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_left(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 testShiftLeft(self):
x1 = np.zeros((5, 7, 1, 11))
x1[:, 0, :] = np.ones_like(x1[:, 0, :])
expected = np.zeros((5, 7, 1, 11))
expected[:, 1, :] = np.ones_like(expected[:, 1, :])
with self.test_session() as session:
a = common_layers.shift_left(tf.constant(x1, dtype=tf.float32))
actual = session.run(a)
self.assertAllEqual(actual, expected)
def decode(cond_vec, cond_add, gold, c, ed, hparams):
"""Transformer decoder."""
drop_gold = tf.nn.dropout(gold, 1.0 - hparams.layer_prepostprocess_dropout)
decoder_input = common_layers.shift_left(drop_gold, pad_value=cond_vec)
if cond_add is not None:
decoder_input += cond_add
decoder_input = tf.squeeze(decoder_input, axis=2)
decoder_input = common_attention.add_timing_signal_1d(decoder_input)
bias = common_attention.attention_bias_lower_triangle(tf.shape(gold)[1])
if c is not None and len(c.get_shape()) > 3:
c = tf.squeeze(c, axis=2)
return transformer.transformer_decoder(decoder_input, c, bias, ed, hparams)
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_left(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"):
# 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_left(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 lstm_seq2seq_internal(inputs, targets, hparams, train):
"""The basic LSTM seq2seq model, main step used for training."""
with tf.variable_scope("lstm_seq2seq"):
# Flatten inputs.
inputs = common_layers.flatten4d3d(inputs)
# LSTM encoder.
_, final_encoder_state = lstm(tf.reverse(inputs, axis=[1]), hparams,
train, "encoder")
# LSTM decoder.
shifted_targets = common_layers.shift_left(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)
