def fit(words, tags, labels, model, builders):
"""
compute joint error of the
:param words: list of indices
:param tags: list of indices
:param labels: index
:param model: current model to access parameters
:param builders: builder to create state combinations
:return: joint error
"""
# retrieve model parameters
if MLP:
H = pycnn.parameter(pH)
O = pycnn.parameter(pO)
else:
O = pycnn.parameter(pO)
errs = []
for (forward_state, backward_state), tag in zip(build_tagging_graph(words, model, builders), tags):
f_b = pycnn.concatenate([forward_state, backward_state])
if MLP:
# TODO: add bias terms
r_t = O * (pycnn.tanh(H * f_b))
else:
r_t = O * f_b
err = pycnn.pickneglogsoftmax(r_t, tag)
errs.append(err)
return pycnn.esum(errs)
def calc_sentence_error(self, sentence):
word_expression_list = self._build_word_expression_list(sentence, is_train=True)
sentence_errors = []
for word, word_expression in zip(sentence, word_expression_list):
gold_label_index = self.tag_indexer.get_index(word.gold_label)
word_error = pickneglogsoftmax(word_expression, gold_label_index)
sentence_errors.append(word_error)
return esum(sentence_errors)
def calc_sentence_error(self, sentence):
word_expression_list = self._build_word_expression_list(sentence,
is_train=True)
sentence_errors = []
for word, word_expression in zip(sentence, word_expression_list):
gold_label_index = self.tag_indexer.get_index(word.gold_label)
word_error = pickneglogsoftmax(word_expression, gold_label_index)
sentence_errors.append(word_error)
return esum(sentence_errors)
def compute_loss(model, encoder_frnn, encoder_rrnn, decoder_rnn, lemma, feats,
word, alphabet_index, feat_index, feature_types):
pc.renew_cg()
# read the parameters
char_lookup = model["char_lookup"]
feat_lookup = model["feat_lookup"]
R = pc.parameter(model["R"])
bias = pc.parameter(model["bias"])
W_c = pc.parameter(model["W_c"])
W__a = pc.parameter(model["W__a"])
U__a = pc.parameter(model["U__a"])
v__a = pc.parameter(model["v__a"])
blstm_outputs = encode_chars(alphabet_index, char_lookup, encoder_frnn,
encoder_rrnn, lemma)
# initialize the decoder rnn
s_0 = decoder_rnn.initial_state()
s = s_0
# convert features to matching embeddings, if UNK handle properly
feats_input = encode_feats(feat_index, feat_lookup, feats, feature_types)
# set prev_output_vec for first lstm step as BEGIN_WORD
prev_output_vec = char_lookup[alphabet_index[BEGIN_WORD]]
loss = []
padded_word = word + END_WORD
# run the decoder through the output sequence and aggregate loss
for i, output_char in enumerate(padded_word):
# get current h of the decoder
s = s.add_input(pc.concatenate([prev_output_vec, feats_input]))
decoder_rnn_output = s.output()
attention_output_vector, alphas, W = task1_attention_implementation.attend(
blstm_outputs, decoder_rnn_output, W_c, v__a, W__a, U__a)
# compute output probabilities
# print 'computing readout layer...'
readout = R * attention_output_vector + bias
current_loss = pc.pickneglogsoftmax(readout,
alphabet_index[output_char])
# print 'computed readout layer'
loss.append(current_loss)
# prepare for the next iteration - "feedback"
prev_output_vec = char_lookup[alphabet_index[output_char]]
total_sequence_loss = pc.esum(loss)
# loss = average(loss)
return total_sequence_loss
def compute_loss(model, encoder_frnn, encoder_rrnn, decoder_rnn, lemma, feats, word, alphabet_index, feat_index,
feature_types):
pc.renew_cg()
# read the parameters
char_lookup = model["char_lookup"]
feat_lookup = model["feat_lookup"]
R = pc.parameter(model["R"])
bias = pc.parameter(model["bias"])
W_c = pc.parameter(model["W_c"])
W__a = pc.parameter(model["W__a"])
U__a = pc.parameter(model["U__a"])
v__a = pc.parameter(model["v__a"])
blstm_outputs = encode_chars(alphabet_index, char_lookup, encoder_frnn, encoder_rrnn, lemma)
# initialize the decoder rnn
s_0 = decoder_rnn.initial_state()
s = s_0
# convert features to matching embeddings, if UNK handle properly
feats_input = encode_feats(feat_index, feat_lookup, feats, feature_types)
# set prev_output_vec for first lstm step as BEGIN_WORD
prev_output_vec = char_lookup[alphabet_index[BEGIN_WORD]]
loss = []
padded_word = word + END_WORD
# run the decoder through the output sequence and aggregate loss
for i, output_char in enumerate(padded_word):
# get current h of the decoder
s = s.add_input(pc.concatenate([prev_output_vec, feats_input]))
decoder_rnn_output = s.output()
attention_output_vector, alphas, W = task1_attention_implementation.attend(blstm_outputs, decoder_rnn_output,
W_c, v__a, W__a, U__a)
# compute output probabilities
# print 'computing readout layer...'
readout = R * attention_output_vector + bias
current_loss = pc.pickneglogsoftmax(readout, alphabet_index[output_char])
# print 'computed readout layer'
loss.append(current_loss)
# prepare for the next iteration - "feedback"
prev_output_vec = char_lookup[alphabet_index[output_char]]
total_sequence_loss = pc.esum(loss)
# loss = average(loss)
return total_sequence_loss
def attend(model, vectors, state):
w = pc.parameter(model['attention_w'])
attention_weights = []
for vector in vectors:
#concatenate each encoded vector with the current decoder state
attention_input = pc.concatenate([vector, pc.concatenate(list(state.s()))])
#get the attention wieght for the decoded vector
attention_weights.append(w * attention_input)
#normalize the weights
attention_weights = pc.softmax(pc.concatenate(attention_weights))
#apply the weights
vectors = pc.esum([vector*attention_weight for vector, attention_weight in zip(vectors, attention_weights)])
return vectors
def attend(model, input_vectors, state):
w1 = pc.parameter(model['attention_w1'])
w2 = pc.parameter(model['attention_w2'])
v = pc.parameter(model['attention_v'])
attention_weights = []
w2dt = w2*pc.concatenate(list(state.s()))
for input_vector in input_vectors:
attention_weight = v*pc.tanh(w1*input_vector + w2dt)
attention_weights.append(attention_weight)
attention_weights = pc.softmax(pc.concatenate(attention_weights))
output_vectors = pc.esum([vector*attention_weight for vector, attention_weight in zip(input_vectors, attention_weights)])
return output_vectors
def attend(model, input_vectors, state):
w1 = pc.parameter(model['attention_w1'])
w2 = pc.parameter(model['attention_w2'])
v = pc.parameter(model['attention_v'])
attention_weights = []
w2dt = w2*pc.concatenate(list(state.s()))
for input_vector in input_vectors:
attention_weight = v*pc.tanh(w1*input_vector + w2dt)
attention_weights.append(attention_weight)
attention_weights = pc.softmax(pc.concatenate(attention_weights))
output_vectors = pc.esum([vector*attention_weight for vector, attention_weight in zip(input_vectors, attention_weights)])
return output_vectors
def fit(self, list_folders_name, num_iterations, train_algo, dev=None):
"""
train the tagger
"""
print("read training data",file=sys.stderr)
nb_tasks = len( list_folders_name )
train_X, train_Y, task_labels, w2i, c2i, task2t2i = self.get_train_data(list_folders_name)
## after calling get_train_data we have self.tasks_ids
self.task2layer = {task_id: out_layer for task_id, out_layer in zip(self.tasks_ids, self.pred_layer)}
print("task2layer", self.task2layer, file=sys.stderr)
# store mappings of words and tags to indices
self.set_indices(w2i,c2i,task2t2i)
# init lookup parameters and define graph
print("build graph",file=sys.stderr)
num_words = len(self.w2i)
num_chars = len(self.c2i)
assert(nb_tasks==len(self.pred_layer))
self.predictors, self.char_rnn, self.wembeds, self.cembeds = self.build_computation_graph(num_words, num_chars)
if train_algo == "sgd":
trainer = pycnn.SimpleSGDTrainer(self.model)
elif train_algo == "adam":
trainer = pycnn.AdamTrainer(self.model)
train_data = list(zip(train_X,train_Y, task_labels))
for iter in range(num_iterations):
total_loss=0.0
total_tagged=0.0
random.shuffle(train_data)
for ((word_indices,char_indices),y, task_of_instance) in train_data:
# use same predict function for training and testing
output = self.predict(word_indices, char_indices, task_of_instance, train=True)
loss1 = pycnn.esum([self.pick_neg_log(pred,gold) for pred, gold in zip(output, y)])
lv = loss1.value()
total_loss += lv
total_tagged += len(word_indices)
loss1.backward()
trainer.update()
print("iter {2} {0:>12}: {1:.2f}".format("total loss",total_loss/total_tagged,iter), file=sys.stderr)
def calc_sentence_error(self, sentence):
renew_cg()
for word in sentence:
# word.vector = noise(self._get_word_vector(word), 0.1)
word.vector = self._get_word_vector(word, use_dropout=True)
sentence_expressions = self._build_sentence_expressions(sentence)
sentence_errors = []
for word, word_expression in zip(sentence, sentence_expressions):
gold_label_index = self.tag_indexer.get_index(word.gold_label)
word_error = pickneglogsoftmax(word_expression, gold_label_index)
sentence_errors.append(word_error)
return esum(sentence_errors)
def calc_sentence_error(self, sentence):
renew_cg()
for word in sentence:
# word.vector = noise(self._get_word_vector(word), 0.1)
word.vector = self._get_word_vector(word, use_dropout=True)
sentence_expressions = self._build_sentence_expressions(sentence)
sentence_errors = []
for word, word_expression in zip(sentence, sentence_expressions):
gold_label_index = self.tag_indexer.get_index(word.gold_label)
word_error = pickneglogsoftmax(word_expression, gold_label_index)
sentence_errors.append(word_error)
return esum(sentence_errors)
def decode(model, dec_lstm, vectors, output):
output = [EOS] + list(output) + [EOS]
output = [char2int[c] for c in output]
w = pc.parameter(model["decoder_w"])
b = pc.parameter(model["decoder_b"])
s = dec_lstm.initial_state().add_input(pc.vecInput(STATE_SIZE * 2))
loss = []
for char in output:
vector = attend(model, vectors, s)
s = s.add_input(vector)
out_vector = w * s.output() + b
probs = pc.softmax(out_vector)
loss.append(-pc.log(pc.pick(probs, char)))
loss = pc.esum(loss)
return loss
def decode(model, dec_lstm, vectors, output):
output = [EOS] + list(output) + [EOS]
output = [char2int[c] for c in output]
w = pc.parameter(model["decoder_w"])
b = pc.parameter(model["decoder_b"])
s = dec_lstm.initial_state().add_input(pc.vecInput(STATE_SIZE*2))
loss = []
for char in output:
vector = attend(model, vectors, s)
s = s.add_input(vector)
out_vector = w * s.output() + b
probs = pc.softmax(out_vector)
loss.append(-pc.log(pc.pick(probs, char)))
loss = pc.esum(loss)
return loss
def train(
feature_mapper,
word_dims,
tag_dims,
lstm_units,
hidden_units,
epochs,
batch_size,
train_data_file,
dev_data_file,
model_save_file,
droprate,
unk_param,
alpha=1.0,
beta=0.0,
):
start_time = time.time()
fm = feature_mapper
word_count = fm.total_words()
tag_count = fm.total_tags()
network = Network(
word_count=word_count,
tag_count=tag_count,
word_dims=word_dims,
tag_dims=tag_dims,
lstm_units=lstm_units,
hidden_units=hidden_units,
struct_out=2,
label_out=fm.total_label_actions(),
droprate=droprate,
)
network.init_params()
print('Hidden units: {}, per-LSTM units: {}'.format(
hidden_units,
lstm_units,
))
print('Embeddings: word={} tag={}'.format(
(word_count, word_dims),
(tag_count, tag_dims),
))
print('Dropout rate: {}'.format(droprate))
print('Parameters initialized in [-0.01, 0.01]')
print('Random UNKing parameter z = {}'.format(unk_param))
print('Exploration: alpha={} beta={}'.format(alpha, beta))
training_data = fm.gold_data_from_file(train_data_file)
num_batches = -(-len(training_data) // batch_size)
print('Loaded {} training sentences ({} batches of size {})!'.format(
len(training_data),
num_batches,
batch_size,
))
parse_every = -(-num_batches // 4)
dev_trees = PhraseTree.load_treefile(dev_data_file)
print('Loaded {} validation trees!'.format(len(dev_trees)))
best_acc = FScore()
for epoch in xrange(1, epochs + 1):
print('........... epoch {} ...........'.format(epoch))
total_cost = 0.0
total_states = 0
training_acc = FScore()
np.random.shuffle(training_data)
for b in xrange(num_batches):
batch = training_data[(b * batch_size):((b + 1) * batch_size)]
explore = [
Parser.exploration(
example,
fm,
network,
alpha=alpha,
beta=beta,
) for example in batch
]
for (_, acc) in explore:
training_acc += acc
batch = [example for (example, _) in explore]
pycnn.renew_cg()
network.prep_params()
errors = []
for example in batch:
## random UNKing ##
for (i, w) in enumerate(example['w']):
if w <= 2:
continue
freq = fm.word_freq_list[w]
drop_prob = unk_param / (unk_param + freq)
r = np.random.random()
if r < drop_prob:
example['w'][i] = 0
fwd, back = network.evaluate_recurrent(
example['w'],
example['t'],
)
for (left,
right), correct in example['struct_data'].items():
scores = network.evaluate_struct(
fwd, back, left, right)
probs = pycnn.softmax(scores)
loss = -pycnn.log(pycnn.pick(probs, correct))
errors.append(loss)
total_states += len(example['struct_data'])
for (left,
right), correct in example['label_data'].items():
scores = network.evaluate_label(fwd, back, left, right)
probs = pycnn.softmax(scores)
loss = -pycnn.log(pycnn.pick(probs, correct))
errors.append(loss)
total_states += len(example['label_data'])
batch_error = pycnn.esum(errors)
total_cost += batch_error.scalar_value()
batch_error.backward()
network.trainer.update()
mean_cost = total_cost / total_states
print(
'\rBatch {} Mean Cost {:.4f} [Train: {}]'.format(
b,
mean_cost,
training_acc,
),
end='',
)
sys.stdout.flush()
if ((b + 1) % parse_every) == 0 or b == (num_batches - 1):
dev_acc = Parser.evaluate_corpus(
dev_trees,
fm,
network,
)
print(' [Val: {}]'.format(dev_acc))
if dev_acc > best_acc:
best_acc = dev_acc
network.save(model_save_file)
print(' [saved model: {}]'.format(model_save_file))
current_time = time.time()
runmins = (current_time - start_time) / 60.
print(' Elapsed time: {:.2f}m'.format(runmins))
def compute_loss(model, encoder_frnn, encoder_rrnn, decoder_rnn, lemma, feats,
word, alphabet_index, feat_index, feature_types, alignment):
pc.renew_cg()
# read the parameters
char_lookup = model["char_lookup"]
feat_lookup = model["feat_lookup"]
R = pc.parameter(model["R"])
bias = pc.parameter(model["bias"])
W_c = pc.parameter(model["W_c"])
W__a = pc.parameter(model["W__a"])
U__a = pc.parameter(model["U__a"])
v__a = pc.parameter(model["v__a"])
template = task1_ms2s.generate_template_from_alignment(alignment)
blstm_outputs = encode_chars(alphabet_index, char_lookup, encoder_frnn,
encoder_rrnn, lemma)
# initialize the decoder rnn
s_0 = decoder_rnn.initial_state()
s = s_0
# convert features to matching embeddings, if UNK handle properly
feats_input = encode_feats(feat_index, feat_lookup, feats, feature_types)
# set prev_output_vec for first lstm step as BEGIN_WORD
prev_output_vec = char_lookup[alphabet_index[BEGIN_WORD]]
prev_char_vec = char_lookup[alphabet_index[BEGIN_WORD]]
loss = []
padded_word = word + END_WORD
padded_template = template + [END_WORD]
# run the decoder through the output sequence and aggregate loss
for i, output_char in enumerate(padded_word):
# find all possible actions - copy from index, output specific character etc.
possible_outputs = list(set([padded_template[i]] + [output_char]))
# get current h of the decoder
s = s.add_input(
pc.concatenate([prev_output_vec, prev_char_vec, feats_input]))
decoder_rnn_output = s.output()
attention_output_vector, alphas, W = task1_attention_implementation.attend(
blstm_outputs, decoder_rnn_output, W_c, v__a, W__a, U__a)
# compute output probabilities
# print 'computing readout layer...'
readout = R * attention_output_vector + bias
# choose which feedback based on minimum neg. log likelihood: initialize with the character loss
min_neg_log_loss = pc.pickneglogsoftmax(readout,
alphabet_index[output_char])
prev_output_char = output_char
prev_output_action = output_char
for output in possible_outputs:
current_loss = pc.pickneglogsoftmax(readout,
alphabet_index[output])
# append the loss of all options
loss.append(current_loss)
if current_loss < min_neg_log_loss:
min_neg_log_loss = current_loss
prev_output_action = output
# prepare for the next iteration - "feedback"
prev_output_vec = char_lookup[alphabet_index[prev_output_action]]
prev_char_vec = char_lookup[alphabet_index[prev_output_char]]
total_sequence_loss = pc.esum(loss)
# loss = average(loss)
return total_sequence_loss
def compute_loss(model, encoder_frnn, encoder_rrnn, decoder_rnn, lemma, feats, word, alphabet_index, feat_index,
feature_types, alignment):
pc.renew_cg()
# read the parameters
char_lookup = model["char_lookup"]
feat_lookup = model["feat_lookup"]
R = pc.parameter(model["R"])
bias = pc.parameter(model["bias"])
W_c = pc.parameter(model["W_c"])
W__a = pc.parameter(model["W__a"])
U__a = pc.parameter(model["U__a"])
v__a = pc.parameter(model["v__a"])
template = task1_ms2s.generate_template_from_alignment(alignment)
blstm_outputs = task1_attention_implementation.encode_feats_and_chars(alphabet_index, char_lookup, encoder_frnn, encoder_rrnn, feat_index,
feat_lookup, feats, feature_types, lemma)
# initialize the decoder rnn
s_0 = decoder_rnn.initial_state()
s = s_0
# set prev_output_vec for first lstm step as BEGIN_WORD
prev_output_vec = char_lookup[alphabet_index[BEGIN_WORD]]
prev_char_vec = char_lookup[alphabet_index[BEGIN_WORD]]
loss = []
padded_word = word + END_WORD
padded_template = template + [END_WORD]
# run the decoder through the output sequence and aggregate loss
for i, output_char in enumerate(padded_word):
# find all possible actions - copy from index, output specific character etc.
possible_outputs = list(set([padded_template[i]]))# + [output_char]))
# get current h of the decoder
s = s.add_input(pc.concatenate([prev_output_vec, prev_char_vec]))
decoder_rnn_output = s.output()
attention_output_vector, alphas, W = task1_attention_implementation.attend(blstm_outputs, decoder_rnn_output,
W_c, v__a, W__a, U__a)
# compute output probabilities
# print 'computing readout layer...'
readout = R * attention_output_vector + bias
# choose which feedback based on minimum neg. log likelihood: initialize with the character loss
min_neg_log_loss = pc.pickneglogsoftmax(readout, alphabet_index[output_char])
prev_output_char = output_char
prev_output_action = output_char
for output in possible_outputs:
current_loss = pc.pickneglogsoftmax(readout, alphabet_index[output])
# append the loss of all options
loss.append(current_loss)
if current_loss < min_neg_log_loss:
min_neg_log_loss = current_loss
prev_output_action = output
# prepare for the next iteration - "feedback"
prev_output_vec = char_lookup[alphabet_index[prev_output_action]]
prev_char_vec = char_lookup[alphabet_index[prev_output_char]]
total_sequence_loss = pc.esum(loss)
# loss = average(loss)
return total_sequence_loss
