def build_model(self):
# build index table
index_table = tf.contrib.lookup.index_table_from_file(
vocabulary_file=self.config.vocab_list,
num_oov_buckets=0,
default_value=0)
# get data iterator
self.data_iterator = self.data.get_data_iterator(index_table,
mode=self.mode)
# get inputs
with tf.variable_scope("inputs"):
# get next batch if there is no feeded data
next_batch = self.data_iterator.get_next()
self.input_queries = tf.placeholder_with_default(
next_batch["input_queries"], [None, self.config.max_length],
name="input_queries")
self.input_replies = tf.placeholder_with_default(
next_batch["input_replies"], [None, self.config.max_length],
name="input_replies")
self.query_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["query_lengths"]), [None],
name="query_lengths")
self.reply_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["reply_lengths"]), [None],
name="reply_lengths")
# get hyperparams
self.embed_dropout_keep_prob = tf.placeholder(
tf.float64, name="embed_dropout_keep_prob")
self.lstm_dropout_keep_prob = tf.placeholder(
tf.float32, name="lstm_dropout_keep_prob")
self.num_negative_samples = tf.placeholder(
tf.int32, name="num_negative_samples")
self.dense_dropout_keep_prob = tf.placeholder(
tf.float64, name="dense_dropout_keep_prob")
with tf.variable_scope("properties"):
# length properties
cur_batch_length = tf.shape(self.input_queries)[0]
query_max_length = tf.shape(self.input_queries)[1]
reply_max_length = tf.shape(self.input_replies)[1]
# learning rate and optimizer
learning_rate = tf.train.exponential_decay(
self.config.learning_rate,
self.global_step_tensor,
decay_steps=50000,
decay_rate=0.96)
self.optimizer = tf.train.AdamOptimizer(learning_rate)
# embedding layer
with tf.variable_scope("embedding"):
embeddings = tf.Variable(get_embeddings(
self.config.vocab_list, self.config.pretrained_embed_dir,
self.config.vocab_size, self.config.embed_dim),
trainable=True,
name="embeddings")
embeddings = tf.nn.dropout(embeddings,
keep_prob=self.embed_dropout_keep_prob,
noise_shape=[90000, 1])
queries_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_queries,
name="queries_embedded"))
replies_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_replies,
name="replies_embedded"))
# build LSTM layer
with tf.variable_scope("query_lstm_layer") as vs:
lstm_cell_fw = tf.nn.rnn_cell.LSTMCell(self.config.lstm_dim,
forget_bias=2.0,
use_peepholes=True,
state_is_tuple=True)
lstm_cell_fw = tf.contrib.rnn.DropoutWrapper(
lstm_cell_fw, input_keep_prob=self.lstm_dropout_keep_prob)
lstm_cell_bw = tf.nn.rnn_cell.LSTMCell(self.config.lstm_dim,
forget_bias=2.0,
use_peepholes=True,
state_is_tuple=True)
lstm_cell_bw = tf.contrib.rnn.DropoutWrapper(
lstm_cell_bw, input_keep_prob=self.lstm_dropout_keep_prob)
_, queries_encoded = tf.nn.bidirectional_dynamic_rnn(
cell_fw=lstm_cell_fw,
cell_bw=lstm_cell_bw,
inputs=queries_embedded,
sequence_length=self.query_lengths,
dtype=tf.float32)
self.queries_encoded = tf.cast(
tf.concat([queries_encoded[0].h, queries_encoded[1].h], 1),
tf.float64)
with tf.variable_scope("reply_lstm_layer") as vs:
lstm_cell_fw = tf.nn.rnn_cell.LSTMCell(self.config.lstm_dim,
forget_bias=2.0,
use_peepholes=True,
state_is_tuple=True,
reuse=tf.AUTO_REUSE)
lstm_cell_fw = tf.contrib.rnn.DropoutWrapper(
lstm_cell_fw, input_keep_prob=self.lstm_dropout_keep_prob)
lstm_cell_bw = tf.nn.rnn_cell.LSTMCell(self.config.lstm_dim,
forget_bias=2.0,
use_peepholes=True,
state_is_tuple=True,
reuse=tf.AUTO_REUSE)
lstm_cell_bw = tf.contrib.rnn.DropoutWrapper(
lstm_cell_bw, input_keep_prob=self.lstm_dropout_keep_prob)
_, replies_encoded = tf.nn.bidirectional_dynamic_rnn(
cell_fw=lstm_cell_fw,
cell_bw=lstm_cell_bw,
inputs=replies_embedded,
sequence_length=self.reply_lengths,
dtype=tf.float32)
self.replies_encoded = tf.cast(
tf.concat([replies_encoded[0].h, replies_encoded[1].h], 1),
tf.float64)
# build dense layer
with tf.variable_scope("dense_layer"):
M = tf.get_variable(
"M",
shape=[self.config.lstm_dim * 2, self.config.lstm_dim * 2],
initializer=tf.contrib.layers.xavier_initializer())
M = tf.nn.dropout(M, keep_prob=self.config.dense_dropout_keep_prob)
self.queries_transformed = tf.matmul(self.queries_encoded,
tf.cast(M, tf.float64))
with tf.variable_scope("sampling"):
self.distances = tf.matmul(self.queries_encoded,
self.replies_encoded,
transpose_b=True)
positive_mask = tf.reshape(tf.eye(cur_batch_length), [-1])
negative_mask = tf.reshape(
make_negative_mask(
self.distances,
method=self.config.negative_sampling,
num_negative_samples=self.num_negative_samples), [-1])
with tf.variable_scope("prediction"):
distances_flattened = tf.reshape(self.distances, [-1])
self.positive_logits = tf.gather(distances_flattened,
tf.where(positive_mask), 1)
self.negative_logits = tf.gather(distances_flattened,
tf.where(negative_mask), 1)
self.logits = tf.concat(
[self.positive_logits, self.negative_logits], axis=0)
self.labels = tf.concat([
tf.ones_like(self.positive_logits),
tf.zeros_like(self.negative_logits)
],
axis=0)
self.positive_probs = tf.sigmoid(self.positive_logits)
self.probs = tf.sigmoid(self.logits)
self.predictions = tf.cast(self.probs > 0.5, dtype=tf.int32)
with tf.variable_scope("loss"):
self.loss = tf.reduce_mean(
tf.nn.sigmoid_cross_entropy_with_logits(labels=self.labels,
logits=self.logits))
# gvs = self.optimizer.compute_gradients(self.loss)
# capped_gvs = [(tf.clip_by_norm(grad, 5), var) for grad, var in gvs]
# self.train_step = self.optimizer.apply_gradients(capped_gvs)
self.train_step = self.optimizer.minimize(self.loss)
with tf.variable_scope("score"):
correct_predictions = tf.equal(self.predictions,
tf.to_int32(self.labels))
self.accuracy = tf.reduce_mean(tf.cast(correct_predictions,
"float"),
name="accuracy")
def build_model(self):
# build index table
index_table = tf.contrib.lookup.index_table_from_file(
vocabulary_file=self.config.vocab_list,
num_oov_buckets=0,
default_value=0)
# get data iterator
self.data_iterator = self.data.get_data_iterator(index_table,
mode=self.mode)
# get inputs
with tf.variable_scope("inputs"):
# get next batch if there is no feeded data
next_batch = self.data_iterator.get_next()
self.input_queries = tf.placeholder_with_default(
next_batch["input_queries"], [None, self.config.max_length],
name="input_queries")
self.input_replies = tf.placeholder_with_default(
next_batch["input_replies"], [None, self.config.max_length],
name="input_replies")
self.query_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["query_lengths"]), [None],
name="query_lengths")
self.reply_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["reply_lengths"]), [None],
name="reply_lengths")
self.weak_distances = tf.placeholder(tf.float32, [None, None],
name="weak_distances")
# get hyperparams
self.embed_dropout_keep_prob = tf.placeholder(
tf.float32, name="embed_dropout_keep_prob")
self.lstm_dropout_keep_prob = tf.placeholder(
tf.float32, name="lstm_dropout_keep_prob")
self.num_negative_samples = tf.placeholder(
tf.int32, name="num_negative_samples")
self.add_echo = tf.placeholder(tf.bool, name="add_echo")
with tf.variable_scope("properties"):
# length properties
cur_batch_length = tf.shape(self.input_queries)[0]
query_max_length = tf.shape(self.input_queries)[1]
reply_max_length = tf.shape(self.input_replies)[1]
# learning rate and optimizer
# self.optimizer = tf.train.GradientDescentOptimizer(self.config.learning_rate) # delstm1024_nsrandom9_ws_sgd_lr1e-1
learning_rate = tf.train.exponential_decay(
self.config.learning_rate,
self.global_step_tensor,
decay_steps=50000,
decay_rate=0.96)
self.optimizer = tf.train.AdamOptimizer(
learning_rate) # delstm1024_nsrandom9_ws_adam_lr1e-3
# embedding layer
with tf.variable_scope("embedding"):
embeddings = tf.Variable(get_embeddings(
self.config.vocab_list, self.config.pretrained_embed_dir,
self.config.vocab_size, self.config.embed_dim),
trainable=True,
name="embeddings")
queries_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_queries,
name="queries_embedded"))
replies_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_replies,
name="replies_embedded"))
# build LSTM layer
with tf.variable_scope("lstm_layer") as vs:
query_lstm_cell = tf.nn.rnn_cell.LSTMCell(
self.config.lstm_dim,
forget_bias=2.0,
use_peepholes=True,
state_is_tuple=True,
# initializer=tf.orthogonal_initializer(),
)
query_lstm_cell = tf.contrib.rnn.DropoutWrapper(
query_lstm_cell, input_keep_prob=self.lstm_dropout_keep_prob)
reply_lstm_cell = tf.nn.rnn_cell.LSTMCell(
self.config.lstm_dim,
forget_bias=2.0,
use_peepholes=True,
state_is_tuple=True,
# initializer=tf.orthogonal_initializer(),
reuse=True)
reply_lstm_cell = tf.contrib.rnn.DropoutWrapper(
reply_lstm_cell, input_keep_prob=self.lstm_dropout_keep_prob)
_, queries_encoded = tf.nn.dynamic_rnn(
cell=query_lstm_cell,
inputs=queries_embedded,
sequence_length=tf.cast(self.query_lengths, tf.float32),
dtype=tf.float32,
)
_, replies_encoded = tf.nn.dynamic_rnn(
cell=reply_lstm_cell,
inputs=replies_embedded,
sequence_length=tf.cast(self.reply_lengths, tf.float32),
dtype=tf.float32,
)
self.queries_encoded = tf.cast(queries_encoded.h, tf.float64)
self.replies_encoded = tf.cast(replies_encoded.h, tf.float64)
# build dense layer
with tf.variable_scope("dense_layer"):
M = tf.get_variable(
"M",
shape=[self.config.lstm_dim, self.config.lstm_dim],
initializer=tf.initializers.truncated_normal())
self.queries_transformed = tf.matmul(self.queries_encoded,
tf.cast(M, tf.float64))
with tf.variable_scope("sampling"):
self.distances = tf.matmul(self.queries_transformed,
self.replies_encoded,
transpose_b=True)
positive_mask = tf.reshape(tf.eye(cur_batch_length), [-1])
negative_mask = tf.reshape(
make_negative_mask(
self.distances,
method=self.config.negative_sampling,
num_negative_samples=self.num_negative_samples), [-1])
candidates_mask = positive_mask + negative_mask
with tf.variable_scope("weak_supervision"):
self.weak_positives = tf.gather(
tf.reshape(self.weak_distances, [-1]), tf.where(positive_mask),
1)
self.weak_positives_tiled = tf.tile(self.weak_positives,
[1, cur_batch_length])
self.weak_distances_normalized = tf.maximum(
0.,
self.weak_distances * tf.reciprocal(self.weak_positives_tiled)
- 1)
with tf.variable_scope("prediction"):
distances_flattened = tf.reshape(self.distances, [-1])
self.positive_logits = tf.gather(distances_flattened,
tf.where(positive_mask), 1)
self.negative_logits = tf.gather(distances_flattened,
tf.where(negative_mask), 1)
self.positive_logits_tiled = tf.transpose(
tf.tile(self.positive_logits, [1, cur_batch_length]))
self.logits = tf.concat(
[self.positive_logits, self.negative_logits], axis=0)
self.labels = tf.concat([
tf.ones_like(self.positive_logits),
tf.zeros_like(self.negative_logits)
],
axis=0)
with tf.variable_scope("loss"):
self.supervised_distances = tf.maximum(
0.,
tf.to_float(self.distances) -
tf.to_float(self.positive_logits_tiled) +
self.weak_distances_normalized)
self.loss = tf.reduce_sum(
tf.gather(tf.reshape(self.supervised_distances, [-1]),
tf.where(candidates_mask), 1))
#gvs = self.optimizer.compute_gradients(self.loss)
#capped_gvs = [(tf.clip_by_norm(grad, 5), var) for grad, var in gvs]
#self.train_step = self.optimizer.apply_gradients(capped_gvs)
self.train_step = self.optimizer.minimize(self.loss)
with tf.variable_scope("score"):
self.positive_probs = tf.sigmoid(self.positive_logits)
self.probs = tf.sigmoid(self.logits)
self.predictions = tf.to_int32(self.probs > 0.5)
correct_predictions = tf.equal(self.predictions,
tf.to_int32(self.labels))
self.accuracy = tf.reduce_mean(tf.cast(correct_predictions,
"float"),
name="accuracy")
def build_model(self):
# build index table
index_table = tf.contrib.lookup.index_table_from_file(
vocabulary_file=self.config.vocab_list,
num_oov_buckets=0,
default_value=0)
# get data iterator
self.data_iterator = self.data.get_data_iterator(index_table,
mode=self.mode)
# get inputs
with tf.variable_scope("inputs"):
# get next batch if there is no feeded data
next_batch = self.data_iterator.get_next()
self.input_queries = tf.placeholder_with_default(
next_batch["input_queries"], [None, self.config.max_length],
name="input_queries")
self.input_replies = tf.placeholder_with_default(
next_batch["input_replies"], [None, self.config.max_length],
name="input_replies")
self.query_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["query_lengths"]), [None],
name="query_lengths")
self.reply_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["reply_lengths"]), [None],
name="reply_lengths")
# get hyperparams
self.embed_dropout_keep_prob = tf.placeholder(
tf.float32, name="embed_dropout_keep_prob")
self.lstm_dropout_keep_prob = tf.placeholder(
tf.float32, name="lstm_dropout_keep_prob")
self.num_negative_samples = tf.placeholder(
tf.int32, name="num_negative_samples")
self.add_echo = tf.placeholder(tf.bool, name="add_echo")
with tf.variable_scope("properties"):
# length properties
cur_batch_length = tf.shape(self.input_queries)[0]
# learning rate and optimizer
learning_rate = tf.train.exponential_decay(
self.config.learning_rate,
self.global_step_tensor,
decay_steps=100000,
decay_rate=0.9)
self.optimizer = tf.train.AdamOptimizer(learning_rate)
# embedding layer
with tf.variable_scope("embedding"):
embeddings = tf.Variable(get_embeddings(
self.config.vocab_list, self.config.pretrained_embed_dir,
self.config.vocab_size, self.config.embed_dim),
trainable=True,
name="embeddings")
queries_embedded = tf.expand_dims(
tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_queries,
name="queries_embedded")), -1)
replies_embedded = tf.expand_dims(
tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_replies,
name="replies_embedded")), -1)
# build CNN layer
with tf.variable_scope("convolution_layer"):
queries_pooled_outputs = list()
replies_pooled_outputs = list()
for i, filter_size in enumerate(self.filter_sizes):
filter_shape = [
filter_size, self.config.embed_dim, 1,
self.config.num_filters
]
with tf.name_scope(
"conv-maxpool-query-{}".format(filter_size)):
W = tf.Variable(tf.truncated_normal(filter_shape,
stddev=0.1),
name="W")
b = tf.Variable(tf.constant(
0.1, shape=[self.config.num_filters]),
name="b")
conv = tf.nn.conv2d(queries_embedded,
W,
strides=[1, 1, 1, 1],
padding="VALID",
name="conv")
h = tf.nn.relu(tf.nn.bias_add(conv, b), name="relu")
pooled = tf.nn.max_pool(h,
ksize=[
1, self.config.max_length -
filter_size + 1, 1, 1
],
strides=[1, 1, 1, 1],
padding="VALID",
name="pool")
queries_pooled_outputs.append(pooled)
with tf.name_scope(
"conv-maxpool-reply-{}".format(filter_size)):
W = tf.Variable(tf.truncated_normal(filter_shape,
stddev=0.1),
name="W")
b = tf.Variable(tf.constant(
0.1, shape=[self.config.num_filters]),
name="b")
conv = tf.nn.conv2d(
replies_embedded,
W,
strides=[1, 1, 1, 1],
padding="VALID",
name="conv",
# reuse=True,
)
h = tf.nn.relu(tf.nn.bias_add(conv, b), name="relu")
pooled = tf.nn.max_pool(h,
ksize=[
1, self.config.max_length -
filter_size + 1, 1, 1
],
strides=[1, 1, 1, 1],
padding="VALID",
name="pool")
replies_pooled_outputs.append(pooled)
# conv_echo = tf.nn.conv2d(queries_embedded,
# W,
# strides=[1, 1, 1, 1],
# padding="VALID",
# name="conv",
# reuse=True)
# h_echo = tf.nn.relu(tf.nn.bias_add(conv_echo, b), name="relu_echo")
# pooled_echo = tf.nn.max_pool(h_echo,
# ksize=[1, self.config.max_length - filter_size + 1, 1, 1],
# strides=[1, 1, 1, 1],
# padding="VALID",
# name="pool_echo")
# echo_pooled_outputs.append(pooled_echo)
# combine all pooled outputs
num_filters_total = self.config.num_filters * len(self.filter_sizes)
self.queries_encoded = tf.reshape(tf.concat(queries_pooled_outputs, 3),
[-1, num_filters_total],
name="queries_encoded")
self.replies_encoded = tf.reshape(tf.concat(replies_pooled_outputs, 3),
[-1, num_filters_total],
name="replies_encoded")
with tf.variable_scope("dense_layer"):
M = tf.get_variable(
"M",
shape=[num_filters_total, num_filters_total],
initializer=tf.contrib.layers.xavier_initializer())
self.queries_transformed = tf.matmul(self.queries_encoded, M)
with tf.variable_scope("sampling"):
self.distances = tf.matmul(self.queries_transformed,
self.replies_encoded,
transpose_b=True)
# self.echo_distances = tf.matmul(self.queries_transformed, self.echo_encoded, transpose_b=True)
positive_mask = tf.reshape(tf.eye(cur_batch_length), [-1])
negative_mask = tf.reshape(
make_negative_mask(
self.distances,
method=self.config.negative_sampling,
num_negative_samples=self.num_negative_samples), [-1])
with tf.variable_scope("prediction"):
distances_flattened = tf.reshape(self.distances, [-1])
# echo_distances_flattened = tf.reshape(self.echo_distances, [-1])
self.positive_logits = tf.gather(distances_flattened,
tf.where(positive_mask), 1)
self.negative_logits = tf.gather(distances_flattened,
tf.where(negative_mask), 1)
self.logits = tf.concat(
[self.positive_logits, self.negative_logits], axis=0)
self.labels = tf.concat([
tf.ones_like(self.positive_logits),
tf.zeros_like(self.negative_logits)
],
axis=0)
# self.echo_logits = tf.gather(echo_distances_flattened, tf.where(positive_mask), 1)
# self.logits = tf.cond(self.add_echo,
# lambda: tf.concat([self.positive_logits,
# self.negative_logits,
# self.echo_logits], axis=0),
# lambda: tf.concat([self.positive_logits,
# self.negative_logits], axis=0))
# self.labels = tf.cond(self.add_echo,
# lambda: tf.concat([tf.ones_like(self.positive_logits),
# tf.zeros_like(self.negative_logits),
# tf.zeros_like(self.echo_logits)], axis=0),
# lambda: tf.concat([tf.ones_like(self.positive_logits),
# tf.zeros_like(self.negative_logits)], axis=0))
self.positive_probs = tf.sigmoid(self.positive_logits)
# self.echo_probs = tf.sigmoid(self.echo_logits)
self.probs = tf.sigmoid(self.logits)
self.predictions = tf.cast(self.probs > 0.5, dtype=tf.int32)
with tf.variable_scope("loss"):
self.loss = tf.reduce_mean(
tf.nn.sigmoid_cross_entropy_with_logits(labels=self.labels,
logits=self.logits))
gvs = self.optimizer.compute_gradients(self.loss)
capped_gvs = [(tf.clip_by_norm(grad, 5), var) for grad, var in gvs]
self.train_step = self.optimizer.apply_gradients(capped_gvs)
# self.train_step = self.optimizer.minimize(self.loss)
with tf.variable_scope("score"):
correct_predictions = tf.equal(self.predictions,
tf.to_int32(self.labels))
self.accuracy = tf.reduce_mean(tf.cast(correct_predictions,
"float"),
name="accuracy")
def build_model(self):
# build index table
index_table = tf.contrib.lookup.index_table_from_file(
vocabulary_file=self.config.vocab_list,
num_oov_buckets=0,
default_value=0)
# get data iterator
self.data_iterator = self.data.get_data_iterator(index_table,
mode=self.mode)
with tf.variable_scope("inputs"):
# get next batch if there is no feeded data
next_batch = self.data_iterator.get_next()
self.input_queries = tf.placeholder_with_default(
next_batch["input_queries"], [None, self.config.max_length],
name="input_queries")
self.input_replies = tf.placeholder_with_default(
next_batch["input_replies"], [None, self.config.max_length],
name="input_replies")
self.query_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["query_lengths"]), [None],
name="query_lengths")
self.reply_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["reply_lengths"]), [None],
name="reply_lengths")
# get hyperparams
self.embed_dropout_keep_prob = tf.placeholder(
tf.float64, name="embed_dropout_keep_prob")
self.lstm_dropout_keep_prob = tf.placeholder(
tf.float32, name="lstm_dropout_keep_prob")
self.dense_dropout_keep_prob = tf.placeholder(
tf.float32, name="dense_dropout_keep_prob")
self.num_negative_samples = tf.placeholder(
tf.int32, name="num_negative_samples")
with tf.variable_scope("properties"):
# length properties
cur_batch_length = tf.shape(self.input_queries)[0]
# learning rate and optimizer
learning_rate = tf.train.exponential_decay(
self.config.learning_rate,
self.global_step_tensor,
decay_steps=100000,
decay_rate=0.96)
self.optimizer = tf.train.AdamOptimizer(learning_rate)
# embedding layer
with tf.variable_scope("embedding"):
embeddings = tf.Variable(get_embeddings(
self.config.vocab_list, self.config.pretrained_embed_dir,
self.config.vocab_size, self.config.embed_dim),
trainable=True,
name="embeddings")
embeddings = tf.nn.dropout(
embeddings,
keep_prob=self.embed_dropout_keep_prob,
noise_shape=[tf.shape(embeddings)[0], 1])
queries_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_queries,
name="queries_embedded"))
replies_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_replies,
name="replies_embedded"))
# gru layer
with tf.variable_scope("gru_layer"):
sentence_gru_cell = tf.nn.rnn_cell.GRUCell(
self.config.lstm_dim,
kernel_initializer=tf.initializers.orthogonal(),
reuse=tf.AUTO_REUSE)
sentence_gru_cell = tf.contrib.rnn.DropoutWrapper(
sentence_gru_cell, input_keep_prob=self.lstm_dropout_keep_prob)
self.query_rnn_outputs, _ = tf.nn.dynamic_rnn(
sentence_gru_cell,
queries_embedded,
sequence_length=self.query_lengths,
dtype=tf.float32,
scope="sentence_gru")
self.reply_rnn_outputs, _ = tf.nn.dynamic_rnn(
sentence_gru_cell,
replies_embedded,
sequence_length=self.reply_lengths,
dtype=tf.float32,
scope="sentence_gru")
# negative sampling
with tf.variable_scope("negative_sampling"):
negative_mask = make_negative_mask(
tf.zeros([cur_batch_length, cur_batch_length]),
method=self.config.negative_sampling,
num_negative_samples=self.num_negative_samples)
negative_queries_indices, negative_replies_indices = tf.split(
tf.where(tf.not_equal(negative_mask, 0)), [1, 1], 1)
self.negative_queries_indices = tf.squeeze(
negative_queries_indices)
self.negative_replies_indices = tf.squeeze(
negative_replies_indices)
self.num_negatives = tf.shape(self.negative_replies_indices)[0]
queries_embedded_neg = tf.nn.embedding_lookup(
queries_embedded, self.negative_queries_indices)
replies_embedded_neg = tf.nn.embedding_lookup(
replies_embedded, self.negative_replies_indices)
self.query_rnn_outputs_neg = tf.reshape(
tf.nn.embedding_lookup(self.query_rnn_outputs,
self.negative_queries_indices),
[
self.num_negatives, self.config.max_length,
self.config.lstm_dim
])
self.reply_rnn_outputs_neg = tf.reshape(
tf.nn.embedding_lookup(self.reply_rnn_outputs,
self.negative_replies_indices),
[
self.num_negatives, self.config.max_length,
self.config.lstm_dim
])
# build matrix for convolution
with tf.variable_scope("matrix"):
A_matrix = tf.get_variable(
"A_matrix_v",
shape=(self.config.lstm_dim, self.config.lstm_dim),
initializer=tf.contrib.layers.xavier_initializer(),
dtype=tf.float32)
replies_embedded_transposed = tf.transpose(replies_embedded,
[0, 2, 1])
reply_rnn_outputs_transposed = tf.transpose(
self.reply_rnn_outputs, [0, 2, 1])
replies_embedded_neg_transposed = tf.transpose(
replies_embedded_neg, [0, 2, 1])
reply_rnn_outputs_neg_transposed = tf.transpose(
self.reply_rnn_outputs_neg, [0, 2, 1])
embed_matrix = tf.matmul(queries_embedded,
replies_embedded_transposed)
rnn_outputs = tf.einsum("aij,jk->aik", self.query_rnn_outputs,
A_matrix)
rnn_outputs = tf.matmul(rnn_outputs, reply_rnn_outputs_transposed)
self.matrix_stacked = tf.stack([embed_matrix, rnn_outputs],
axis=3,
name="matrix_stacked")
# build negative matrix for convolution
with tf.variable_scope("matrix", reuse=True):
A_matrix_neg = tf.get_variable(
"A_matrix_v",
shape=(self.config.lstm_dim, self.config.lstm_dim),
initializer=tf.contrib.layers.xavier_initializer(),
dtype=tf.float32)
embed_matrix_neg = tf.matmul(queries_embedded_neg,
replies_embedded_neg_transposed)
rnn_outputs_neg = tf.einsum("aij,jk->aik",
self.query_rnn_outputs_neg,
A_matrix_neg)
rnn_outputs_neg = tf.matmul(rnn_outputs_neg,
reply_rnn_outputs_neg_transposed)
self.matrix_stacked_neg = tf.stack(
[embed_matrix_neg, rnn_outputs_neg],
axis=3,
name="matrix_stacked_neg")
# cnn layer
with tf.variable_scope("convolution_layer"):
conv = tf.layers.conv2d(
self.matrix_stacked,
filters=8,
kernel_size=(3, 3),
padding="VALID",
kernel_initializer=tf.contrib.layers.xavier_initializer(),
activation=tf.nn.relu,
reuse=None,
name="conv")
pooled = tf.layers.max_pooling2d(conv, (3, 3),
strides=(3, 3),
padding="VALID",
name="max_pooling")
self.hidden_outputs = tf.expand_dims(
tf.layers.dense(
tf.contrib.layers.flatten(pooled),
50,
kernel_initializer=tf.contrib.layers.xavier_initializer()),
-1)
# cnn layer
with tf.variable_scope("convolution_layer", reuse=True):
conv_neg = tf.layers.conv2d(
self.matrix_stacked_neg,
filters=8,
kernel_size=(3, 3),
padding="VALID",
kernel_initializer=tf.contrib.layers.xavier_initializer(),
activation=tf.nn.relu,
reuse=True,
name="conv")
pooled_neg = tf.layers.max_pooling2d(conv_neg, (3, 3),
strides=(3, 3),
padding="VALID",
name="max_pooling_neg")
self.hidden_outputs_neg = tf.expand_dims(
tf.layers.dense(
tf.contrib.layers.flatten(pooled_neg),
50,
kernel_initializer=tf.contrib.layers.xavier_initializer(),
reuse=True), -1)
# matching gru layer
with tf.variable_scope("matching_gru_layer"):
matching_gru_cell = tf.nn.rnn_cell.GRUCell(
self.config.lstm_dim,
kernel_initializer=tf.initializers.orthogonal(),
name="gru_cell",
reuse=tf.AUTO_REUSE)
_, positive_state = tf.nn.dynamic_rnn(matching_gru_cell,
self.hidden_outputs,
dtype=tf.float32,
scope="matching_gru")
_, negative_state = tf.nn.dynamic_rnn(matching_gru_cell,
self.hidden_outputs_neg,
dtype=tf.float32,
scope="matching_gru")
self.positive_logits = tf.layers.dense(
positive_state,
2,
kernel_initializer=tf.contrib.layers.xavier_initializer(),
name="predict")
self.negative_logits = tf.layers.dense(
negative_state,
2,
kernel_initializer=tf.contrib.layers.xavier_initializer(),
name="predict",
reuse=True)
# build loss
with tf.variable_scope("loss"):
self.logits = tf.concat(
[self.positive_logits, self.negative_logits], 0)
self.positive_probs = tf.nn.softmax(self.positive_logits)
self.probs = tf.nn.softmax(self.logits)
self.labels = tf.concat([
tf.ones_like(self.positive_logits),
tf.zeros_like(self.negative_logits)
], 0)
losses = tf.nn.softmax_cross_entropy_with_logits_v2(
labels=self.labels, logits=self.logits)
self.loss = tf.reduce_mean(losses)
self.train_step = self.optimizer.minimize(self.loss)
with tf.variable_scope("score"):
self.predictions = tf.argmax(self.probs, 1)
correct_predictions = tf.equal(self.predictions,
tf.argmax(self.labels, 1))
self.accuracy = tf.reduce_mean(tf.cast(correct_predictions,
"float"),
name="accuracy")
def build_model(self):
# build index table
index_table = tf.contrib.lookup.index_table_from_file(
vocabulary_file=self.config.vocab_list,
num_oov_buckets=0,
default_value=0)
# get data iterator
self.data_iterator = self.data.get_data_iterator(index_table,
mode=self.mode)
# get inputs
with tf.variable_scope("inputs"):
# get next batch if there is no feeded data
next_batch = self.data_iterator.get_next()
self.input_queries = tf.placeholder_with_default(
next_batch["input_queries"], [None, self.config.max_length],
name="input_queries")
self.input_replies = tf.placeholder_with_default(
next_batch["input_replies"], [None, self.config.max_length],
name="input_replies")
self.query_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["query_lengths"]), [None],
name="query_lengths")
self.reply_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["reply_lengths"]), [None],
name="reply_lengths")
# get hyperparams
self.embed_dropout_keep_prob = tf.placeholder(
tf.float64, name="embed_dropout_keep_prob")
self.lstm_dropout_keep_prob = tf.placeholder(
tf.float32, name="lstm_dropout_keep_prob")
self.dense_dropout_keep_prob = tf.placeholder(
tf.float32, name="dense_dropout_keep_prob")
self.num_negative_samples = tf.placeholder(
tf.int32, name="num_negative_samples")
with tf.variable_scope("properties"):
# length properties
cur_batch_length = tf.shape(self.input_queries)[0]
# get hparms from tensor2tensor.models.transformer
hparams = transformer.transformer_small()
hparams.batch_size = self.config.batch_size
hparams.learning_rate_decay_steps = 10000
hparams.learning_rate_minimum = 3e-5
# learning rate
lr = learning_rate.learning_rate_schedule(hparams)
self.learning_rate = lr
# embedding layer
with tf.variable_scope("embedding"):
embeddings = tf.Variable(get_embeddings(
self.config.vocab_list, self.config.pretrained_embed_dir,
self.config.vocab_size, self.config.embed_dim),
trainable=True,
name="embeddings")
embeddings = tf.nn.dropout(
embeddings,
keep_prob=self.embed_dropout_keep_prob,
noise_shape=[tf.shape(embeddings)[0], 1])
queries_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_queries,
name="queries_embedded"))
replies_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_replies,
name="replies_embedded"))
self.queries_embedded = queries_embedded
self.replies_embedded = replies_embedded
# transformer layer
with tf.variable_scope("transformer"):
queries_expanded = tf.expand_dims(queries_embedded,
axis=2,
name="queries_expanded")
replies_expanded = tf.expand_dims(replies_embedded,
axis=2,
name="replies_expanded")
hparams = transformer.transformer_small()
hparams.set_hparam("batch_size", self.config.batch_size)
hparams.set_hparam("hidden_size", self.config.embed_dim)
encoder = transformer.TransformerEncoder(hparams, mode=self.mode)
self.queries_encoded = encoder({
"inputs": queries_expanded,
"targets": queries_expanded
})[0]
self.replies_encoded = encoder({
"inputs": replies_expanded,
"targets": replies_expanded
})[0]
self.queries_encoded = tf.squeeze(
tf.reduce_sum(self.queries_encoded, axis=1, keep_dims=True))
self.replies_encoded = tf.squeeze(
tf.reduce_sum(self.replies_encoded, axis=1, keep_dims=True))
with tf.variable_scope("sampling"):
positive_mask = tf.eye(cur_batch_length)
negative_mask = make_negative_mask(
tf.zeros([cur_batch_length, cur_batch_length]),
method=self.config.negative_sampling,
num_negative_samples=self.num_negative_samples)
negative_queries_indices, negative_replies_indices = tf.split(
tf.where(tf.not_equal(negative_mask, 0)), [1, 1], 1)
self.distances = tf.matmul(self.queries_encoded,
self.replies_encoded,
transpose_b=True)
self.distances_flattened = tf.reshape(self.distances, [-1])
self.positive_distances = tf.gather(
self.distances_flattened,
tf.where(tf.reshape(positive_mask, [-1])))
self.negative_distances = tf.gather(
self.distances_flattened,
tf.where(tf.reshape(negative_mask, [-1])))
self.negative_queries_indices = tf.squeeze(
negative_queries_indices)
self.negative_replies_indices = tf.squeeze(
negative_replies_indices)
self.positive_inputs = tf.concat([
self.queries_encoded, self.positive_distances,
self.replies_encoded
], 1)
self.negative_inputs = tf.reshape(
tf.concat([
tf.nn.embedding_lookup(self.queries_encoded,
self.negative_queries_indices),
self.negative_distances,
tf.nn.embedding_lookup(self.replies_encoded,
self.negative_replies_indices)
], 1), [
tf.shape(negative_queries_indices)[0],
self.config.embed_dim * 2 + 1
])
with tf.variable_scope("prediction"):
self.hidden_outputs = tf.layers.dense(tf.concat(
[self.positive_inputs, self.negative_inputs], 0),
256,
tf.nn.relu,
name="hidden_layer")
self.logits = tf.layers.dense(self.hidden_outputs,
2,
tf.nn.relu,
name="output_layer")
labels = tf.concat([
tf.ones([tf.shape(self.positive_inputs)[0]], tf.float64),
tf.zeros([tf.shape(self.negative_inputs)[0]], tf.float64)
], 0)
self.labels = tf.one_hot(tf.to_int32(labels), 2)
self.probs = tf.sigmoid(self.logits)
self.predictions = tf.argmax(self.probs, 1)
with tf.variable_scope("loss"):
self.loss = tf.reduce_mean(
tf.nn.softmax_cross_entropy_with_logits_v2(labels=self.labels,
logits=self.logits))
self.train_step = optimize.optimize(self.loss,
lr,
hparams,
use_tpu=False)
with tf.variable_scope("score"):
correct_predictions = tf.equal(self.predictions,
tf.argmax(self.labels, 1))
self.accuracy = tf.reduce_mean(tf.cast(correct_predictions,
"float"),
name="accuracy")
def build_model(self):
# build index table
index_table = tf.contrib.lookup.index_table_from_file(
vocabulary_file=self.config.vocab_list,
num_oov_buckets=0,
default_value=0)
# get data iterator
self.data_iterator = self.data.get_data_iterator(index_table,
mode=self.mode)
# get inputs
with tf.variable_scope("inputs"):
# get next batch if there is no feeded data
next_batch = self.data_iterator.get_next()
self.input_queries = tf.placeholder_with_default(
next_batch["input_queries"], [None, self.config.max_length],
name="input_queries")
self.input_replies = tf.placeholder_with_default(
next_batch["input_replies"], [None, self.config.max_length],
name="input_replies")
self.query_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["query_lengths"]), [None],
name="query_lengths")
self.reply_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["reply_lengths"]), [None],
name="reply_lengths")
# get hyperparams
self.embed_dropout_keep_prob = tf.placeholder(
tf.float64, name="embed_dropout_keep_prob")
self.lstm_dropout_keep_prob = tf.placeholder(
tf.float32, name="lstm_dropout_keep_prob")
self.dense_dropout_keep_prob = tf.placeholder(
tf.float32, name="dense_dropout_keep_prob")
self.num_negative_samples = tf.placeholder(
tf.int32, name="num_negative_samples")
with tf.variable_scope("properties"):
# length properties
cur_batch_length = tf.shape(self.input_queries)[0]
query_max_length = tf.shape(self.input_queries)[1]
reply_max_length = tf.shape(self.input_replies)[1]
# learning rate and optimizer
learning_rate = tf.train.exponential_decay(
self.config.learning_rate,
self.global_step_tensor,
decay_steps=20000,
decay_rate=0.96)
self.optimizer = tf.train.AdamOptimizer(learning_rate)
# embedding layer
with tf.variable_scope("embedding"):
embeddings = tf.Variable(get_embeddings(
self.config.vocab_list, self.config.pretrained_embed_dir,
self.config.vocab_size, self.config.embed_dim),
trainable=True,
name="embeddings")
embeddings = tf.nn.dropout(embeddings,
keep_prob=self.embed_dropout_keep_prob,
noise_shape=[90000, 1])
queries_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_queries,
name="queries_embedded"))
replies_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_replies,
name="replies_embedded"))
self.queries_embedded = queries_embedded
self.replies_embedded = replies_embedded
# build LSTM layer
with tf.variable_scope("lstm_layer") as vs:
query_lstm_cell = tf.nn.rnn_cell.LSTMCell(self.config.lstm_dim,
forget_bias=2.0,
use_peepholes=True,
state_is_tuple=True)
query_lstm_cell = tf.contrib.rnn.DropoutWrapper(
query_lstm_cell, input_keep_prob=self.lstm_dropout_keep_prob)
reply_lstm_cell = tf.nn.rnn_cell.LSTMCell(self.config.lstm_dim,
forget_bias=2.0,
use_peepholes=True,
state_is_tuple=True,
reuse=True)
reply_lstm_cell = tf.contrib.rnn.DropoutWrapper(
reply_lstm_cell, input_keep_prob=self.lstm_dropout_keep_prob)
queries_encoded, queries_state = tf.nn.dynamic_rnn(
cell=query_lstm_cell,
inputs=queries_embedded,
sequence_length=tf.cast(self.query_lengths, tf.float32),
dtype=tf.float32,
)
replies_encoded, replies_state = tf.nn.dynamic_rnn(
cell=reply_lstm_cell,
inputs=replies_embedded,
sequence_length=tf.cast(self.reply_lengths, tf.float32),
dtype=tf.float32,
)
self.queries_encoded = tf.expand_dims(queries_encoded, -1)
self.replies_encoded = tf.expand_dims(replies_encoded, -1)
# Create a convolution + maxpool layer for each filter size
queries_pooled_outputs = list()
replies_pooled_outputs = list()
for i, filter_size in enumerate([1, 2, 3, 4, 5]):
filter_shape = [filter_size, self.config.lstm_dim, 1, 128]
# queries
with tf.name_scope("conv-maxpool-query-%s" % filter_size):
# Convolution Layer
W = tf.Variable(tf.truncated_normal(filter_shape, stddev=0.1),
name="W")
b = tf.Variable(tf.constant(0.1, shape=[128]), name="bias")
conv = tf.nn.conv2d(self.queries_encoded,
W,
strides=[1, 1, 1, 1],
padding="VALID",
name="conv")
# Apply nonlinearity
h = tf.nn.relu(tf.nn.bias_add(conv, b), name="relu")
# Maxpooling over the outputs
pooled = tf.nn.max_pool(
h,
ksize=[1, self.config.max_length - filter_size + 1, 1, 1],
strides=[1, 1, 1, 1],
padding='VALID',
name="pool")
queries_pooled_outputs.append(pooled)
# replies
with tf.name_scope("conv-maxpool-reply-%s" % filter_size):
# Convolution Layer
W = tf.Variable(tf.truncated_normal(filter_shape, stddev=0.1),
name="W")
b = tf.Variable(tf.constant(0.1, shape=[128]), name="bias")
conv = tf.nn.conv2d(self.replies_encoded,
W,
strides=[1, 1, 1, 1],
padding="VALID",
name="conv")
# Apply nonlinearity
h = tf.nn.relu(tf.nn.bias_add(conv, b), name="relu")
# Maxpooling over the outputs
pooled = tf.nn.max_pool(
h,
ksize=[1, self.config.max_length - filter_size + 1, 1, 1],
strides=[1, 1, 1, 1],
padding='VALID',
name="pool")
replies_pooled_outputs.append(pooled)
# Combine all the pooled features
num_filters_total = 128 * 5
self.queries_conv_output = tf.reshape(
tf.concat(queries_pooled_outputs, 3), [-1, num_filters_total])
self.replies_conv_output = tf.reshape(
tf.concat(replies_pooled_outputs, 3), [-1, num_filters_total])
with tf.variable_scope("sampling"):
positive_mask = tf.reshape(tf.eye(cur_batch_length), [-1])
negative_mask = make_negative_mask(
tf.zeros([cur_batch_length, cur_batch_length]),
method=self.config.negative_sampling,
num_negative_samples=self.num_negative_samples)
negative_queries_indices, negative_replies_indices = tf.split(
tf.where(tf.not_equal(negative_mask, 0)), [1, 1], 1)
self.negative_queries_indices = tf.squeeze(
negative_queries_indices)
self.negative_replies_indices = tf.squeeze(
negative_replies_indices)
self.distances = tf.matmul(queries_state.h,
replies_state.h,
transpose_b=True)
self.distances_flattened = tf.reshape(self.distances, [-1])
self.positive_distances = tf.gather(self.distances_flattened,
tf.where(positive_mask), 1)
self.negative_distances = tf.gather(
self.distances_flattened,
tf.where(tf.reshape(negative_mask, [-1])), 1)
self.positive_inputs = tf.concat([
self.queries_conv_output, self.positive_distances,
self.replies_conv_output
], 1)
self.negative_inputs = tf.reshape(
tf.concat([
tf.nn.embedding_lookup(self.queries_conv_output,
self.negative_queries_indices),
self.negative_distances,
tf.nn.embedding_lookup(self.replies_conv_output,
self.negative_replies_indices)
], 1), [
tf.shape(negative_queries_indices)[0],
num_filters_total * 2 + 1
])
self.num_positives = tf.shape(self.positive_inputs)[0]
self.num_negatives = tf.shape(self.negative_inputs)[0]
# hidden layer
with tf.name_scope("hidden"):
W = tf.get_variable(
"W_hidden",
shape=[2 * num_filters_total + 1, 100],
initializer=tf.contrib.layers.xavier_initializer())
b = tf.Variable(tf.constant(0.1, shape=[100]), name="bias")
self.hidden_output = tf.nn.relu(
tf.nn.xw_plus_b(tf.concat(
[self.positive_inputs, self.negative_inputs], 0),
W,
b,
name="hidden_output"))
# Add dropout
with tf.name_scope("dropout"):
self.h_drop = tf.nn.dropout(self.hidden_output,
self.dense_dropout_keep_prob,
name="hidden_output_drop")
# Final (unnormalized) scores and predictions
with tf.name_scope("output"):
W = tf.get_variable(
"W_output",
shape=[100, 1],
initializer=tf.contrib.layers.xavier_initializer())
b = tf.Variable(tf.constant(0.1, shape=[1]), name="bias")
self.logits = tf.nn.xw_plus_b(self.h_drop, W, b, name="logits")
self.positive_logits, self.negative_logits = tf.split(
self.logits, [self.num_positives, self.num_negatives])
self.probs = tf.sigmoid(self.logits)
self.predictions = tf.to_int32(self.probs > 0.5,
name="predictions")
labels = tf.concat([
tf.ones([self.num_positives], tf.float64),
tf.zeros([self.num_negatives], tf.float64)
], 0)
self.labels = tf.to_int32(labels)
with tf.variable_scope("loss"):
self.positive_scores = tf.expand_dims(self.positive_logits, 1)
self.negative_scores = self.negative_logits
self.ranking_loss = tf.reduce_sum(
tf.maximum(
0.0, self.config.hinge_loss - self.positive_scores +
self.negative_scores))
l2_vars = [
v for v in tf.trainable_variables()
if 'bias' not in v.name and 'embedding' not in v.name
]
l2_loss = tf.add_n([tf.nn.l2_loss(v) for v in l2_vars])
self.loss = self.ranking_loss + l2_loss
self.train_step = self.optimizer.minimize(
self.loss, global_step=self.global_step_tensor)
with tf.variable_scope("score"):
correct_predictions = tf.equal(self.predictions, self.labels)
self.accuracy = tf.reduce_mean(tf.cast(correct_predictions,
"float"),
name="accuracy")
def build_model(self):
# build index table
index_table = tf.contrib.lookup.index_table_from_file(
vocabulary_file=self.config.vocab_list,
num_oov_buckets=0,
default_value=0)
# get data iterator
self.data_iterator = self.data.get_data_iterator(index_table,
mode=self.mode)
# get inputs
with tf.variable_scope("inputs"):
# get next batch if there is no feeded data
next_batch = self.data_iterator.get_next()
self.input_queries = tf.placeholder_with_default(
next_batch["input_queries"], [None, self.config.max_length],
name="input_queries")
self.input_replies = tf.placeholder_with_default(
next_batch["input_replies"], [None, self.config.max_length],
name="input_replies")
self.query_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["query_lengths"]), [None],
name="query_lengths")
self.reply_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["reply_lengths"]), [None],
name="reply_lengths")
# get hyperparams
self.embed_dropout_keep_prob = tf.placeholder(
tf.float64, name="embed_dropout_keep_prob")
self.lstm_dropout_keep_prob = tf.placeholder(
tf.float32, name="lstm_dropout_keep_prob")
self.dense_dropout_keep_prob = tf.placeholder(
tf.float32, name="dense_dropout_keep_prob")
self.num_negative_samples = tf.placeholder(
tf.int32, name="num_negative_samples")
with tf.variable_scope("properties"):
# length properties
cur_batch_length = tf.shape(self.input_queries)[0]
# learning rate and optimizer
learning_rate = tf.train.exponential_decay(
self.config.learning_rate,
self.global_step_tensor,
decay_steps=100000,
decay_rate=0.96)
self.optimizer = tf.train.AdamOptimizer(learning_rate)
# embedding layer
with tf.variable_scope("embedding"):
embeddings = tf.Variable(get_embeddings(
self.config.vocab_list, self.config.pretrained_embed_dir,
self.config.vocab_size, self.config.embed_dim),
trainable=True,
name="embeddings")
embeddings = tf.nn.dropout(embeddings,
keep_prob=self.embed_dropout_keep_prob,
noise_shape=[90000, 1])
queries_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_queries,
name="queries_embedded"))
replies_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_replies,
name="replies_embedded"))
self.queries_embedded = queries_embedded
self.replies_embedded = replies_embedded
# build LSTM layer
with tf.variable_scope("lstm_layer") as vs:
query_lstm_cell = tf.nn.rnn_cell.LSTMCell(self.config.lstm_dim,
forget_bias=2.0,
use_peepholes=True,
state_is_tuple=True)
query_lstm_cell = tf.contrib.rnn.DropoutWrapper(
query_lstm_cell, input_keep_prob=self.lstm_dropout_keep_prob)
reply_lstm_cell = tf.nn.rnn_cell.LSTMCell(self.config.lstm_dim,
forget_bias=2.0,
use_peepholes=True,
state_is_tuple=True,
reuse=True)
reply_lstm_cell = tf.contrib.rnn.DropoutWrapper(
reply_lstm_cell, input_keep_prob=self.lstm_dropout_keep_prob)
_, queries_encoded = tf.nn.dynamic_rnn(
cell=query_lstm_cell,
inputs=queries_embedded,
sequence_length=tf.cast(self.query_lengths, tf.float32),
dtype=tf.float32,
)
_, replies_encoded = tf.nn.dynamic_rnn(
cell=reply_lstm_cell,
inputs=replies_embedded,
sequence_length=tf.cast(self.reply_lengths, tf.float32),
dtype=tf.float32,
)
self.queries_encoded = tf.cast(queries_encoded.h, tf.float64)
self.replies_encoded = tf.cast(replies_encoded.h, tf.float64)
with tf.variable_scope("sampling"):
negative_mask = make_negative_mask(
tf.zeros([cur_batch_length, cur_batch_length]),
method=self.config.negative_sampling,
num_negative_samples=self.num_negative_samples)
negative_queries_indices, negative_replies_indices = tf.split(
tf.where(tf.not_equal(negative_mask, 0)), [1, 1], 1)
# self.distances = tf.matmul(self.queries_encoded, self.replies_encoded, transpose_b=True)
# self.distances_flattened = tf.reshape(self.distances, [-1])
# self.positive_distances = tf.gather(self.distances_flattened, tf.where(tf.reshape(tf.eye(cur_batch_length), -1)))
# self.negative_distances = tf.gather(self.distances_flattened, tf.where(tf.reshape(negative_mask, -1)))
self.negative_queries_indices = tf.squeeze(
negative_queries_indices)
self.negative_replies_indices = tf.squeeze(
negative_replies_indices)
self.positive_inputs = tf.concat(
[self.queries_encoded, self.replies_encoded], 1)
self.negative_inputs = tf.reshape(
tf.concat([
tf.nn.embedding_lookup(self.queries_encoded,
self.negative_queries_indices),
tf.nn.embedding_lookup(self.replies_encoded,
self.negative_replies_indices)
], 1), [
tf.shape(negative_queries_indices)[0],
self.config.lstm_dim * 2
])
with tf.variable_scope("prediction"):
self.hidden_outputs = tf.layers.dense(tf.concat(
[self.positive_inputs, self.negative_inputs], 0),
256,
tf.nn.relu,
name="hidden_layer")
self.logits = tf.layers.dense(self.hidden_outputs,
2,
tf.nn.relu,
name="output_layer")
labels = tf.concat([
tf.ones([tf.shape(self.positive_inputs)[0]], tf.float64),
tf.zeros([tf.shape(self.negative_inputs)[0]], tf.float64)
], 0)
self.labels = tf.one_hot(tf.to_int32(labels), 2)
self.probs = tf.sigmoid(self.logits)
self.predictions = tf.argmax(self.probs, 1)
self.positive_probs = tf.slice(self.probs, [0, 0],
[cur_batch_length, -1])
with tf.variable_scope("loss"):
self.loss = tf.reduce_mean(
tf.nn.softmax_cross_entropy_with_logits_v2(labels=self.labels,
logits=self.logits))
self.train_step = self.optimizer.minimize(
self.loss, global_step=self.global_step_tensor)
with tf.variable_scope("score"):
correct_predictions = tf.equal(self.predictions,
tf.argmax(self.labels, 1))
self.accuracy = tf.reduce_mean(tf.cast(correct_predictions,
"float"),
name="accuracy")
def build_model(self):
# build index table
index_table = tf.contrib.lookup.index_table_from_file(
vocabulary_file=self.config.vocab_list,
num_oov_buckets=0,
default_value=0)
# get data iterator
self.data_iterator = self.data.get_data_iterator(index_table,
mode=self.mode)
# get inputs
with tf.variable_scope("inputs"):
# get next batch if there is no feeded data
next_batch = self.data_iterator.get_next()
self.input_queries = tf.placeholder_with_default(
next_batch["input_queries"], [None, self.config.max_length],
name="input_queries")
self.input_replies = tf.placeholder_with_default(
next_batch["input_replies"], [None, self.config.max_length],
name="input_replies")
self.query_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["query_lengths"]), [None],
name="query_lengths")
self.reply_lengths = tf.placeholder_with_default(
tf.squeeze(next_batch["reply_lengths"]), [None],
name="reply_lengths")
# get hyperparams
self.embed_dropout_keep_prob = tf.placeholder(
tf.float64, name="embed_dropout_keep_prob")
self.lstm_dropout_keep_prob = tf.placeholder(
tf.float32, name="lstm_dropout_keep_prob")
self.dense_dropout_keep_prob = tf.placeholder(
tf.float32, name="dense_dropout_keep_prob")
self.num_negative_samples = tf.placeholder(
tf.int32, name="num_negative_samples")
with tf.variable_scope("properties"):
# length properties
cur_batch_length = tf.shape(self.input_queries)[0]
# get hparms from tensor2tensor.models.transformer
hparams = transformer.transformer_small()
hparams.batch_size = self.config.batch_size
# learning rate
lr = learning_rate.learning_rate_schedule(hparams)
# embedding layer
with tf.variable_scope("embedding"):
embeddings = tf.Variable(get_embeddings(
self.config.vocab_list, self.config.pretrained_embed_dir,
self.config.vocab_size, self.config.embed_dim),
trainable=True,
name="embeddings")
embeddings = tf.nn.dropout(
embeddings,
keep_prob=self.embed_dropout_keep_prob,
noise_shape=[tf.shape(embeddings)[0], 1])
queries_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_queries,
name="queries_embedded"))
replies_embedded = tf.to_float(
tf.nn.embedding_lookup(embeddings,
self.input_replies,
name="replies_embedded"))
self.queries_embedded = queries_embedded
self.replies_embedded = replies_embedded
# transformer layer
with tf.variable_scope("transformer"):
queries_expanded = tf.expand_dims(queries_embedded,
axis=2,
name="queries_expanded")
replies_expanded = tf.expand_dims(replies_embedded,
axis=2,
name="replies_expanded")
hparams = transformer.transformer_small()
hparams.set_hparam("batch_size", self.config.batch_size)
hparams.set_hparam("hidden_size", self.config.embed_dim)
encoder = transformer.TransformerEncoder(hparams, mode=self.mode)
self.queries_encoded = encoder({
"inputs": queries_expanded,
"targets": queries_expanded
})[0]
self.replies_encoded = encoder({
"inputs": replies_expanded,
"targets": replies_expanded
})[0]
self.queries_pooled = tf.nn.max_pool(
self.queries_encoded,
ksize=[1, self.config.max_length, 1, 1],
strides=[1, 1, 1, 1],
padding='VALID',
name="queries_pooled")
self.replies_pooled = tf.nn.max_pool(
self.replies_encoded,
ksize=[1, self.config.max_length, 1, 1],
strides=[1, 1, 1, 1],
padding='VALID',
name="replies_pooled")
self.queries_flattened = tf.reshape(self.queries_pooled,
[cur_batch_length, -1])
self.replies_flattened = tf.reshape(self.replies_pooled,
[cur_batch_length, -1])
# build dense layer
with tf.variable_scope("dense_layer"):
M = tf.get_variable(
"M",
shape=[self.config.embed_dim, self.config.embed_dim],
initializer=tf.initializers.truncated_normal())
M = tf.nn.dropout(M, self.dense_dropout_keep_prob)
self.queries_transformed = tf.matmul(self.queries_flattened, M)
with tf.variable_scope("sampling"):
self.distances = tf.matmul(self.queries_transformed,
self.replies_flattened,
transpose_b=True)
positive_mask = tf.reshape(tf.eye(cur_batch_length), [-1])
negative_mask = tf.reshape(
make_negative_mask(
self.distances,
method=self.config.negative_sampling,
num_negative_samples=self.num_negative_samples), [-1])
with tf.variable_scope("prediction"):
distances_flattened = tf.reshape(self.distances, [-1])
self.positive_logits = tf.gather(distances_flattened,
tf.where(positive_mask), 1)
self.negative_logits = tf.gather(distances_flattened,
tf.where(negative_mask), 1)
self.logits = tf.concat(
[self.positive_logits, self.negative_logits], axis=0)
self.labels = tf.concat([
tf.ones_like(self.positive_logits),
tf.zeros_like(self.negative_logits)
],
axis=0)
self.positive_probs = tf.sigmoid(self.positive_logits)
self.probs = tf.sigmoid(self.logits)
self.predictions = tf.cast(self.probs > 0.5, dtype=tf.int32)
with tf.variable_scope("loss"):
self.loss = tf.reduce_mean(
tf.nn.sigmoid_cross_entropy_with_logits(labels=self.labels,
logits=self.logits))
self.train_step = optimize.optimize(self.loss,
lr,
hparams,
use_tpu=False)
with tf.variable_scope("score"):
correct_predictions = tf.equal(self.predictions,
tf.to_int32(self.labels))
self.accuracy = tf.reduce_mean(tf.cast(correct_predictions,
"float"),
name="accuracy")
