def m_step(self, all_word_paths):
# keep a dictionary of score-weighted pseudocounts of aligned elements
pseudocounts = {}
for word in all_word_paths:
# get the total score to scale the paths
# word_total_score = logSum([path.get_score() for path in word])
if not len(word):
continue
word_total_score = logSum([path[1] for path in word \
if not isinf(path[1])])
for path in word:
'''
path_elements = path.get_elements()
path_score = path.get_score()
'''
path_elements, path_score = path
path_score_scaled = path_score - word_total_score
for a_element, b_element in path_elements:
if a_element not in self.alignment_scores[-1]:
a_element = None
if a_element not in pseudocounts:
pseudocounts[a_element] = {}
if b_element not in pseudocounts[a_element] \
or isinf(pseudocounts[a_element][b_element]):
pseudocounts[a_element][b_element] = path_score_scaled
else:
pseudocounts[a_element][b_element] = \
logAdd(path_score_scaled,
pseudocounts[a_element][b_element])
self.pseudocounts.append(pseudocounts)
# rescale all the pseudocounts so they sum to 1
pseudoprobs = {}
for a_element in pseudocounts:
pseudoprobs[a_element] = {}
a_element_total = logSum([v for v in \
pseudocounts[a_element].values() \
if not isinf(v)])
for b_element in pseudocounts[a_element]:
b_element_pseudocount = pseudocounts[a_element][b_element]
if isinf(a_element_total):
b_element_prob = log(0)
else:
b_element_prob = b_element_pseudocount - a_element_total
pseudoprobs[a_element][b_element] = b_element_prob
return pseudoprobs
def m_step(self, all_word_paths):
# keep a dictionary of score-weighted pseudocounts of aligned elements
pseudocounts = {}
for word in all_word_paths:
# get the total score to scale the paths
# word_total_score = logSum([path.get_score() for path in word])
if not len(word):
continue
word_total_score = logSum([path[1] for path in word \
if not isinf(path[1])])
for path in word:
'''
path_elements = path.get_elements()
path_score = path.get_score()
'''
path_elements, path_score = path
path_score_scaled = path_score - word_total_score
for a_element, b_element in path_elements:
if a_element not in self.alignment_scores[-1]:
a_element = None
if a_element not in pseudocounts:
pseudocounts[a_element] = {}
if b_element not in pseudocounts[a_element] \
or isinf(pseudocounts[a_element][b_element]):
pseudocounts[a_element][b_element] = path_score_scaled
else:
pseudocounts[a_element][b_element] = \
logAdd(path_score_scaled,
pseudocounts[a_element][b_element])
self.pseudocounts.append(pseudocounts)
# rescale all the pseudocounts so they sum to 1
pseudoprobs = {}
for a_element in pseudocounts:
pseudoprobs[a_element] = {}
a_element_total = logSum([v for v in \
pseudocounts[a_element].values() \
if not isinf(v)])
for b_element in pseudocounts[a_element]:
b_element_pseudocount = pseudocounts[a_element][b_element]
if isinf(a_element_total):
b_element_prob = log(0)
else:
b_element_prob = b_element_pseudocount - a_element_total
pseudoprobs[a_element][b_element] = b_element_prob
return pseudoprobs
def convert_allowables(allowables, delete_prob, insert_prob):
""" convert a dict of {letter: phone} allowables to a
{letter : {phone : alignment_probability} dict """
alignment_scores = {}
for letter in allowables:
alignment_scores[letter] = {}
phones = allowables[letter]
phone_scores = []
for phone in phones:
score = 0
# penalize deletions
if phone is None:
score += log(delete_prob)
# really penalize insertions
if letter is None:
score += log(insert_prob)
phone_scores.append(score)
total_phone_scores = logSum(phone_scores)
for idx, score in enumerate(phone_scores):
alignment_scores[letter][phones[idx]] = score - total_phone_scores
return alignment_scores
def convert_allowables(allowables, delete_prob, insert_prob):
""" convert a dict of {letter: phone} allowables to a
{letter : {phone : alignment_probability} dict """
alignment_scores = {}
for letter in allowables:
alignment_scores[letter] = {}
phones = allowables[letter]
phone_scores = []
for phone in phones:
score = 0
# penalize deletions
if (phone is None):
score += log(delete_prob)
# really penalize insertions
if (letter is None):
score += log(insert_prob)
phone_scores.append(score)
total_phone_scores = logSum(phone_scores)
for idx, score in enumerate(phone_scores):
alignment_scores[letter][phones[idx]] = score - total_phone_scores
return alignment_scores