def dynamic_decode_and_search(self,
embedding,
start_tokens,
end_token,
vocab_size=None,
initial_state=None,
beam_width=5,
length_penalty=0.0,
maximum_iterations=250,
memory=None,
memory_sequence_len=None,
memory_out_ids=None,
mode=tf.estimator.ModeKeys.PREDICT):
batch_size = tf.shape(start_tokens)[0]
if initial_state is not None:
initial_state = tf.contrib.seq2seq.tile_batch(
initial_state, multiplier=beam_width)
if memory is not None:
memory = tf.contrib.seq2seq.tile_batch(
memory, multiplier=beam_width)
if memory_sequence_len is not None:
memory_sequence_len = tf.contrib.seq2seq.tile_batch(
memory_sequence_len, multiplier=beam_width)
cell, initial_state = build_cell(
self.num_units, self.num_layers,
initial_state=initial_state,
copy_state=self.copy_state,
cell_fn=self.cell_fn,
batch_size=batch_size * beam_width,
output_dropout_rate=self.output_dropout_rate,
attention_mechanism_fn=self.attention_mechanism_fn,
memory=memory,
memory_sequence_len=memory_sequence_len,
mode=mode)
if vocab_size is not None:
projection_layer = tf.layers.Dense(vocab_size, use_bias=False)
else:
projection_layer = None
decoder = tf.contrib.seq2seq.BeamSearchDecoder(
cell,
embedding,
start_tokens,
end_token,
initial_state,
beam_width,
output_layer=projection_layer,
length_penalty_weight=length_penalty)
outputs, beam_state, length = tf.contrib.seq2seq.dynamic_decode(
decoder, maximum_iterations=maximum_iterations)
predicted_ids = outputs.predicted_ids[:, :, 0]
log_probs = beam_state.log_probs[:, 0]
return predicted_ids, log_probs
def dynamic_decode(self,
embedding,
start_tokens,
end_token,
vocab_size=None,
initial_state=None,
output_layer=None,
maximum_iterations=250,
memory=None,
memory_sequence_len=None,
memory_out_ids=None,
mode=tf.estimator.ModeKeys.PREDICT):
cell, initial_state = build_cell(
self.num_units,
self.num_layers,
initial_state=initial_state,
copy_state=self.copy_state,
cell_fn=self.cell_fn,
output_dropout_rate=self.output_dropout_rate,
attention_mechanism_fn=self.attention_mechanism_fn,
memory=memory,
memory_sequence_len=memory_sequence_len,
mode=mode)
if vocab_size is not None:
projection_layer = tf.layers.Dense(vocab_size, use_bias=False)
else:
projection_layer = None
vocab_size = self.num_units
# helper and decoder
helper = tf.contrib.seq2seq.GreedyEmbeddingHelper(
embedding, start_tokens, end_token)
extended_vocab_size = tf.maximum(
tf.reduce_max(memory_out_ids) + 1, vocab_size)
copying_mechanism = unnormalized_luong_attention(
self.num_units, memory, memory_sequence_len)
cell = CopyingWrapper(cell=cell,
copying_mechanism=copying_mechanism,
memory_out_ids=memory_out_ids,
extended_vocab_size=extended_vocab_size,
output_layer=projection_layer)
initial_state = cell.zero_state(
tf.shape(memory)[0], tf.float32).clone(cell_state=initial_state)
decoder = tf.contrib.seq2seq.BasicDecoder(cell, helper, initial_state)
# decode and extract logits and predictions
outputs, state, _ = tf.contrib.seq2seq.dynamic_decode(
decoder, maximum_iterations=maximum_iterations, swap_memory=True)
logits = outputs.rnn_output
predicted_ids = outputs.sample_id
return predicted_ids, logits
def build(self, node_features_size: int, num_edge_types: int,
mode=tf.estimator.ModeKeys.TRAIN) -> None:
if self.encoder_type == "bidirectional_rnn":
self.fwd_cell = build_cell(
self.num_units/2, self.num_layers,
cell_fn=self.cell_fn,
output_dropout_rate=self.dropout_rate,
# input_shape=tf.TensorShape([None, node_features_size]),
mode=mode,
name="fwd_cell")
self.bwd_cell = build_cell(
self.num_units/2, self.num_layers,
cell_fn=self.cell_fn,
output_dropout_rate=self.dropout_rate,
# input_shape=tf.TensorShape([None, node_features_size]),
mode=mode,
name="bwd_cell")
elif self.encoder_type == "rnn":
self.rnn_cell = build_cell(
self.num_units, self.num_layers,
cell_fn=self.cell_fn,
# input_shape=tf.TensorShape([None, node_features_size]),
output_dropout_rate=self.dropout_rate,
mode=mode)
self.merge_layer = tf.layers.Dense(
self.gnn_input_size if self.gnn_input_size is not None else self.num_units,
use_bias=False)
self.merge_layer.build(
(None, None, node_features_size + self.num_units))
self.base_graph_encoder.build(
self.gnn_input_size if self.gnn_input_size is not None else self.num_units,
num_edge_types)
self.output_map = tf.layers.Dense(
name="output_map",
units=self.num_units,
use_bias=False,
kernel_initializer=eye_glorot)
# same for state map
# TODO: This is much easier to just do in the actual call, this will be cropped there
# in the future needs to be put back in the build method
self.built = True
def build(
self,
initial_node_features_size: int,
num_edge_types: int,
mode: tf.estimator.ModeKeys = tf.estimator.ModeKeys.TRAIN) -> None:
"""
Args:
initial_node_features_size: Dimensionality of initial node features;
will be padded to size of node features used in GNN.
num_edge_types: Number of edge types.
"""
super().build(self.node_features_size, num_edge_types)
self.initial_node_features_size = initial_node_features_size
if self.initial_node_features_size > self.node_features_size:
raise ValueError(
"GGNN currently only support initial features size smaller "
"than state size")
self._message_weights = [] # type: List[tf.Variable]
self._update_grus = [] # type: List[tf.nn.rnn_cell.GRUCell]
self._edge_bias = [] # type: List[tf.Variable]
for layer_id, _ in enumerate(self.timesteps_per_layer):
# weights for the message_fun
self._message_weights.append(
tf.get_variable(name="message_weights_%d" % layer_id,
shape=(self.num_edge_types,
self.node_features_size,
self.node_features_size),
initializer=tf.glorot_normal_initializer()))
# bias for the message_fun
if self.use_edge_bias:
self._edge_bias.append(
tf.get_variable(
"edge_bias_%d" % layer_id,
(self.num_edge_types, self.node_features_size)))
# gru for the update_fun
cell = build_cell(num_units=self.node_features_size,
num_layers=1,
cell_fn=tf.nn.rnn_cell.GRUCell,
output_dropout_rate=self.gru_dropout_rate,
input_shape=tf.TensorShape(
[None, self.node_features_size]),
name="update_gru_%d" % layer_id,
mode=mode)
self._update_grus.append(cell)
# final linear layer
self.final_layer = tf.layers.Dense(self.node_features_size,
use_bias=False)
self.final_layer.build((None, self.node_features_size))
def dynamic_decode(self,
embedding,
start_tokens,
end_token,
vocab_size=None,
initial_state=None,
maximum_iterations=250,
memory=None,
memory_sequence_len=None,
memory_out_ids=None,
mode=tf.estimator.ModeKeys.PREDICT):
cell, initial_state = build_cell(
self.num_units, self.num_layers,
initial_state=initial_state,
cell_fn=self.cell_fn,
copy_state=self.copy_state,
output_dropout_rate=self.output_dropout_rate,
attention_mechanism_fn=self.attention_mechanism_fn,
memory=memory,
memory_sequence_len=memory_sequence_len,
mode=mode)
if vocab_size is not None:
projection_layer = tf.layers.Dense(vocab_size, use_bias=False)
else:
projection_layer = None
# helper and decoder
helper = tf.contrib.seq2seq.GreedyEmbeddingHelper(
embedding, start_tokens, end_token)
decoder = tf.contrib.seq2seq.BasicDecoder(
cell, helper, initial_state,
output_layer=projection_layer)
# decode and extract logits and predictions
outputs, _, _ = tf.contrib.seq2seq.dynamic_decode(
decoder,
maximum_iterations=maximum_iterations,
swap_memory=True)
logits = outputs.rnn_output
ids = outputs.sample_id
return ids, logits
def decode(self,
inputs: tf.Tensor,
sequence_length: tf.Tensor,
vocab_size: int = None,
initial_state: tf.Tensor = None,
sampling_probability=None,
embedding=None,
memory=None,
memory_sequence_len=None,
memory_out_ids=None,
mode=tf.estimator.ModeKeys.TRAIN):
print("decode input:", inputs)
if (sampling_probability is not None and
(isinstance(sampling_probability, tf.Tensor) or sampling_probability > 0.0)):
if embedding is None:
raise ValueError(
"embedding argument must be set when using scheduled sampling")
tf.summary.scalar("sampling_probability", sampling_probability)
helper = tf.contrib.seq2seq.ScheduledEmbeddingTrainingHelper(
inputs,
sequence_length,
embedding,
sampling_probability)
else:
helper = tf.contrib.seq2seq.TrainingHelper(inputs, sequence_length)
cell, initial_state = build_cell(
self.num_units, self.num_layers,
initial_state=initial_state,
copy_state=self.copy_state,
cell_fn=self.cell_fn,
output_dropout_rate=self.output_dropout_rate,
attention_mechanism_fn=self.attention_mechanism_fn,
memory=memory,
memory_sequence_len=memory_sequence_len,
mode=mode,
alignment_history=self.coverage_loss_lambda > 0)
if vocab_size is not None:
projection_layer = tf.layers.Dense(vocab_size, use_bias=False)
else:
projection_layer = None
decoder = tf.contrib.seq2seq.BasicDecoder(
cell, helper, initial_state,
output_layer=projection_layer)
# decode and extract logits and predictions
outputs, state, _ = tf.contrib.seq2seq.dynamic_decode(
decoder,
swap_memory=True)
logits = outputs.rnn_output
ids = outputs.sample_id
if hasattr(state, 'alignment_history') and \
not isinstance(state.alignment_history, tuple):
attention = tf.transpose(
state.alignment_history.stack(), (1, 0, 2))
decoder_loss = self.coverage_loss(attention, memory_sequence_len)
else:
decoder_loss = None
return ids, logits, decoder_loss
def decode(self,
inputs: tf.Tensor,
sequence_length: tf.Tensor,
vocab_size: int = None,
initial_state: tf.Tensor = None,
sampling_probability=None,
embedding=None,
memory=None,
memory_sequence_len=None,
memory_out_ids=None,
mode=tf.estimator.ModeKeys.TRAIN):
if (sampling_probability is not None
and (isinstance(sampling_probability, tf.Tensor)
or sampling_probability > 0.0)):
if embedding is None:
raise ValueError(
"embedding argument must be set when using scheduled sampling"
)
tf.summary.scalar("sampling_probability", sampling_probability)
helper = tf.contrib.seq2seq.ScheduledEmbeddingTrainingHelper(
inputs, sequence_length, embedding, sampling_probability)
else:
helper = tf.contrib.seq2seq.TrainingHelper(inputs, sequence_length)
cell, initial_state = build_cell(
self.num_units,
self.num_layers,
initial_state=initial_state,
copy_state=self.copy_state,
cell_fn=self.cell_fn,
output_dropout_rate=self.output_dropout_rate,
attention_mechanism_fn=self.attention_mechanism_fn,
memory=memory,
memory_sequence_len=memory_sequence_len,
mode=mode,
alignment_history=self.coverage_loss_lambda > 0)
if vocab_size is not None:
projection_layer = tf.layers.Dense(vocab_size, use_bias=False)
else:
projection_layer = None
vocab_size = self.num_units
# helper and decode
helper = tf.contrib.seq2seq.TrainingHelper(inputs,
sequence_length,
time_major=False)
extended_vocab_size = tf.maximum(
tf.reduce_max(memory_out_ids) + 1, tf.cast(vocab_size, tf.int64))
copying_mechanism = unnormalized_luong_attention(
self.num_units, memory, memory_sequence_len)
cell = CopyingWrapper(cell=cell,
copying_mechanism=copying_mechanism,
memory_out_ids=memory_out_ids,
extended_vocab_size=extended_vocab_size,
output_layer=projection_layer)
initial_state = cell.zero_state(
tf.shape(memory)[0], tf.float32).clone(cell_state=initial_state)
decoder = tf.contrib.seq2seq.BasicDecoder(cell, helper, initial_state)
outputs, state, _ = tf.contrib.seq2seq.dynamic_decode(decoder,
swap_memory=True)
print(state.cell_state.alignment_history)
if hasattr(state.cell_state, 'alignment_history') and \
not isinstance(state.cell_state.alignment_history, tuple):
attention = tf.transpose(
state.cell_state.alignment_history.stack(), (1, 0, 2))
decoder_loss = self.coverage_loss(attention, memory_sequence_len)
else:
decoder_loss = None
logits = outputs.rnn_output
ids = outputs.sample_id
return ids, logits, decoder_loss
