def update_batch(self, words_batch, tags_batch):
dynet.renew_cg()
length = max(len(words) for words in words_batch)
word_ids = np.zeros((length, len(words_batch)), dtype='int32')
for j, words in enumerate(words_batch):
for i, word in enumerate(words):
word_ids[i, j] = self.vw.w2i.get(word, self.UNK)
tag_ids = np.zeros((length, len(words_batch)), dtype='int32')
for j, tags in enumerate(tags_batch):
for i, tag in enumerate(tags):
tag_ids[i, j] = self.vt.w2i.get(tag, self.UNK)
wembs = [dynet.lookup_batch(self._E, word_ids[i]) for i in range(length)]
wembs = [dynet.noise(we, 0.1) for we in wembs]
f_state = self._fwd_lstm.initial_state()
b_state = self._bwd_lstm.initial_state()
fw = [x.output() for x in f_state.add_inputs(wembs)]
bw = [x.output() for x in b_state.add_inputs(reversed(wembs))]
H = dynet.parameter(self._pH)
O = dynet.parameter(self._pO)
errs = []
for i, (f, b) in enumerate(zip(fw, reversed(bw))):
f_b = dynet.concatenate([f,b])
r_t = O * (dynet.tanh(H * f_b))
err = dynet.pickneglogsoftmax_batch(r_t, tag_ids[i])
errs.append(dynet.sum_batches(err))
sum_errs = dynet.esum(errs)
squared = -sum_errs # * sum_errs
losses = sum_errs.scalar_value()
sum_errs.backward()
self._sgd.update()
return losses
def do_gpu(): G.renew_cg() W = G.parameter(gpW) W = W*W*W*W*W*W*W z = G.squared_distance(W,W) z.value() z.backward()
def predict_batch(self, words_batch):
dynet.renew_cg()
length = max(len(words) for words in words_batch)
word_ids = np.zeros((length, len(words_batch)), dtype='int32')
for j, words in enumerate(words_batch):
for i, word in enumerate(words):
word_ids[i, j] = self.vw.w2i.get(word, self.UNK)
wembs = [dynet.lookup_batch(self._E, word_ids[i]) for i in range(length)]
f_state = self._fwd_lstm.initial_state()
b_state = self._bwd_lstm.initial_state()
fw = [x.output() for x in f_state.add_inputs(wembs)]
bw = [x.output() for x in b_state.add_inputs(reversed(wembs))]
H = dynet.parameter(self._pH)
O = dynet.parameter(self._pO)
tags_batch = [[] for _ in range(len(words_batch))]
for i, (f, b) in enumerate(zip(fw, reversed(bw))):
r_t = O * (dynet.tanh(H * dynet.concatenate([f, b])))
out = dynet.softmax(r_t).npvalue()
for j in range(len(words_batch)):
tags_batch[j].append(self.vt.i2w[np.argmax(out.T[j])])
return tags_batch
def train(self, train_set_de, train_set_en, n_epochs):
batched_X_Y = minibatched_data(train_set_de, train_set_en, BATCH_SIZE)
for i in range(n_epochs):
random.shuffle(batched_X_Y)
j = 0
for batch in batched_X_Y:
j += BATCH_SIZE
batched_X = [x[0] for x in batch]
batched_Y = [x[1] for x in batch]
#print CURR_BATCH_SIZE, batched_X
dy.renew_cg()
enc_sentence, dec_sentence = batched_X, batched_Y
loss = self.get_loss(enc_sentence, dec_sentence, encoder_fwd_lstm, encoder_bwd_lstm, decoder_lstm)
loss_value = loss.value()
loss.backward()
trainer.update()
perplexity = np.exp(loss.value() * len(batched_Y) / float(sum([len(sent) for sent in batched_Y])) )
if j % 1000 == 0:
with codecs.open('models_batched/output_loss_samples.txt', 'a+') as open_file:
open_file.write("Epoch: " + str(i) + " Samples:" + str(j) + " LOSS: " + str(loss_value) + " Perplexity: " + str(perplexity) + "\n")
print ("Epoch: " + str(i) + " Samples:" + str(j) + " LOSS: " + str(loss_value) + " Perplexity: " + str(perplexity) )
#dy.renew_cg()
#open_file.write(self.generate(enc_sentence, encoder_fwd_lstm, encoder_bwd_lstm, decoder_lstm) + "\n")
#open_file.write("BLEU SCORE : " + str(self.calculate_bleu_score()) + "\n")
if j % 20000 == 0:
model.save('models_batched/model_'+str(i) + '_' + str(j), [encoder_fwd_lstm, encoder_bwd_lstm, decoder_lstm, input_lookup, output_lookup,
attention_w1, attention_w2, attention_v, decoder_w, decoder_b])
def get_loss(self, input_sentence, output_sentence, enc_fwd_lstm,
enc_bwd_lstm, dec_lstm):
dy.renew_cg()
embedded = self.embed_sentence(input_sentence)
encoded = self.encode_sentence(encoder_fwd_lstm, encoder_bwd_lstm,
embedded)
return self.decode(dec_lstm, encoded, output_sentence)
def calculate_bleu_score(self):
print "generating sentences"
with open("gen_e1k_18.txt", "w") as out:
for i, sent in enumerate(encoder_test_wids):
dy.renew_cg()
decoded_test_sent = self.generate(sent, enc_fwd_lstm, enc_bwd_lstm, dec_lstm)
out.write(decoded_test_sent + "\n")
def predictNextWord(sentence, builder, wlookup, mR, mB):
dy.renew_cg()
init_state = builder.initial_state()
R = dy.parameter(mR)
bias = dy.parameter(mB)
state = init_state
for cw in sentence:
# assume word is already a word-id
x_t = dy.lookup(wlookup, int(cw))
state = state.add_input(x_t)
y_t = state.output()
r_t = bias + (R * y_t)
prob = dy.softmax(r_t)
return prob
def encode_sentence(self, enc_fwd_lstm, enc_bwd_lstm, sentence):
dy.renew_cg()
enc_sents, _ = self.pad_zero(sentence)
sent_embed = self.embed_sentence(enc_sents)
sentrev_embed = sent_embed[::-1]
enc_fwd = enc_fwd_lstm.initial_state()
enc_bwd = enc_bwd_lstm.initial_state()
fwd_vectors = enc_fwd.transduce(sent_embed)
bwd_vectors = enc_bwd.transduce(sentrev_embed)
bwd_vectors = bwd_vectors[::-1]
vectors = [dy.concatenate(list(p)) for p in zip(fwd_vectors, bwd_vectors)]
return vectors
def calc_lm_loss(sents):
dy.renew_cg()
# parameters -> expressions
W_exp = dy.parameter(W_sm)
b_exp = dy.parameter(b_sm)
# initialize the RNN
f_init = RNN.initial_state()
# get the wids and masks for each step
tot_words = 0
wids = []
masks = []
for i in range(len(sents[0])):
wids.append([(vw.w2i[sent[i]] if len(sent) > i else STOP) for sent in sents])
mask = [(1 if len(sent) > i else 0) for sent in sents]
masks.append(mask)
tot_words += sum(mask)
# start the rnn by inputting "<start>"
init_ids = [START] * len(sents)
s = f_init.add_input(dy.lookup_batch(WORDS_LOOKUP, init_ids))
# feed word vectors into the RNN and predict the next word
losses = []
for wid, mask in zip(wids, masks):
# calculate the softmax and loss
score = W_exp * s.output() + b_exp
loss = dy.pickneglogsoftmax_batch(score, wid)
# mask the loss if at least one sentence is shorter
if mask[-1] != 1:
mask_expr = dy.inputVector(mask)
mask_expr = dy.reshape(mask_expr, (1,), MB_SIZE)
loss = loss * mask_expr
losses.append(loss)
# update the state of the RNN
wemb = dy.lookup_batch(WORDS_LOOKUP, wid)
s = s.add_input(wemb)
return dy.sum_batches(dy.esum(losses)), tot_words
def __call__(self, words):
dynet.renew_cg()
word_ids = [self.vw.w2i.get(w, self.UNK) for w in words]
wembs = [self._E[w] for w in word_ids]
f_state = self._fwd_lstm.initial_state()
b_state = self._bwd_lstm.initial_state()
fw = [x.output() for x in f_state.add_inputs(wembs)]
bw = [x.output() for x in b_state.add_inputs(reversed(wembs))]
H = dynet.parameter(self._pH)
O = dynet.parameter(self._pO)
tags = []
for i, (f, b) in enumerate(zip(fw, reversed(bw))):
r_t = O * (dynet.tanh(H * dynet.concatenate([f, b])))
out = dynet.softmax(r_t)
tags.append(self.vt.i2w[np.argmax(out.npvalue())])
return tags
def predict_emb(self, chars):
dy.renew_cg()
finit = self.char_fwd_lstm.initial_state()
binit = self.char_bwd_lstm.initial_state()
H = dy.parameter(self.lstm_to_rep_params)
Hb = dy.parameter(self.lstm_to_rep_bias)
O = dy.parameter(self.mlp_out)
Ob = dy.parameter(self.mlp_out_bias)
pad_char = self.c2i[PADDING_CHAR]
char_ids = [pad_char] + chars + [pad_char]
embeddings = [self.char_lookup[cid] for cid in char_ids]
bi_fwd_out = finit.transduce(embeddings)
bi_bwd_out = binit.transduce(reversed(embeddings))
rep = dy.concatenate([bi_fwd_out[-1], bi_bwd_out[-1]])
return O * dy.tanh(H * rep + Hb) + Ob
def generate(in_seq, enc_fwd_lstm, enc_bwd_lstm, dec_lstm): #print "in generate" dy.renew_cg() embedded = embed_sentence(in_seq) encoded = encode_batch(enc_fwd_lstm, enc_bwd_lstm, embedded) w = dy.parameter(decoder_w) b = dy.parameter(decoder_b) w1 = dy.parameter(attention_w1) input_mat = dy.concatenate_cols(encoded) w1dt = None last_output_embeddings = output_lookup[BOS] #s = dec_lstm.initial_state([encoded[-1]]) s = dec_lstm.initial_state() c_t_minus_1 = dy.vecInput(state_size*2) out = [] count_EOS = 0 for i in range(len(in_seq)*2): if count_EOS == 1: break # w1dt can be computed and cached once for the entire decoding phase w1dt = w1dt or w1 * input_mat vector = dy.concatenate([last_output_embeddings, c_t_minus_1]) s = s.add_input(vector) h_t = s.output() c_t = attend_batch(input_mat, s, w1dt, 1, 1) out_vector = dy.affine_transform([b, w, dy.concatenate([h_t, c_t])]) probs = dy.softmax(out_vector).vec_value() next_word = probs.index(max(probs)) last_output_embeddings = output_lookup[next_word] c_t_minus_1 = c_t if next_word == EOS: count_EOS += 1 continue out.append(english_word_vocab.i2w[next_word]) return " ".join(out[1:])
def __step_batch(self, batch):
dy.renew_cg()
W_y = dy.parameter(self.W_y)
b_y = dy.parameter(self.b_y)
F = len(batch[0][0])
num_words = F * len(batch)
src_batch = [x[0] for x in batch]
tgt_batch = [x[1] for x in batch]
src_rev_batch = [list(reversed(x)) for x in src_batch]
# batch = [ [a1,a2,a3,a4,a5], [b1,b2,b3,b4,b5], [c1,c2,c3,c4] ..]
# transpose the batch into
# src_cws: [[a1,b1,c1,..], [a2,b2,c2,..], .. [a5,b5,</S>]]
src_cws = map(list, zip(*src_batch)) # transpose
src_rev_cws = map(list, zip(*src_rev_batch))
# Bidirectional representations
l2r_state = self.l2r_builder.initial_state()
r2l_state = self.r2l_builder.initial_state()
l2r_contexts = []
r2l_contexts = []
for (cw_l2r_list, cw_r2l_list) in zip(src_cws, src_rev_cws):
l2r_state = l2r_state.add_input(
dy.lookup_batch(self.src_lookup, [
self.src_token_to_id.get(cw_l2r, 0)
for cw_l2r in cw_l2r_list
]))
r2l_state = r2l_state.add_input(
dy.lookup_batch(self.src_lookup, [
self.src_token_to_id.get(cw_r2l, 0)
for cw_r2l in cw_r2l_list
]))
l2r_contexts.append(
l2r_state.output()) #[<S>, x_1, x_2, ..., </S>]
r2l_contexts.append(
r2l_state.output()) #[</S> x_n, x_{n-1}, ... <S>]
r2l_contexts.reverse() #[<S>, x_1, x_2, ..., </S>]
# Combine the left and right representations for every word
h_fs = []
for (l2r_i, r2l_i) in zip(l2r_contexts, r2l_contexts):
h_fs.append(dy.concatenate([l2r_i, r2l_i]))
h_fs_matrix = dy.concatenate_cols(h_fs)
losses = []
# Decoder
# batch = [ [a1,a2,a3,a4,a5], [b1,b2,b3,b4,b5], [c1,c2,c3,c4] ..]
# transpose the batch into
# tgt_cws: [[a1,b1,c1,..], [a2,b2,c2,..], .. [a5,b5,</S>]]
# masks: [1,1,1,..], [1,1,1,..], ...[1,1,0,..]]
tgt_cws = []
masks = []
maxLen = max([len(l) for l in tgt_batch])
for i in range(maxLen):
tgt_cws.append([])
masks.append([])
for sentence in tgt_batch:
for j in range(maxLen):
if j > len(sentence) - 1:
tgt_cws[j].append('</S>')
masks[j].append(0)
else:
tgt_cws[j].append(sentence[j])
masks[j].append(1)
c_t = dy.vecInput(self.hidden_size * 2)
start = dy.concatenate(
[dy.lookup(self.tgt_lookup, self.tgt_token_to_id['<S>']), c_t])
dec_state = self.dec_builder.initial_state().add_input(start)
for (cws, nws, mask) in zip(tgt_cws, tgt_cws[1:], masks):
h_e = dec_state.output()
_, c_t = self.__attention_mlp(h_fs_matrix, h_e, F)
# Get the embedding for the current target word
embed_t = dy.lookup_batch(
self.tgt_lookup,
[self.tgt_token_to_id.get(cw, 0) for cw in cws])
# Create input vector to the decoder
x_t = dy.concatenate([embed_t, c_t])
dec_state = dec_state.add_input(x_t)
y_star = dy.affine_transform([b_y, W_y, dec_state.output()])
loss = dy.pickneglogsoftmax_batch(
y_star, [self.tgt_token_to_id.get(nw, 0) for nw in nws])
mask_exp = dy.reshape(dy.inputVector(mask), (1, ), len(mask))
loss = loss * mask_exp
losses.append(loss)
return dy.sum_batches(dy.esum(losses)), num_words
def get_batch_loss(input_sentences, output_sentences, enc_fwd_lstm, enc_bwd_lstm, dec_lstm): #print "in batch loss" dy.renew_cg() encoded_batch = encode_batch(enc_fwd_lstm, enc_bwd_lstm, input_sentences) return decode_batch(dec_lstm, encoded_batch, output_sentences)
def translate_sentence(self, sent):
dy.renew_cg()
W_y = dy.parameter(self.W_y)
b_y = dy.parameter(self.b_y)
F = len(sent)
sent_rev = list(reversed(sent))
# Bidirectional representations
l2r_state = self.l2r_builder.initial_state()
r2l_state = self.r2l_builder.initial_state()
l2r_contexts = []
r2l_contexts = []
for (cw_l2r, cw_r2l) in zip(sent, sent_rev):
l2r_state = l2r_state.add_input(
dy.lookup(self.src_lookup, self.src_token_to_id.get(cw_l2r,
0)))
r2l_state = r2l_state.add_input(
dy.lookup(self.src_lookup, self.src_token_to_id.get(cw_r2l,
0)))
l2r_contexts.append(
l2r_state.output()) #[<S>, x_1, x_2, ..., </S>]
r2l_contexts.append(
r2l_state.output()) #[</S> x_n, x_{n-1}, ... <S>]
r2l_contexts.reverse()
h_fs = []
for (l2r_i, r2l_i) in zip(l2r_contexts, r2l_contexts):
h_fs.append(dy.concatenate([l2r_i, r2l_i]))
h_fs_matrix = dy.concatenate_cols(h_fs)
# Decoder
trans_sentence = ['<S>']
cw = trans_sentence[-1]
c_t = dy.vecInput(l2r_contexts[0].npvalue().shape[0] * 2)
start = dy.concatenate(
[dy.lookup(self.tgt_lookup, self.tgt_token_to_id['<S>']), c_t])
dec_state = self.dec_builder.initial_state().add_input(start)
while len(trans_sentence) < MAX_LEN:
h_e = dec_state.output()
alignment, c_t = self.__attention_mlp(h_fs_matrix, h_e, F)
embed_t = dy.lookup(self.tgt_lookup,
self.tgt_token_to_id.get(cw, 0))
# Create input vector to the decoder
x_t = dy.concatenate([embed_t, c_t])
dec_state = dec_state.add_input(x_t)
y_star = dy.affine_transform([b_y, W_y, dec_state.output()])
cw = self.tgt_id_to_token[np.argmax(y_star.npvalue())]
if cw == '<unk>': #unknown words replacement
a = alignment.npvalue()
if np.argmax(a) == 0:
a[0] = 0
if np.argmax(a) == len(a) - 1:
a[len(a) - 1] = 0
trans_sentence.append(sent[np.argmax(a)])
continue
if cw == '</S>':
break
trans_sentence.append(cw)
return ' '.join(trans_sentence[1:])
def get_loss(input_sentence, output_sentence, enc_fwd_lstm, enc_bwd_lstm, dec_lstm):
dy.renew_cg()
embedded = embed_sentence(input_sentence)
encoded = encode_sentence(enc_fwd_lstm, enc_bwd_lstm, embedded)
#print "Encoded: ", encoded
return decode(dec_lstm, encoded, output_sentence)
def translate_sentence_beam_compact(self, sent, k=2):
dy.renew_cg()
F = len(sent)
W_y = dy.parameter(self.W_y)
b_y = dy.parameter(self.b_y)
sent_rev = list(reversed(sent))
# Bidirectional representations
l2r_state = self.l2r_builder.initial_state()
r2l_state = self.r2l_builder.initial_state()
l2r_contexts = []
r2l_contexts = []
for (cw_l2r, cw_r2l) in zip(sent, sent_rev):
l2r_state = l2r_state.add_input(
dy.lookup(self.src_lookup, self.src_token_to_id.get(cw_l2r,
0)))
r2l_state = r2l_state.add_input(
dy.lookup(self.src_lookup, self.src_token_to_id.get(cw_r2l,
0)))
l2r_contexts.append(
l2r_state.output()) #[<S>, x_1, x_2, ..., </S>]
r2l_contexts.append(
r2l_state.output()) #[</S> x_n, x_{n-1}, ... <S>]
r2l_contexts.reverse()
h_fs = []
for (l2r_i, r2l_i) in zip(l2r_contexts, r2l_contexts):
h_fs.append(dy.concatenate([l2r_i, r2l_i]))
h_fs_matrix = dy.concatenate_cols(h_fs)
valid = [True for i in range(k)]
trans = [['<S>'] for i in range(k)]
prob = [0 for i in range(k)]
used = [set([0, F - 1]) for i in range(k)]
cw = [trans[i][-1] for i in range(k)]
c_t = dy.vecInput(l2r_contexts[0].npvalue().shape[0] * 2)
start = dy.concatenate(
[dy.lookup(self.tgt_lookup, self.tgt_token_to_id['<S>']), c_t])
dec_state = [
self.dec_builder.initial_state().add_input(start) for i in range(k)
]
b = [i for i in range(k)]
FIRST = True
while True in valid:
h_e = [dec_state[i].output() for i in range(k)]
ac = [self.__attention_mlp(h_fs_matrix, elem, F) for elem in h_e]
alignment = [elem[0] for elem in ac]
c_t = [elem[1] for elem in ac]
embed_t = [
dy.lookup(self.tgt_lookup, self.tgt_token_to_id.get(cw[i], 0))
for i in range(k)
]
x_t = [dy.concatenate([embed_t[i], c_t[i]]) for i in range(k)]
dec_state = [dec_state[b[i]].add_input(x_t[i]) for i in range(k)]
y_star = [
dy.affine_transform([b_y, W_y, dec_state[i].output()])
for i in range(k)
]
p = [dy.log_softmax(y_star[i]) for i in range(k)]
tmp = [p[i].npvalue() for i in range(k)]
l = []
if not FIRST:
idx = [np.argpartition(-tmp[i].T, k)[0][:k] for i in range(k)]
val = [-np.partition(-tmp[i].T, k)[0][:k] for i in range(k)]
for i in range(k):
for j in range(k):
l.append((self.tgt_id_to_token[idx[i][j]],
val[i][j] + prob[i], i))
else:
idx = np.argpartition(-tmp[0].T, k)[0][:k]
val = -np.partition(-tmp[0].T, k)[0][:k]
FIRST = False
for i in range(k):
l.append((self.tgt_id_to_token[idx[i]], val[i], i))
l = sorted(l, key=lambda x: -x[1])[:k]
# print l
cw = [l[i][0] for i in range(k)]
prob = [l[i][1] for i in range(k)]
b = [l[i][2] for i in range(k)]
trans = [list(trans[b[i]]) for i in range(k)]
valid = [valid[b[i]] for i in range(k)]
for i in range(k):
if valid[i] == False: continue
if cw[i] != '</S>' and len(trans[i]) < MAX_LEN:
if cw[i] == '<unk>': #unknown words replacement
a = alignment[i].npvalue()
am = np.argmax(a)
while am in used:
a[am] = -1
am = np.argmax(a)
used[i].add(am)
if len(used[i]) == F / 2:
used[i] = set([0, F - 1])
trans[i].append(sent[am])
else:
trans[i].append(cw[i])
else:
valid[i] = False
index = prob.index(max(prob))
return ' '.join(trans[index][1:])
