def lstm_seq2seq_internal_bid_encoder(inputs, targets, hparams, train):
"""The basic LSTM seq2seq model with bidirectional encoder."""
with tf.variable_scope("lstm_seq2seq_bid_encoder"):
if inputs is not None:
inputs_length = common_layers.length_from_embedding(inputs)
# Flatten inputs.
inputs = common_layers.flatten4d3d(inputs)
# LSTM encoder.
_, final_encoder_state = lstm_bid_encoder(
inputs, inputs_length, hparams, train, "encoder")
else:
inputs_length = None
final_encoder_state = None
# LSTM decoder.
shifted_targets = common_layers.shift_right(targets)
# Add 1 to account for the padding added to the left from shift_right
targets_length = common_layers.length_from_embedding(shifted_targets) + 1
hparams_decoder = copy.copy(hparams)
hparams_decoder.hidden_size = 2 * hparams.hidden_size
decoder_outputs, _ = lstm(
common_layers.flatten4d3d(shifted_targets),
targets_length,
hparams_decoder,
train,
"decoder",
initial_state=final_encoder_state)
return tf.expand_dims(decoder_outputs, axis=2)
def lstm_seq2seq_internal(inputs, targets, hparams, train):
"""The basic LSTM seq2seq model, main step used for training."""
with tf.variable_scope("lstm_seq2seq"):
if inputs is not None:
inputs_length = common_layers.length_from_embedding(inputs)
# Flatten inputs.
inputs = common_layers.flatten4d3d(inputs)
# LSTM encoder.
inputs = tf.reverse_sequence(inputs, inputs_length, seq_axis=1)
_, final_encoder_state = lstm(inputs, inputs_length, hparams, train,
"encoder")
else:
final_encoder_state = None
# LSTM decoder.
shifted_targets = common_layers.shift_right(targets)
# Add 1 to account for the padding added to the left from shift_right
targets_length = common_layers.length_from_embedding(shifted_targets) + 1
decoder_outputs, _ = lstm(
common_layers.flatten4d3d(shifted_targets),
targets_length,
hparams,
train,
"decoder",
initial_state=final_encoder_state)
return tf.expand_dims(decoder_outputs, axis=2)
def body(self, features):
hparams = self._hparams
targets = features["targets"]
inputs = features["inputs"]
target_space = features["target_space_id"]
inputs = common_layers.flatten4d3d(inputs)
targets = common_layers.flatten4d3d(targets)
(encoder_input, encoder_self_attention_bias,
encoder_decoder_attention_bias) = (transformer.transformer_prepare_encoder(
inputs, target_space, hparams))
(decoder_input,
decoder_self_attention_bias) = transformer.transformer_prepare_decoder(
targets, hparams)
encoder_input = tf.nn.dropout(encoder_input,
1.0 - hparams.layer_prepostprocess_dropout)
decoder_input = tf.nn.dropout(decoder_input,
1.0 - hparams.layer_prepostprocess_dropout)
encoder_output = transformer_revnet_encoder(
encoder_input, encoder_self_attention_bias, hparams)
decoder_output = transformer_revnet_decoder(
decoder_input, encoder_output, decoder_self_attention_bias,
encoder_decoder_attention_bias, hparams)
decoder_output = tf.expand_dims(decoder_output, 2)
return decoder_output
def body(self, features):
hp = self.hparams
# pylint: disable=eval-used
if hp.image_input_type == "image":
image_feat = vqa_layers.image_embedding(
features["inputs"],
model_fn=eval(hp.image_model_fn),
trainable=hp.train_resnet,
is_training=hp.mode == tf.estimator.ModeKeys.TRAIN)
else:
image_feat = features["inputs"]
image_feat = common_layers.flatten4d3d(image_feat)
image_feat = common_layers.dense(image_feat, hp.hidden_size)
utils.collect_named_outputs("norms", "image_feat_after_proj",
tf.norm(image_feat, axis=-1))
question = common_layers.flatten4d3d(features["question"])
utils.collect_named_outputs("norms", "question_embedding",
tf.norm(question, axis=-1))
(encoder_input, encoder_self_attention_bias,
encoder_decoder_attention_bias) = prepare_image_question_encoder(
image_feat, question, hp)
encoder_input = tf.nn.dropout(
encoder_input, keep_prob=1.-hp.layer_prepostprocess_dropout)
encoder_output, _ = recurrent_transformer_decoder(
encoder_input, None, encoder_self_attention_bias, None,
hp, name="encoder")
utils.collect_named_outputs(
"norms", "encoder_output", tf.norm(encoder_output, axis=-1))
# scale query by sqrt(hidden_size)
query = tf.get_variable("query", [hp.hidden_size]) * hp.hidden_size **0.5
query = tf.expand_dims(tf.expand_dims(query, axis=0), axis=0)
batch_size = common_layers.shape_list(encoder_input)[0]
query = tf.tile(query, [batch_size, 1, 1])
query = tf.nn.dropout(
query, keep_prob=1.-hp.layer_prepostprocess_dropout)
decoder_output, _ = recurrent_transformer_decoder(
query, encoder_output, None, encoder_decoder_attention_bias,
hp, name="decoder")
utils.collect_named_outputs("norms", "decoder_output",
tf.norm(decoder_output, axis=-1))
norm_tensors = utils.convert_collection_to_dict("norms")
vqa_layers.summarize_tensors(norm_tensors, tag="norms/")
# Expand dimension 1 and 2
return tf.expand_dims(decoder_output, axis=1)
def lstm_seq2seq_internal_attention(inputs, targets, hparams, train):
"""LSTM seq2seq model with attention, main step used for training."""
with tf.variable_scope("lstm_seq2seq_attention"):
# Flatten inputs.
inputs = common_layers.flatten4d3d(inputs)
# LSTM encoder.
encoder_outputs, final_encoder_state = lstm(
tf.reverse(inputs, axis=[1]), hparams, train, "encoder")
# LSTM decoder with attention
shifted_targets = common_layers.shift_right(targets)
decoder_outputs, _ = lstm_attention_decoder(
common_layers.flatten4d3d(shifted_targets), hparams, train, "decoder",
final_encoder_state, encoder_outputs)
return tf.expand_dims(decoder_outputs, axis=2)
def bytenet_internal(inputs, targets, hparams):
"""ByteNet, main step used for training."""
with tf.variable_scope("bytenet"):
# Flatten inputs and extend length by 50%.
inputs = tf.expand_dims(common_layers.flatten4d3d(inputs), axis=2)
extend_length = tf.to_int32(0.5 * tf.to_float(tf.shape(inputs)[1]))
inputs_shape = inputs.shape.as_list()
inputs = tf.pad(inputs, [[0, 0], [0, extend_length], [0, 0], [0, 0]])
inputs_shape[1] = None
inputs.set_shape(inputs_shape) # Don't lose the other shapes when padding.
# Pad inputs and targets to be the same length, divisible by 50.
inputs, targets = common_layers.pad_to_same_length(
inputs, targets, final_length_divisible_by=50)
final_encoder = residual_dilated_conv(inputs, hparams.num_block_repeat,
"SAME", "encoder", hparams)
shifted_targets = common_layers.shift_right(targets)
kernel = (hparams.kernel_height, hparams.kernel_width)
decoder_start = common_layers.conv_block(
tf.concat([final_encoder, shifted_targets], axis=3),
hparams.hidden_size, [((1, 1), kernel)],
padding="LEFT")
return residual_dilated_conv(decoder_start, hparams.num_block_repeat,
"LEFT", "decoder", hparams)
def slicenet_internal(inputs, targets, target_space, hparams, run_decoder=True):
"""The slicenet model, main step used for training."""
with tf.variable_scope("slicenet"):
# Project to hidden size if necessary
if inputs.get_shape().as_list()[-1] != hparams.hidden_size:
inputs = common_layers.conv_block(
inputs,
hparams.hidden_size, [((1, 1), (3, 3))],
first_relu=False,
padding="SAME",
force2d=True)
# Flatten inputs and encode.
inputs = tf.expand_dims(common_layers.flatten4d3d(inputs), axis=2)
inputs_mask = 1.0 - embedding_to_padding(inputs)
inputs = common_layers.add_timing_signal(inputs) # Add position info.
target_space_emb = embed_target_space(target_space, hparams.hidden_size)
extra_layers = int(hparams.num_hidden_layers * 1.5)
inputs_encoded = multi_conv_res(
inputs, "SAME", "encoder", extra_layers, hparams, mask=inputs_mask)
if not run_decoder:
return inputs_encoded
# Do the middle part.
decoder_start, similarity_loss = slicenet_middle(
inputs_encoded, targets, target_space_emb, inputs_mask, hparams)
# Decode.
decoder_final = multi_conv_res(
decoder_start,
"LEFT",
"decoder",
hparams.num_hidden_layers,
hparams,
mask=inputs_mask,
source=inputs_encoded)
return decoder_final, tf.reduce_mean(similarity_loss)
def encode(self, inputs, target_space, hparams, features=None):
"""Encode transformer inputs.
Args:
inputs: Transformer inputs [batch_size, input_length, input_height,
hidden_dim] which will be flattened along the two spatial dimensions.
target_space: scalar, target space ID.
hparams: hyperparmeters for model.
features: optionally pass the entire features dictionary as well.
This is needed now for "packed" datasets.
Returns:
Tuple of:
encoder_output: Encoder representation.
[batch_size, input_length, hidden_dim]
encoder_decoder_attention_bias: Bias and mask weights for
encodre-decoder attention. [batch_size, input_length]
"""
inputs = common_layers.flatten4d3d(inputs)
encoder_input, self_attention_bias, encoder_decoder_attention_bias = (
transformer_prepare_encoder(
inputs, target_space, hparams, features=features))
encoder_input = tf.nn.dropout(encoder_input,
1.0 - hparams.layer_prepostprocess_dropout)
encoder_output = transformer_encoder(
encoder_input, self_attention_bias,
hparams, nonpadding=features_to_nonpadding(features, "inputs"),
save_weights_to=self.attention_weights)
return encoder_output, encoder_decoder_attention_bias
def preprocess_targets(targets, i):
"""Performs preprocessing steps on the targets to prepare for the decoder.
This includes:
- Embedding the ids.
- Flattening to 3D tensor.
- Optionally adding timing signals.
Args:
targets: inputs ids to the decoder. [batch_size, 1]
i: scalar, Step number of the decoding loop.
Returns:
Processed targets [batch_size, 1, hidden_dim]
"""
# _shard_features called to ensure that the variable names match
targets = self._shard_features({"targets": targets})["targets"]
with tf.variable_scope(target_modality.name):
targets = target_modality.targets_bottom_sharded(targets, dp)[0]
targets = common_layers.flatten4d3d(targets)
# TODO(llion): Explain! Is this even needed?
targets = tf.cond(
tf.equal(i, 0), lambda: tf.zeros_like(targets), lambda: targets)
if hparams.pos == "timing":
targets += timing_signal[:, i:i + 1]
return targets
def transformer_text_encoder(inputs,
target_space,
hparams,
name=None):
"""Transformer text encoder over inputs with unmasked full attention.
Args:
inputs: Tensor of shape [batch, length, 1, hparams.hidden_size].
target_space: int. Used for encoding inputs under a target space id.
hparams: tf.contrib.training.HParams.
name: string, variable scope.
Returns:
encoder_output: Tensor of shape [batch, length, hparams.hidden_size].
ed: Tensor of shape [batch, 1, 1, length]. Encoder-decoder attention bias
for any padded tokens.
"""
with tf.variable_scope(name, default_name="transformer_text_encoder"):
inputs = common_layers.flatten4d3d(inputs)
[
encoder_input,
encoder_self_attention_bias,
ed,
] = transformer_layers.transformer_prepare_encoder(
inputs, target_space=target_space, hparams=hparams)
encoder_input = tf.nn.dropout(encoder_input, 1.0 - hparams.dropout)
encoder_output = transformer_layers.transformer_encoder(
encoder_input, encoder_self_attention_bias, hparams)
return encoder_output, ed
def model_fn_body(self, features):
"""Transformer main model_fn.
Args:
features: Map of features to the model. Should contain the following:
"inputs": Transformer inputs [batch_size, input_length, hidden_dim]
"tragets": Target decoder outputs.
[batch_size, decoder_length, hidden_dim]
"target_space_id"
Returns:
Final decoder representation. [batch_size, decoder_length, hidden_dim]
"""
hparams = self._hparams
inputs = features.get("inputs")
encoder_output, encoder_decoder_attention_bias = (None, None)
if inputs is not None:
target_space = features["target_space_id"]
encoder_output, encoder_decoder_attention_bias = self.encode(
inputs, target_space, hparams, features=features)
targets = features["targets"]
targets = common_layers.flatten4d3d(targets)
decoder_input, decoder_self_attention_bias = transformer_prepare_decoder(
targets, hparams, features=features)
return self.decode(decoder_input, encoder_output,
encoder_decoder_attention_bias,
decoder_self_attention_bias, hparams,
nonpadding=_features_to_nonpadding(features, "targets"))
def transformer_text_encoder(x,
space_id,
hparams,
name="transformer_text_encoder"):
"""Transformer text encoder over inputs with unmasked full attention.
Args:
x: Tensor of shape [batch, length, 1, hparams.hidden_size].
space_id: int, id.
hparams: tf.contrib.training.HParams.
name: string, variable scope.
Returns:
encoder_output: Tensor of shape [batch, length, hparams.hidden_size].
ed: Tensor of shape [batch, 1, 1, length]. Encoder-decoder attention bias
for any padded tokens.
"""
with tf.variable_scope(name):
x = common_layers.flatten4d3d(x)
(encoder_input, encoder_self_attention_bias,
ed) = transformer.transformer_prepare_encoder(x, space_id, hparams)
encoder_input = tf.nn.dropout(encoder_input, 1.0 - hparams.dropout)
encoder_output = transformer.transformer_encoder(
encoder_input, encoder_self_attention_bias, hparams)
return encoder_output, ed
def body(self, features):
hp = self.hparams
# pylint: disable=eval-used
if hp.image_input_type == "image":
image_feat = vqa_layers.image_embedding(
features["inputs"],
model_fn=eval(hp.image_model_fn),
trainable=hp.train_resnet,
is_training=hp.mode == tf.estimator.ModeKeys.TRAIN)
else:
image_feat = features["inputs"]
image_feat = common_layers.flatten4d3d(image_feat)
# image feature self attention
# image_feat = tf.nn.dropout(
# image_feat, keep_prob=1.-hp.layer_prepostprocess_dropout)
# image_feat = image_feat - tf.reduce_mean(
# image_feat, axis=-1, keepdims=True)
# image_feat = tf.nn.l2_normalize(image_feat, -1)
# utils.collect_named_outputs("norms", "image_feat_after_l2",
# tf.norm(image_feat, axis=-1))
image_feat = tf.nn.dropout(image_feat, keep_prob=1.-hp.dropout)
image_feat = image_encoder(image_feat, hp)
utils.collect_named_outputs("norms", "image_feat_encoded",
tf.norm(image_feat, axis=-1))
image_feat = common_layers.l2_norm(image_feat)
utils.collect_named_outputs("norms", "image_feat_encoded_l2",
tf.norm(image_feat, axis=-1))
query = question_encoder(features["question"], hp)
utils.collect_named_outputs("norms", "query",
tf.norm(query, axis=-1))
image_ave = attn(image_feat, query, hp)
utils.collect_named_outputs("norms", "image_ave",
tf.norm(image_ave, axis=-1))
image_question = tf.concat([image_ave, query], axis=1)
utils.collect_named_outputs("norms", "image_question",
tf.norm(image_question, axis=-1))
image_question = tf.nn.dropout(image_question, 1. - hp.dropout)
output = mlp(image_question, hp)
utils.collect_named_outputs("norms", "output",
tf.norm(output, axis=-1))
norm_tensors = utils.convert_collection_to_dict("norms")
vqa_layers.summarize_tensors(norm_tensors, tag="norms/")
# Expand dimension 1 and 2
return tf.expand_dims(tf.expand_dims(output, axis=1), axis=2)
def decode_transformer(encoder_output,
encoder_decoder_attention_bias,
targets,
hparams,
name,
task=None):
"""Original Transformer decoder."""
with tf.variable_scope(name):
if task is None:
task = hparams.task
if task == "translate":
targets = common_layers.flatten4d3d(targets)
decoder_input, decoder_self_bias = (
transformer.transformer_prepare_decoder(targets, hparams))
decoder_input = tf.nn.dropout(decoder_input,
1.0 - hparams.layer_prepostprocess_dropout)
decoder_output = transformer.transformer_decoder(
decoder_input,
encoder_output,
decoder_self_bias,
encoder_decoder_attention_bias,
hparams)
decoder_output = tf.expand_dims(decoder_output, axis=2)
else:
assert task == "image"
inputs = None
# have to reshape targets as b, 32, 32, 3 * hidden size] beacuse otherwise
# prepare_image will choke
targets = tf.reshape(targets, [tf.shape(targets)[0], hparams.img_len,
hparams.img_len,
hparams.num_channels*hparams.hidden_size])
# Prepare decoder inputs and bias.
decoder_input, _, _, bias = cia.prepare_decoder(targets, hparams)
# Add class label to decoder input.
if not hparams.drop_inputs:
decoder_input += tf.reshape(
inputs,
[common_layers.shape_list(targets)[0], 1, 1, hparams.hidden_size])
decoder_output = cia.transformer_decoder_layers(
decoder_input,
None,
bias,
hparams.num_decoder_layers or hparams.num_hidden_layers,
hparams,
attention_type=hparams.dec_attention_type,
name="decoder")
decoder_output_shape = common_layers.shape_list(decoder_output)
decoder_output = tf.reshape(decoder_output, [decoder_output_shape[0], -1, 1,
hparams.hidden_size])
# Expand since t2t expects 4d tensors.
return decoder_output
def body(self, features):
if self._hparams.initializer == "orthogonal":
raise ValueError("LSTM models fail with orthogonal initializer.")
train = self._hparams.mode == tf.estimator.ModeKeys.TRAIN
inputs = features.get("inputs")
# Flatten inputs.
inputs = common_layers.flatten4d3d(inputs)
# LSTM encoder.
encoder_output, _ = lstm(
tf.reverse(inputs, axis=[1]), self._hparams, train, "encoder")
return tf.expand_dims(encoder_output, axis=2)
def lstm_seq2seq_internal(inputs, targets, hparams, train):
"""The basic LSTM seq2seq model, main step used for training."""
with tf.variable_scope("lstm_seq2seq"):
if inputs is not None:
# Flatten inputs.
inputs = common_layers.flatten4d3d(inputs)
# LSTM encoder.
_, final_encoder_state = lstm(
tf.reverse(inputs, axis=[1]), hparams, train, "encoder")
else:
final_encoder_state = None
# LSTM decoder.
shifted_targets = common_layers.shift_right(targets)
decoder_outputs, _ = lstm(
common_layers.flatten4d3d(shifted_targets),
hparams,
train,
"decoder",
initial_state=final_encoder_state)
return tf.expand_dims(decoder_outputs, axis=2)
def lstm_seq2seq_internal_attention(inputs, targets, hparams, train,
inputs_length, targets_length):
"""LSTM seq2seq model with attention, main step used for training."""
with tf.variable_scope("lstm_seq2seq_attention"):
# Flatten inputs.
inputs = common_layers.flatten4d3d(inputs)
# LSTM encoder.
inputs = tf.reverse_sequence(inputs, inputs_length, seq_axis=1)
encoder_outputs, final_encoder_state = lstm(
inputs, inputs_length, hparams, train, "encoder")
# LSTM decoder with attention.
shifted_targets = common_layers.shift_right(targets)
# Add 1 to account for the padding added to the left from shift_right
targets_length = targets_length + 1
decoder_outputs = lstm_attention_decoder(
common_layers.flatten4d3d(shifted_targets), hparams, train, "decoder",
final_encoder_state, encoder_outputs, inputs_length, targets_length)
return tf.expand_dims(decoder_outputs, axis=2)
def lstm_seq2seq_internal_attention_bid_encoder(inputs, targets, hparams,
train):
"""LSTM seq2seq model with attention, main step used for training."""
with tf.variable_scope("lstm_seq2seq_attention_bid_encoder"):
inputs_length = common_layers.length_from_embedding(inputs)
# Flatten inputs.
inputs = common_layers.flatten4d3d(inputs)
# LSTM encoder.
encoder_outputs, final_encoder_state = lstm_bid_encoder(
inputs, inputs_length, hparams, train, "encoder")
# LSTM decoder with attention
shifted_targets = common_layers.shift_right(targets)
# Add 1 to account for the padding added to the left from shift_right
targets_length = common_layers.length_from_embedding(shifted_targets) + 1
hparams_decoder = copy.copy(hparams)
hparams_decoder.hidden_size = 2 * hparams.hidden_size
decoder_outputs = lstm_attention_decoder(
common_layers.flatten4d3d(shifted_targets), hparams_decoder, train,
"decoder", final_encoder_state, encoder_outputs,
inputs_length, targets_length)
return tf.expand_dims(decoder_outputs, axis=2)
def _prepare_decoder(self, targets):
"""Process the transformer decoder input."""
targets = common_layers.flatten4d3d(targets)
output = transformer.transformer_prepare_decoder(
targets, self._hparams, features=None,
)
deco_input, deco_self_attention_bias = output
deco_input = tf.nn.dropout(
deco_input, 1.0 - self._hparams.layer_prepostprocess_dropout
)
return deco_input, deco_self_attention_bias
def lstm_seq2seq_internal_bid_encoder(inputs, targets, hparams, train):
"""The basic LSTM seq2seq model with bidirectional encoder."""
with tf.variable_scope("lstm_seq2seq_bid_encoder"):
if inputs is not None:
# Flatten inputs.
inputs = common_layers.flatten4d3d(inputs)
# LSTM encoder.
_, final_encoder_state = lstm_bid_encoder(
tf.reverse(inputs, axis=[1]), hparams, train, "encoder")
else:
final_encoder_state = None
# LSTM decoder.
shifted_targets = common_layers.shift_right(targets)
hparams_decoder = copy.copy(hparams)
hparams_decoder.hidden_size = 2 * hparams.hidden_size
decoder_outputs, _ = lstm(
common_layers.flatten4d3d(shifted_targets),
hparams_decoder,
train,
"decoder",
initial_state=final_encoder_state)
return tf.expand_dims(decoder_outputs, axis=2)
def body(self, features):
if self._hparams.initializer == "orthogonal":
raise ValueError("LSTM models fail with orthogonal initializer.")
train = self._hparams.mode == tf.estimator.ModeKeys.TRAIN
inputs = features.get("inputs")
inputs_length = common_layers.length_from_embedding(inputs)
# Flatten inputs.
inputs = common_layers.flatten4d3d(inputs)
# LSTM encoder.
inputs = tf.reverse_sequence(inputs, inputs_length, seq_axis=1)
encoder_output, _ = lstm(inputs, inputs_length, self._hparams, train,
"encoder")
return tf.expand_dims(encoder_output, axis=2)
def question_encoder(question, hparams, name="encoder"):
"""Question encoder, run LSTM encoder and get the last output as encoding."""
with tf.variable_scope(name, "encoder", values=[question]):
question = common_layers.flatten4d3d(question)
padding = common_attention.embedding_to_padding(question)
length = common_attention.padding_to_length(padding)
max_question_length = hparams.max_question_length
question = question[:, :max_question_length, :]
actual_question_length = common_layers.shape_list(question)[1]
length = tf.minimum(length, max_question_length)
padding = [[0, 0],
[0, max_question_length-actual_question_length],
[0, 0]]
question = tf.pad(question, padding)
question_shape = question.get_shape().as_list()
question_shape[1] = max_question_length
question.set_shape(question_shape)
# apply tanh dropout on question embedding
question = tf.tanh(question)
question = tf.nn.dropout(question, keep_prob=1.-hparams.dropout)
question = [question[:, i, :] for i in range(max_question_length)]
# rnn_layers = [_get_rnn_cell(hparams)
# for _ in range(hparams.num_rnn_layers)]
# rnn_multi_cell = tf.contrib.rnn.MultiRNNCell(rnn_layers)
rnn_cell = _get_rnn_cell(hparams)
# outputs, _ = tf.nn.dynamic_rnn(
# rnn_cell, question, length, dtype=tf.float32)
_, state = tf.nn.static_rnn(rnn_cell, question, sequence_length=length,
dtype=tf.float32)
# outputs = [tf.expand_dims(output, axis=1) for output in outputs]
# outputs = tf.concat(outputs, axis=1)
# utils.collect_named_outputs("vqa_attention_debug", "question_output",
# outputs)
# utils.collect_named_outputs("vqa_attention_debug", "question_state",
# state.h)
# batch_size = common_layers.shape_list(outputs)[0]
# row_indices = tf.range(batch_size)
# # length - 1 as index
# indices = tf.transpose([row_indices, tf.maximum(length-1, 0)])
# last_output = tf.gather_nd(outputs, indices)
# utils.collect_named_outputs("vqa_attention_debug",
# "question_final_output", last_output)
return state.h
def slicenet_middle(inputs_encoded, targets, target_space_emb, mask, hparams):
"""Middle part of slicenet, connecting encoder and decoder."""
def norm_fn(x, name):
with tf.variable_scope(name, default_name="norm"):
return common_layers.apply_norm(x, hparams.norm_type, hparams.hidden_size,
hparams.norm_epsilon)
# Flatten targets and embed target_space_id.
targets_flat = tf.expand_dims(common_layers.flatten4d3d(targets), axis=2)
target_space_emb = tf.tile(target_space_emb,
[tf.shape(targets_flat)[0], 1, 1, 1])
# Calculate similarity loss (but don't run if not needed).
if len(hparams.problems) > 1 and hparams.sim_loss_mult > 0.00001:
targets_timed = common_layers.add_timing_signal(targets_flat)
extra_layers = int(hparams.num_hidden_layers * 1.5)
with tf.variable_scope(tf.get_variable_scope(), reuse=True):
targets_encoded = multi_conv_res(targets_timed, "SAME", "encoder",
extra_layers, hparams)
with tf.variable_scope("similarity_loss"):
similarity_loss = similarity_cost(inputs_encoded, targets_encoded)
similarity_loss *= hparams.sim_loss_mult
else:
similarity_loss = 0.0
# Use attention from each target to look at input and retrieve.
targets_shifted = common_layers.shift_right(
targets_flat, pad_value=target_space_emb)
if hparams.attention_type == "none":
targets_with_attention = tf.zeros_like(targets_shifted)
else:
inputs_padding_bias = (1.0 - mask) * -1e9 # Bias to not attend to padding.
targets_with_attention = attention(
targets_shifted,
inputs_encoded,
norm_fn,
hparams,
bias=inputs_padding_bias)
# Positional targets: merge attention and raw.
kernel = (hparams.kernel_height, hparams.kernel_width)
targets_merged = common_layers.subseparable_conv_block(
tf.concat([targets_with_attention, targets_shifted], axis=3),
hparams.hidden_size, [((1, 1), kernel)],
normalizer_fn=norm_fn,
padding="LEFT",
separability=4,
name="targets_merge")
return targets_merged, similarity_loss
def lstm_seq2seq_internal_attention(inputs, targets, hparams, train):
"""LSTM seq2seq model with attention, main step used for training."""
with tf.variable_scope("lstm_seq2seq_attention"):
# This is a temporary fix for varying-length sequences within in a batch.
# A more complete fix should pass a length tensor from outside so that
# all the lstm variants can use it.
inputs_length = common_layers.length_from_embedding(inputs)
# Flatten inputs.
inputs = common_layers.flatten4d3d(inputs)
# LSTM encoder.
inputs = tf.reverse_sequence(inputs, inputs_length, seq_axis=1)
encoder_outputs, final_encoder_state = lstm(
inputs, inputs_length, hparams, train, "encoder")
# LSTM decoder with attention.
shifted_targets = common_layers.shift_right(targets)
# Add 1 to account for the padding added to the left from shift_right
targets_length = common_layers.length_from_embedding(shifted_targets) + 1
decoder_outputs = lstm_attention_decoder(
common_layers.flatten4d3d(shifted_targets), hparams, train, "decoder",
final_encoder_state, encoder_outputs, inputs_length, targets_length)
return tf.expand_dims(decoder_outputs, axis=2)
def targets_bottom(self, inputs):
with tf.variable_scope(self.name):
# Reshape inputs to 2-d tensor and embed the RGB pixel values.
ret = common_layers.embedding(
tf.to_int32(common_layers.flatten4d3d(inputs)),
self.top_dimensionality,
self._body_input_depth,
name="input_rgb_embedding")
if self._model_hparams.multiply_embedding_mode == "sqrt_depth":
ret *= self._body_input_depth**0.5
reshape_shape = common_layers.shape_list(inputs)[:3]
reshape_shape.append(self._body_input_depth * 3)
ret = tf.reshape(ret, reshape_shape)
return tf.layers.dense(ret, self._body_input_depth)
def _prepare_encoder(self, inputs, target_space):
"""Process the transformer encoder inputs."""
inputs = common_layers.flatten4d3d(inputs)
output = transformer.transformer_prepare_encoder(
inputs,
target_space,
self._hparams,
features=None,
)
enco_input, enco_self_att_bias, enco_deco_att_bias = output
enco_input = tf.nn.dropout(
enco_input, 1.0 - self._hparams.layer_prepostprocess_dropout)
return enco_input, enco_self_att_bias, enco_deco_att_bias
def encode(self, inputs, target_space, hparams, features=None, losses=None):
"""Encode Universal Transformer inputs.
It is similar to "transformer.encode", but it uses
"universal_transformer_util.universal_transformer_encoder" instead of
"transformer.transformer_encoder".
Args:
inputs: Transformer inputs [batch_size, input_length, input_height,
hidden_dim] which will be flattened along the two spatial dimensions.
target_space: scalar, target space ID.
hparams: hyperparmeters for model.
features: optionally pass the entire features dictionary as well.
This is needed now for "packed" datasets.
losses: Unused.
Returns:
Tuple of:
encoder_output: Encoder representation.
[batch_size, input_length, hidden_dim]
encoder_decoder_attention_bias: Bias and mask weights for
encoder-decoder attention. [batch_size, input_length]
encoder_extra_output: which is extra encoder output used in some
variants of the model (e.g. in ACT, to pass the ponder-time to body)
"""
del losses
inputs = common_layers.flatten4d3d(inputs)
encoder_input, self_attention_bias, encoder_decoder_attention_bias = (
transformer.transformer_prepare_encoder(
inputs, target_space, hparams, features=features))
encoder_input = tf.nn.dropout(encoder_input,
1.0 - hparams.layer_prepostprocess_dropout)
(encoder_output, encoder_extra_output) = (
universal_transformer_util.universal_transformer_encoder(
encoder_input,
self_attention_bias,
hparams,
nonpadding=transformer.features_to_nonpadding(features, "inputs"),
save_weights_to=self.attention_weights))
return encoder_output, encoder_decoder_attention_bias, encoder_extra_output
def body(self, features):
hparams = self._hparams
inputs = features["inputs"]
target_space = features["target_space_id"]
inputs = common_layers.flatten4d3d(inputs)
(encoder_input, encoder_self_attention_bias, _) = (
transformer_prepare_encoder(inputs, target_space, hparams))
encoder_input = tf.nn.dropout(encoder_input,
1.0 - hparams.layer_prepostprocess_dropout)
encoder_output = transformer_encoder(
encoder_input, encoder_self_attention_bias, hparams,
nonpadding=features_to_nonpadding(features, "inputs"))
encoder_output = tf.expand_dims(encoder_output, 2)
return encoder_output
def body(self, features):
"""Transformer main model_fn.
Args:
features: Map of features to the model. Should contain the following:
"inputs": Transformer inputs [batch_size, input_length, hidden_dim]
"tragets": Target decoder outputs.
[batch_size, decoder_length, hidden_dim]
"target_space_id"
Returns:
Final decoder representation. [batch_size, decoder_length, hidden_dim]
"""
hparams = self._hparams
if self.has_input:
inputs = features["inputs"]
target_space = features["target_space_id"]
encoder_output, encoder_decoder_attention_bias = self.encode(
inputs, target_space, hparams, features=features)
else:
encoder_output, encoder_decoder_attention_bias = (None, None)
targets = features["targets"]
targets = common_layers.flatten4d3d(targets)
decoder_input, decoder_self_attention_bias = transformer_prepare_decoder(
targets, hparams, features=features)
decoder_output = self.decode(
decoder_input,
encoder_output,
encoder_decoder_attention_bias,
decoder_self_attention_bias,
hparams,
nonpadding=features_to_nonpadding(features, "targets"))
expected_attentions = features.get("expected_attentions")
if expected_attentions is not None:
attention_loss = common_attention.encoder_decoder_attention_loss(
expected_attentions, self.attention_weights)
return decoder_output, {"attention_loss": attention_loss}
return decoder_output
def encode(self, features, input_key):
hparams = self._hparams
inputs = common_layers.flatten4d3d(features[input_key])
(encoder_input, encoder_self_attention_bias, _) = (
transformer.transformer_prepare_encoder(inputs, problem.SpaceID.EN_TOK,
hparams))
encoder_input = tf.nn.dropout(encoder_input,
1.0 - hparams.layer_prepostprocess_dropout)
encoder_output = transformer.transformer_encoder(
encoder_input,
encoder_self_attention_bias,
hparams,
nonpadding=transformer.features_to_nonpadding(features, input_key))
encoder_output = tf.reduce_mean(encoder_output, axis=1)
return encoder_output
def internal(self, features, real_features):
"""Main procedure for both training and inference."""
inputs = common_layers.flatten4d3d(features["inputs"])
targets = common_layers.flatten4d3d(features["targets"])
target_space = features["target_space_id"]
hparams = self._hparams
inputs_mask = ops.embedding_to_non_padding(inputs)
inputs_length = tf.reduce_sum(inputs_mask, axis=-1)
encoder_output, encoder_decoder_attention_bias = (ops.encoder(
"encoder", hparams, inputs, target_space))
kwargs = {
"encoder_output": encoder_output,
"encoder_decoder_attention_bias": encoder_decoder_attention_bias
}
losses, monitor = {}, {}
log_abs_det = tf.constant(0.0)
if not self.is_predicting:
# Training
targets_mask = ops.embedding_to_non_padding(targets)
targets_length = tf.reduce_sum(targets_mask, axis=-1)
length_diff = targets_length - inputs_length
decoder_self_attention_bias = (
common_attention.attention_bias_ignore_padding(1.0 -
targets_mask))
z_q, log_q_z, q_dist = self.sample_q(targets,
targets_mask,
decoder_self_attention_bias,
n_samples=1,
temp=1.0,
**kwargs)
body_output = ops.decoder("decoder", z_q, hparams,
decoder_self_attention_bias, **kwargs)
logits = self.top(body_output, real_features)
numerator, denominator = self.loss(logits, real_features)
if not (self.is_evaluating and (hparams.compute_kl_refinement
or hparams.compute_iw_marginal)):
targets_length_pred, lenpred_loss = ops.predict_target_lengths(
encoder_output, inputs_mask, hparams, length_diff)
log_p_z_base, log_abs_det = self.compute_prior_log_prob(
z_q,
targets_mask,
decoder_self_attention_bias,
check_invertibility=False,
**kwargs)
losses, monitor = ops.save_log_loss(
hparams, targets_mask, numerator, denominator, log_q_z,
log_abs_det, log_p_z_base, z_q, lenpred_loss,
targets_length_pred, targets_length)
if self.is_evaluating:
if hparams.compute_kl_refinement:
z_p, _ = self.sample_p(targets_length,
temp=self._decode_hparams.temp,
check_invertibility=False,
targets_mask=targets_mask,
**kwargs)
z_dq = self.delta_posterior(
z_p, targets_mask, decoder_self_attention_bias,
self._decode_hparams.n_gibbs_steps, **kwargs)
log_q_z_ = q_dist.log_prob(z_dq)
log_q_z_ = gops.reduce_mean_over_bl_sum_over_c(
log_q_z_, targets_mask)
losses = {"training": log_q_z_}
if hparams.compute_iw_marginal:
# if True:
log_p_y_x = self.compute_iw_marginal(
targets, targets_mask, decoder_self_attention_bias,
real_features, self._decode_hparams.n_samples,
**kwargs)
# real_features, 1, **kwargs)
losses = {"training": log_p_y_x}
return logits, losses, monitor, targets_mask
else:
# Inference
targets_length, _ = ops.predict_target_lengths(
encoder_output, inputs_mask, hparams)
targets_mask = ops.sequence_mask(targets_length, hparams)
decoder_self_attention_bias = (
common_attention.attention_bias_ignore_padding(1.0 -
targets_mask))
z_p, _ = self.sample_p(targets_length,
temp=self._decode_hparams.temp,
check_invertibility=False,
**kwargs)
z_q = self.delta_posterior(z_p, targets_mask,
decoder_self_attention_bias,
self._decode_hparams.n_gibbs_steps,
**kwargs)
# 0, **kwargs)
body_output = ops.decoder("decoder", z_q, hparams,
decoder_self_attention_bias, **kwargs)
return body_output, losses, monitor, targets_mask
def ae_transformer_internal(inputs,
targets,
target_space,
hparams,
cache=None,
predict_mask=1.0):
"""AE Transformer, main step used for training."""
# Summaries break with the do_refine cond, turn them off in that case.
global _DO_SUMMARIES
if hparams.do_refine:
_DO_SUMMARIES = False
# Prepare.
if inputs is not None:
batch_size = common_layers.shape_list(inputs)[0]
else:
batch_size = common_layers.shape_list(targets)[0]
targets = tf.reshape(targets, [batch_size, -1, 1, hparams.hidden_size])
# Encoder.
if inputs is not None:
inputs = common_layers.flatten4d3d(inputs)
inputs, ed = encode(inputs, target_space, hparams, "input_enc")
inputs_ex, ed_ex = inputs, ed
else:
ed, inputs_ex, ed_ex = None, None, None
# Autoencoding.
losses = {
"extra": tf.constant(0.0),
"latent_pred": tf.constant(0.0),
"neg_q_entropy": tf.constant(0.0)
}
if hparams.do_ae:
# flatten here
original_targets_shape = tf.shape(targets)
if hparams.task == "image":
cia.maybe_reshape_4d_to_3d(targets)
if hparams.task == "translate":
if inputs is not None:
max_targets_len_from_inputs = tf.concat([inputs, inputs],
axis=1)
else:
max_targets_len_from_inputs = targets
else:
assert hparams.task == "image"
max_targets_len_from_inputs = targets
if hparams.word_shuffle:
tf.logging.info("Using word shuffle with rate = {}".format(
hparams.word_shuffle))
targets_idx = tf.range(start=0,
limit=common_layers.shape_list(targets)[1],
delta=1)
targets_idx = tf.to_float(targets_idx)
noise = tf.random_uniform(
shape=common_layers.shape_list(targets_idx),
minval=0,
maxval=1 + hparams.word_shuffle)
targets_idx += noise
permutation = tf.contrib.framework.argsort(targets_idx)
targets_permuted = tf.gather(targets, indices=permutation, axis=1)
targets = targets_permuted
targets, _ = common_layers.pad_to_same_length(
targets,
max_targets_len_from_inputs,
final_length_divisible_by=2**hparams.num_compress_steps)
if hparams.word_dropout:
mask = tf.random_uniform(shape=common_layers.shape_list(targets),
minval=0.0,
maxval=1.0)
targets_noisy = tf.where(mask > hparams.word_dropout, targets,
tf.zeros_like(targets))
else:
targets_noisy = targets
targets_c = compress(targets_noisy, inputs, False, hparams, "compress")
if hparams.mode != tf.estimator.ModeKeys.PREDICT:
# Compress and bottleneck.
latents_dense, latents_discrete, extra_loss, embed, neg_q_entropy = (
hparams.bottleneck(inputs=targets_c,
filter_size=hparams.compress_filter_size,
mode=hparams.mode,
name="vc"))
if _DO_SUMMARIES:
tf.summary.histogram(
"b0", tf.reshape(latents_discrete[:, 0, :], [-1]))
pc = common_layers.inverse_exp_decay(hparams.startup_steps)
pc = pc if hparams.mode == tf.estimator.ModeKeys.TRAIN else 1.0
cond = tf.less(tf.random_uniform([batch_size]), pc)
latents_dense = tf.where(cond, latents_dense, targets_c)
# TODO(lukaszkaiser): return extra losses batchwise, multiply before mean.
losses["extra"] = extra_loss * tf.reduce_mean(tf.to_float(cond))
# Extra loss predicting latent code from input. Discrete only.
if hparams.bottleneck_kind not in ["dense", "vae"]:
latents_pred = decode_transformer(inputs_ex,
ed_ex,
embed(latents_discrete),
hparams,
"extra",
task="translate")
_, latent_pred_loss = ae_latent_softmax(
latents_pred, tf.stop_gradient(latents_discrete), hparams)
# Scale by latent dimension for summary so we can compare across
# batches.
if _DO_SUMMARIES:
tf.summary.scalar("latent_pred_loss_mean",
tf.reduce_mean(latent_pred_loss))
if hparams.sum_over_latents:
latent_pred_loss = tf.reduce_sum(latent_pred_loss, [1, 2])
losses["latent_pred"] = tf.reduce_mean(
latent_pred_loss * tf.to_float(cond)) * hparams.prior_scale
losses["neg_q_entropy"] = neg_q_entropy * hparams.entropy_scale
else:
inputs_c = decode_transformer(inputs, ed, targets_c, hparams,
"dec_c")
losses["latent_pred"] = tf.reduce_mean(
(inputs_c - targets_c)**2) * 20
def bn_inputs():
with tf.variable_scope(tf.get_variable_scope(),
reuse=True):
bn, _, _, _, _ = hparams.bottleneck(
inputs=inputs_c,
filter_size=hparams.compress_filter_size,
mode=hparams.mode,
name="vc")
return bn
inputs_c = bn_inputs()
ptc = 1.0 - common_layers.inverse_lin_decay(200000) * 0.5
ptc = ptc if hparams.mode == tf.estimator.ModeKeys.TRAIN else 1.0
latents_dense = tf.where(
tf.less(tf.random_uniform([batch_size]), ptc),
latents_dense, inputs_c)
else:
if hparams.bottleneck_kind in ["dense", "vae"]:
inputs_c = decode_transformer(inputs, ed, targets_c, hparams,
"dec_c")
latents_dense, _, _, _, _ = hparams.bottleneck(
inputs=inputs_c,
filter_size=hparams.compress_filter_size,
mode=hparams.mode,
name="vc")
else:
latent_len = common_layers.shape_list(targets_c)[1]
_, _, _, embed, _ = hparams.bottleneck(
inputs=targets_c,
filter_size=hparams.compress_filter_size,
name="vc")
latents_dense = tf.zeros_like(targets_c[:, :latent_len, :, :])
if cache is None:
cache = ae_latent_sample(latents_dense, inputs_ex, ed_ex,
embed, 16, hparams)
latents_dense = embed(cache)
# Postprocess.
d = latents_dense
latent_len = common_layers.shape_list(latents_dense)[1]
if isinstance(latent_len, tf.Tensor):
# TODO(trandustin): Fix this in a better manner.
latent_len = max(1000, hparams.max_length)
pos = tf.get_variable("pos",
[1, latent_len + 1, 1, hparams.hidden_size])
pos = pos[:, :common_layers.shape_list(latents_dense)[1] + 1, :, :]
latents_dense = tf.pad(latents_dense,
[[0, 0], [1, 0], [0, 0], [0, 0]]) + pos
# decompressing the dense latents
for i in range(hparams.num_compress_steps):
j = hparams.num_compress_steps - i - 1
d = residual_conv(d, 1, (3, 1), hparams, "decompress_rc_%d" % j)
if inputs is not None and hparams.do_attend_decompress:
d = attend(d, inputs, hparams, "decompress_attend_%d" % j)
d = decompress_step(d, hparams, i > 0, False, "decompress_%d" % j)
# Masking.
if hparams.do_mask:
masking = common_layers.inverse_lin_decay(
hparams.mask_startup_steps)
masking *= common_layers.inverse_exp_decay(
hparams.mask_startup_steps // 4) # Not much at start.
if not hparams.do_refine:
masking -= tf.random_uniform([]) * hparams.unmasked_percentage
masking = tf.minimum(tf.maximum(masking, 0.0), 1.0)
if hparams.use_predict_mask:
masking = predict_mask
if hparams.mode == tf.estimator.ModeKeys.PREDICT:
masking = predict_mask
mask = tf.less(
masking,
tf.random_uniform(common_layers.shape_list(targets)[:-1]))
mask = tf.expand_dims(tf.to_float(mask), 3)
# targets is always [batch, length, 1, depth]
targets = mask * targets + (1.0 - mask) * d
# reshape back to 4d here
if hparams.task == "image":
targets = tf.reshape(targets, original_targets_shape)
res = decode_transformer(inputs,
ed,
targets,
hparams,
"decoder",
causal=hparams.causal)
if hparams.do_ae:
if hparams.do_mask and hparams.do_refine:
def refine_res():
# return residual_conv(res, 1, (5, 1), hparams, "refine")
r, _ = encode(tf.squeeze(res, axis=[2]), target_space, hparams,
"refine_enc")
return tf.expand_dims(r, axis=2)
masked_batches = tf.reduce_sum(mask, axis=[1, 2, 3])
all_masked = tf.less(masked_batches, 0.1)
res = tf.where(all_masked, refine_res(), res)
# We'll start training the extra model of latents after mask_startup_steps.
nonlatent_steps = hparams.mask_startup_steps
latent_time = tf.less(nonlatent_steps,
tf.to_int32(tf.train.get_global_step()))
losses["latent_pred"] *= tf.to_float(latent_time)
# res was generated from padded targets, which means it has some extra
# elements. These can cause shape problems when computing loss with respect to
# the original (unpadded) targets. So we remove their extra elements here.
res = res[:, :original_targets_shape[1], :, :]
return res, losses, cache
def ae_transformer_internal(inputs,
targets,
target_space,
hparams,
cache=None,
predict_mask=1.0,
means=None,
ema_count=None,
ema_means=None):
"""AE Transformer, main step used for training."""
# Summaries break with the do_refine cond, turn them off in that case.
global _DO_SUMMARIES
if hparams.do_refine:
_DO_SUMMARIES = False
# Prepare.
batch_size = common_layers.shape_list(inputs)[0]
targets = tf.reshape(targets, [batch_size, -1, 1, hparams.hidden_size])
# Encoder.
if inputs is not None:
inputs = common_layers.flatten4d3d(inputs)
inputs, ed = encode(inputs, target_space, hparams, "input_enc")
else:
ed = None
# Autoencoding.
losses = {"extra": tf.constant(0.0), "latent_pred": tf.constant(0.0)}
if hparams.do_ae:
max_targets_len_from_inputs = tf.concat([inputs, inputs], axis=1)
targets, _ = common_layers.pad_to_same_length(
targets, max_targets_len_from_inputs,
final_length_divisible_by=2**hparams.num_compress_steps)
targets_c = compress(targets, False, hparams, "compress")
if hparams.mode != tf.estimator.ModeKeys.PREDICT:
# Compress and bottleneck.
latents_dense, latents_discrete, extra_loss, _ = bottleneck(
targets_c, hparams, 2 * 2048, "vc", means, ema_count, ema_means)
if _DO_SUMMARIES:
tf.summary.histogram("b0", tf.reshape(latents_discrete[:, 0, :], [-1]))
pc = common_layers.inverse_exp_decay(hparams.startup_steps) * 0.95
pc = pc if hparams.mode == tf.estimator.ModeKeys.TRAIN else 1.0
cond = tf.less(tf.random_uniform([batch_size]), pc)
latents_dense = tf.where(cond, latents_dense, targets_c)
# TODO(lukaszkaiser): return extra losses batchwise, multiply before mean.
losses["extra"] = extra_loss * tf.reduce_mean(tf.to_float(cond))
# Extra loss predicting latent code from input. Discrete only.
if hparams.bottleneck_kind not in ["dense", "vae"]:
latents_pred = decode_transformer(
tf.stop_gradient(inputs), tf.stop_gradient(ed),
tf.stop_gradient(latents_dense), hparams, "extra")
latents_pred = tf.layers.dense(latents_pred, 2**16, name="extra_logits")
losses["latent_pred"] = tf.nn.sparse_softmax_cross_entropy_with_logits(
labels=latents_discrete, logits=latents_pred)
losses["latent_pred"] = tf.reduce_mean(
losses["latent_pred"] * 0.5 * tf.to_float(cond))
else:
inputs_c = decode_transformer(inputs, ed, targets_c, hparams, "dec_c")
losses["latent_pred"] = tf.reduce_mean((inputs_c - targets_c)**2) * 20
def bn_inputs():
with tf.variable_scope(tf.get_variable_scope(), reuse=True):
bn, _, _, _ = bottleneck(inputs_c, hparams, 2 * 2048, "vc", means,
ema_count, ema_means)
return bn
pbn = 0.8 if hparams.mode == tf.estimator.ModeKeys.TRAIN else 1.0
inputs_c = tf.cond(tf.less(tf.random_uniform([]), pbn),
bn_inputs, lambda: inputs_c)
ptc = 1.0 - common_layers.inverse_lin_decay(200000) * 0.5
ptc = ptc if hparams.mode == tf.estimator.ModeKeys.TRAIN else 1.0
latents_dense = tf.where(tf.less(tf.random_uniform([batch_size]), ptc),
latents_dense, inputs_c)
else:
if hparams.bottleneck_kind in ["dense", "vae"]:
inputs_c = decode_transformer(inputs, ed, targets_c, hparams, "dec_c")
latents_dense, _, _, _ = bottleneck(inputs_c, hparams, 2 * 2048, "vc",
means, ema_count, ema_means)
else:
latent_len = common_layers.shape_list(targets_c)[1]
_, _, _, embed = bottleneck(targets_c, hparams, 2 * 2048, "vc", means,
ema_count, ema_means)
latents_dense = tf.zeros_like(targets_c[:, :latent_len, :, :])
if cache is None:
cache = ae_latent_sample(latents_dense, inputs, ed, embed, 8, hparams)
latents_dense = embed(cache)
# Postprocess.
d = latents_dense
pos = tf.get_variable("pos", [1, 1000, 1, hparams.hidden_size])
pos = pos[:, :common_layers.shape_list(latents_dense)[1] + 1, :, :]
latents_dense = tf.pad(latents_dense,
[[0, 0], [1, 0], [0, 0], [0, 0]]) + pos
# Masking.
if hparams.do_mask:
masking = common_layers.inverse_lin_decay(100000)
masking *= common_layers.inverse_exp_decay(25000) # Not much at start.
if not hparams.do_refine:
masking -= tf.random_uniform([]) * 0.3
masking = tf.minimum(tf.maximum(masking, 0.0), 1.0)
if hparams.mode == tf.estimator.ModeKeys.PREDICT:
masking = predict_mask
mask = tf.less(masking, tf.random_uniform(
common_layers.shape_list(targets)[:-1]))
mask = tf.expand_dims(tf.to_float(mask), 3)
for i in xrange(hparams.num_compress_steps):
j = hparams.num_compress_steps - i - 1
d = residual_conv(d, 1, (3, 1), hparams, "decompress_rc_%d" % j)
d = decompress_step(d, hparams, i > 0, False, "decompress_%d" % j)
targets = mask * targets + (1.0 - mask) * d
targets = tf.concat([tf.reverse(latents_dense, [1]), targets], axis=1)
res = decode_transformer(inputs, ed, targets, hparams, "decoder")
if hparams.do_ae:
res = res[:, common_layers.shape_list(latents_dense)[1]:, :, :]
if hparams.do_mask and hparams.do_refine:
def refine_res():
return residual_conv(res, 1, (5, 1), hparams, "refine")
masked_batches = tf.reduce_sum(mask, axis=[1, 2, 3])
all_masked = tf.less(masked_batches, 0.1)
res = tf.where(all_masked, refine_res(), res)
# We'll start training only the extra model of latents after 400K steps.
# Before we train only this, we decrease lr for other weights.
latent_time = tf.less(300000, tf.to_int32(tf.train.get_global_step()))
decreased_lr = common_layers.inverse_lin_decay(400000)
losses["latent_pred"] *= tf.to_float(latent_time)
losses["extra"] *= 1.0 - tf.to_float(latent_time)
decreased_lr_res = tf.stop_gradient(decreased_lr * res)
decreased_lr_res += (1.0 - decreased_lr) * res
res = tf.cond(latent_time, lambda: decreased_lr_res, lambda: res)
return res, losses, cache
def body(self, features):
"""Seq2Edits main model_fn.
Args:
features: Feature dictionary. Should contain the following fields:
"inputs": [batch_size, input_length, 1, hidden_dim] float tensor with
input token embeddings.
"targets": [batch_size, target_length, 1, hidden_dim] float tensor
with target token embeddings.
"targets_error_tag": [batch_size, target_length, 1, hidden_dim] float
tensor with target error tag embeddings.
"target_space_id": A scalar int from data_generators.problem.SpaceID.
Returns:
Final decoder representation. Dictionary containing the following fields:
"targets": [batch_size, target_length, hidden_dim] float tensor with
decoder outputs
"targets_error_tag": [batch_size, target_length, hidden_dim] float
tensor with decoder outputs
"""
hparams = self._hparams
losses = []
if self.has_input:
target_space = features['target_space_id']
encoder_output, encoder_decoder_attention_bias = self.encode(
features['inputs'],
target_space,
hparams,
features=features,
losses=losses,
)
else:
encoder_output, encoder_decoder_attention_bias = (None, None)
targets = features['targets']
targets_shape = common_layers.shape_list(targets)
targets = common_layers.flatten4d3d(targets)
decoder_input, decoder_self_attention_bias = self._prepare_decoder_fn(
targets, hparams, features=features)
nonpadding = features_to_nonpadding(features, 'targets')
# Add edit ops layer to condition on start_token, end_token, and error_tag
decoder_input = transformer_edit_ops_layer(
decoder_input,
hparams,
encoder_output,
features,
nonpadding=nonpadding,
losses=losses,
)
if hparams.middle_prediction:
num_decoder_layers = (hparams.num_decoder_layers
or hparams.num_hidden_layers)
hparams.num_decoder_layers = int(
num_decoder_layers / hparams.middle_prediction_layer_factor)
decode_kwargs = {}
decoder_output = self.decode(decoder_input,
encoder_output,
encoder_decoder_attention_bias,
decoder_self_attention_bias,
hparams,
nonpadding=nonpadding,
losses=losses,
**decode_kwargs)
loss_mask = common_layers.weights_nonzero(
maybe_flatten4d2d(features['targets_raw']))
self.loss_den = tf.reduce_sum(loss_mask)
decoder_output = self._prediction_cascade(
hparams=hparams,
features=features,
losses=losses,
loss_mask=loss_mask,
nonpadding=nonpadding,
encoder_decoder_attention_bias=encoder_decoder_attention_bias,
encoder_output=encoder_output,
decoder_output=decoder_output,
)
if hparams.middle_prediction:
with tf.variable_scope('after_prediction'):
decoder_output = self.decode(decoder_input + decoder_output,
encoder_output,
encoder_decoder_attention_bias,
decoder_self_attention_bias,
hparams,
nonpadding=nonpadding,
losses=losses,
**decode_kwargs)
ret = {'targets': tf.reshape(decoder_output, targets_shape)}
ret.update(self.logits)
if losses:
return ret, {'extra_loss': tf.add_n(losses)}
else:
return ret
def render2cmd_v3_internal(self, features, hparams, train):
# inputs and targets are both sequences with
# shape = [batch, seq_len, 1, hparams.problem.feature_dim]
targets = features['targets']
losses = {}
sampled_bottleneck = self.pretrained_visual_encoder(features, hparams)
if hparams.sg_bottleneck:
sampled_bottleneck = tf.stop_gradient(sampled_bottleneck)
with tf.variable_scope('render2cmd_v3_internal'):
# override bottleneck, or return it, if requested
if 'bottleneck' in features:
if common_layers.shape_list(features['bottleneck'])[0] == 0:
# return sampled_bottleneck,
# set losses['training'] = 0 so self.top() doesn't get called on it
return sampled_bottleneck, {'training': 0.0}
else:
# we want to use the given bottleneck
sampled_bottleneck = features['bottleneck']
# finalize bottleneck
unbottleneck_dim = hparams.hidden_size * 2 # twice because using LSTM
if hparams.twice_decoder:
unbottleneck_dim = unbottleneck_dim * 2
# unbottleneck back to LSTMStateTuple
dec_initial_state = []
for hi in range(hparams.num_hidden_layers):
unbottleneck = self.unbottleneck(sampled_bottleneck, unbottleneck_dim,
name_append='_{}'.format(hi))
dec_initial_state.append(
tf.nn.rnn_cell.LSTMStateTuple(
c=unbottleneck[:, :unbottleneck_dim // 2],
h=unbottleneck[:, unbottleneck_dim // 2:]))
dec_initial_state = tuple(dec_initial_state)
shifted_targets = common_layers.shift_right(targets)
# Add 1 to account for the padding added to the left from shift_right
targets_length = common_layers.length_from_embedding(shifted_targets) + 1
# LSTM decoder
hparams_decoder = copy.copy(hparams)
if hparams.twice_decoder:
hparams_decoder.hidden_size = 2 * hparams.hidden_size
if hparams.mode == tf.estimator.ModeKeys.PREDICT:
decoder_outputs, _ = self.lstm_decoder_infer(
common_layers.flatten4d3d(shifted_targets),
targets_length, hparams_decoder, features['targets_cls'],
train, initial_state=dec_initial_state,
bottleneck=sampled_bottleneck)
else:
decoder_outputs, _ = self.lstm_decoder(
common_layers.flatten4d3d(shifted_targets),
targets_length, hparams_decoder, features['targets_cls'],
train, initial_state=dec_initial_state,
bottleneck=sampled_bottleneck)
ret = tf.expand_dims(decoder_outputs, axis=2)
return ret, losses
def adv_transformer_internal(inputs, targets, target_space, hparams):
"""Adversarial Transformer, main step used for training."""
with tf.variable_scope("adv_transformer"):
batch_size = tf.shape(targets)[0]
targets = tf.reshape(targets, [batch_size, -1, 1])
intermediate = tf.constant(34 * 1024 - 1)
intermediate += tf.zeros_like(targets)
targets = tf.concat([targets, intermediate], axis=2)
targets = tf.reshape(targets, [batch_size, -1, 1])
embedding = tf.get_variable("embedding",
[34 * 1024, hparams.hidden_size])
targets_emb = tf.gather(embedding, targets)
# Noisy embedded targets.
targets_noisy = tf.one_hot(targets, 34 * 1024)
noise_val = hparams.noise_val
targets_noisy += tf.random_uniform(tf.shape(targets_noisy),
minval=-noise_val,
maxval=noise_val)
targets_emb_noisy = softmax_embed(targets_noisy, embedding, batch_size,
hparams)
# Encoder.
if inputs is not None:
inputs_emb = common_layers.flatten4d3d(inputs)
inputs, ed = encode(inputs_emb, target_space, hparams, "input_enc")
else:
ed = None
# Masking.
masking = common_layers.inverse_lin_decay(200000)
masking *= common_layers.inverse_exp_decay(50000) # Not much at start.
masking -= tf.random_uniform([]) * 0.4
masking = tf.minimum(tf.maximum(masking, 0.0), 1.0)
mask = tf.less(masking, tf.random_uniform(tf.shape(targets)))
mask = tf.expand_dims(tf.to_float(mask), 3)
noise = tf.random_uniform(tf.shape(targets_emb))
targets_emb = mask * targets_emb + (1.0 - mask) * noise
# Decoder.
res_dec = decode(inputs, ed, targets_emb, hparams, "decoder")
res = tf.layers.dense(res_dec, 34 * 1024, name="res_sm")
res_emb = softmax_embed(res, embedding, batch_size, hparams)
# Extra steps.
extra_step_prob = masking * 0.6 + 0.3
if hparams.mode != tf.estimator.ModeKeys.TRAIN:
extra_step_prob = 1.0
for _ in xrange(hparams.extra_steps):
def another_step(emb):
res_dec = decode(inputs,
ed,
emb,
hparams,
"decoder",
reuse=True)
res = tf.layers.dense(res_dec,
34 * 1024,
name="res_sm",
reuse=True)
return softmax_embed(res, embedding, batch_size, hparams), res
res_emb, res = tf.cond(tf.less(tf.random_uniform([]),
extra_step_prob),
lambda e=res_emb: another_step(e),
lambda: (res_emb, res))
# Adversary.
delta = masking * hparams.delta_max
true_logit = adversary(tf.stop_gradient(targets_emb_noisy),
tf.stop_gradient(inputs + inputs_emb), hparams,
"adversary")
gen_logit = adversary(reverse_gradient(res_emb, delta),
tf.stop_gradient(inputs + inputs_emb),
hparams,
"adversary",
reuse=True)
losses = {"adv": gen_logit - true_logit}
res = tf.stop_gradient(masking * res) + (1.0 - masking) * res
return res, losses
def render2cmd_v3_internal(self, features, hparams, train):
# inputs and targets are both sequences with
# shape = [batch, seq_len, 1, hparams.problem.feature_dim]
print(
"render2cmd_v3_internal render2cmd_v3_internalrender2cmd_v3_internalrender2cmd_v3_internalrender2cmd_v3_internal"
)
all_targets = features['targets']
all_targets_cls = features['targets_cls']
all_targets_font_cls = features['targets_fnt']
all_targets_psr = features['targets_psr']
all_batch_size = common_layers.shape_list(all_targets)[0]
batch_size = all_batch_size // 2
sources = all_targets[:batch_size, ...]
sources_cls = all_targets_cls[:batch_size, ...]
sources_fnt = all_targets_font_cls[:batch_size, ...]
sources_psr = all_targets_psr[:batch_size, ...]
targets = all_targets[batch_size:, ...]
targets_cls = all_targets_cls[batch_size:, ...]
targets_fnt = all_targets_font_cls[batch_size:, ...]
targets_psr = all_targets_psr[batch_size:, ...]
losses = {}
# sampled_bottleneck = self.pretrained_visual_encoder(features, hparams)
# if hparams.sg_bottleneck:
# sampled_bottleneck = tf.stop_gradient(sampled_bottleneck)
# embd = self.cls_embedding(sources_cls, sources_fnt, targets_cls, targets_fnt)
vis_embd = self.vis_encoder(sources_psr, targets_psr, targets_cls)
# print("embd embd embd embd embd embd embd ", embd.shape)
print("vis embd vis embd vis embd vis embd vis", vis_embd.shape)
sampled_bottleneck = vis_embd
with tf.variable_scope('render2cmd_v3_internal'):
# override bottleneck, or return it, if requested
# if 'bottleneck' in features:
# if common_layers.shape_list(features['bottleneck'])[0] == 0:
# # return sampled_bottleneck,
# # set losses['training'] = 0 so self.top() doesn't get called on it
# print("RETURNRETURNRETURNRETURNRETURNRETURNRETURNRETURNRETURNRETURNRETURN")
# return sampled_bottleneck, {'training': 0.0}
# else:
# # we want to use the given bottleneck
# sampled_bottleneck = features['bottleneck']
# finalize bottleneck
unbottleneck_dim = hparams.hidden_size * 2 # twice because using LSTM
if hparams.twice_decoder:
unbottleneck_dim = unbottleneck_dim * 2
dec_initial_state = []
# LSTM encoder
_, encoder_output_states = self.lstm_encoder(
common_layers.flatten4d3d(sources), hparams)
print(
"targets shape targets shape targets shape targets shape targets shape ",
targets.shape)
print('run stacking...')
print(
"sample bottleneck shape sample bottleneck shape sample bottleneck shape ",
sampled_bottleneck.shape)
print(
"sources shape sources shape sources shape sources shape sources shape",
sources.shape)
# input()
for hi in range(hparams.num_hidden_layers):
unbottleneck = self.unbottleneck(sampled_bottleneck,
unbottleneck_dim,
name_append='_{}'.format(hi))
c, h = encoder_output_states[hi]
# print(unbottleneck.shape)
# print(c.shape, h.shape)
# first_dim = common_layers.shape_list(unbottleneck)[0]
# print(first_dim)
# c = tf.tile(c,[first_dim,1])
# h = tf.tile(h,[first_dim,1])
# input()
dec_initial_state.append(
tf.nn.rnn_cell.LSTMStateTuple(
c=tf.concat(
[unbottleneck[:, :unbottleneck_dim // 2], c], 1),
h=tf.concat(
[unbottleneck[:, unbottleneck_dim // 2:], h], 1)))
dec_initial_state = tuple(dec_initial_state)
# print('checkshape dec_initial_state')
# print(dec_initial_state)
# input()
shifted_targets = common_layers.shift_right(targets)
# Add 1 to account for the padding added to the left from shift_right
targets_length = common_layers.length_from_embedding(
shifted_targets) + 1
# LSTM decoder
hparams_decoder = copy.copy(hparams)
if hparams.twice_decoder:
hparams_decoder.hidden_size = 2 * hparams.hidden_size
if hparams.mode == tf.estimator.ModeKeys.PREDICT:
decoder_outputs, _ = self.lstm_decoder_infer(
common_layers.flatten4d3d(shifted_targets),
targets_length,
hparams_decoder,
targets_cls,
train,
initial_state=dec_initial_state,
bottleneck=sampled_bottleneck)
else:
decoder_outputs, _ = self.lstm_decoder(
common_layers.flatten4d3d(shifted_targets),
targets_length,
hparams_decoder,
targets_cls,
train,
initial_state=dec_initial_state,
bottleneck=sampled_bottleneck)
ret = tf.expand_dims(decoder_outputs, axis=2)
return ret, losses
def transformer_autoencoder(inputs,
targets,
target_space,
hparams,
cache=None,
predict_mask=1.0):
"""AE Transformer, main step used for training."""
# Define losses
losses = {"extra": tf.constant(0.0), "latent_pred": tf.constant(0.0)}
# Reshape image targets as 4d tensor.
original_targets_shape = common_layers.shape_list(targets)
if len(original_targets_shape) == 4:
compress_fn = compress_encoder_2d
decompress_fn = decompress_decoder_2d
else:
compress_fn = compress_encoder_1d
decompress_fn = decompress_decoder_1d
# Encoder decoder attention bias.
ed_attention_bias = None
# Input Encoder if present.
if inputs is not None:
inputs = common_layers.flatten4d3d(inputs)
inputs, ed_attention_bias = transformer_text_encoder(
inputs, target_space, hparams, "input_enc")
# Encode targets to compute targets compressed.
targets_c = compress_fn(targets, hparams, "compress")
targets, _, _ = cia.maybe_reshape_4d_to_3d(targets)
# Following code creates an exponentially decaying variable based on which
# we rescale the los values.
batch_size = common_layers.shape_list(targets_c)[0]
pc = common_layers.inverse_exp_decay(hparams.startup_steps)
pc = pc if hparams.mode == tf.estimator.ModeKeys.TRAIN else 1.0
cond = tf.less(tf.random_uniform([batch_size]), pc)
# TODO(lukaszkaiser): return extra losses batchwise, multiply before mean.
# Call bottleneck layer to get the latents.
# Returns embedded latents, discrete latents, loss and the embedding function.
latents_dense, latents_discrete, extra_loss, embed = (bottleneck_layer(
targets_c, hparams))
extra_loss = tf.reduce_mean(extra_loss) * tf.to_float(cond)
# Call the autoregressive latent prediction model.
_, latents_pred_loss = latent_prediction_model(targets_c,
ed_attention_bias,
latents_discrete,
embed,
hparams,
name="latent_pred")
latents_pred_loss = tf.reduce_mean(latents_pred_loss) * tf.to_float(cond)
# Assign latent loss
losses["latent_pred"] = latents_pred_loss
losses["extra_loss"] = extra_loss
latents_decoder = latents_dense
if len(original_targets_shape) == 4:
cmp_img_len = hparams.img_len / (2**(hparams.num_compress_steps // 2))
latents_decoder = tf.reshape(latents_decoder, [
batch_size, cmp_img_len, cmp_img_len,
hparams.num_latents * hparams.hidden_size
])
# Decompress either using 1D or 2D upconvs.
latents_decoder = decompress_fn(latents_decoder,
hparams,
name="decompress")
# if we're operating in 2d space on images, then we're assuming that the
# last dimension will not be a multiple of channels
latents_decoder = tf.reshape(
latents_decoder,
shape=[-1, hparams.img_len, hparams.img_len, hparams.hidden_size])
if hparams.use_gold_targets:
latents_decoder, _, _ = cia.maybe_reshape_4d_to_3d(latents_decoder)
masking = common_layers.inverse_exp_decay(hparams.mask_startup_steps)
if hparams.mode == tf.estimator.ModeKeys.PREDICT:
masking = predict_mask
mask = tf.less(
masking, tf.random_uniform(common_layers.shape_list(targets)[:-1]))
mask = tf.expand_dims(tf.to_float(mask), 2)
targets = mask * targets + (1.0 - mask) * latents_decoder
else:
targets = latents_decoder
# reshape back to 4d here
targets = tf.reshape(targets, original_targets_shape)
if hparams.decode_autoregressive:
# Transformer decoder, that goes from inputs->targets
res = transformer_image_decoder(inputs, ed_attention_bias, targets,
hparams, "decoder")
else:
res = targets
# We'll start training the extra model of latents after mask_startup_steps.
latent_time = tf.less(hparams.mask_startup_steps,
tf.to_int32(tf.train.get_global_step()))
losses["latent_pred"] *= tf.to_float(latent_time)
return res, losses, cache
def body(self, features):
hp = self.hparams
# pylint: disable=eval-used
if hp.image_input_type == "image":
image_feat = vqa_layers.image_embedding(
features["inputs"],
model_fn=eval(hp.image_model_fn),
trainable=hp.train_resnet,
is_training=hp.mode == tf.estimator.ModeKeys.TRAIN)
else:
image_feat = features["inputs"]
image_feat = common_layers.flatten4d3d(image_feat)
image_hidden_size = hp.image_hidden_size or hp.hidden_size
if hp.image_feat_preprocess_proj:
image_feat = common_layers.dense(image_feat, image_hidden_size)
utils.collect_named_outputs("norms", "image_feat_after_proj",
tf.norm(image_feat, axis=-1))
else:
assert image_hidden_size == 2048
image_feat = tf.nn.dropout(image_feat,
keep_prob=1. -
hp.layer_prepostprocess_dropout)
if hp.image_feat_encode:
image_feat = image_encoder(image_feat, hp)
utils.collect_named_outputs("norms", "image_feat_encoded",
tf.norm(image_feat, axis=-1))
else:
image_feat = common_layers.layer_norm(image_feat)
utils.collect_named_outputs("norms", "image_feat_after_layer",
tf.norm(image_feat, axis=-1))
question = common_layers.flatten4d3d(features["question"])
utils.collect_named_outputs("norms", "question_embedding",
tf.norm(question, axis=-1))
question, question_self_attention_bias = prepare_question_encoder(
question, hp)
question = tf.nn.dropout(question,
keep_prob=1. -
hp.layer_prepostprocess_dropout)
query = question_encoder(question, question_self_attention_bias, hp)
utils.collect_named_outputs("norms", "query_encode",
tf.norm(query, axis=-1))
query = (query + tf.expand_dims(
tf.squeeze(question_self_attention_bias, [1, 2]), axis=2))
query = tf.reduce_max(query, axis=1)
utils.collect_named_outputs("norms", "query_maxpool",
tf.norm(query, axis=-1))
# query = common_layers.l2_norm(query)
# utils.collect_named_outputs("norms", "query_after_l2",
# tf.norm(query, axis=-1))
image_ave = attn(image_feat, query, hp)
utils.collect_named_outputs("norms", "image_ave",
tf.norm(image_ave, axis=-1))
if hp.multimodal_combine == "concat":
image_question = tf.concat([image_ave, query], axis=1)
elif hp.multimodal_combine == "sum":
image_question = image_ave + query
elif hp.multimodal_combine == "product":
image_question = image_ave * query
utils.collect_named_outputs("norms", "image_question",
tf.norm(image_question, axis=-1))
image_question = tf.nn.dropout(image_question, 1. - hp.dropout)
output = mlp(image_question, hp)
utils.collect_named_outputs("norms", "output", tf.norm(output,
axis=-1))
norm_tensors = utils.convert_collection_to_dict("norms")
vqa_layers.summarize_tensors(norm_tensors, tag="norms/")
# Expand dimension 1 and 2
return tf.expand_dims(tf.expand_dims(output, axis=1), axis=2)
def baseline_perf_transformer_encode(encoder_function,
inputs,
target_space,
hparams,
attention_weights=None,
features=None,
losses=None,
prepare_encoder_fn=None,
**kwargs):
"""Encoding for baseline performance transformer, no mean-aggregation.
Args:
encoder_function: the encoder function
inputs: Transformer inputs [batch_size, input_length, 1, hidden_dim] which
will be flattened along the two spatial dimensions.
target_space: scalar, target space ID.
hparams: hyperparameters for model.
attention_weights: weight to store attention to.
features: optionally pass the entire features dictionary as well. This is
needed now for "packed" datasets.
losses: optional list onto which to append extra training losses
prepare_encoder_fn: optional, alternative to transformer_prepare_encoder.
**kwargs: additional arguments to pass to encoder_function
Returns:
Tuple of:
encoder_output: Encoder representation.
[batch_size, input_length, hidden_dim]
encoder_decoder_attention_bias: Bias and mask weights for
encoder-decoder attention. [batch_size, input_length]
"""
inputs = common_layers.flatten4d3d(inputs)
if not prepare_encoder_fn:
prepare_encoder_fn = transformer_prepare_encoder
encoder_input, self_attention_bias, encoder_decoder_attention_bias = (
prepare_encoder_fn(inputs,
target_space,
hparams,
features=features,
reuse_target_embedding=tf.AUTO_REUSE))
mlperf_log.transformer_print(
key=mlperf_log.MODEL_HP_LAYER_POSTPROCESS_DROPOUT,
value=hparams.layer_prepostprocess_dropout,
hparams=hparams)
encoder_input = tf.nn.dropout(encoder_input,
1.0 - hparams.layer_prepostprocess_dropout)
attn_bias_for_padding = None
# Otherwise the encoder will just use encoder_self_attention_bias.
if hparams.unidirectional_encoder:
attn_bias_for_padding = encoder_decoder_attention_bias
encoder_output = encoder_function(
encoder_input,
self_attention_bias,
hparams,
name="encoder",
nonpadding=features_to_nonpadding(features, "inputs"),
save_weights_to=attention_weights,
make_image_summary=not common_layers.is_xla_compiled(),
losses=losses,
attn_bias_for_padding=attn_bias_for_padding,
**kwargs)
# no aggregation --> just return everything normally
return encoder_output, encoder_decoder_attention_bias
def transformer_autoencoder(inputs,
targets,
target_space,
hparams,
cache=None,
predict_mask=1.0):
"""Auto-encoder using transformer decoder and prior over latents."""
# Define losses
losses = {"extra": tf.constant(0.0), "latent_pred": tf.constant(0.0)}
# Reshape image targets as 4d tensor.
original_targets_shape = common_layers.shape_list(targets)
batch_size = original_targets_shape[0]
if len(original_targets_shape) == 4:
compress_fn = compress_encoder_2d
decompress_fn = decompress_decoder_2d
else:
compress_fn = compress_encoder_1d
decompress_fn = decompress_decoder_1d
# Encoder decoder attention bias.
ed_attention_bias = None
# Input Encoder if present.
if inputs is not None:
inputs = common_layers.flatten4d3d(inputs)
inputs, ed_attention_bias = transformer_text_encoder(
inputs, target_space, hparams, "input_enc")
# Encode targets to compute targets compressed.
targets_c = compress_fn(targets, hparams, "compress")
targets, _, _ = cia.maybe_reshape_4d_to_3d(targets)
# Following code creates an exponentially decaying variable based on which
# we rescale the loss values.
pc = common_layers.inverse_exp_decay(hparams.startup_steps)
pc = pc if hparams.mode == tf.estimator.ModeKeys.TRAIN else 1.0
cond = tf.less(tf.random_uniform([batch_size]), pc)
# Call bottleneck layer, that takes encoder output and outputs the latents.
# Returns embedded latents, discrete latent codes, loss.
if hparams.mode != tf.estimator.ModeKeys.PREDICT:
latents_dense, latents_discrete, extra_loss = (bottleneck_layer(
targets_c, hparams))
extra_loss = tf.reduce_mean(extra_loss) * tf.to_float(cond)
# Call the autoregressive latent prediction model.
_, latents_pred_loss = latent_prediction_model(inputs,
ed_attention_bias,
latents_discrete,
latents_dense,
hparams,
name="latent_pred")
latents_pred_loss = tf.reduce_mean(latents_pred_loss) * tf.to_float(
cond)
# Latent dropout.
latents_shape = common_layers.shape_list(latents_dense)
latents_dense = tf.nn.dropout(
latents_dense,
1 - hparams.latent_dropout,
noise_shape=[latents_shape[0], latents_shape[1], 1])
# Assign latent loss.
losses["latent_pred"] = latents_pred_loss
losses["extra_loss"] = extra_loss
else:
latent_len = (hparams.img_len * hparams.img_len *
hparams.num_latents) / 2**(hparams.num_compress_steps)
embed = functools.partial(discretization.parametrized_unbottleneck,
hparams=hparams)
latents_dense = tf.zeros(
[batch_size, latent_len, 1, hparams.hidden_size])
if cache is None:
cache = ae_latent_sample_beam(latents_dense, inputs,
ed_attention_bias, embed, hparams)
latents_dense = embed(
tf.one_hot(cache, depth=2**hparams.bottleneck_bits),
hparams.hidden_size)
latents_decoder = latents_dense
if len(original_targets_shape) == 4:
cmp_img_len = hparams.img_len / (2**(hparams.num_compress_steps // 2))
latents_decoder = tf.reshape(latents_decoder, [
batch_size, cmp_img_len, cmp_img_len,
hparams.num_latents * hparams.hidden_size
])
# Decompress either using 1D or 2D upconvs.
latents_decoder = decompress_fn(latents_decoder,
hparams,
name="decompress")
# if we're operating in 2d space on images, then we're assuming that the
# last dimension will not be a multiple of channels
output = tf.reshape(
latents_decoder,
shape=[-1, hparams.img_len, hparams.img_len, hparams.hidden_size])
if hparams.use_gold_targets:
latents_decoder, _, _ = cia.maybe_reshape_4d_to_3d(latents_decoder)
masking = common_layers.inverse_exp_decay(hparams.mask_startup_steps)
if hparams.mode == tf.estimator.ModeKeys.PREDICT:
masking = predict_mask
mask = tf.less(
masking, tf.random_uniform(common_layers.shape_list(targets)[:-1]))
mask = tf.expand_dims(tf.to_float(mask), 2)
output = mask * targets + (1.0 - mask) * output
# reshape back to 4d here
output = tf.reshape(output, original_targets_shape)
if hparams.decode_autoregressive:
# Transformer decoder, that goes from inputs->targets
decoder_output = transformer_image_decoder(output, inputs,
ed_attention_bias, hparams,
"decoder")
else:
decoder_output = output
# We'll start training the extra model of latents after mask_startup_steps.
latent_time = tf.less(hparams.mask_startup_steps,
tf.to_int32(tf.train.get_global_step()))
losses["latent_pred"] *= tf.to_float(latent_time)
return decoder_output, losses, cache
def body(self, features):
"""Transformer main model_fn.
Args:
features: Map of features to the model. Should contain the following:
"inputs": Transformer inputs. [batch_size, input_length, 1,
hidden_dim].
"targets": Target decoder outputs. [batch_size, decoder_length, 1,
hidden_dim]
"target_space_id": A scalar int from data_generators.problem.SpaceID.
Returns:
Final decoder representation. [batch_size, decoder_length, hidden_dim]
"""
hparams = self._hparams
losses = []
if self.has_input:
# use melody-only as input features
inputs = features["melody"]
target_space = features["target_space_id"]
encoder_output, encoder_decoder_attention_bias = self.encode(
inputs,
target_space,
hparams,
features=features,
losses=losses)
else:
encoder_output, encoder_decoder_attention_bias = (None, None)
targets = features["targets"]
targets_shape = common_layers.shape_list(targets)
targets = common_layers.flatten4d3d(targets)
decoder_input, decoder_self_attention_bias = self._prepare_decoder_fn(
targets, hparams, features=features)
# Not all subclasses of Transformer support keyword arguments related to
# recurrent memory, so only pass these arguments if memory is enabled.
decode_kwargs = {}
if self.recurrent_memory_by_layer is not None:
# TODO(kitaev): The chunk_number feature currently has the same shape as
# "targets", but this is only for the purposes of sharing sharding code.
# In fact every token within an example must have the same chunk number.
chunk_number_each_token = tf.squeeze(features["chunk_number"],
(-1, -2))
chunk_number_each_example = chunk_number_each_token[:, 0]
# Uncomment the code below to verify that tokens within a batch share the
# same chunk number:
# with tf.control_dependencies([
# tf.assert_equal(chunk_number_each_token,
# chunk_number_each_example[:, None])
# ]):
# chunk_number_each_example = tf.identity(chunk_number_each_example)
decode_kwargs = dict(
recurrent_memory_by_layer=self.recurrent_memory_by_layer,
chunk_number=chunk_number_each_example,
)
decoder_output = six.ensure_text(self,
decoder_input,
encoder_output,
encoder_decoder_attention_bias,
decoder_self_attention_bias,
hparams,
nonpadding=features_to_nonpadding(
features, "targets"),
losses=losses,
**decode_kwargs)
expected_attentions = features.get("expected_attentions")
if expected_attentions is not None:
attention_loss = common_attention.encoder_decoder_attention_loss(
expected_attentions, self.attention_weights,
hparams.expected_attention_loss_type,
hparams.expected_attention_loss_multiplier)
return decoder_output, {"attention_loss": attention_loss}
ret = tf.reshape(decoder_output, targets_shape)
if losses:
return ret, {"extra_loss": tf.add_n(losses)}
else:
return ret
def main():
FLAGS = Args()
# Enable TF Eager execution
tfe = tf.contrib.eager
tfe.enable_eager_execution()
# sample sentence
input_str = 'Twas brillig, and the slithy toves Did gyre and gimble in the wade; All mimsy were the borogoves, And the mome raths outgrabe.'
# convert sentence into index in vocab
wmt_problem = problems.problem(FLAGS.problem)
encoders = wmt_problem.feature_encoders(FLAGS.data_dir)
inputs = encoders["inputs"].encode(input_str) + [1] # add EOS id
batch_inputs = tf.reshape(inputs, [1, -1, 1]) # Make it 3D.
features = {"inputs": batch_inputs}
# initialize translation model
hparams_set = FLAGS.hparams_set
Modes = tf.estimator.ModeKeys
hparams = trainer_lib.create_hparams(hparams_set, data_dir=FLAGS.data_dir, problem_name=FLAGS.problem)
translate_model = registry.model(FLAGS.model)(hparams, Modes.EVAL)
# recover parameters and conduct recurrent conduction
ckpt_dir = tf.train.latest_checkpoint(FLAGS.model_dir)
with tfe.restore_variables_on_create(ckpt_dir):
with variable_scope.EagerVariableStore().as_default():
with tf.variable_scope('universal_transformer'):
# Convert word index to word embedding
features = translate_model.bottom(features)
with tf.variable_scope('universal_transformer/body'):
input_tensor = tf.convert_to_tensor(features['inputs'])
input_tensor = common_layers.flatten4d3d(input_tensor)
encoder_input, self_attention_bias, _ = (
transformer.transformer_prepare_encoder(
input_tensor, tf.convert_to_tensor([0]), translate_model.hparams, features=None))
with tf.variable_scope('universal_transformer/body/encoder'):
ffn_unit = functools.partial(
universal_transformer_util.transformer_encoder_ffn_unit,
hparams=translate_model.hparams)
attention_unit = functools.partial(
universal_transformer_util.transformer_encoder_attention_unit,
hparams=translate_model.hparams,
encoder_self_attention_bias=None,
attention_dropout_broadcast_dims=[],
save_weights_to={},
make_image_summary=True)
storing_list = []
transformed_state = encoder_input
for step_index in range(1024):
storing_list.append(transformed_state.numpy())
with tf.variable_scope('universal_transformer/body/encoder/universal_transformer_{}'.format(FLAGS.ut_type)):
transformed_state = universal_transformer_util.step_preprocess(
transformed_state,
tf.convert_to_tensor(step_index % FLAGS.step_num),
translate_model.hparams
)
with tf.variable_scope('universal_transformer/body/encoder/universal_transformer_{}/rec_layer_0'.format(FLAGS.ut_type)):
transformed_new_state = ffn_unit(attention_unit(transformed_state))
with tf.variable_scope('universal_transformer/body/encoder'):
if (step_index + 1) % FLAGS.step_num == 0:
transformed_new_state = common_layers.layer_preprocess(transformed_new_state, translate_model.hparams)
if step_index == 5:
print(transformed_new_state)
transformed_state = transformed_new_state
storing_list = np.asarray(storing_list)
np.save(FLAGS.save_dir, storing_list)
def body(self, features):
hp = self.hparams
# pylint: disable=eval-used
if hp.image_input_type == "image":
image_feat = vqa_layers.image_embedding(
features["inputs"],
model_fn=eval(hp.image_model_fn),
trainable=hp.train_resnet,
is_training=hp.mode == tf.estimator.ModeKeys.TRAIN)
else:
image_feat = features["inputs"]
image_feat = common_layers.flatten4d3d(image_feat)
image_feat = common_layers.dense(image_feat, hp.hidden_size)
utils.collect_named_outputs("norms", "image_feat_after_proj",
tf.norm(image_feat, axis=-1))
question = common_layers.flatten4d3d(features["question"])
utils.collect_named_outputs("norms", "question_embedding",
tf.norm(question, axis=-1))
(encoder_input, encoder_self_attention_bias,
encoder_decoder_attention_bias) = prepare_image_question_encoder(
image_feat, question, hp)
encoder_input = tf.nn.dropout(encoder_input,
keep_prob=1. -
hp.layer_prepostprocess_dropout)
encoder_output, _ = recurrent_transformer_decoder(
encoder_input,
None,
encoder_self_attention_bias,
None,
hp,
name="encoder")
utils.collect_named_outputs("norms", "encoder_output",
tf.norm(encoder_output, axis=-1))
# scale query by sqrt(hidden_size)
query = tf.get_variable("query",
[hp.hidden_size]) * hp.hidden_size**0.5
query = tf.expand_dims(tf.expand_dims(query, axis=0), axis=0)
batch_size = common_layers.shape_list(encoder_input)[0]
query = tf.tile(query, [batch_size, 1, 1])
query = tf.nn.dropout(query,
keep_prob=1. - hp.layer_prepostprocess_dropout)
decoder_output, _ = recurrent_transformer_decoder(
query,
encoder_output,
None,
encoder_decoder_attention_bias,
hp,
name="decoder")
utils.collect_named_outputs("norms", "decoder_output",
tf.norm(decoder_output, axis=-1))
norm_tensors = utils.convert_collection_to_dict("norms")
vqa_layers.summarize_tensors(norm_tensors, tag="norms/")
# Expand dimension 1 and 2
return tf.expand_dims(decoder_output, axis=1)
def encode(self, inputs_context, inputs, target_space, hparams, features=None, losses=None):
"""Encode transformer inputs.
Args:
inputs_context: contextual input [batch_size, input_length, hidden_dim]
inputs: Transformer inputs [batch_size, input_length, input_height,
hidden_dim] which will be flattened along the two spatial dimensions.
target_space: scalar, target space ID.
hparams: hyperparameters for model.
features: optionally pass the entire features dictionary as well.
This is needed now for "packed" datasets.
losses: optional list onto which to append extra training losses
Returns:
Tuple of:
encoder_output: Encoder representation.
[batch_size, input_length, hidden_dim]
encoder_output_context: Contextual encoder representation
[batch_size, input_length, hidden_dim]
encoder_decoder_attention_bias: Bias and mask weights for
encoder-decoder attention. [batch_size, input_length]
"""
inputs = common_layers.flatten4d3d(inputs)
encoder_input, self_attention_bias, encoder_decoder_attention_bias = (
transformer_prepare_encoder(
inputs, target_space, hparams, features=features))
encoder_input = tf.nn.dropout(encoder_input,
1.0 - hparams.layer_prepostprocess_dropout)
encoder_output = transformer_encoder(
encoder_input,
self_attention_bias,
hparams,
nonpadding=features_to_nonpadding(features, "inputs"),
save_weights_to=self.attention_weights,
losses=losses)
if inputs_context is None:
return None, encoder_output, encoder_decoder_attention_bias
inputs_context = common_layers.flatten4d3d(inputs_context)
encoder_input_context, self_attention_bias_context, encoder_decoder_attention_bias_context = (
transformer_prepare_encoder(
inputs_context, target_space, hparams, features=features))
encoder_input_context = tf.nn.dropout(encoder_input_context,
1.0 - hparams.layer_prepostprocess_dropout)
encoder_output_context_0 = transformer_encoder(
encoder_input_context,
self_attention_bias_context,
hparams,
name="encoder_context",
nonpadding=features_to_nonpadding(features, "inputs"),
save_weights_to=self.attention_weights,
losses=losses)
encoder_output_context = transformer_decoder(
encoder_input,
encoder_output_context_0,
encoder_decoder_attention_bias,
encoder_decoder_attention_bias_context,
hparams,
name="decoder_input_context")
return encoder_output_context, encoder_output, encoder_decoder_attention_bias
def infer_step(logits_so_far, current_hidden):
"""Inference step of LSTM while loop."""
# unflatten hidden:
current_hidden = tuple(
tf.nn.rnn_cell.LSTMStateTuple(c=s[0], h=s[1])
for s in current_hidden)
# put logits_so_far through top
tm = self._problem_hparams.modality['targets']
# need to reuse top params
reset_scope = tf.variable_scope(tf.VariableScope(
tf.AUTO_REUSE, ''),
reuse=tf.AUTO_REUSE,
auxiliary_name_scope=False)
top_scope = tf.variable_scope('svg_decoder/{}_modality'.format(tm),
reuse=tf.AUTO_REUSE)
with reset_scope, top_scope:
samples_so_far = self.hparams.top['targets'](
logits_so_far, None, self.hparams,
self.problem_hparams.vocab_size)
# append a zero pad to the samples. this effectively shifts the samples
# right, but, unlike shift_right, by not removing the last element, we
# allow an empty samples_so_far to not be empty after padding
samples_so_far = tf.concat([zero_pad, samples_so_far], axis=1)
shifted_targets = common_layers.flatten4d3d(samples_so_far)
# now take the very last one here, will be the actual input to the rnn
shifted_targets = shifted_targets[:, -1:, :]
# tile and append the bottleneck to inputs
sln_offset = 0
if hparams.condition_on_sln:
sln_offset = 51
pre_tile_y = tf.reshape(bottleneck, [
common_layers.shape_list(bottleneck)[0], 1,
hparams.bottleneck_bits + hparams.num_categories + sln_offset
])
overlay_x = tf.tile(
pre_tile_y,
[1, common_layers.shape_list(shifted_targets)[1], 1])
inputs = tf.concat([shifted_targets, overlay_x], -1)
seq_len_batch = tf.ones([common_layers.shape_list(inputs)[0]])
# RUN PRE-LSTM LAYER
with tf.variable_scope('pre_decoder', reuse=tf.AUTO_REUSE):
inputs = tf.layers.dense(inputs,
hparams.hidden_size,
name='bottom')
inputs = tf.nn.tanh(inputs)
# RUN LSTM
with tf.variable_scope('lstm_decoder', reuse=tf.AUTO_REUSE):
next_step, next_state = tf.nn.dynamic_rnn(
layers,
inputs,
seq_len_batch,
initial_state=current_hidden,
dtype=tf.float32,
time_major=False)
next_step = tf.expand_dims(next_step, [1])
logits_so_far = tf.concat([logits_so_far, next_step], 1)
# flatten state
next_state = tuple((s.c, s.h) for s in next_state)
return logits_so_far, next_state
def body(self, features):
"""Transformer main model_fn.
Args:
features: Map of features to the model. Should contain the following:
"inputs": Transformer inputs [batch_size, input_length, hidden_dim]
"targets": Target decoder outputs.
[batch_size, decoder_length, hidden_dim]
"target_space_id": A scalar int from data_generators.problem.SpaceID.
Returns:
Final decoder representation. [batch_size, decoder_length, hidden_dim]
"""
hparams = self._hparams
losses = []
if self.has_input:
inputs_context = features.get("inputs_context")
inputs = features["inputs"]
target_space = features["target_space_id"]
encoder_output_context, encoder_output, encoder_decoder_attention_bias = self.encode(
inputs_context, inputs, target_space, hparams, features=features, losses=losses)
else:
encoder_output_context, encoder_output, encoder_decoder_attention_bias = (None, None, None)
targets = features["targets"]
targets_shape = common_layers.shape_list(targets)
targets = common_layers.flatten4d3d(targets)
decoder_input, decoder_self_attention_bias = transformer_prepare_decoder(
targets, hparams, features=features)
decoder_output = self.decode(
decoder_input,
encoder_output,
encoder_decoder_attention_bias,
decoder_self_attention_bias,
hparams,
name="decoder_output_input",
nonpadding=features_to_nonpadding(features, "targets"),
losses=losses)
if encoder_output_context is not None:
decoder_output_context = self.decode(
decoder_input,
encoder_output_context,
encoder_decoder_attention_bias,
decoder_self_attention_bias,
hparams,
name="decoder_output_input_context",
nonpadding=features_to_nonpadding(features, "targets"),
losses=losses)
decoder_output = self.cat_and_compress(decoder_output_context, decoder_output, hparams)
expected_attentions = features.get("expected_attentions")
if expected_attentions is not None:
attention_loss = common_attention.encoder_decoder_attention_loss(
expected_attentions, self.attention_weights,
hparams.expected_attention_loss_type,
hparams.expected_attention_loss_multiplier)
return decoder_output, {"attention_loss": attention_loss}
ret = tf.reshape(decoder_output, targets_shape)
if losses:
return ret, {"extra_loss": tf.add_n(losses)}
else:
return ret
def flatten(inputs): return tf.expand_dims(common_layers.flatten4d3d(inputs), axis=2)
def encode(self,
inputs,
target_space,
hparams,
features=None,
losses=None,
**kwargs):
"""Encode Universal Transformer inputs.
It is similar to "transformer.encode", but it uses
"universal_transformer_util.universal_transformer_encoder" instead of
"transformer.transformer_encoder".
Args:
inputs: Transformer inputs [batch_size, input_length, input_height,
hidden_dim] which will be flattened along the two spatial dimensions.
target_space: scalar, target space ID.
hparams: hyperparmeters for model.
features: optionally pass the entire features dictionary as well.
This is needed now for "packed" datasets.
losses: Unused.
**kwargs: additional arguments to pass to encoder_function
Returns:
Tuple of:
encoder_output: Encoder representation.
[batch_size, input_length, hidden_dim]
encoder_decoder_attention_bias: Bias and mask weights for
encoder-decoder attention. [batch_size, input_length]
encoder_extra_output: which is extra encoder output used in some
variants of the model (e.g. in ACT, to pass the ponder-time to body)
"""
####
## DEBUG
####
# with open("invertible_UT_params.json", "w") as f:
# json.dump(dict(hparams.__dict__), f, default=lambda o: '<not serializable>', sort_keys=True,
# indent=4, separators=(',', ': '))
# sys.exit()
del losses
inputs = common_layers.flatten4d3d(inputs)
encoder_input, self_attention_bias, encoder_decoder_attention_bias = (
transformer.transformer_prepare_encoder(inputs,
target_space,
hparams,
features=features))
encoder_input = tf.nn.dropout(
encoder_input, 1.0 - hparams.layer_prepostprocess_dropout)
(encoder_output, encoder_extra_output) = (invertible_UT_encoder(
encoder_input,
self_attention_bias,
hparams,
nonpadding=transformer.features_to_nonpadding(features, "inputs"),
save_weights_to=self.attention_weights))
for var in tf.trainable_variables():
print(var)
return encoder_output, encoder_decoder_attention_bias, encoder_extra_output
def testFlatten4D3D(self):
x = np.random.random_integers(1, high=8, size=(3, 5, 2))
y = common_layers.flatten4d3d(common_layers.embedding(x, 10, 7))
self.evaluate(tf.global_variables_initializer())
res = self.evaluate(y)
self.assertEqual(res.shape, (3, 5 * 2, 7))
def ae_transformer_internal(inputs,
targets,
target_space,
hparams,
cache=None,
predict_mask=1.0):
"""AE Transformer, main step used for training."""
# Summaries break with the do_refine cond, turn them off in that case.
global _DO_SUMMARIES
if hparams.do_refine:
_DO_SUMMARIES = False
# Change hyperparameters for the latent prediction model.
hparams_ex = copy.copy(hparams)
hparams_ex.filter_size *= 2
hparams_ex.hidden_size *= 2
hparams_ex.dropout = 0.0
hparams_ex.relu_dropout = 0.0
hparams_ex.z_dropout = 0.0
hparams_ex.layer_prepostprocess_dropout = 0.0
hparams_ex.symbol_dropout = 0.0
hparams.ex = hparams_ex
# Prepare.
if inputs is not None:
batch_size = common_layers.shape_list(inputs)[0]
else:
batch_size = common_layers.shape_list(targets)[0]
targets = tf.reshape(targets, [batch_size, -1, 1, hparams.hidden_size])
# Encoder.
if inputs is not None:
inputs = common_layers.flatten4d3d(inputs)
inputs_ex = tf.layers.dense(tf.stop_gradient(inputs),
hparams_ex.hidden_size,
name="extra_embed")
inputs, ed = encode(inputs, target_space, hparams, "input_enc")
inputs_ex, ed_ex = encode(inputs_ex, target_space, hparams_ex,
"extra_ienc")
else:
ed, inputs_ex, ed_ex = None, None, None
# Autoencoding.
losses = {"extra": tf.constant(0.0), "latent_pred": tf.constant(0.0)}
if hparams.do_ae:
# flatten here
original_targets_shape = tf.shape(targets)
if hparams.task == "image":
cia.maybe_reshape_4d_to_3d(targets)
if hparams.task == "translate":
max_targets_len_from_inputs = tf.concat([inputs, inputs], axis=1)
else:
assert hparams.task == "image"
max_targets_len_from_inputs = targets
targets, _ = common_layers.pad_to_same_length(
targets,
max_targets_len_from_inputs,
final_length_divisible_by=2**hparams.num_compress_steps)
targets_c = compress(targets, inputs, False, hparams, "compress")
if hparams.mode != tf.estimator.ModeKeys.PREDICT:
# Compress and bottleneck.
latents_dense, latents_discrete, extra_loss, embed = hparams.bottleneck(
x=targets_c,
filter_size=hparams.compress_filter_size,
name="vc",
mode=hparams.mode)
if _DO_SUMMARIES:
tf.summary.histogram(
"b0", tf.reshape(latents_discrete[:, 0, :], [-1]))
pc = common_layers.inverse_exp_decay(hparams.startup_steps)
pc = pc if hparams.mode == tf.estimator.ModeKeys.TRAIN else 1.0
cond = tf.less(tf.random_uniform([batch_size]), pc)
latents_dense = tf.where(cond, latents_dense, targets_c)
# TODO(lukaszkaiser): return extra losses batchwise, multiply before mean.
losses["extra"] = extra_loss * tf.reduce_mean(tf.to_float(cond))
# Extra loss predicting latent code from input. Discrete only.
if hparams.bottleneck_kind not in ["dense", "vae"]:
latents_pred = decode_transformer(inputs_ex,
ed_ex,
tf.stop_gradient(
embed(latents_discrete)),
hparams,
"extra",
task="translate")
_, latent_pred_loss = ae_latent_softmax(
latents_pred, tf.stop_gradient(latents_discrete), hparams)
losses["latent_pred"] = tf.reduce_mean(latent_pred_loss *
tf.to_float(cond))
else:
inputs_c = decode_transformer(inputs, ed, targets_c, hparams,
"dec_c")
losses["latent_pred"] = tf.reduce_mean(
(inputs_c - targets_c)**2) * 20
def bn_inputs():
with tf.variable_scope(tf.get_variable_scope(),
reuse=True):
bn, _, _, _ = hparams.bottleneck(
x=inputs_c,
filter_size=hparams.compress_filter_size,
name="vc",
mode=hparams.mode)
return bn
inputs_c = bn_inputs
ptc = 1.0 - common_layers.inverse_lin_decay(200000) * 0.5
ptc = ptc if hparams.mode == tf.estimator.ModeKeys.TRAIN else 1.0
latents_dense = tf.where(
tf.less(tf.random_uniform([batch_size]), ptc),
latents_dense, inputs_c)
else:
if hparams.bottleneck_kind in ["dense", "vae"]:
inputs_c = decode_transformer(inputs, ed, targets_c, hparams,
"dec_c")
latents_dense, _, _, _ = hparams.bottleneck(
x=inputs_c,
filter_size=hparams.compress_filter_size,
name="vc",
mode=hparams.mode)
else:
latent_len = common_layers.shape_list(targets_c)[1]
_, _, _, embed = hparams.bottleneck(
x=targets_c,
filter_size=hparams.compress_filter_size,
name="vc")
latents_dense = tf.zeros_like(targets_c[:, :latent_len, :, :])
if cache is None:
cache = ae_latent_sample(latents_dense, inputs_ex, ed_ex,
embed, 16, hparams)
latents_dense = embed(cache)
# Postprocess.
d = latents_dense
pos = tf.get_variable("pos", [1, 1000, 1, hparams.hidden_size])
pos = pos[:, :common_layers.shape_list(latents_dense)[1] + 1, :, :]
latents_dense = tf.pad(latents_dense,
[[0, 0], [1, 0], [0, 0], [0, 0]]) + pos
# Masking.
if hparams.do_mask:
masking = common_layers.inverse_lin_decay(
hparams.mask_startup_steps)
masking *= common_layers.inverse_exp_decay(
hparams.mask_startup_steps // 4) # Not much at start.
if not hparams.do_refine:
masking -= tf.random_uniform([]) * hparams.unmasked_percentage
masking = tf.minimum(tf.maximum(masking, 0.0), 1.0)
if hparams.use_predict_mask:
masking = predict_mask
if hparams.mode == tf.estimator.ModeKeys.PREDICT:
masking = predict_mask
mask = tf.less(
masking,
tf.random_uniform(common_layers.shape_list(targets)[:-1]))
mask = tf.expand_dims(tf.to_float(mask), 3)
for i in xrange(hparams.num_compress_steps):
j = hparams.num_compress_steps - i - 1
d = residual_conv(d, 1, (3, 1), hparams,
"decompress_rc_%d" % j)
if hparams.do_attend_decompress:
d = attend(d, inputs, hparams, "decompress_attend_%d" % j)
d = decompress_step(d, hparams, i > 0, False,
"decompress_%d" % j)
# targets is always [batch, length, 1, depth]
targets = mask * targets + (1.0 - mask) * d
# reshape back to 4d here
if hparams.task == "image":
targets = tf.reshape(targets, original_targets_shape)
if hparams.task == "translate":
targets = tf.concat([tf.reverse(latents_dense, [1]), targets],
axis=1)
res = decode_transformer(inputs,
ed,
targets,
hparams,
"decoder",
causal=hparams.causal)
if hparams.do_ae:
if hparams.task == "translate":
res = res[:, common_layers.shape_list(latents_dense)[1]:, :, :]
if hparams.do_mask and hparams.do_refine:
def refine_res():
# return residual_conv(res, 1, (5, 1), hparams, "refine")
r, _ = encode(tf.squeeze(res, axis=[2]), target_space, hparams,
"refine_enc")
return tf.expand_dims(r, axis=2)
masked_batches = tf.reduce_sum(mask, axis=[1, 2, 3])
all_masked = tf.less(masked_batches, 0.1)
res = tf.where(all_masked, refine_res(), res)
# We'll start training the extra model of latents after mask_startup_steps.
nonlatent_steps = hparams.mask_startup_steps
latent_time = tf.less(nonlatent_steps,
tf.to_int32(tf.train.get_global_step()))
# Learning rate warmup for the latent model for 20K steps.
latent_warmup = tf.to_float(
tf.train.get_global_step()) - nonlatent_steps
latent_warmup = tf.maximum(0.0, tf.minimum(1.0,
latent_warmup / 20000.0))
losses["latent_pred"] *= tf.to_float(latent_time) * latent_warmup
return res, losses, cache
def ae_transformer_internal(inputs,
targets,
target_space,
hparams,
cache=None):
"""Main step used for training."""
# Encoder.
inputs = common_layers.flatten4d3d(inputs)
inputs, ed = encode(inputs, target_space, hparams, "input_enc")
# Autoencoding.
losses = {"extra": tf.constant(0.0), "latent_pred": tf.constant(0.0)}
max_targets_len_from_inputs = tf.concat([inputs, inputs], axis=1)
targets, _ = common_layers.pad_to_same_length(
targets,
max_targets_len_from_inputs,
final_length_divisible_by=2**hparams.num_compress_steps)
targets_c = compress(targets, hparams, "compress")
if hparams.mode != tf.estimator.ModeKeys.PREDICT:
# Compress and bottleneck.
latents_discrete_hot, extra_loss = vq_discrete_bottleneck(
x=targets_c, hparams=hparams)
latents_dense = vq_discrete_unbottleneck(latents_discrete_hot,
hparams=hparams)
latents_dense = targets_c + tf.stop_gradient(latents_dense - targets_c)
latents_discrete = tf.argmax(latents_discrete_hot, axis=-1)
tf.summary.histogram("codes",
tf.reshape(latents_discrete[:, 0, :], [-1]))
losses["extra"] = extra_loss
# Extra loss predicting latent code from input.
latents_pred = decode_transformer(inputs, ed, latents_dense, hparams,
"extra")
latent_pred_loss = get_latent_pred_loss(latents_pred,
latents_discrete_hot, hparams)
losses["latent_pred"] = tf.reduce_mean(latent_pred_loss)
else:
latent_len = common_layers.shape_list(targets_c)[1]
embed = functools.partial(vq_discrete_unbottleneck, hparams=hparams)
latents_dense = tf.zeros_like(targets_c[:, :latent_len, :, :])
if cache is None:
cache = ae_latent_sample_beam(latents_dense, inputs, ed, embed,
hparams)
cache_hot = tf.one_hot(cache, depth=2**hparams.bottleneck_bits)
latents_dense = embed(cache_hot)
# Postprocess.
d = latents_dense
pos = tf.get_variable("pos", [1, 1000, 1, hparams.hidden_size])
pos = pos[:, :common_layers.shape_list(latents_dense)[1] + 1, :, :]
latents_dense = tf.pad(latents_dense,
[[0, 0], [1, 0], [0, 0], [0, 0]]) + pos
# Decompressing the dense latents
for i in range(hparams.num_compress_steps):
j = hparams.num_compress_steps - i - 1
d = residual_conv(d, 1, (3, 1), hparams, "decompress_rc_%d" % j)
d = decompress_step(d, hparams, i > 0, "decompress_%d" % j)
masking = common_layers.inverse_lin_decay(hparams.mask_startup_steps)
masking *= common_layers.inverse_exp_decay(hparams.mask_startup_steps //
4) # Not much at start.
masking = tf.minimum(tf.maximum(masking, 0.0), 1.0)
if hparams.mode == tf.estimator.ModeKeys.PREDICT:
masking = 1.0
mask = tf.less(masking,
tf.random_uniform(common_layers.shape_list(targets)[:-1]))
mask = tf.expand_dims(tf.to_float(mask), 3)
# targets is always [batch, length, 1, depth]
targets = mask * targets + (1.0 - mask) * d
res = decode_transformer(inputs, ed, targets, hparams, "decoder")
latent_time = tf.less(hparams.mask_startup_steps,
tf.to_int32(tf.train.get_global_step()))
losses["latent_pred"] *= tf.to_float(latent_time)
return res, losses, cache
def lstm_decoder_infer(self, inputs, sequence_length, hparams, clss, train,
initial_state=None, bottleneck=None):
# IN PREDICT MODE, RUN tf.while RNN
max_decode_length = 51
batch_size = common_layers.shape_list(inputs)[0]
zero_pad, logits_so_far = self.create_initial_input_for_decode(batch_size)
layers = contrib_rnn.MultiRNNCell([
self.lstm_cell(hparams, train) for _ in range(hparams.num_hidden_layers)
])
if initial_state is None:
raise Exception('initial state should be init from bottleneck!')
# append one-hot class to bottleneck, which will be given per step
clss = tf.reshape(clss, [-1])
if not hparams.use_cls:
clss = tf.zeros_like(clss)
if hparams.condition_on_sln:
sln = tf.reshape(sequence_length, [-1])
bottleneck = tf.concat((bottleneck,
tf.one_hot(clss, hparams.num_categories),
tf.one_hot(sln, max_decode_length)), -1)
else:
bottleneck = tf.concat((bottleneck,
tf.one_hot(clss, hparams.num_categories)), -1)
def infer_step(logits_so_far, current_hidden):
"""Inference step of LSTM while loop."""
# unflatten hidden:
current_hidden = tuple(tf.nn.rnn_cell.LSTMStateTuple(c=s[0], h=s[1])
for s in current_hidden)
# put logits_so_far through top
tm = self._problem_hparams.modality['targets']
# need to reuse top params
reset_scope = tf.variable_scope(tf.VariableScope(tf.AUTO_REUSE, ''),
reuse=tf.AUTO_REUSE,
auxiliary_name_scope=False)
top_scope = tf.variable_scope('svg_decoder/{}_modality'.format(tm),
reuse=tf.AUTO_REUSE)
with reset_scope, top_scope:
samples_so_far = self.hparams.top['targets'](
logits_so_far, None, self.hparams, self.problem_hparams.vocab_size)
# append a zero pad to the samples. this effectively shifts the samples
# right, but, unlike shift_right, by not removing the last element, we
# allow an empty samples_so_far to not be empty after padding
samples_so_far = tf.concat([zero_pad, samples_so_far], axis=1)
shifted_targets = common_layers.flatten4d3d(samples_so_far)
# now take the very last one here, will be the actual input to the rnn
shifted_targets = shifted_targets[:, -1:, :]
# tile and append the bottleneck to inputs
sln_offset = 0
if hparams.condition_on_sln:
sln_offset = 51
pre_tile_y = tf.reshape(
bottleneck,
[common_layers.shape_list(bottleneck)[0], 1,
hparams.bottleneck_bits + hparams.num_categories + sln_offset])
overlay_x = tf.tile(pre_tile_y,
[1, common_layers.shape_list(shifted_targets)[1], 1])
inputs = tf.concat([shifted_targets, overlay_x], -1)
seq_len_batch = tf.ones([common_layers.shape_list(inputs)[0]])
# RUN PRE-LSTM LAYER
with tf.variable_scope('pre_decoder', reuse=tf.AUTO_REUSE):
inputs = tf.layers.dense(inputs, hparams.hidden_size, name='bottom')
inputs = tf.nn.tanh(inputs)
# RUN LSTM
with tf.variable_scope('lstm_decoder', reuse=tf.AUTO_REUSE):
next_step, next_state = tf.nn.dynamic_rnn(
layers, inputs, seq_len_batch, initial_state=current_hidden,
dtype=tf.float32, time_major=False)
next_step = tf.expand_dims(next_step, [1])
logits_so_far = tf.concat([logits_so_far, next_step], 1)
# flatten state
next_state = tuple((s.c, s.h) for s in next_state)
return logits_so_far, next_state
def while_exit_cond(logits_so_far, unused_current_hidden):
length = common_layers.shape_list(logits_so_far)[1]
return length < max_decode_length
# passing state must be flattened:
initial_state = tuple([(s.c, s.h) for s in initial_state])
# actually run tf.while:
logits, final_state = tf.while_loop(
while_exit_cond, infer_step,
[logits_so_far, initial_state],
shape_invariants=[
tf.TensorShape([None, None, 1, hparams.hidden_size]),
tuple([(s[0].get_shape(), s[1].get_shape())
for s in initial_state]),
],
back_prop=False,
parallel_iterations=1
)
# logits should be returned in 3d mode:
logits = common_layers.flatten4d3d(logits)
return logits, final_state
def body(self, features):
"""R-Transformer main model_fn.
Args:
features: Map of features to the model. Should contain the following:
"inputs": Transformer inputs [batch_size, input_length, hidden_dim]
"targets": Target decoder outputs.
[batch_size, decoder_length, hidden_dim]
"target_space_id"
Returns:
Final decoder representation. [batch_size, decoder_length, hidden_dim]
"""
hparams = self._hparams
if hparams.add_position_timing_signal:
# Turning off addition of positional embedding in the encoder/decoder
# preparation as we do it in the beginning of each step.
hparams.pos = None
if self.has_input:
inputs = features["inputs"]
target_space = features["target_space_id"]
(encoder_output, encoder_decoder_attention_bias,
enc_extra_output) = self.encode(inputs,
target_space,
hparams,
features=features)
else:
(encoder_output, encoder_decoder_attention_bias,
enc_extra_output) = (None, None, (None, None))
targets = features["targets"]
targets = common_layers.flatten4d3d(targets)
(decoder_input, decoder_self_attention_bias
) = transformer.transformer_prepare_decoder(targets,
hparams,
features=features)
decoder_output, dec_extra_output = self.decode(
decoder_input,
encoder_output,
encoder_decoder_attention_bias,
decoder_self_attention_bias,
hparams,
nonpadding=transformer.features_to_nonpadding(features, "targets"))
expected_attentions = features.get("expected_attentions")
if expected_attentions is not None:
attention_loss = common_attention.encoder_decoder_attention_loss(
expected_attentions, self.attention_weights,
hparams.expected_attention_loss_type,
hparams.expected_attention_loss_multiplier)
return decoder_output, {"attention_loss": attention_loss}
if hparams.recurrence_type == "act" and hparams.act_loss_weight != 0:
if self.has_input:
enc_ponder_times, enc_remainders = enc_extra_output
enc_act_loss = (
hparams.act_loss_weight *
tf.reduce_mean(enc_ponder_times + enc_remainders))
else:
enc_act_loss = 0.0
(dec_ponder_times, dec_remainders) = dec_extra_output
dec_act_loss = (hparams.act_loss_weight *
tf.reduce_mean(dec_ponder_times + dec_remainders))
act_loss = enc_act_loss + dec_act_loss
tf.contrib.summary.scalar("act_loss", act_loss)
return decoder_output, {"act_loss": act_loss}
return decoder_output
def decode_transformer(encoder_output,
encoder_decoder_attention_bias,
targets,
hparams,
name,
task=None,
causal=True):
"""Original Transformer decoder."""
orig_hparams = hparams
with tf.variable_scope(name):
if task is None:
task = hparams.task
if task == "translate":
targets = common_layers.flatten4d3d(targets)
decoder_input, decoder_self_bias = (
transformer.transformer_prepare_decoder(targets, hparams))
decoder_input = tf.nn.dropout(
decoder_input, 1.0 - hparams.layer_prepostprocess_dropout)
if not causal:
decoder_self_bias *= 0.
decoder_output = transformer.transformer_decoder(
decoder_input, encoder_output, decoder_self_bias,
encoder_decoder_attention_bias, hparams)
decoder_output = tf.expand_dims(decoder_output, axis=2)
else:
assert task == "image"
inputs = None
# have to reshape targets as b, 32, 32, 3 * hidden size] beacuse otherwise
# prepare_image will choke
targets = tf.reshape(targets, [
tf.shape(targets)[0], hparams.img_len, hparams.img_len,
hparams.num_channels * hparams.hidden_size
])
# Prepare decoder inputs and bias.
# TODO(nikip): Make prepare_decoder return bias
decoder_input, _, _ = cia.prepare_decoder(targets, hparams)
bias = None
# Add class label to decoder input.
if not hparams.drop_inputs:
decoder_input += tf.reshape(inputs, [
common_layers.shape_list(targets)[0], 1, 1,
hparams.hidden_size
])
decoder_output = cia.transformer_decoder_layers(
decoder_input,
encoder_output=None,
num_layers=hparams.num_decoder_layers
or hparams.num_hidden_layers,
hparams=hparams,
self_attention_bias=bias,
attention_type=hparams.dec_attention_type,
name="decoder")
decoder_output_shape = common_layers.shape_list(decoder_output)
decoder_output = tf.reshape(
decoder_output,
[decoder_output_shape[0], -1, 1, hparams.hidden_size])
# Expand since t2t expects 4d tensors.
hparams = orig_hparams
return decoder_output
def body(self, features, original_features):
"""Transformer main model_fn.
Args:
features: Map of features to the model. Should contain the following:
"inputs": Transformer inputs [batch_size, input_length, hidden_dim]
"targets": Target decoder outputs.
[batch_size, decoder_length, hidden_dim]
"target_space_id"
Returns:
Final decoder representation. [batch_size, decoder_length, hidden_dim]
"""
hparams = self._hparams
snippets = features.get(searchqa_problem.FeatureNames.SNIPPETS)
questions = features.get(searchqa_problem.FeatureNames.QUESTION)
target_space = features["target_space_id"]
with tf.variable_scope('input'):
# [batch_size, search_results_len, embed_sz]
encoded_snippets = self.inputs_encoding(
input=snippets,
original_input=original_features.get(
searchqa_problem.FeatureNames.SNIPPETS),
initializer=tf.constant_initializer(1.0),
scope='snippets_encoding')
# [batch_size, 1, embed_sz]
encoded_question = self.inputs_encoding(
input=questions,
original_input=original_features.get(
searchqa_problem.FeatureNames.QUESTION),
initializer=tf.constant_initializer(1.0),
scope='question_encoding')
# Concat snippets and questions to creat the inputs
inputs = tf.concat([encoded_snippets, encoded_question], axis=1)
# the input is 4D by default and it gets squeezed from 4D to 3D in the
# encode function, so we need to make it 4D by inserting channel dim.
inputs = tf.expand_dims(inputs, axis=2)
losses = []
encoder_output, encoder_decoder_attention_bias = self.encode(
inputs, target_space, hparams, features=features, losses=losses)
targets = features["targets"]
targets_shape = common_layers.shape_list(targets)
targets = common_layers.flatten4d3d(targets)
decoder_input, decoder_self_attention_bias = transformer.transformer_prepare_decoder(
targets, hparams, features=features)
decoder_output = self.decode(decoder_input,
encoder_output,
encoder_decoder_attention_bias,
decoder_self_attention_bias,
hparams,
nonpadding=features_to_nonpadding(
features, "targets"),
losses=losses)
ret = tf.reshape(decoder_output, targets_shape)
if losses:
return ret, {"extra_loss": tf.add_n(losses)}
else:
return ret
def body(self, features):
"""Transformer main model_fn.
Args:
features: Map of features to the model. Should contain the following:
"inputs": Transformer inputs [batch_size, input_length, hidden_dim]
"targets": Target decoder outputs. [batch_size, decoder_length,
hidden_dim]
"target_space_id": A scalar int from data_generators.problem.SpaceID.
Returns:
Final decoder representation. [batch_size, decoder_length, hidden_dim]
"""
tf.logging.info("Using PgScratch BODY function.")
hparams = self._hparams
losses = {}
inputs = features["inputs"]
target_space = features["target_space_id"]
# encoder_output: <tf.float32>[batch_size, input_length, hidden_dim]
# encoder_decoder_attention_bias: <tf.float32>[batch_size, input_length]
encoder_output, encoder_decoder_attention_bias = self.encode(
inputs, target_space, hparams, features=features, losses=losses)
with tf.variable_scope("knowledge"):
with tf.name_scope("knowledge_encoding"):
# Encode knowledge.
# <tf.float32>[batch_size, triple_num, emb_dim]
fact_embedding, fact_lengths = self.encode_knowledge_bottom(
features)
tf.logging.info("Encoded knowledge")
with tf.name_scope("knowledge_selection_and_loss"):
# Compute knowledge selection and loss.
triple_logits, avg_triple_selection_loss, knowledge_encoder_output, transe_loss = self.compute_knowledge_selection_and_loss(
features, encoder_output, fact_embedding, fact_lengths,
hparams.margin, hparams.num_negative_samples)
losses["kb_loss"] = avg_triple_selection_loss
losses["transe_loss"] = transe_loss
if hparams.attend_kb:
tf.logging.info("ATTEND_KB is ACTIVE")
with tf.name_scope("knowledge_attention"):
knowledge_padding = tf.zeros_like(triple_logits,
dtype=tf.float32)
knowledge_attention_bias = common_attention.attention_bias_ignore_padding(
knowledge_padding)
encoder_output = tf.concat(
[knowledge_encoder_output, encoder_output], 1)
encoder_decoder_attention_bias = tf.concat(
[knowledge_attention_bias, encoder_decoder_attention_bias],
-1)
else:
tf.logging.info("ATTEND_KB is INACTIVE")
targets = features["targets"]
targets_shape = common_layers.shape_list(targets)
targets = common_layers.flatten4d3d(targets)
(decoder_input, decoder_self_attention_bias
) = transformer.transformer_prepare_decoder(targets,
hparams,
features=features)
decode_kwargs = {}
decoder_output = self.decode(
decoder_input,
encoder_output,
encoder_decoder_attention_bias,
decoder_self_attention_bias,
hparams,
nonpadding=transformer.features_to_nonpadding(features, "targets"),
losses=losses,
**decode_kwargs)
expected_attentions = features.get("expected_attentions")
if expected_attentions is not None:
attention_loss = common_attention.encoder_decoder_attention_loss(
expected_attentions, self.attention_weights,
hparams.expected_attention_loss_type,
hparams.expected_attention_loss_multiplier)
return decoder_output, {"attention_loss": attention_loss}
ret = tf.reshape(decoder_output, targets_shape)
if losses:
return ret, losses
else:
return ret
def ae_transformer_internal(inputs,
targets,
target_space,
hparams,
beam_size,
cache=None,
predict_mask=1.0):
"""AE Transformer, main step used for training."""
# Summaries break with the do_refine cond, turn them off in that case.
global _DO_SUMMARIES
if hparams.do_refine:
_DO_SUMMARIES = False
# Prepare.
orig_targets = targets
batch_size = tf.shape(orig_targets)[0]
targets = tf.reshape(targets, [batch_size, -1, 1, hparams.hidden_size])
# Encoder.
if inputs is not None:
inputs = common_layers.flatten4d3d(inputs)
inputs, ed = encode(inputs, target_space, hparams, "input_enc")
else:
ed = None
# Autoencoding.
losses = {"extra": tf.constant(0.0), "latent_pred": tf.constant(0.0)}
if hparams.do_ae:
max_targets_len_from_inputs = tf.concat([inputs, inputs], axis=1)
targets, _ = common_layers.pad_to_same_length(
targets,
max_targets_len_from_inputs,
final_length_divisible_by=2**hparams.num_compress_steps)
targets_c = compress(targets, False, hparams, "compress")
if hparams.mode != tf.estimator.ModeKeys.PREDICT:
# Compress and bottleneck.
t_c, t_bit, vc_loss, _ = bottleneck(targets_c, hparams, 2 * 2048,
"vc")
if _DO_SUMMARIES:
tf.summary.histogram("bit0", tf.reshape(t_bit[:, 0, :], [-1]))
pc = common_layers.inverse_exp_decay(hparams.startup_steps) * 0.95
pc = pc if hparams.mode == tf.estimator.ModeKeys.TRAIN else 1.0
cond = tf.less(tf.random_uniform([]), pc)
t_c = tf.cond(cond, lambda: t_c, lambda: targets_c)
losses["extra"] = vc_loss * tf.to_float(cond)
# Extra loss predicting latent code from input. Discrete only.
if hparams.bottleneck_kind not in ["dense", "vae"]:
t_pred = decode_transformer(inputs, ed, tf.stop_gradient(t_c),
hparams, "extra")
t_pred = tf.layers.dense(t_pred, 2**16, name="extra_logits")
losses[
"latent_pred"] = tf.nn.sparse_softmax_cross_entropy_with_logits(
labels=t_bit, logits=t_pred)
losses["latent_pred"] = tf.reduce_mean(
losses["latent_pred"]) * 0.5 * tf.to_float(cond)
else:
if hparams.bottleneck_kind in ["dense", "vae"]:
targets_rand = tf.random_uniform(tf.shape(targets_c))
t_c, _, _, _ = bottleneck(targets_rand, hparams, 2 * 2048,
"vc")
else:
latent_len = tf.shape(targets_c)[1]
_, _, _, embed = bottleneck(targets_c, hparams, 2 * 2048, "vc")
t_c = tf.zeros_like(targets_c[:, :latent_len, :, :])
if cache is None:
cache = ae_latent_sample(t_c, inputs, ed, embed, 8,
hparams)
cache = cache[0, :, :]
cache = tf.reshape(cache, [1, latent_len, 1])
cache = tf.tile(cache, [beam_size, 1, 1])
t_c = embed(cache)
# Postprocess.
d = t_c
pos = tf.get_variable("pos", [1, 1000, 1, hparams.hidden_size])
pos = pos[:, :tf.shape(t_c)[1] + 1, :, :]
t_c = tf.pad(t_c, [[0, 0], [1, 0], [0, 0], [0, 0]]) + pos
# Masking.
if hparams.do_mask:
masking = common_layers.inverse_lin_decay(100000)
masking *= common_layers.inverse_exp_decay(
25000) # Not much at start.
if not hparams.do_refine:
masking -= tf.random_uniform([]) * 0.3
masking = tf.minimum(tf.maximum(masking, 0.0), 1.0)
if hparams.mode == tf.estimator.ModeKeys.PREDICT:
masking = predict_mask
mask = tf.less(masking, tf.random_uniform(tf.shape(targets)[:-1]))
mask = tf.expand_dims(tf.to_float(mask), 3)
for i in xrange(hparams.num_compress_steps):
j = hparams.num_compress_steps - i - 1
d = residual_conv(d, 1, (3, 1), hparams,
"decompress_rc_%d" % j)
d = decompress_step(d, hparams, i > 0, False,
"decompress_%d" % j)
targets = mask * targets + (1.0 - mask) * d
targets = tf.concat([tf.reverse(t_c, [1]), targets], axis=1)
res = decode_transformer(inputs, ed, targets, hparams, "decoder")
if hparams.do_ae:
res = res[:, tf.shape(t_c)[1]:, :, :]
if hparams.do_mask and hparams.do_refine:
def refine_res():
return residual_conv(res, 1, (5, 1), hparams, "refine")
all_masked = tf.less(tf.reduce_sum(mask), 0.1)
res = tf.cond(all_masked, refine_res, lambda: res)
return res, losses, cache
def mel_perf_transformer_encode(encoder_function,
perf_inputs,
mel_inputs,
target_space,
hparams,
attention_weights=None,
features=None,
losses=None,
prepare_encoder_fn=None,
**kwargs):
"""Encode transformer inputs. Used for melody & performance autoencoder.
Performance is mean-aggregated across time and combined with melody in a
variety of different ways.
Args:
encoder_function: the encoder function
perf_inputs: Transformer inputs [batch_size, input_length, 1, hidden_dim]
which will be flattened along the two spatial dimensions.
mel_inputs: Transformer inputs [batch_size, input_length, 1, hidden_dim]
which will be flattened along the two spatial dimensions.
target_space: scalar, target space ID.
hparams: hyperparameters for model.
attention_weights: weight to store attention to.
features: optionally pass the entire features dictionary as well. This is
needed now for "packed" datasets.
losses: optional list onto which to append extra training losses
prepare_encoder_fn: optional, alternative to transformer_prepare_encoder.
**kwargs: additional arguments to pass to encoder_function
Returns:
Tuple of:
encoder_output: Encoder representation.
[batch_size, input_length, hidden_dim]
encoder_decoder_attention_bias: Bias and mask weights for
encoder-decoder attention. [batch_size, input_length]
"""
perf_inputs = common_layers.flatten4d3d(perf_inputs)
mel_inputs = common_layers.flatten4d3d(mel_inputs)
if not prepare_encoder_fn:
prepare_encoder_fn = transformer_prepare_encoder
perf_encoder_input, perf_self_attention_bias, perf_encdec_attention_bias = (
prepare_encoder_fn(perf_inputs,
target_space,
hparams,
features=features,
reuse_target_embedding=tf.AUTO_REUSE))
mlperf_log.transformer_print(
key=mlperf_log.MODEL_HP_LAYER_POSTPROCESS_DROPOUT,
value=hparams.layer_prepostprocess_dropout,
hparams=hparams)
perf_encoder_input = tf.nn.dropout(
perf_encoder_input, 1.0 - hparams.layer_prepostprocess_dropout)
perf_attn_bias_for_padding = None
# Otherwise the encoder will just use encoder_self_attention_bias.
if hparams.unidirectional_encoder:
perf_attn_bias_for_padding = perf_encdec_attention_bias
# do the same thing for melody
mel_encoder_input, mel_self_attention_bias, mel_encdec_attention_bias = (
prepare_encoder_fn(mel_inputs,
target_space,
hparams,
features=features,
reuse_target_embedding=tf.AUTO_REUSE))
mlperf_log.transformer_print(
key=mlperf_log.MODEL_HP_LAYER_POSTPROCESS_DROPOUT,
value=hparams.layer_prepostprocess_dropout,
hparams=hparams)
mel_encoder_input = tf.nn.dropout(
mel_encoder_input, 1.0 - hparams.layer_prepostprocess_dropout)
mel_attn_bias_for_padding = None
# Otherwise the encoder will just use encoder_self_attention_bias.
if hparams.unidirectional_encoder:
mel_attn_bias_for_padding = mel_encdec_attention_bias
# use the proper encoder function for perf/melody
perf_encoder_output = encoder_function(
perf_encoder_input,
perf_self_attention_bias,
hparams,
name="perf_encoder",
nonpadding=features_to_nonpadding(features, "inputs"),
save_weights_to=attention_weights,
make_image_summary=not common_layers.is_xla_compiled(),
losses=losses,
attn_bias_for_padding=perf_attn_bias_for_padding,
**kwargs)
# same thing for melody
mel_encoder_output = encoder_function(
mel_encoder_input,
mel_self_attention_bias,
hparams,
name="mel_encoder",
nonpadding=features_to_nonpadding(features, "inputs"),
save_weights_to=attention_weights,
make_image_summary=not common_layers.is_xla_compiled(),
losses=losses,
attn_bias_for_padding=mel_attn_bias_for_padding,
**kwargs)
# concatenate the global mean vector/bias term with the full melody encoding
perf_mean_vector = tf.math.reduce_mean(perf_encoder_output,
axis=1,
keep_dims=True)
# different methods of aggregating over the performance + melody vectors!
if hparams.aggregation == "sum":
# add both mean performance and melody vectors together
perf_mean_bias = tf.math.reduce_mean(perf_encdec_attention_bias,
axis=-1,
keep_dims=True)
encoder_output = mel_encoder_output + perf_mean_vector
encoder_decoder_attention_bias = mel_encdec_attention_bias + perf_mean_bias
elif hparams.aggregation == "concat":
# concatenate melody with mean-aggregated performance embedding
stop_token = tf.zeros((1, 1, 384))
encoder_output = tf.concat(
[mel_encoder_output, stop_token, perf_mean_vector], axis=1)
perf_mean_bias = tf.math.reduce_mean(perf_encdec_attention_bias,
axis=-1,
keep_dims=True)
stop_bias = tf.zeros((1, 1, 1, 1))
encoder_decoder_attention_bias = tf.concat(
[mel_encdec_attention_bias, stop_bias, perf_mean_bias], axis=-1)
elif hparams.aggregation == "tile":
# tile performance embedding across each dimension of melody embedding!
dynamic_val = tf.shape(mel_encoder_output)[1]
shp = tf.convert_to_tensor([1, dynamic_val, 1], dtype=tf.int32)
tiled_mean = tf.tile(perf_mean_vector, shp)
encoder_output = tf.concat([mel_encoder_output, tiled_mean], axis=-1)
encoder_decoder_attention_bias = mel_encdec_attention_bias
else:
NotImplementedError(
"aggregation method must be in [sum, concat, tile].")
return encoder_output, encoder_decoder_attention_bias
def maybe_flatten4d3d(x):
xshape = common_layers.shape_list(x)
return common_layers.flatten4d3d(x) if len(xshape) == 4 else x
