def create_model(bert_config, is_training, input_ids, input_mask, segment_ids,
labels, num_labels, multilabel):
"""Creates a classification model."""
model = modeling.BertModel(config=bert_config,
is_training=is_training,
input_ids=input_ids,
input_mask=input_mask,
token_type_ids=segment_ids)
# Here, we are doing a classification task on the entire segment. For
# token-level output, use model.get_sequece_output() instead.
output_layer = model.get_pooled_output()
hidden_size = output_layer.shape[-1].value
output_weights = tf.get_variable(
"output_weights", [FLAGS.original_target_size, hidden_size],
initializer=tf.truncated_normal_initializer(stddev=0.02))
output_bias = tf.get_variable("output_bias", [FLAGS.original_target_size],
initializer=tf.zeros_initializer())
new_output_weights = tf.get_variable(
"new_output_weights", [num_labels, FLAGS.original_target_size],
initializer=tf.truncated_normal_initializer(stddev=0.02))
new_output_bias = tf.get_variable("new_output_bias", [num_labels],
initializer=tf.zeros_initializer())
with tf.variable_scope("loss"):
if is_training:
# I.e., 0.1 dropout
output_layer = tf.nn.dropout(output_layer, keep_prob=0.9)
logits = tf.matmul(output_layer, output_weights, transpose_b=True)
logits = tf.nn.bias_add(logits, output_bias)
logits = tf.matmul(logits, new_output_weights, transpose_b=True)
logits = tf.nn.bias_add(logits, new_output_bias)
# Labels both for single and multilabel classification
labels = tf.cast(labels, tf.float32)
if multilabel:
probabilities = tf.nn.sigmoid(logits)
tf.logging.info("num_labels:{};logits:{};labels:{}".format(
num_labels, logits, labels))
per_example_loss = tf.nn.sigmoid_cross_entropy_with_logits(
labels=labels, logits=logits)
else:
probabilities = tf.nn.softmax(logits, axis=-1)
per_example_loss = tf.nn.softmax_cross_entropy_with_logits(
labels=labels, logits=logits)
loss = tf.reduce_mean(per_example_loss)
tf.summary.scalar("loss", loss)
return (loss, per_example_loss, logits, probabilities)
def create_model(bert_config, is_training, input_ids, input_mask, segment_ids,
labels, num_labels, multilabel, sent_rels, sentiment,
entailment_rels, entailment, corr_rels, correlation):
"""Creates a classification model."""
model = modeling.BertModel(config=bert_config,
is_training=is_training,
input_ids=input_ids,
input_mask=input_mask,
token_type_ids=segment_ids)
# Here, we are doing a classification task on the entire segment. For
# token-level output, use model.get_sequece_output() instead.
output_layer = model.get_pooled_output()
hidden_size = output_layer.shape[-1].value
output_weights = tf.get_variable(
"output_weights", [num_labels, hidden_size],
initializer=tf.truncated_normal_initializer(stddev=0.02))
output_bias = tf.get_variable("output_bias", [num_labels],
initializer=tf.zeros_initializer())
with tf.variable_scope("loss"):
if is_training:
# I.e., 0.1 dropout
output_layer = tf.nn.dropout(output_layer, keep_prob=0.9)
logits = tf.matmul(output_layer, output_weights, transpose_b=True)
logits = tf.nn.bias_add(logits, output_bias)
# Labels both for single and multilabel classification
labels = tf.cast(labels, tf.float32)
if multilabel:
probabilities = tf.nn.sigmoid(logits)
tf.logging.info("num_labels:{};logits:{};labels:{}".format(
num_labels, logits, labels))
per_example_loss = tf.nn.sigmoid_cross_entropy_with_logits(
labels=labels, logits=logits)
else:
probabilities = tf.nn.softmax(logits, axis=-1)
per_example_loss = tf.nn.softmax_cross_entropy_with_logits(
labels=labels, logits=logits)
loss = tf.reduce_mean(per_example_loss)
# Add regularization based on label relations prior
probs_exp = tf.expand_dims(probabilities, 1)
m = tf.tile(probs_exp, [1, num_labels, 1])
probs_exp_t = tf.transpose(probs_exp, perm=[0, 2, 1])
# Subtract each prediction from all others:
# Example (with batch size=1):
# tiled predictions: [0.1] [0.1] [0.1]
# [0.2] [0.2] [0.2]
# [0.3] [0.3] [0.3]
# subtract [0.1, 0.2, 0.3] row-wise
# result: [0.0] [-.1] [-.2] --> row represents difference between
# emotion 1 and all other emotions
# [0.1] [0.0] [-.1]
# [0.2] [0.1] [0.0]
dists = tf.square(tf.subtract(m, probs_exp_t)) # square distances
dists = tf.transpose(dists, perm=[0, 2, 1])
# Sentiment-based regularization
sent_reg = tf.multiply(
tf.constant(sentiment),
tf.reduce_mean(
tf.multiply(dists, tf.constant(sent_rels, dtype=tf.float32))))
tf.summary.scalar("sentiment_regularization", sent_reg)
loss += sent_reg
# Entailment-based regularization
ent_reg = tf.multiply(
tf.constant(entailment),
tf.reduce_mean(
tf.multiply(dists,
tf.constant(entailment_rels, dtype=tf.float32))))
tf.summary.scalar("entailment_regularization", ent_reg)
loss += ent_reg
# Correlation-based regularization
corr_reg = tf.multiply(
tf.constant(correlation),
tf.reduce_mean(
tf.multiply(dists, tf.constant(corr_rels, dtype=tf.float32))))
tf.summary.scalar("correlation_regularization", corr_reg)
loss += corr_reg
tf.summary.scalar("loss", loss)
return (loss, per_example_loss, logits, probabilities)
