parameters
+    ----------
+    x, y, z : array_like, compatible objects
+        The three dimensional series is evaluated at the points in the
+        Cartesian product of `x`, `y`, and `z`.  If `x`,`y`, or `z` is a
+        list or tuple, it is first converted to an ndarray, otherwise it is
+        left unchanged and, if it isn't an ndarray, it is treated as a
+        scalar.
+    c : array_like
+        Array of coefficients ordered so that the coefficients for terms of
+        degree i,j are contained in ``c[i,j]``. If `c` has dimension
+        greater than two the remaining indices enumerate multiple sets of
+        coefficients.
+
+    Returns
+    -------
+    values : ndarray, compatible object
+        The values of the two dimensional polynomial at points in the Cartesian
+        product of `x` and `y`.
+
+    See Also
+    --------
+    chebval, chebval2d, chebgrid2d, chebval3d
+
+    Notes
+    -----
+
+    .. versionadded:: 1.7.0
+
+    """
+    return pu._gridnd(chebval, c, x, y, z)
+
+
+def chebvander(x, deg):
+    """Pseudo-Vandermonde matrix of given degree.
+
+    Returns the pseudo-Vandermonde matrix of degree `deg` and sample points
+    `x`. The pseudo-Vandermonde matrix is defined by
+
+    .. math:: V[..., i] = T_i(x),
+
+    where `0 <= i <= deg`. The leading indices of `V` index the elements of
+    `x` and the last index is the degree of the Chebyshev polynomial.
+
+    If `c` is a 1-D array of coefficients of length `n + 1` and `V` is the
+    matrix ``V = chebvander(x, n)``, then ``np.dot(V, c)`` and
+    ``chebval(x, c)`` are the same up to roundoff.  This equivalence is
+    useful both for least squares fitting and for the evaluation of a large
+    number of Chebyshev series of the same degree and sample points.
+
+    Parameters
+    ----------
+    x : array_like
+        Array of points. The dtype is converted to float64 or complex128
+        depending on whether any of the elements are complex. If `x` is
+        scalar it is converted to a 1-D array.
+    deg : int
+        Degree of the resulting matrix.
+
+    Returns
+    -------
+    vander : ndarray
+        The pseudo Vandermonde matrix. The shape of the returned matrix is
+        ``x.shape + (deg + 1,)``, where The last index is the degree of the
+        corresponding Chebyshev polynomial.  The dtype will be the same as
+        the converted `x`.
+
+    """
+    ideg = pu._deprecate_as_int(deg, "deg")
+    if ideg < 0:
+        raise ValueError("deg must be non-negative")
+
+    x = np.array(x, copy=False, ndmin=1) + 0.0
+    dims = (ideg + 1,) + x.shape
+    dtyp = x.dtype
+    v = np.empty(dims, dtype=dtyp)
+    # Use forward recursion to generate the entries.
+    v[0] = x*0 + 1
+    if ideg > 0:
+        x2 = 2*x
+        v[1] = x
+        for i in range(2, ideg + 1):
+            v[i] = v[i-1]*x2 - v[i-2]
+    return np.moveaxis(v, 0, -1)
+
+
+def chebvander2d(x, y, deg):
+    """Pseudo-Vandermonde matrix of given degrees.
+
+    Returns the pseudo-Vandermonde matrix of degrees `deg` and sample
+    points `(x, y)`. The pseudo-Vandermonde matrix is defined by
+
+    .. math:: V[..., (deg[1] + 1)*i + j] = T_i(x) * T_j(y),
+
+    where `0 <= i <= deg[0]` and `0 <= j <= deg[1]`. The leading indices of
+    `V` index the points `(x, y)` and the last index encodes the degrees of
+    the Chebyshev polynomials.
+
+    If ``V = chebvander2d(x, y, [xdeg, ydeg])``, then the columns of `V`
+    correspond to the elements of a 2-D coefficient array `c` of shape
+    (xdeg + 1, ydeg + 1) in the order
+
+    .. math:: c_{00}, c_{01}, c_{02} ... , c_{10}, c_{11}, c_{12} ...
+
+    and ``np.dot(V, c.flat)`` and ``chebval2d(x, y, c)`` will be the same
+    up to roundoff. This equivalence is useful both for least squares
+    fitting and for the evaluation of a large number of 2-D Chebyshev
+    series of the same degrees and sample points.
+
+    Parameters
+    ----------
+    x, y : array_like
+        Arrays of point coordinates, all of the same shape. The dtypes
+        will be converted to either float64 or complex128 depending on
+        whether any of the elements are complex. Scalars are converted to
+        1-D arrays.
+    deg : list of ints
+        List of maximum degrees of the form [x_deg, y_deg].
+
+    Returns
+    -------
+    vander2d : ndarray
+        The shape of the returned matrix is ``x.shape + (order,)``, where
+        :math:`order = (deg[0]+1)*(deg[1]+1)`.  The dtype will be the same
+        as the converted `x` and `y`.
+
+    See Also
+    --------
+    chebvander, chebvander3d, chebval2d, chebval3d
+
+    Notes
+    -----
+
+    .. versionadded:: 1.7.0
+
+    """
+    return pu._vander_nd_flat((chebvander, chebvander), (x, y), deg)
+
+
+def chebvander3d(x, y, z, deg):
+    """Pseudo-Vandermonde matrix of given degrees.
+
+    Returns the pseudo-Vandermonde matrix of degrees `deg` and sample
+    points `(x, y, z)`. If `l, m, n` are the given degrees in `x, y, z`,
+    then The pseudo-Vandermonde matrix is defined by
+
+    .. math:: V[..., (m+1)(n+1)i + (n+1)j + k] = T_i(x)*T_j(y)*T_k(z),
+
+    where `0 <= i <= l`, `0 <= j <= m`, and `0 <= j <= n`.  The leading
+    indices of `V` index the points `(x, y, z)` and the last index encodes
+    the degrees of the Chebyshev polynomials.
+
+    If ``V = chebvander3d(x, y, z, [xdeg, ydeg, zdeg])``, then the columns
+    of `V` correspond to the elements of a 3-D coefficient array `c` of
+    shape (xdeg + 1, ydeg + 1, zdeg + 1) in the order
+
+    .. math:: c_{000}, c_{001}, c_{002},... , c_{010}, c_{011}, c_{012},...
+
+    and ``np.dot(V, c.flat)`` and ``chebval3d(x, y, z, c)`` will be the
+    same up to roundoff. This equivalence is useful both for least squares
+    fitting and for the evaluation of a large number of 3-D Chebyshev
+    series of the same degrees and sample points.
+
+    Parameters
+    ----------
+    x, y, z : array_like
+        Arrays of point coordinates, all of the same shape. The dtypes will
+        be converted to either float64 or complex128 depending on whether
+        any of the elements are complex. Scalars are converted to 1-D
+        arrays.
+    deg : list of ints
+        List of maximum degrees of the form [x_deg, y_deg, z_deg].
+
+    Returns
+    -------
+    vander3d : ndarray
+        The shape of the returned matrix is ``x.shape + (order,)``, where
+        :math:`order = (deg[0]+1)*(deg[1]+1)*(deg[2]+1)`.  The dtype will
+        be the same as the converted `x`, `y`, and `z`.
+
+    See Also
+    --------
+    chebvander, chebvander3d, chebval2d, chebval3d
+
+    Notes
+    -----
+
+    .. versionadded:: 1.7.0
+
+    """
+    return pu._vander_nd_flat((chebvander, chebvander, chebvander), (x, y, z), deg)
+
+
+def chebfit(x, y, deg, rcond=None, full=False, w=None):
+    """
+    Least squares fit of Chebyshev series to data.
+
+    Return the coefficients of a Chebyshev series of degree `deg` that is the
+    least squares fit to the data values `y` given at points `x`. If `y` is
+    1-D the returned coefficients will also be 1-D. If `y` is 2-D multiple
+    fits are done, one for each column of `y`, and the resulting
+    coefficients are stored in the corresponding columns of a 2-D return.
+    The fitted polynomial(s) are in the form
+
+    .. math::  p(x) = c_0 + c_1 * T_1(x) + ... + c_n * T_n(x),
+
+    where `n` is `deg`.
+
+    Parameters
+    ----------
+    x : array_like, shape (M,)
+        x-coordinates of the M sample points ``(x[i], y[i])``.
+    y : array_like, shape (M,) or (M, K)
+        y-coordinates of the sample points. Several data sets of sample
+        points sharing the same x-coordinates can be fitted at once by
+        passing in a 2D-array that contains one dataset per column.
+    deg : int or 1-D array_like
+        Degree(s) of the fitting polynomials. If `deg` is a single integer,
+        all terms up to and including the `deg`'th term are included in the
+        fit. For NumPy versions >= 1.11.0 a list of integers specifying the
+        degrees of the terms to include may be used instead.
+    rcond : float, optional
+        Relative condition number of the fit. Singular values smaller than
+        this relative to the largest singular value will be ignored. The
+        default value is len(x)*eps, where eps is the relative precision of
+        the float type, about 2e-16 in most cases.
+    full : bool, optional
+        Switch determining nature of return value. When it is False (the
+        default) just the coefficients are returned, when True diagnostic
+        information from the singular value decomposition is also returned.
+    w : array_like, shape (`M`,), optional
+        Weights. If not None, the weight ``w[i]`` applies to the unsquared
+        residual ``y[i] - y_hat[i]`` at ``x[i]``. Ideally the weights are
+        chosen so that the errors of the products ``w[i]*y[i]`` all have the
+        same variance.  When using inverse-variance weighting, use
+        ``w[i] = 1/sigma(y[i])``.  The default value is None.
+
+        .. versionadded:: 1.5.0
+
+    Returns
+    -------
+    coef : ndarray, shape (M,) or (M, K)
+        Chebyshev coefficients ordered from low to high. If `y` was 2-D,
+        the coefficients for the data in column k  of `y` are in column
+        `k`.
+
+    [residuals, rank, singular_values, rcond] : list
+        These values are only returned if ``full == True``
+
+        - residuals -- sum of squared residuals of the least squares fit
+        - rank -- the numerical rank of the scaled Vandermonde matrix
+        - singular_values -- singular values of the scaled Vandermonde matrix
+        - rcond -- value of `rcond`.
+
+        For more details, see `numpy.linalg.lstsq`.
+
+    Warns
+    -----
+    RankWarning
+        The rank of the coefficient matrix in the least-squares fit is
+        deficient. The warning is only raised if ``full == False``.  The
+        warnings can be turned off by
+
+        >>> import warnings
+        >>> warnings.simplefilter('ignore', np.RankWarning)
+
+    See Also
+    --------
+    numpy.polynomial.polynomial.polyfit
+    numpy.polynomial.legendre.legfit
+    numpy.polynomial.laguerre.lagfit
+    numpy.polynomial.hermite.hermfit
+    numpy.polynomial.hermite_e.hermefit
+    chebval : Evaluates a Chebyshev series.
+    chebvander : Vandermonde matrix of Chebyshev series.
+    chebweight : Chebyshev weight function.
+    numpy.linalg.lstsq : Computes a least-squares fit from the matrix.
+    scipy.interpolate.UnivariateSpline : Computes spline fits.
+
+    Notes
+    -----
+    The solution is the coefficients of the Chebyshev series `p` that
+    minimizes the sum of the weighted squared errors
+
+    .. math:: E = \\sum_j w_j^2 * |y_j - p(x_j)|^2,
+
+    where :math:`w_j` are the weights. This problem is solved by setting up
+    as the (typically) overdetermined matrix equation
+
+    .. math:: V(x) * c = w * y,
+
+    where `V` is the weighted pseudo Vandermonde matrix of `x`, `c` are the
+    coefficients to be solved for, `w` are the weights, and `y` are the
+    observed values.  This equation is then solved using the singular value
+    decomposition of `V`.
+
+    If some of the singular values of `V` are so small that they are
+    neglected, then a `RankWarning` will be issued. This means that the
+    coefficient values may be poorly determined. Using a lower order fit
+    will usually get rid of the warning.  The `rcond` parameter can also be
+    set to a value smaller than its default, but the resulting fit may be
+    spurious and have large contributions from roundoff error.
+
+    Fits using Chebyshev series are usually better conditioned than fits
+    using power series, but much can depend on the distribution of the
+    sample points and the smoothness of the data. If the quality of the fit
+    is inadequate splines may be a good alternative.
+
+    References
+    ----------
+    .. [1] Wikipedia, "Curve fitting",
+           https://en.wikipedia.org/wiki/Curve_fitting
+
+    Examples
+    --------
+
+    """
+    return pu._fit(chebvander, x, y, deg, rcond, full, w)
+
+
+def chebcompanion(c):
+    """Return the scaled companion matrix of c.
+
+    The basis polynomials are scaled so that the companion matrix is
+    symmetric when `c` is a Chebyshev basis polynomial. This provides
+    better eigenvalue estimates than the unscaled case and for basis
+    polynomials the eigenvalues are guaranteed to be real if
+    `numpy.linalg.eigvalsh` is used to obtain them.
+
+    Parameters
+    ----------
+    c : array_like
+        1-D array of Chebyshev series coefficients ordered from low to high
+        degree.
+
+    Returns
+    -------
+    mat : ndarray
+        Scaled companion matrix of dimensions (deg, deg).
+
+    Notes
+    -----
+
+    .. versionadded:: 1.7.0
+
+    """
+    # c is a trimmed copy
+    [c] = pu.as_series([c])
+    if len(c) < 2:
+        raise ValueError('Series must have maximum degree of at least 1.')
+    if len(c) == 2:
+        return np.array([[-c[0]/c[1]]])
+
+    n = len(c) - 1
+    mat = np.zeros((n, n), dtype=c.dtype)
+    scl = np.array([1.] + [np.sqrt(.5)]*(n-1))
+    top = mat.reshape(-1)[1::n+1]
+    bot = mat.reshape(-1)[n::n+1]
+    top[0] = np.sqrt(.5)
+    top[1:] = 1/2
+    bot[...] = top
+    mat[:, -1] -= (c[:-1]/c[-1])*(scl/scl[-1])*.5
+    return mat
+
+
+def chebroots(c):
+    """
+    Compute the roots of a Chebyshev series.
+
+    Return the roots (a.k.a. "zeros") of the polynomial
+
+    .. math:: p(x) = \\sum_i c[i] * T_i(x).
+
+    Parameters
+    ----------
+    c : 1-D array_like
+        1-D array of coefficients.
+
+    Returns
+    -------
+    out : ndarray
+        Array of the roots of the series. If all the roots are real,
+        then `out` is also real, otherwise it is complex.
+
+    See Also
+    --------
+    numpy.polynomial.polynomial.polyroots
+    numpy.polynomial.legendre.legroots
+    numpy.polynomial.laguerre.lagroots
+    numpy.polynomial.hermite.hermroots
+    numpy.polynomial.hermite_e.hermeroots
+
+    Notes
+    -----
+    The root estimates are obtained as the eigenvalues of the companion
+    matrix, Roots far from the origin of the complex plane may have large
+    errors due to the numerical instability of the series for such
+    values. Roots with multiplicity greater than 1 will also show larger
+    errors as the value of the series near such points is relatively
+    insensitive to errors in the roots. Isolated roots near the origin can
+    be improved by a few iterations of Newton's method.
+
+    The Chebyshev series basis polynomials aren't powers of `x` so the
+    results of this function may seem unintuitive.
+
+    Examples
+    --------
+    >>> import numpy.polynomial.chebyshev as cheb
+    >>> cheb.chebroots((-1, 1,-1, 1)) # T3 - T2 + T1 - T0 has real roots
+    array([ -5.00000000e-01,   2.60860684e-17,   1.00000000e+00]) # may vary
+
+    """
+    # c is a trimmed copy
+    [c] = pu.as_series([c])
+    if len(c) < 2:
+        return np.array([], dtype=c.dtype)
+    if len(c) == 2:
+        return np.array([-c[0]/c[1]])
+
+    # rotated companion matrix reduces error
+    m = chebcompanion(c)[::-1,::-1]
+    r = la.eigvals(m)
+    r.sort()
+    return r
+
+
+def chebinterpolate(func, deg, args=()):
+    """Interpolate a function at the Chebyshev points of the first kind.
+
+    Returns the Chebyshev series that interpolates `func` at the Chebyshev
+    points of the first kind in the interval [-1, 1]. The interpolating
+    series tends to a minmax approximation to `func` with increasing `deg`
+    if the function is continuous in the interval.
+
+    .. versionadded:: 1.14.0
+
+    Parameters
+    ----------
+    func : function
+        The function to be approximated. It must be a function of a single
+        variable of the form ``f(x, a, b, c...)``, where ``a, b, c...`` are
+        extra arguments passed in the `args` parameter.
+    deg : int
+        Degree of the interpolating polynomial
+    args : tuple, optional
+        Extra arguments to be used in the function call. Default is no extra
+        arguments.
+
+    Returns
+    -------
+    coef : ndarray, shape (deg + 1,)
+        Chebyshev coefficients of the interpolating series ordered from low to
+        high.
+
+    Examples
+    --------
+    >>> import numpy.polynomial.chebyshev as C
+    >>> C.chebfromfunction(lambda x: np.tanh(x) + 0.5, 8)
+    array([  5.00000000e-01,   8.11675684e-01,  -9.86864911e-17,
+            -5.42457905e-02,  -2.71387850e-16,   4.51658839e-03,
+             2.46716228e-17,  -3.79694221e-04,  -3.26899002e-16])
+
+    Notes
+    -----
+
+    The Chebyshev polynomials used in the interpolation are orthogonal when
+    sampled at the Chebyshev points of the first kind. If it is desired to
+    constrain some of the coefficients they can simply be set to the desired
+    value after the interpolation, no new interpolation or fit is needed. This
+    is especially useful if it is known apriori that some of coefficients are
+    zero. For instance, if the function is even then the coefficients of the
+    terms of odd degree in the result can be set to zero.
+
+    """
+    deg = np.asarray(deg)
+
+    # check arguments.
+    if deg.ndim > 0 or deg.dtype.kind not in 'iu' or deg.size == 0:
+        raise TypeError("deg must be an int")
+    if deg < 0:
+        raise ValueError("expected deg >= 0")
+
+    order = deg + 1
+    xcheb = chebpts1(order)
+    yfunc = func(xcheb, *args)
+    m = chebvander(xcheb, deg)
+    c = np.dot(m.T, yfunc)
+    c[0] /= order
+    c[1:] /= 0.5*order
+
+    return c
+
+
+def chebgauss(deg):
+    """
+    Gauss-Chebyshev quadrature.
+
+    Computes the sample points and weights for Gauss-Chebyshev quadrature.
+    These sample points and weights will correctly integrate polynomials of
+    degree :math:`2*deg - 1` or less over the interval :math:`[-1, 1]` with
+    the weight function :math:`f(x) = 1/\\sqrt{1 - x^2}`.
+
+    Parameters
+    ----------
+    deg : int
+        Number of sample points and weights. It must be >= 1.
+
+    Returns
+    -------
+    x : ndarray
+        1-D ndarray containing the sample points.
+    y : ndarray
+        1-D ndarray containing the weights.
+
+    Notes
+    -----
+
+    .. versionadded:: 1.7.0
+
+    The results have only been tested up to degree 100, higher degrees may
+    be problematic. For Gauss-Chebyshev there are closed form solutions for
+    the sample points and weights. If n = `deg`, then
+
+    .. math:: x_i = \\cos(\\pi (2 i - 1) / (2 n))
+
+    .. math:: w_i = \\pi / n
+
+    """
+    ideg = pu._deprecate_as_int(deg, "deg")
+    if ideg <= 0:
+        raise ValueError("deg must be a positive integer")
+
+    x = np.cos(np.pi * np.arange(1, 2*ideg, 2) / (2.0*ideg))
+    w = np.ones(ideg)*(np.pi/ideg)
+
+    return x, w
+
+
+def chebweight(x):
+    """
+    The weight function of the Chebyshev polynomials.
+
+    The weight function is :math:`1/\\sqrt{1 - x^2}` and the interval of
+    integration is :math:`[-1, 1]`. The Chebyshev polynomials are
+    orthogonal, but not normalized, with respect to this weight function.
+
+    Parameters
+    ----------
+    x : array_like
+       Values at which the weight function will be computed.
+
+    Returns
+    -------
+    w : ndarray
+       The weight function at `x`.
+
+    Notes
+    -----
+
+    .. versionadded:: 1.7.0
+
+    """
+    w = 1./(np.sqrt(1. + x) * np.sqrt(1. - x))
+    return w
+
+
+def chebpts1(npts):
+    """
+    Chebyshev points of the first kind.
+
+    The Chebyshev points of the first kind are the points ``cos(x)``,
+    where ``x = [pi*(k + .5)/npts for k in range(npts)]``.
+
+    Parameters
+    ----------
+    npts : int
+        Number of sample points desired.
+
+    Returns
+    -------
+    pts : ndarray
+        The Chebyshev points of the first kind.
+
+    See Also
+    --------
+    chebpts2
+
+    Notes
+    -----
+
+    .. versionadded:: 1.5.0
+
+    """
+    _npts = int(npts)
+    if _npts != npts:
+        raise ValueError("npts must be integer")
+    if _npts < 1:
+        raise ValueError("npts must be >= 1")
+
+    x = 0.5 * np.pi / _npts * np.arange(-_npts+1, _npts+1, 2)
+    return np.sin(x)
+
+
+def chebpts2(npts):
+    """
+    Chebyshev points of the second kind.
+
+    The Chebyshev points of the second kind are the points ``cos(x)``,
+    where ``x = [pi*k/(npts - 1) for k in range(npts)]`` sorted in ascending
+    order.
+
+    Parameters
+    ----------
+    npts : int
+        Number of sample points desired.
+
+    Returns
+    -------
+    pts : ndarray
+        The Chebyshev points of the second kind.
+
+    Notes
+    -----
+
+    .. versionadded:: 1.5.0
+
+    """
+    _npts = int(npts)
+    if _npts != npts:
+        raise ValueError("npts must be integer")
+    if _npts < 2:
+        raise ValueError("npts must be >= 2")
+
+    x = np.linspace(-np.pi, 0, _npts)
+    return np.cos(x)
+
+
+#
+# Chebyshev series class
+#
+
+class Chebyshev(ABCPolyBase):
+    """A Chebyshev series class.
+
+    The Chebyshev class provides the standard Python numerical methods
+    '+', '-', '*', '//', '%', 'divmod', '**', and '()' as well as the
+    methods listed below.
+
+    Parameters
+    ----------
+    coef : array_like
+        Chebyshev coefficients in order of increasing degree, i.e.,
+        ``(1, 2, 3)`` gives ``1*T_0(x) + 2*T_1(x) + 3*T_2(x)``.
+    domain : (2,) array_like, optional
+        Domain to use. The interval ``[domain[0], domain[1]]`` is mapped
+        to the interval ``[window[0], window[1]]`` by shifting and scaling.
+        The default value is [-1, 1].
+    window : (2,) array_like, optional
+        Window, see `domain` for its use. The default value is [-1, 1].
+
+        .. versionadded:: 1.6.0
+    symbol : str, optional
+        Symbol used to represent the independent variable in string
+        representations of the polynomial expression, e.g. for printing.
+        The symbol must be a valid Python identifier. Default value is 'x'.
+
+        .. versionadded:: 1.24
+
+    """
+    # Virtual Functions
+    _add = staticmethod(chebadd)
+    _sub = staticmethod(chebsub)
+    _mul = staticmethod(chebmul)
+    _div = staticmethod(chebdiv)
+    _pow = staticmethod(chebpow)
+    _val = staticmethod(chebval)
+    _int = staticmethod(chebint)
+    _der = staticmethod(chebder)
+    _fit = staticmethod(chebfit)
+    _line = staticmethod(chebline)
+    _roots = staticmethod(chebroots)
+    _fromroots = staticmethod(chebfromroots)
+
+    @classmethod
+    def interpolate(cls, func, deg, domain=None, args=()):
+        """Interpolate a function at the Chebyshev points of the first kind.
+
+        Returns the series that interpolates `func` at the Chebyshev points of
+        the first kind scaled and shifted to the `domain`. The resulting series
+        tends to a minmax approximation of `func` when the function is
+        continuous in the domain.
+
+        .. versionadded:: 1.14.0
+
+        Parameters
+        ----------
+        func : function
+            The function to be interpolated. It must be a function of a single
+            variable of the form ``f(x, a, b, c...)``, where ``a, b, c...`` are
+            extra arguments passed in the `args` parameter.
+        deg : int
+            Degree of the interpolating polynomial.
+        domain : {None, [beg, end]}, optional
+            Domain over which `func` is interpolated. The default is None, in
+            which case the domain is [-1, 1].
+        args : tuple, optional
+            Extra arguments to be used in the function call. Default is no
+            extra arguments.
+
+        Returns
+        -------
+        polynomial : Chebyshev instance
+            Interpolating Chebyshev instance.
+
+        Notes
+        -----
+        See `numpy.polynomial.chebfromfunction` for more details.
+
+        """
+        if domain is None:
+            domain = cls.domain
+        xfunc = lambda x: func(pu.mapdomain(x, cls.window, domain), *args)
+        coef = chebinterpolate(xfunc, deg)
+        return cls(coef, domain=domain)
+
+    # Virtual properties
+    domain = np.array(chebdomain)
+    window = np.array(chebdomain)
+    basis_name = 'T'

venv/lib/python3.10/site-packages/numpy/polynomial/chebyshev.pyi

@@ -0,0 +1,51 @@
+from typing import Any
+
+from numpy import ndarray, dtype, int_
+from numpy.polynomial._polybase import ABCPolyBase
+from numpy.polynomial.polyutils import trimcoef
+
+__all__: list[str]
+
+chebtrim = trimcoef
+
+def poly2cheb(pol): ...
+def cheb2poly(c): ...
+
+chebdomain: ndarray[Any, dtype[int_]]
+chebzero: ndarray[Any, dtype[int_]]
+chebone: ndarray[Any, dtype[int_]]
+chebx: ndarray[Any, dtype[int_]]
+
+def chebline(off, scl): ...
+def chebfromroots(roots): ...
+def chebadd(c1, c2): ...
+def chebsub(c1, c2): ...
+def chebmulx(c): ...
+def chebmul(c1, c2): ...
+def chebdiv(c1, c2): ...
+def chebpow(c, pow, maxpower=...): ...
+def chebder(c, m=..., scl=..., axis=...): ...
+def chebint(c, m=..., k = ..., lbnd=..., scl=..., axis=...): ...
+def chebval(x, c, tensor=...): ...
+def chebval2d(x, y, c): ...
+def chebgrid2d(x, y, c): ...
+def chebval3d(x, y, z, c): ...
+def chebgrid3d(x, y, z, c): ...
+def chebvander(x, deg): ...
+def chebvander2d(x, y, deg): ...
+def chebvander3d(x, y, z, deg): ...
+def chebfit(x, y, deg, rcond=..., full=..., w=...): ...
+def chebcompanion(c): ...
+def chebroots(c): ...
+def chebinterpolate(func, deg, args = ...): ...
+def chebgauss(deg): ...
+def chebweight(x): ...
+def chebpts1(npts): ...
+def chebpts2(npts): ...
+
+class Chebyshev(ABCPolyBase):
+    @classmethod
+    def interpolate(cls, func, deg, domain=..., args = ...): ...
+    domain: Any
+    window: Any
+    basis_name: Any