def is_finished(self, step_idx, source_length, alive_log_probs, finished_scores, finished_in_finished):
"""
is_finished
"""
base_1 = layers.cast(source_length, 'float32') + 55.0
base_1 /= 6.0
max_length_penalty = layers.pow(base_1, self.alpha)
flat_alive_log_probs = layers.reshape(alive_log_probs, [-1])
lower_bound_alive_scores_1 = layers.gather(flat_alive_log_probs, [self.get_alive_index])
lower_bound_alive_scores = lower_bound_alive_scores_1 / max_length_penalty
lowest_score_of_finished_in_finish = layers.reduce_min(finished_scores * finished_in_finished, dim=1)
finished_in_finished = layers.cast(finished_in_finished, 'bool')
lowest_score_of_finished_in_finish += \
((1.0 - layers.cast(layers.reduce_any(finished_in_finished, 1), 'float32')) * -INF)
#print lowest_score_of_finished_in_finish
bound_is_met = layers.reduce_all(layers.greater_than(lowest_score_of_finished_in_finish,
lower_bound_alive_scores))
decode_length = source_length + 50
length_cond = layers.less_than(x=step_idx, y=decode_length)
return layers.logical_and(x=layers.logical_not(bound_is_met), y=length_cond)
def reduce_compare(x, op_str, y):
element_wise_result = eval("x " + op_str + " y")
if op_str == "!=":
return reduce_any(element_wise_result)
elif op_str == "is" or op_str == "is not" or op_str == "in" or op_str == "not in":
return element_wise_result
else:
return reduce_all(element_wise_result)
def forward(self, x):
"""Forward network"""
mask = layers.reduce_any(x != self.pad_index, -1)
lens = nn.reduce_sum(mask, -1)
masked_x = nn.masked_select(x, mask)
h, _ = self.transformer(masked_x)
feat_embed = nn.pad_sequence_paddle(
layers.split(h, lens.numpy().tolist(), dim=0), self.pad_index)
return feat_embed
def _push_to_stack(gmr_desc, gmr_pos, gmr_lens, gmr_stack_info):
"""push grammar id in gmr_desc from gmr_pos to gmr_lens to
gmr_stack. and update step_gmr_pos
Args:
gmr_desc (TYPE): NULL
gmr_pos (TYPE): NULL
gmr_lens (TYPE): NULL
gmr_stack_info (tuple): [in/out] (gmr_stack, gmr_stack_pos)
Returns: tuple (gmr_stack, gmr_stack_pos)
Raises: NULL
"""
gmr_stack, gmr_stack_pos = gmr_stack_info
mv_step = layers.cast(layers.greater_than(gmr_lens,
layers.zeros_like(gmr_lens)),
dtype=gmr_lens.dtype)
gmr_mv_pos = layers.elementwise_sub(gmr_lens, mv_step)
cond = layers.reduce_any(layers.greater_than(gmr_mv_pos, gmr_pos))
while_op = layers.While(cond)
with while_op.block():
gmr_ids = nn_utils.batch_gather(gmr_desc, gmr_mv_pos)
gmr_stack_tmp, gmr_stack_pos_tmp = data_structure.Stack.push(
gmr_stack_info, gmr_ids, in_place=False)
mv_cond = layers.greater_than(gmr_mv_pos, gmr_pos)
gmr_mv_pos_tmp = fluider.elementwise_sub(gmr_mv_pos,
mv_cond,
force=True)
new_gmr_stack, new_gmr_stack_pos = nn_utils.ifelse(
mv_cond, [gmr_stack_tmp, gmr_stack_pos_tmp],
[gmr_stack, gmr_stack_pos])
layers.utils.map_structure(layers.assign,
[new_gmr_stack, new_gmr_stack_pos],
[gmr_stack, gmr_stack_pos])
layers.assign(gmr_mv_pos_tmp, gmr_mv_pos)
layers.assign(
layers.reduce_any(layers.greater_than(gmr_mv_pos, gmr_pos)), cond)
return gmr_stack, gmr_stack_pos
def forward(self, x):
"""Forward network"""
mask = layers.reduce_any(x != self.pad_index, -1)
lens = nn.reduce_sum(mask, -1)
masked_x = nn.masked_select(x, mask)
char_mask = masked_x != self.pad_index
emb = self.embed(masked_x)
_, (h, _) = self.lstm(emb, char_mask, self.pad_index)
h = layers.concat(layers.unstack(h), axis=-1)
feat_embed = nn.pad_sequence_paddle(
layers.split(h, lens.numpy().tolist(), dim=0), self.pad_index)
return feat_embed
def beam_search(enc_output, enc_bias, source_length):
"""
beam_search
"""
max_len = layers.fill_constant(
shape=[1], dtype='int64', value=max_out_len)
step_idx = layers.fill_constant(
shape=[1], dtype='int64', value=0)
cond = layers.less_than(x=step_idx, y=max_len)
while_op = layers.While(cond)
caches_batch_size = batch_size * beam_size
init_score = np.zeros([1, beam_size]).astype('float32')
init_score[:, 1:] = -INF
initial_log_probs = layers.assign(init_score)
alive_log_probs = layers.expand(initial_log_probs, [batch_size, 1])
# alive seq [batch_size, beam_size, 1]
initial_ids = layers.zeros([batch_size, 1, 1], 'float32')
alive_seq = layers.expand(initial_ids, [1, beam_size, 1])
alive_seq = layers.cast(alive_seq, 'int64')
enc_output = layers.unsqueeze(enc_output, axes=[1])
enc_output = layers.expand(enc_output, [1, beam_size, 1, 1])
enc_output = layers.reshape(enc_output, [caches_batch_size, -1, d_model])
tgt_src_attn_bias = layers.unsqueeze(enc_bias, axes=[1])
tgt_src_attn_bias = layers.expand(tgt_src_attn_bias, [1, beam_size, n_head, 1, 1])
enc_bias_shape = layers.shape(tgt_src_attn_bias)
tgt_src_attn_bias = layers.reshape(tgt_src_attn_bias, [-1, enc_bias_shape[2],
enc_bias_shape[3], enc_bias_shape[4]])
beam_search = BeamSearch(beam_size, batch_size, decode_alpha, trg_vocab_size, d_model)
caches = [{
"k": layers.fill_constant(
shape=[caches_batch_size, 0, d_model],
dtype=enc_output.dtype,
value=0),
"v": layers.fill_constant(
shape=[caches_batch_size, 0, d_model],
dtype=enc_output.dtype,
value=0)
} for i in range(n_layer)]
finished_seq = layers.zeros_like(alive_seq)
finished_scores = layers.fill_constant([batch_size, beam_size],
dtype='float32', value=-INF)
finished_flags = layers.fill_constant([batch_size, beam_size],
dtype='float32', value=0)
with while_op.block():
pos = layers.fill_constant([caches_batch_size, 1, 1], dtype='int64', value=1)
pos = layers.elementwise_mul(pos, step_idx, axis=0)
alive_seq_1 = layers.reshape(alive_seq, [caches_batch_size, -1])
alive_seq_2 = alive_seq_1[:, -1:]
alive_seq_2 = layers.unsqueeze(alive_seq_2, axes=[1])
logits = wrap_decoder(
trg_vocab_size, max_in_len, n_layer, n_head, d_key,
d_value, d_model, d_inner_hid, prepostprocess_dropout,
attention_dropout, relu_dropout, preprocess_cmd,
postprocess_cmd, weight_sharing, embedding_sharing,
dec_inputs=(alive_seq_2, alive_seq_2, pos, None, tgt_src_attn_bias),
enc_output=enc_output, caches=caches, is_train=False, params_type=params_type)
alive_seq_2, alive_log_probs_2, finished_seq_2, finished_scores_2, finished_flags_2, caches_2 = \
beam_search.inner_func(step_idx, logits, alive_seq_1, alive_log_probs, finished_seq,
finished_scores, finished_flags, caches, enc_output,
tgt_src_attn_bias)
layers.increment(x=step_idx, value=1.0, in_place=True)
finish_cond = beam_search.is_finished(step_idx, source_length, alive_log_probs_2,
finished_scores_2, finished_flags_2)
layers.assign(alive_seq_2, alive_seq)
layers.assign(alive_log_probs_2, alive_log_probs)
layers.assign(finished_seq_2, finished_seq)
layers.assign(finished_scores_2, finished_scores)
layers.assign(finished_flags_2, finished_flags)
for i in xrange(len(caches_2)):
layers.assign(caches_2[i]["k"], caches[i]["k"])
layers.assign(caches_2[i]["v"], caches[i]["v"])
layers.logical_and(x=cond, y=finish_cond, out=cond)
finished_flags = layers.reduce_sum(finished_flags, dim=1, keep_dim=True) / beam_size
finished_flags = layers.cast(finished_flags, 'bool')
mask = layers.cast(layers.reduce_any(input=finished_flags, dim=1, keep_dim=True), 'float32')
mask = layers.expand(mask, [1, beam_size])
mask2 = 1.0 - mask
finished_seq = layers.cast(finished_seq, 'float32')
alive_seq = layers.cast(alive_seq, 'float32')
#print mask
finished_seq = layers.elementwise_mul(finished_seq, mask, axis=0) + \
layers.elementwise_mul(alive_seq, mask2, axis = 0)
finished_seq = layers.cast(finished_seq, 'int32')
finished_scores = layers.elementwise_mul(finished_scores, mask, axis=0) + \
layers.elementwise_mul(alive_log_probs, mask2)
finished_seq.persistable = True
finished_scores.persistable = True
return finished_seq, finished_scores
