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@ -10,12 +10,6 @@ import numpy as np
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vocab = ['-', '_', 'a']
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def ids_str2list(ids_str):
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ids_str = ids_str.split(' ')
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ids_list = [int(elem) for elem in ids_str]
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return ids_list
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def ids_list2str(ids_list):
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ids_str = [str(elem) for elem in ids_list]
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ids_str = ' '.join(ids_str)
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@ -39,21 +33,45 @@ def ctc_beam_search_decoder(input_probs_matrix,
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space_id=1,
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num_results_per_sample=None):
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'''
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beam search decoder for CTC-trained network, called outside of the recurrent group.
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adapted from Algorithm 1 in https://arxiv.org/abs/1408.2873.
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Beam search decoder for CTC-trained network, adapted from Algorithm 1
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in https://arxiv.org/abs/1408.2873.
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:param input_probs_matrix: probs matrix for input sequence, row major
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:type input_probs_matrix: 2D matrix.
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:param beam_size: width for beam search
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:type beam_size: int
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:max_time_steps: maximum steps' number for input sequence,
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<=len(input_probs_matrix)
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:type max_time_steps: int
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:lang_model: language model for scoring
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:type lang_model: function
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:param alpha: parameter associated with language model.
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:type alpha: float
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:param beta: parameter associated with word count
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:type beta: float
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:param blank_id: id of blank, default 0.
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:type blank_id: int
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:param space_id: id of space, default 1.
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:type space_id: int
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:param num_result_per_sample: the number of output decoding results
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per given sample, <=beam_size.
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:type num_result_per_sample: int
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'''
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param input_probs_matrix: probs matrix for input sequence, row major
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type input_probs_matrix: 2D matrix.
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param beam_size: width for beam search
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type beam_size: int
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max_time_steps: maximum steps' number for input sequence, <=len(input_probs_matrix)
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type max_time_steps: int
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lang_model: language model for scoring
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type lang_model: function
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# function to convert ids in string to list
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def ids_str2list(ids_str):
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ids_str = ids_str.split(' ')
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ids_list = [int(elem) for elem in ids_str]
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return ids_list
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......
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# counting words in a character list
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def word_count(ids_list):
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cnt = 0
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for elem in ids_list:
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if elem == space_id:
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cnt += 1
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return cnt
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'''
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if num_results_per_sample is None:
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num_results_per_sample = beam_size
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assert num_results_per_sample <= beam_size
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