Spaces:
Sleeping
Sleeping
import torch | |
import random | |
from masking_methods import MaskingProcessor | |
class SamplingProcessor: | |
def __init__(self, tokenizer): | |
self.tokenizer = tokenizer | |
def fill_masked_sentence(self, original_sentence, mask_logits, sampling_technique, temperature=1.0): | |
""" | |
Fills each mask in the masked sentence using the specified sampling technique. | |
Args: | |
original_sentence (str): The original masked sentence. | |
mask_logits (dict): Logits for each [MASK] token. | |
sampling_technique (str): Sampling technique to use (e.g., "inverse_transform", "exponential_minimum", "temperature", "greedy"). | |
temperature (float): Temperature parameter for sampling methods. | |
Returns: | |
str: Sentence with the masks filled. | |
""" | |
sentence_tokens = self.tokenizer.tokenize(original_sentence) | |
mask_token_indices = [i for i, token in enumerate(sentence_tokens) if token == self.tokenizer.mask_token] | |
if len(mask_token_indices) != len(mask_logits): | |
raise ValueError("Mismatch between number of [MASK] tokens and logits provided.") | |
for mask_idx, filtered_logits in zip(mask_token_indices, mask_logits.values()): | |
# Convert logits to a tensor | |
filtered_logits = torch.tensor(filtered_logits) | |
# filtered_logits, _ = torch.sort(filtered_logits, descending=True) | |
# print(f' type of filtered_logits : {type(filtered_logits)}') | |
# filtered_logits = filtered_logits[:5] | |
if sampling_technique == "inverse_transform": | |
probs = torch.softmax(filtered_logits / temperature, dim=-1) | |
cumulative_probs = torch.cumsum(probs, dim=-1) | |
random_prob = random.random() | |
sampled_index = torch.where(cumulative_probs >= random_prob)[0][0].item() | |
elif sampling_technique == "exponential_minimum": | |
probs = torch.softmax(filtered_logits / temperature, dim=-1) | |
exp_probs = torch.exp(-torch.log(probs)) | |
random_probs = torch.rand_like(exp_probs) | |
sampled_index = torch.argmax(random_probs * exp_probs).item() | |
elif sampling_technique == "temperature": | |
filtered_logits = torch.clamp(filtered_logits, min=-1e8, max=1e8) | |
probs = torch.softmax(filtered_logits / temperature, dim=-1) | |
if torch.any(torch.isnan(probs)) or torch.any(torch.isinf(probs)): | |
raise ValueError("The computed probabilities contain NaN or inf values.") | |
probs = torch.max(probs, torch.tensor(1e-8, device=filtered_logits.device)) | |
probs = probs / torch.sum(probs) | |
probs = probs.flatten() | |
if probs.size(0) > 1: | |
sampled_index = torch.multinomial(probs, 1).item() | |
else: | |
sampled_index = torch.argmax(probs).item() | |
elif sampling_technique == 'greedy': | |
sampled_index = torch.argmax(filtered_logits).item() | |
else: | |
raise ValueError(f"Unknown sampling technique: {sampling_technique}") | |
sampled_token = self.tokenizer.convert_ids_to_tokens([sampled_index])[0] | |
sentence_tokens[mask_idx] = sampled_token | |
return self.tokenizer.convert_tokens_to_string(sentence_tokens) | |
def process_samples(self, masked_sentences, mask_logits, sampling_technique, temperature=1.0): | |
""" | |
Process multiple masked sentences and fill their masks using the specified sampling technique. | |
Args: | |
masked_sentences (list): List of masked sentences. | |
mask_logits (dict): Logits for each [MASK] token in each sentence. | |
sampling_technique (str): Sampling technique to use. | |
temperature (float): Temperature parameter for sampling methods. | |
Returns: | |
list: List of sentences with masks filled. | |
""" | |
filled_sentences = [] | |
for sentence, logits in zip(masked_sentences, mask_logits): | |
filled_sentence = self.fill_masked_sentence(sentence, logits, sampling_technique, temperature) | |
filled_sentences.append(filled_sentence) | |
return filled_sentences | |
# Example usage | |
if __name__ == "__main__": | |
from transformers import BertTokenizer | |
# tokenizer = BertTokenizer.from_pretrained("bert-large-cased-whole-word-masking") | |
tokenizer = BertTokenizer.from_pretrained("bert-base-uncased") | |
processor = SamplingProcessor(tokenizer) | |
sentences = [ | |
"The quick brown fox jumps over the lazy dog.", | |
"A quick brown dog outpaces a lazy fox.", | |
"Quick brown dog leaps over lazy the fox." | |
] | |
result_dict = { | |
"The quick brown fox jumps over the lazy dog.": {'quick brown': [(0, 1)], 'fox': [(2, 2)], 'lazy': [(4, 4)], 'dog': [(5, 5)]}, | |
"A quick brown dog outpaces a lazy fox.": {'quick brown': [(0, 1)], 'fox': [(5, 5)], 'lazy': [(4, 4)], 'dog': [(2, 2)]}, | |
"Quick brown dog leaps over lazy the fox.": {'quick brown': [(0, 1)], 'fox': [(5, 5)], 'lazy': [(4, 4)], 'dog': [(2, 2)]} | |
} | |
masking_processor = MaskingProcessor() | |
masking_results = masking_processor.process_sentences(sentences, result_dict, method="random", remove_stopwords=False) | |
# masked_sentence = "The [MASK] brown fox jumps [MASK] the lazy dog." | |
# mask_logits = { | |
# 1: torch.randn(len(tokenizer)), # Example logits for first [MASK] | |
# 5: torch.randn(len(tokenizer)), # Example logits for second [MASK] | |
# } | |
# Iterate through masking results to apply sampling | |
for sentence, result in masking_results.items(): | |
print(f"Original Sentence (Random): {sentence}") | |
print(f"Masked Sentence (Random): {result['masked_sentence']}") | |
# print(f"Mask Logits (Random): {output['mask_logits']}") | |
print(f' type(result["mask_logits"]) : {type(result["mask_logits"])}') | |
print(f' length of result["mask_logits"] : {len(result["mask_logits"])}') | |
print(f' result["mask_logits"].keys() : {result["mask_logits"].keys()}') | |
masked_sentence = result["masked_sentence"] | |
mask_logits = result["mask_logits"] | |
print(f"Original Masked Sentence: {masked_sentence}") | |
# Apply different sampling techniques | |
for technique in ["inverse_transform", "exponential_minimum", "temperature", "greedy"]: | |
print(f"Sampling Technique: {technique}") | |
# Fill the masks using the sampling processor | |
filled_sentence = processor.fill_masked_sentence( | |
original_sentence=masked_sentence, | |
mask_logits=mask_logits, | |
sampling_technique=technique, | |
temperature=1.0 # Adjust temperature as needed | |
) | |
print(f"Filled Sentence: {filled_sentence}\n") | |
print('--------------------------------') |