def modified_recall(references, hypothesis, n):
"""
Calculate modified ngram recall.
:param references: A list of reference translations.
:type references: list(list(str))
:param hypothesis: A hypothesis translation.
:type hypothesis: list(str)
:param n: The ngram order.
:type n: int
:return: BLEU's modified precision for the nth order ngram.
:rtype: Fraction
"""
# Extracts all ngrams in hypothesis
# Set an empty Counter if hypothesis is empty.
# pdb.set_trace()
numerator = 0
denominator = 0
counts = Counter(ngrams(hypothesis, n)) if len(hypothesis) >= n else Counter()
# Extract a union of references' counts.
# max_counts = reduce(or_, [Counter(ngrams(ref, n)) for ref in references])
max_counts = {}
for reference_and_weights in references:
reference = reference_and_weights[0]
weights = reference_and_weights[1]
reference_counts = (
Counter(ngrams(reference, n)) if len(reference) >= n else Counter()
)
# for ngram in reference_counts:
# max_counts[ngram] = max(max_counts.get(ngram, 0), counts[ngram])
clipped_counts = {
ngram: min(count, counts[ngram]) for ngram, count in reference_counts.items()
}
# reweight
if n == 1 and len(weights) == len(reference_counts):
def weighted_sum(weights, counts):
sum_counts = 0
for ngram, count in counts.items():
sum_counts += count * (weights[ngram[0]] if ngram[0] in weights else 1)
return sum_counts
numerator += weighted_sum(weights, clipped_counts)
denominator += max(1, weighted_sum(weights, reference_counts))
else:
numerator += sum(clipped_counts.values())
denominator += max(1, sum(reference_counts.values()))
# # Assigns the intersection between hypothesis and references' counts.
# clipped_counts = {
# ngram: min(count, max_counts[ngram]) for ngram, count in counts.items()
# }
# numerator += sum(clipped_counts.values())
# # Ensures that denominator is minimum 1 to avoid ZeroDivisionError.
# # Usually this happens when the ngram order is > len(reference).
# denominator += max(1, sum(counts.values()))
#return Fraction(numerator, denominator, _normalize=False)
return numerator, denominator
def test_ngrams_padding_left():
text = 'hello'
assert [('h',), ('e',), ('l',), ('l',), ('o',)] == \
utils.ngrams(text, 1, padding_left=True)
assert [(utils.START, 'h'), ('h', 'e'), ('e', 'l'), ('l', 'l'),
('l', 'o')] == \
utils.ngrams(text, 2, padding_left=True)
assert [(utils.START, utils.START, 'h'), (utils.START, 'h', 'e'),
('h', 'e', 'l'), ('e', 'l', 'l'), ('l', 'l', 'o')] == \
utils.ngrams(text, 3, padding_left=True)
def test_ngrams_padding_right():
text = 'hello'
assert [('h',), ('e',), ('l',), ('l',), ('o',)] == \
utils.ngrams(text, 1, padding_right=True)
assert [('h', 'e'), ('e', 'l'), ('l', 'l'), ('l', 'o'),
('o', utils.END)] == \
utils.ngrams(text, 2, padding_right=True)
assert [('h', 'e', 'l'), ('e', 'l', 'l'), ('l', 'l', 'o'),
('l', 'o', utils.END), ('o', utils.END, utils.END)] == \
utils.ngrams(text, 3, padding_right=True)
def test_ngrams_padding_left():
text = 'hello'
assert [('h',), ('e',), ('l',), ('l',), ('o',)] == \
utils.ngrams(text, 1, padding_left=True)
assert [(utils.START, 'h'), ('h', 'e'), ('e', 'l'), ('l', 'l'),
('l', 'o')] == \
utils.ngrams(text, 2, padding_left=True)
assert [(utils.START, utils.START, 'h'), (utils.START, 'h', 'e'),
('h', 'e', 'l'), ('e', 'l', 'l'), ('l', 'l', 'o')] == \
utils.ngrams(text, 3, padding_left=True)
def test_ngrams_padding_right():
text = 'hello'
assert [('h',), ('e',), ('l',), ('l',), ('o',)] == \
utils.ngrams(text, 1, padding_right=True)
assert [('h', 'e'), ('e', 'l'), ('l', 'l'), ('l', 'o'),
('o', utils.END)] == \
utils.ngrams(text, 2, padding_right=True)
assert [('h', 'e', 'l'), ('e', 'l', 'l'), ('l', 'l', 'o'),
('l', 'o', utils.END), ('o', utils.END, utils.END)] == \
utils.ngrams(text, 3, padding_right=True)
def generate_batch_text_grams(self):
start = self.start
end = self.end
self.texts_train = np.array([])
self.labels_train = np.array([])
data_split = self.ids[start:end]
for i in range(0, len(data_split)):
ids_index = data_split[i][0].split(" ")
id = int(ids_index[0])
index = int(ids_index[1])
labels = self.labels[index][0]
split_labels = labels.split(" ")
labels_temp = np.zeros(config.label_size)
for j in range(1, len(split_labels)):
try:
label_index = utils.find_label_index(split_labels[j])
labels_temp[label_index] = 1.0
except ValueError:
print("Not have label: ", split_labels[j])
self.labels_train = np.append(self.labels_train, labels_temp)
text_name = str(id) + "newsML.xml"
reuters = et.parse("data/rcv1-2/train-text/" + text_name,
et.XMLParser(encoding='ISO-8859-1')).getroot()
temp_text = ""
for text in reuters.findall("title"):
#print(text.text)
temp_text = temp_text + text.text #.replace(" ", "")
for text in reuters.findall("text"):
for p in text.findall("p"):
temp_text = temp_text + p.text #.replace(" ", "").replace("\t","")
#print("ID TExt: ", id)
temp_text = utils.ngrams(temp_text)
self.texts_train = np.append(self.texts_train, temp_text)
def compute_counts(self, sentences, targets):
"""
Load text and estimate parameters for bigram HMM
:param path: path to data file
"""
for i in range(len(sentences)):
# When at the end of a sentence
# update counts
words = sentences[i]
tags = targets[i]
for i in range(len(tags)):
self.emission_counts[(words[i],
tags[i])] = self.emission_counts.get(
(words[i], tags[i]), 0.0) + 1
# Adding start to have estimate for P(t_i|START) usually denote pi
pos_bigrams = ngrams(['<START>'] + tags, r=2, pad=False)
for gram in pos_bigrams.values():
# Update unigram counts
if len(gram) == 1:
self.pos_unigram_counts[
gram[0]] = self.pos_unigram_counts.get(gram[0],
0.0) + 1
else:
self.transition_counts[gram] = self.transition_counts.get(
gram, 0.0) + 1
def method6(self, p_n, references, hypothesis, hyp_len=None, *args, **kwargs):
"""
Smoothing method 6:
Interpolates the maximum likelihood estimate of the precision *p_n* with
a prior estimate *pi0*. The prior is estimated by assuming that the ratio
between pn and pn−1 will be the same as that between pn−1 and pn−2; from
Gao and He (2013) Training MRF-Based Phrase Translation Models using
Gradient Ascent. In NAACL.
"""
hyp_len = hyp_len if hyp_len else len(hypothesis)
# This smoothing only works when p_1 and p_2 is non-zero.
# Raise an error with an appropriate message when the input is too short
# to use this smoothing technique.
assert p_n[2], "This smoothing method requires non-zero precision for bigrams."
for i, p_i in enumerate(p_n):
if i in [0, 1]: # Skips the first 2 orders of ngrams.
continue
else:
pi0 = 0 if p_n[i - 2] == 0 else p_n[i - 1] ** 2 / p_n[i - 2]
# No. of ngrams in translation that matches the reference.
m = p_i.numerator
# No. of ngrams in translation.
l = sum(1 for _ in ngrams(hypothesis, i + 1))
# Calculates the interpolated precision.
p_n[i] = (m + self.alpha * pi0) / (l + self.alpha)
return p_n
def test_ngrams_simple():
text = 'hello'
assert [('h',), ('e',), ('l',), ('l',), ('o',)] == utils.ngrams(text, 1)
assert [('h', 'e'), ('e', 'l'), ('l', 'l'), ('l', 'o')] == \
utils.ngrams(text, 2)
assert [('h', 'e', 'l'), ('e', 'l', 'l'), ('l', 'l', 'o')] == \
utils.ngrams(text, 3)
text2 = 'hello world'
assert [('h',), ('e',), ('l',), ('l',), ('o',), (' ',), ('w',), ('o',),
('r',), ('l',), ('d',)] == \
utils.ngrams(text2, 1)
assert [('h', 'e'), ('e', 'l'), ('l', 'l'), ('l', 'o'), ('o', ' '),
(' ', 'w'), ('w', 'o'), ('o', 'r'), ('r', 'l'), ('l', 'd')] == \
utils.ngrams(text2, 2)
def _score_compression(abs_list, doc_list, hyp_labels):
abs_tokens = flatten(abs_list)
doc_tokens = []
assert len(doc_list) == len(hyp_labels)
for (sent, mask) in zip(doc_list, hyp_labels):
assert len(sent) == len(mask)
for (token, label) in zip(sent, mask):
if label == 0:
doc_tokens.append(token)
doc_tokens = _preprocess(doc_tokens)
doc_uni = set(ngrams(doc_tokens, 1))
doc_bi = set(ngrams(doc_tokens, 2))
rouge1 = compute_rouge(doc_uni, _abs_uni)
rouge2 = compute_rouge(doc_bi, _abs_bi)
return (rouge1, rouge2)
def greedy_search(abs_list, doc_list, budget=3):
def _rouge_clean(s):
return re.sub(r'[^a-zA-Z0-9 ]', '', s)
max_rouge = 0.0
abs_tokens = _rouge_clean(' '.join(flatten(abs_list))).split()
sents = [_rouge_clean(' '.join(sent)).split() for sent in doc_list]
hyp_unigrams = [ngrams(sent, 1) for sent in sents]
hyp_bigrams = [ngrams(sent, 2) for sent in sents]
ref_unigrams = ngrams(abs_tokens, 1)
ref_bigrams = ngrams(abs_tokens, 2)
selected_idxs = []
for _ in range(budget):
curr_max_rouge = max_rouge
curr_id = -1
for (i, sent) in enumerate(sents):
if i in selected_idxs:
continue
candidate_idxs = selected_idxs + [i]
candidate_unigrams = set.union(
*[set(hyp_unigrams[idx]) for idx in candidate_idxs])
candidate_bigrams = set.union(
*[set(hyp_bigrams[idx]) for idx in candidate_idxs])
rouge1 = approx_rouge(candidate_unigrams, ref_unigrams)
rouge2 = approx_rouge(candidate_bigrams, ref_bigrams)
rouge_score = rouge1 + rouge2
if rouge_score > curr_max_rouge:
curr_max_rouge = rouge_score
curr_id = i
if curr_id == -1:
return (list(sorted(selected_idxs)), max_rouge)
selected_idxs.append(curr_id)
max_rouge = curr_max_rouge
return (list(sorted(selected_idxs)), max_rouge)
def test_ngrams_simple():
text = 'hello'
assert [('h', ), ('e', ), ('l', ), ('l', ),
('o', )] == utils.ngrams(text, 1)
assert [('h', 'e'), ('e', 'l'), ('l', 'l'), ('l', 'o')] == \
utils.ngrams(text, 2)
assert [('h', 'e', 'l'), ('e', 'l', 'l'), ('l', 'l', 'o')] == \
utils.ngrams(text, 3)
text2 = 'hello world'
assert [('h',), ('e',), ('l',), ('l',), ('o',), (' ',), ('w',), ('o',),
('r',), ('l',), ('d',)] == \
utils.ngrams(text2, 1)
assert [('h', 'e'), ('e', 'l'), ('l', 'l'), ('l', 'o'), ('o', ' '),
(' ', 'w'), ('w', 'o'), ('o', 'r'), ('r', 'l'), ('l', 'd')] == \
utils.ngrams(text2, 2)
def preprocess_data(dataset,
embeddings_path,
topn,
min_cos_sim):
path = './' + dataset.dataset_name + '/examples/'
embeddings = load_embeddings(embeddings_path)
# Training part
examples = set((ngram, ngram[1]) for sentence in dataset.get_train_sentences for ngram in ngrams(sentence) if ngram[1] in embeddings)
save_examples(examples, path, 'examples')
# examples = load_examples(path+'examples.pkl')
na_dataset = PerClassDataset(examples)
# Validation part
valid_examples = set((ngram, ngram[1]) for sentence in dataset.get_valid_sentences for ngram in ngrams(sentence) if ngram[1] not in na_dataset and ngram[1] in embeddings)
save_examples(valid_examples, path, 'valid_examples')
valid_dataset = PerClassDataset(valid_examples)
tr_val_dataset = na_dataset | valid_dataset
# Test part
test_examples = set((ngram, ngram[1]) for sentence in dataset.get_test_sentences for ngram in ngrams(
sentence) if ngram[1] not in tr_val_dataset and ngram[1] in embeddings)
save_examples(test_examples, path, 'test_examples')
test_dataset = PerClassDataset(test_examples)
# valid_examples = load_examples(path+'valid_examples.pkl')
# test_examples = load_examples(path+'test_examples.pkl')
save_examples(test_examples | valid_examples, path, 'valid_test_examples')
# OOV part
all_sentences = dataset.get_train_sentences + dataset.get_valid_sentences + dataset.get_test_sentences
oov_examples = set((ngram, ngram[1]) for sentence in all_sentences for ngram in ngrams(sentence) if ngram[1] not in embeddings)
save_examples(oov_examples, path, 'oov_examples')
# Augmented part
all_dataset = tr_val_dataset | test_dataset
filter_cond = lambda label: label not in all_dataset
augmented_examples = augment_data(examples, embeddings_path, filter_cond=filter_cond, topn=topn, min_cos_sim=min_cos_sim)
augmented_examples |= examples # Union
save_examples(augmented_examples, path, 'augmented_examples_topn{topn}_cos_sim{cs}'.format(topn=topn, cs=min_cos_sim))
def get_mentions(dbr, question):
tris = str_to_trigrams_dict(dbr.lower())
sets = []
best_guess = MinStore()
current_mention = MentionSet()
for index, word in enumerate(question.split(' ')):
word_trigrams = ngrams(word.lower())
prob = overlap_trigrams_score(tris, word_trigrams)
if not current_mention.append(word, index, prob):
mention = MentionSet(mention=[word], indexes=[index], prob=prob)
best_guess.store(mention, prob)
if not current_mention.is_empty():
sets.append(current_mention)
current_mention = MentionSet()
if not current_mention.is_empty():
sets.append(current_mention)
if len(sets) == 0:
# no match found, best guess time
best_guess = best_guess.get_item()
sets = [best_guess]
return sets
def character_based_4gram(text):
return utils.ngrams(text, 4, padding_left=True, padding_right=True)
def character_based_4gram(text):
return utils.ngrams(text,
n,
padding_left=padding,
padding_right=padding)
def trigram_overlap(x, y):
x_tri = ngrams(x, 3)
y_tri = ngrams(y, 3)
return any(_y_tri in x_tri for _y_tri in y_tri)
def test(test_dataset):
model.load_state_dict(torch.load(args.ckpt_path))
model.eval()
test_loader = tqdm(
load(test_dataset, args.batch_size, shuffle=False),
ncols=100,
)
true_list = []
pred_list = []
avgs = []
with torch.no_grad():
for i, batch in enumerate(test_loader):
batch_probs = F.softmax(model(batch), 1)
batch_labels = batch['label_ids']
for j in range(batch_probs.size(0)):
probs = unpack(batch_probs[j, 1])
labels = unpack(batch_labels[j])
_probs = []
for (prob, label) in zip(probs, labels):
if label != -1:
true_list.append(label)
pred_list.append(prob)
_probs.append(prob)
abs_list = test_dataset.abs_lists[i][0]
doc_list = test_dataset.doc_lists[i][0]
node_list = test_dataset.node_lists[i]
pred_label_list = [0] * len(doc_list)
opt_nodes = []
for (node, prob) in zip(node_list, _probs):
if prob > 0.7:
for optnode in node_list:
if optnode['group'] == node['group']:
opt_nodes.append(optnode)
for kk in range(node['start_index'],
node['end_index']):
pred_label_list[kk] = 1
for node in optnodes:
for kk in range(node['start_index'], node['end_index']):
pred_label_list[kk] = 1
words = [
word for (word, lab) in zip(doc_list, pred_label_list)
if lab == 0
]
abs_ngrams = set(ngrams(abs_list, 1))
doc_ngrams = set(ngrams(words, 1))
rouge = compute_rouge(abs_ngrams, doc_ngrams)
avgs.append(rouge)
results_dict = {'F1': np.mean(avgs)}
return results_dict
def modified_precision(references, hypothesis, n):
"""
Calculate modified ngram precision.
The normal precision method may lead to some wrong translations with
high-precision, e.g., the translation, in which a word of reference
repeats several times, has very high precision.
This function only returns the Fraction object that contains the numerator
and denominator necessary to calculate the corpus-level precision.
To calculate the modified precision for a single pair of hypothesis and
references, cast the Fraction object into a float.
The famous "the the the ... " example shows that you can get BLEU precision
by duplicating high frequency words.
>>> reference1 = 'the cat is on the mat'.split()
>>> reference2 = 'there is a cat on the mat'.split()
>>> hypothesis1 = 'the the the the the the the'.split()
>>> references = [reference1, reference2]
>>> float(modified_precision(references, hypothesis1, n=1)) # doctest: +ELLIPSIS
0.2857...
In the modified n-gram precision, a reference word will be considered
exhausted after a matching hypothesis word is identified, e.g.
>>> reference1 = ['It', 'is', 'a', 'guide', 'to', 'action', 'that',
... 'ensures', 'that', 'the', 'military', 'will',
... 'forever', 'heed', 'Party', 'commands']
>>> reference2 = ['It', 'is', 'the', 'guiding', 'principle', 'which',
... 'guarantees', 'the', 'military', 'forces', 'always',
... 'being', 'under', 'the', 'command', 'of', 'the',
... 'Party']
>>> reference3 = ['It', 'is', 'the', 'practical', 'guide', 'for', 'the',
... 'army', 'always', 'to', 'heed', 'the', 'directions',
... 'of', 'the', 'party']
>>> hypothesis = 'of the'.split()
>>> references = [reference1, reference2, reference3]
>>> float(modified_precision(references, hypothesis, n=1))
1.0
>>> float(modified_precision(references, hypothesis, n=2))
1.0
An example of a normal machine translation hypothesis:
>>> hypothesis1 = ['It', 'is', 'a', 'guide', 'to', 'action', 'which',
... 'ensures', 'that', 'the', 'military', 'always',
... 'obeys', 'the', 'commands', 'of', 'the', 'party']
>>> hypothesis2 = ['It', 'is', 'to', 'insure', 'the', 'troops',
... 'forever', 'hearing', 'the', 'activity', 'guidebook',
... 'that', 'party', 'direct']
>>> reference1 = ['It', 'is', 'a', 'guide', 'to', 'action', 'that',
... 'ensures', 'that', 'the', 'military', 'will',
... 'forever', 'heed', 'Party', 'commands']
>>> reference2 = ['It', 'is', 'the', 'guiding', 'principle', 'which',
... 'guarantees', 'the', 'military', 'forces', 'always',
... 'being', 'under', 'the', 'command', 'of', 'the',
... 'Party']
>>> reference3 = ['It', 'is', 'the', 'practical', 'guide', 'for', 'the',
... 'army', 'always', 'to', 'heed', 'the', 'directions',
... 'of', 'the', 'party']
>>> references = [reference1, reference2, reference3]
>>> float(modified_precision(references, hypothesis1, n=1)) # doctest: +ELLIPSIS
0.9444...
>>> float(modified_precision(references, hypothesis2, n=1)) # doctest: +ELLIPSIS
0.5714...
>>> float(modified_precision(references, hypothesis1, n=2)) # doctest: +ELLIPSIS
0.5882352941176471
>>> float(modified_precision(references, hypothesis2, n=2)) # doctest: +ELLIPSIS
0.07692...
:param references: A list of reference translations.
:type references: list(list(str))
:param hypothesis: A hypothesis translation.
:type hypothesis: list(str)
:param n: The ngram order.
:type n: int
:return: BLEU's modified precision for the nth order ngram.
:rtype: Fraction
"""
# Extracts all ngrams in hypothesis
# Set an empty Counter if hypothesis is empty.
counts = Counter(ngrams(hypothesis, n)) if len(hypothesis) >= n else Counter()
# Extract a union of references' counts.
# max_counts = reduce(or_, [Counter(ngrams(ref, n)) for ref in references])
max_counts = {}
for reference in references:
reference_counts = (
Counter(ngrams(reference, n)) if len(reference) >= n else Counter()
)
for ngram in counts:
max_counts[ngram] = max(max_counts.get(ngram, 0), reference_counts[ngram])
# Assigns the intersection between hypothesis and references' counts.
clipped_counts = {
ngram: min(count, max_counts[ngram]) for ngram, count in counts.items()
}
numerator = sum(clipped_counts.values())
# Ensures that denominator is minimum 1 to avoid ZeroDivisionError.
# Usually this happens when the ngram order is > len(reference).
denominator = max(1, sum(counts.values()))
return Fraction(numerator, denominator, _normalize=False)
def eval_compressions(abs_list, doc_list, doc_compressions):
def _apply_compression(node, labels):
_labels = copy.deepcopy(labels)
for _i in range(node.start_index, node.end_index):
assert 0 <= node.sent_index <= len(_labels)
assert 0 <= _i <= len(_labels[node.sent_index])
_labels[node.sent_index][_i] = 1 # Delete
return _labels
def _preprocess(tokens):
return [_rouge_clean(token.lower()) for token in tokens]
def _score_compression(abs_list, doc_list, hyp_labels):
abs_tokens = flatten(abs_list)
doc_tokens = []
assert len(doc_list) == len(hyp_labels)
for (sent, mask) in zip(doc_list, hyp_labels):
assert len(sent) == len(mask)
for (token, label) in zip(sent, mask):
if label == 0:
doc_tokens.append(token)
doc_tokens = _preprocess(doc_tokens)
doc_uni = set(ngrams(doc_tokens, 1))
doc_bi = set(ngrams(doc_tokens, 2))
rouge1 = compute_rouge(doc_uni, _abs_uni)
rouge2 = compute_rouge(doc_bi, _abs_bi)
return (rouge1, rouge2)
_abs_tokens = _preprocess(flatten(abs_list))
_abs_uni = set(ngrams(_abs_tokens, 1))
_abs_bi = set(ngrams(_abs_tokens, 2))
compressions_list = []
doc_labels = [[0 for _ in range(len(sent))] for sent in doc_list]
base_rouge1, base_rouge2 = _score_compression(abs_list, doc_list,
doc_labels)
base_rouge = base_rouge1 + base_rouge2
for sent_compressions in doc_compressions:
for i, node in enumerate(sent_compressions):
if [node.sent_index, node.node_index] in compressions_list:
continue
hyp_labels = _apply_compression(node, doc_labels)
mod_rouge1, mod_rouge2 = _score_compression(
abs_list, doc_list, hyp_labels)
mod_rouge = mod_rouge1 + mod_rouge2
if mod_rouge > base_rouge:
compressions_list.append([node.sent_index, node.node_index])
# If a parent constituent gets deleted, then by definition, all child
# constituents must also be deleted.
for child_node in sent_compressions[i + 1:]:
if (node.start_index <= child_node.start_index
and child_node.end_index <= node.end_index):
compressions_list.append(
[child_node.sent_index, child_node.node_index])
return compressions_list
def character_based_4gram(text):
return utils.ngrams(text, n, padding_left=padding, padding_right=padding)
def character_based_4gram(text):
return utils.ngrams(text, 4, padding_left=True, padding_right=True)