def attn_flow(q_enc, p_enc, p_ids_name, args):
"""Bidirectional Attention layer"""
tag = p_ids_name + "__"
drnn = layers.DynamicRNN()
with drnn.block():
h_cur = drnn.step_input(p_enc)
u_all = drnn.static_input(q_enc)
h_expd = layers.sequence_expand(x=h_cur, y=u_all)
s_t_mul = layers.elementwise_mul(x=u_all, y=h_expd, axis=0)
s_t_sum = layers.reduce_sum(input=s_t_mul, dim=1, keep_dim=True)
s_t_re = layers.reshape(s_t_sum, shape=[-1, 0])
s_t = layers.sequence_softmax(input=s_t_re)
u_expr = layers.elementwise_mul(x=u_all, y=s_t, axis=0)
u_expr = layers.sequence_pool(input=u_expr, pool_type='sum')
b_t = layers.sequence_pool(input=s_t_sum, pool_type='max')
drnn.output(u_expr, b_t)
U_expr, b = drnn()
b_norm = layers.sequence_softmax(input=b)
h_expr = layers.elementwise_mul(x=p_enc, y=b_norm, axis=0)
h_expr = layers.sequence_pool(input=h_expr, pool_type='sum')
H_expr = layers.sequence_expand(x=h_expr, y=p_enc)
H_expr = layers.lod_reset(x=H_expr, y=p_enc)
h_u = layers.elementwise_mul(x=p_enc, y=U_expr, axis=0)
h_h = layers.elementwise_mul(x=p_enc, y=H_expr, axis=0)
g = layers.concat(input=[p_enc, U_expr, h_u, h_h], axis=1)
return dropout(g, args)
def custom_dynamic_rnn(p_vec, init_state, decoder_size):
context = layers.fc(input=p_vec,
size=decoder_size,
act=None)
drnn = layers.DynamicRNN()
with drnn.block():
H_s = drnn.step_input(p_vec)
ctx = drnn.static_input(context)
c_prev = drnn.memory(init=init_state, need_reorder=True)
m_prev = drnn.memory(init=init_state, need_reorder=True)
m_prev1 = layers.fc(input=m_prev, size=decoder_size, act=None)
m_prev1 = layers.sequence_expand(x=m_prev1, y=ctx)
Fk = ctx + m_prev1
Fk = layers.fc(input=Fk, size=decoder_size, act='tanh')
logits = layers.fc(input=Fk, size=1, act=None)
scores = layers.sequence_softmax(input=logits)
attn_ctx = layers.elementwise_mul(x=ctx, y=scores, axis=0)
attn_ctx = layers.sequence_pool(input=attn_ctx, pool_type='sum')
hidden_t, cell_t = lstm_step(attn_ctx, hidden_t_prev=m_prev1, cell_t_prev=c_prev, size=decoder_size)
drnn.update_memory(ex_mem=m_prev, new_mem=hidden_t)
drnn.update_memory(ex_mem=c_prev, new_mem=cell_t)
drnn.output(scores)
beta = drnn()
return beta
def test_sequence_softmax(self):
program = Program()
with program_guard(program):
seq_data = layers.data(
name='seq_data', shape=[10, 10], dtype='float32', lod_level=1)
seq = layers.fc(input=seq_data, size=20)
self.assertIsNotNone(layers.sequence_softmax(seq))
print(str(program))
def test_sequence_softmax(self):
program = Program()
with program_guard(program):
seq_data = layers.data(
name='seq_data', shape=[10, 10], dtype='float32', lod_level=1)
seq = layers.fc(input=seq_data, size=20)
self.assertIsNotNone(layers.sequence_softmax(seq))
print(str(program))
def static_rnn(step,
p_vec=p_vec,
init_state=None,
para_name='',
args=args):
tag = para_name + "static_rnn_"
ctx = layers.fc(
input=p_vec,
param_attr=fluid.ParamAttr(name=tag + 'context_fc_w'),
bias_attr=fluid.ParamAttr(name=tag + 'context_fc_b'),
size=hidden_size,
act=None)
beta = []
c_prev = init_state
m_prev = init_state
for i in range(step):
m_prev0 = layers.fc(
input=m_prev,
size=hidden_size,
act=None,
param_attr=fluid.ParamAttr(name=tag + 'm_prev0_fc_w'),
bias_attr=fluid.ParamAttr(name=tag + 'm_prev0_fc_b'))
m_prev1 = layers.sequence_expand(x=m_prev0, y=ctx)
Fk = ctx + m_prev1
Fk = layers.tanh(Fk)
logits = layers.fc(
input=Fk,
size=1,
act=None,
param_attr=fluid.ParamAttr(name=tag + 'logits_fc_w'),
bias_attr=fluid.ParamAttr(name=tag + 'logits_fc_b'))
scores = layers.sequence_softmax(input=logits)
attn_ctx = layers.elementwise_mul(x=p_vec, y=scores, axis=0)
attn_ctx = layers.sequence_pool(input=attn_ctx, pool_type='sum')
hidden_t, cell_t = lstm_step(
attn_ctx,
hidden_t_prev=m_prev,
cell_t_prev=c_prev,
size=hidden_size,
para_name=tag,
args=args)
m_prev = hidden_t
c_prev = cell_t
beta.append(scores)
return beta
def simple_attention(self, encoder_vec, encoder_proj, decoder_state,
decoder_size):
decoder_state_proj = layers.fc(input=decoder_state,
size=decoder_size,
bias_attr=False,
name="decoder_state_proj_fc")
decoder_state_expand = layers.sequence_expand(
x=decoder_state_proj, y=encoder_proj)
concated = layers.elementwise_add(encoder_proj, decoder_state_expand)
concated = layers.tanh(x=concated)
attention_weights = layers.fc(input=concated,
size=1,
act=None,
bias_attr=False,
name="attention_weights_fc")
attention_weights = layers.sequence_softmax(input=attention_weights)
weigths_reshape = layers.reshape(x=attention_weights, shape=[-1])
scaled = layers.elementwise_mul(
x=encoder_vec, y=weigths_reshape, axis=0)
context = layers.sequence_pool(input=scaled, pool_type='sum')
return context
def point_network_decoder(p_vec, q_vec, hidden_size, args):
"""Output layer - pointer network"""
tag = 'pn_decoder_'
init_random = fluid.initializer.Normal(loc=0.0, scale=1.0)
random_attn = layers.create_parameter(
shape=[1, hidden_size],
dtype='float32',
default_initializer=init_random)
random_attn = layers.fc(
input=random_attn,
size=hidden_size,
act=None,
param_attr=fluid.ParamAttr(name=tag + 'random_attn_fc_w'),
bias_attr=fluid.ParamAttr(name=tag + 'random_attn_fc_b'))
random_attn = layers.reshape(random_attn, shape=[-1])
U = layers.fc(input=q_vec,
param_attr=fluid.ParamAttr(name=tag + 'q_vec_fc_w'),
bias_attr=False,
size=hidden_size,
act=None) + random_attn
U = layers.tanh(U)
logits = layers.fc(input=U,
param_attr=fluid.ParamAttr(name=tag + 'logits_fc_w'),
bias_attr=fluid.ParamAttr(name=tag + 'logits_fc_b'),
size=1,
act=None)
scores = layers.sequence_softmax(input=logits)
pooled_vec = layers.elementwise_mul(x=q_vec, y=scores, axis=0)
pooled_vec = layers.sequence_pool(input=pooled_vec, pool_type='sum')
init_state = layers.fc(
input=pooled_vec,
param_attr=fluid.ParamAttr(name=tag + 'init_state_fc_w'),
bias_attr=fluid.ParamAttr(name=tag + 'init_state_fc_b'),
size=hidden_size,
act=None)
def custom_dynamic_rnn(p_vec, init_state, hidden_size, para_name, args):
tag = para_name + "custom_dynamic_rnn_"
def static_rnn(step,
p_vec=p_vec,
init_state=None,
para_name='',
args=args):
tag = para_name + "static_rnn_"
ctx = layers.fc(
input=p_vec,
param_attr=fluid.ParamAttr(name=tag + 'context_fc_w'),
bias_attr=fluid.ParamAttr(name=tag + 'context_fc_b'),
size=hidden_size,
act=None)
beta = []
c_prev = init_state
m_prev = init_state
for i in range(step):
m_prev0 = layers.fc(
input=m_prev,
size=hidden_size,
act=None,
param_attr=fluid.ParamAttr(name=tag + 'm_prev0_fc_w'),
bias_attr=fluid.ParamAttr(name=tag + 'm_prev0_fc_b'))
m_prev1 = layers.sequence_expand(x=m_prev0, y=ctx)
Fk = ctx + m_prev1
Fk = layers.tanh(Fk)
logits = layers.fc(
input=Fk,
size=1,
act=None,
param_attr=fluid.ParamAttr(name=tag + 'logits_fc_w'),
bias_attr=fluid.ParamAttr(name=tag + 'logits_fc_b'))
scores = layers.sequence_softmax(input=logits)
attn_ctx = layers.elementwise_mul(x=p_vec, y=scores, axis=0)
attn_ctx = layers.sequence_pool(input=attn_ctx, pool_type='sum')
hidden_t, cell_t = lstm_step(
attn_ctx,
hidden_t_prev=m_prev,
cell_t_prev=c_prev,
size=hidden_size,
para_name=tag,
args=args)
m_prev = hidden_t
c_prev = cell_t
beta.append(scores)
return beta
return static_rnn(
2, p_vec=p_vec, init_state=init_state, para_name=para_name)
fw_outputs = custom_dynamic_rnn(p_vec, init_state, hidden_size, tag + "fw_",
args)
bw_outputs = custom_dynamic_rnn(p_vec, init_state, hidden_size, tag + "bw_",
args)
start_prob = layers.elementwise_add(
x=fw_outputs[0], y=bw_outputs[1], axis=0) / 2
end_prob = layers.elementwise_add(
x=fw_outputs[1], y=bw_outputs[0], axis=0) / 2
return start_prob, end_prob
def attn_flow(q_enc, p_enc, p_ids_name):
tag = p_ids_name + "::"
drnn = layers.DynamicRNN()
with drnn.block():
h_cur = drnn.step_input(p_enc)
u_all = drnn.static_input(q_enc)
h_expd = layers.sequence_expand(x=h_cur, y=u_all)
s_t_ = layers.elementwise_mul(x=u_all, y=h_expd, axis=0)
s_t1 = layers.reduce_sum(input=s_t_, dim=1)
s_t = layers.sequence_softmax(input=s_t1)
u_expr = layers.elementwise_mul(x=u_all, y=s_t, axis=0)
u_expr = layers.sequence_pool(input=u_expr, pool_type='sum')
if args.debug == True:
'''
layers.Print(h_expd, message='h_expd')
layers.Print(h_cur, message='h_cur')
layers.Print(u_all, message='u_all')
layers.Print(s_t, message='s_t')
layers.Print(s_t_, message='s_t_')
layers.Print(u_expr, message='u_expr')
'''
drnn.output(u_expr)
U_expr = drnn()
#'''
drnn2 = layers.DynamicRNN()
with drnn2.block():
h_cur = drnn2.step_input(p_enc)
u_all = drnn2.static_input(q_enc)
h_expd = layers.sequence_expand(x=h_cur, y=u_all)
s_t_ = layers.elementwise_mul(x=u_all, y=h_expd, axis=0)
s_t2 = layers.reduce_sum(input=s_t_, dim=1, keep_dim=True)
b_t = layers.sequence_pool(input=s_t2, pool_type='max')
if args.debug == True:
'''
layers.Print(s_t2, message='s_t2')
layers.Print(b_t, message='b_t')
'''
drnn2.output(b_t)
b = drnn2()
b_norm = layers.sequence_softmax(input=b)
h_expr = layers.elementwise_mul(x=p_enc, y=b_norm, axis=0)
h_expr = layers.sequence_pool(input=h_expr, pool_type='sum')
H_expr = layers.sequence_expand(x=h_expr, y=p_enc)
H_expr = layers.lod_reset(x=H_expr, y=p_enc)
h_u = layers.elementwise_mul(x=H_expr, y=U_expr, axis=0)
h_h = layers.elementwise_mul(x=H_expr, y=p_enc, axis=0)
g = layers.concat(input=[H_expr, U_expr, h_u, h_h], axis = 1)
#fusion
m = bi_lstm_encoder(input_seq=g, gate_size=embedding_dim)
if args.debug == True:
layers.Print(U_expr, message=tag + 'U_expr')
layers.Print(H_expr, message=tag + 'H_expr')
layers.Print(b, message=tag + 'b')
layers.Print(b_norm, message=tag + 'b_norm')
layers.Print(g, message=tag +'g')
layers.Print(m, message=tag + 'm')
layers.Print(h_h, message=tag + 'h_h')
layers.Print(q_enc, message=tag + 'q_enc')
layers.Print(p_enc, message=tag + 'p_enc')
return m, g
def bidaf(embedding_dim, encoder_size, decoder_size, source_dict_dim,
target_dict_dim, max_length, args):
def bi_lstm_encoder(input_seq, gate_size):
# A bi-directional lstm encoder implementation.
# Linear transformation part for input gate, output gate, forget gate
# and cell activation vectors need be done outside of dynamic_lstm.
# So the output size is 4 times of gate_size.
input_forward_proj = layers.fc(input=input_seq,
size=gate_size * 4,
act='tanh',
bias_attr=False)
forward, _ = layers.dynamic_lstm(
input=input_forward_proj, size=gate_size * 4, use_peepholes=False)
input_reversed_proj = layers.fc(input=input_seq,
size=gate_size * 4,
act='tanh',
bias_attr=False)
reversed, _ = layers.dynamic_lstm(
input=input_reversed_proj,
size=gate_size * 4,
is_reverse=True,
use_peepholes=False)
encoder_out = layers.concat(input=[forward, reversed], axis = 1)
return encoder_out
def encoder(input_name):
input_ids = layers.data(
name=input_name, shape=[1], dtype='int64', lod_level=1)
input_embedding = layers.embedding(
input=input_ids,
size=[source_dict_dim, embedding_dim],
dtype='float32',
is_sparse=True)
encoder_out = bi_lstm_encoder(input_seq=input_embedding, gate_size=embedding_dim)
return encoder_out
def attn_flow(q_enc, p_enc, p_ids_name):
tag = p_ids_name + "::"
drnn = layers.DynamicRNN()
with drnn.block():
h_cur = drnn.step_input(p_enc)
u_all = drnn.static_input(q_enc)
h_expd = layers.sequence_expand(x=h_cur, y=u_all)
s_t_ = layers.elementwise_mul(x=u_all, y=h_expd, axis=0)
s_t1 = layers.reduce_sum(input=s_t_, dim=1)
s_t = layers.sequence_softmax(input=s_t1)
u_expr = layers.elementwise_mul(x=u_all, y=s_t, axis=0)
u_expr = layers.sequence_pool(input=u_expr, pool_type='sum')
if args.debug == True:
'''
layers.Print(h_expd, message='h_expd')
layers.Print(h_cur, message='h_cur')
layers.Print(u_all, message='u_all')
layers.Print(s_t, message='s_t')
layers.Print(s_t_, message='s_t_')
layers.Print(u_expr, message='u_expr')
'''
drnn.output(u_expr)
U_expr = drnn()
#'''
drnn2 = layers.DynamicRNN()
with drnn2.block():
h_cur = drnn2.step_input(p_enc)
u_all = drnn2.static_input(q_enc)
h_expd = layers.sequence_expand(x=h_cur, y=u_all)
s_t_ = layers.elementwise_mul(x=u_all, y=h_expd, axis=0)
s_t2 = layers.reduce_sum(input=s_t_, dim=1, keep_dim=True)
b_t = layers.sequence_pool(input=s_t2, pool_type='max')
if args.debug == True:
'''
layers.Print(s_t2, message='s_t2')
layers.Print(b_t, message='b_t')
'''
drnn2.output(b_t)
b = drnn2()
b_norm = layers.sequence_softmax(input=b)
h_expr = layers.elementwise_mul(x=p_enc, y=b_norm, axis=0)
h_expr = layers.sequence_pool(input=h_expr, pool_type='sum')
H_expr = layers.sequence_expand(x=h_expr, y=p_enc)
H_expr = layers.lod_reset(x=H_expr, y=p_enc)
h_u = layers.elementwise_mul(x=H_expr, y=U_expr, axis=0)
h_h = layers.elementwise_mul(x=H_expr, y=p_enc, axis=0)
g = layers.concat(input=[H_expr, U_expr, h_u, h_h], axis = 1)
#fusion
m = bi_lstm_encoder(input_seq=g, gate_size=embedding_dim)
if args.debug == True:
layers.Print(U_expr, message=tag + 'U_expr')
layers.Print(H_expr, message=tag + 'H_expr')
layers.Print(b, message=tag + 'b')
layers.Print(b_norm, message=tag + 'b_norm')
layers.Print(g, message=tag +'g')
layers.Print(m, message=tag + 'm')
layers.Print(h_h, message=tag + 'h_h')
layers.Print(q_enc, message=tag + 'q_enc')
layers.Print(p_enc, message=tag + 'p_enc')
return m, g
def lstm_step(x_t, hidden_t_prev, cell_t_prev, size):
def linear(inputs):
return layers.fc(input=inputs, size=size, bias_attr=True)
forget_gate = layers.sigmoid(x=linear([hidden_t_prev, x_t]))
input_gate = layers.sigmoid(x=linear([hidden_t_prev, x_t]))
output_gate = layers.sigmoid(x=linear([hidden_t_prev, x_t]))
cell_tilde = layers.tanh(x=linear([hidden_t_prev, x_t]))
cell_t = layers.sums(input=[
layers.elementwise_mul(
x=forget_gate, y=cell_t_prev), layers.elementwise_mul(
x=input_gate, y=cell_tilde)
])
hidden_t = layers.elementwise_mul(
x=output_gate, y=layers.tanh(x=cell_t))
return hidden_t, cell_t
#point network
def point_network_decoder(p_vec, q_vec, decoder_size):
random_attn = layers.gaussian_random(shape=[1, decoder_size])
random_attn = layers.sequence_expand(x=random_attn, y=q_vec)
random_attn = layers.fc(input=random_attn, size=decoder_size, act=None)
U = layers.fc(input=q_vec,
size=decoder_size,
act=None) + random_attn
U = layers.tanh(U)
logits = layers.fc(input=U,
size=1,
act=None)
scores = layers.sequence_softmax(input=logits)
pooled_vec = layers.elementwise_mul(x=q_vec, y=scores, axis=0)
pooled_vec = layers.sequence_pool(input=pooled_vec, pool_type='sum')
init_state = layers.fc(input=pooled_vec,
size=decoder_size,
act=None)
def custom_dynamic_rnn(p_vec, init_state, decoder_size):
context = layers.fc(input=p_vec,
size=decoder_size,
act=None)
drnn = layers.DynamicRNN()
with drnn.block():
H_s = drnn.step_input(p_vec)
ctx = drnn.static_input(context)
c_prev = drnn.memory(init=init_state, need_reorder=True)
m_prev = drnn.memory(init=init_state, need_reorder=True)
m_prev1 = layers.fc(input=m_prev, size=decoder_size, act=None)
m_prev1 = layers.sequence_expand(x=m_prev1, y=ctx)
Fk = ctx + m_prev1
Fk = layers.fc(input=Fk, size=decoder_size, act='tanh')
logits = layers.fc(input=Fk, size=1, act=None)
scores = layers.sequence_softmax(input=logits)
attn_ctx = layers.elementwise_mul(x=ctx, y=scores, axis=0)
attn_ctx = layers.sequence_pool(input=attn_ctx, pool_type='sum')
hidden_t, cell_t = lstm_step(attn_ctx, hidden_t_prev=m_prev1, cell_t_prev=c_prev, size=decoder_size)
drnn.update_memory(ex_mem=m_prev, new_mem=hidden_t)
drnn.update_memory(ex_mem=c_prev, new_mem=cell_t)
drnn.output(scores)
beta = drnn()
return beta
fw_outputs = custom_dynamic_rnn(p_vec, init_state, decoder_size)
bw_outputs = custom_dynamic_rnn(p_vec, init_state, decoder_size)
def sequence_slice(x, index):
#offset = layers.fill_constant(shape=[1, args.batch_size], value=index, dtype='float32')
#length = layers.fill_constant(shape=[1, args.batch_size], value=1, dtype='float32')
#return layers.sequence_slice(x, offset, length)
idx = layers.fill_constant(shape=[1], value=1, dtype='int32')
idx.stop_gradient = True
from paddle.fluid.layers.control_flow import lod_rank_table
from paddle.fluid.layers.control_flow import lod_tensor_to_array
from paddle.fluid.layers.control_flow import array_read
from paddle.fluid.layers.control_flow import array_to_lod_tensor
table = lod_rank_table(x, level=0)
table.stop_gradient = True
array = lod_tensor_to_array(x, table)
slice_array = array_read(array=array, i=idx)
return array_to_lod_tensor(slice_array, table)
start_prob = layers.elementwise_mul(x=sequence_slice(fw_outputs, 0), y=sequence_slice(bw_outputs, 1), axis=0) / 2
end_prob = layers.elementwise_mul(x=sequence_slice(fw_outputs, 1), y=sequence_slice(bw_outputs, 0), axis=0) / 2
return start_prob, end_prob
q_enc = encoder('q_ids')
if args.single_doc:
p_enc = encoder('p_ids')
m, g = attn_flow(q_enc, p_enc, 'p_ids')
else:
p_ids_names = []
ms = []
gs = []
for i in range(args.doc_num):
p_ids_name = "pids_%d" % i
p_ids_names.append(p_ids_name)
p_enc = encoder(p_ids_name)
m_i, g_i = attn_flow(q_enc, p_enc, p_ids_name)
ms.append(m_i)
gs.append(g_i)
m = layers.sequence_concat(x=ms, axis = 0)
g = layers.sequence_concat(x=gs, axis = 0)
if args.simple_decode:
m2 = bi_lstm_encoder(input_seq=m, gate_size=embedding_dim)
gm1 = layers.concat(input=[g, m], axis = 1)
gm2 = layers.concat(input=[g, m2], axis = 1)
start_prob = layers.fc(input=gm1, size=1, act='softmax')
end_prob = layers.fc(input=gm2, size=1, act='softmax')
else:
p_vec = layers.sequence_concat(x=m, axis = 0)
q_vec = bi_lstm_encoder(input_seq=q_enc, gate_size=embedding_dim)
start_prob, end_prob = point_network_decoder(p_vec=p_vec, q_vec=q_vec, decoder_size = decoder_size)
start_prob = layers.sequence_softmax(start_prob)
end_prob = layers.sequence_softmax(end_prob)
pred = layers.concat(input=[start_prob, end_prob], axis = 0)
#'''
start_labels = layers.data(
name="start_lables", shape=[1], dtype='float32', lod_level=1)
end_labels = layers.data(
name="end_lables", shape=[1], dtype='float32', lod_level=1)
label = layers.concat(input=[start_labels, end_labels], axis=0)
label.stop_gradient = True
#compute loss
cost = layers.cross_entropy(input=pred, label=label, soft_label=True)
#cost = layers.cross_entropy(input=decode_out, label=end_labels, soft_label=True)
cost = layers.reduce_sum(cost) / args.batch_size
if args.debug == True:
layers.Print(p1, message='p1')
layers.Print(pred, message='pred')
layers.Print(label, message='label')
layers.Print(start_labels, message='start_labels')
layers.Print(cost, message='cost')
if args.single_doc:
feeding_list = ['q_ids', "start_lables", "end_lables", 'p_ids']
else:
feeding_list = ['q_ids', "start_lables", "end_lables" ] + p_ids_names
return cost, feeding_list
def point_network_decoder(p_vec, q_vec, decoder_size):
random_attn = layers.gaussian_random(shape=[1, decoder_size])
random_attn = layers.sequence_expand(x=random_attn, y=q_vec)
random_attn = layers.fc(input=random_attn, size=decoder_size, act=None)
U = layers.fc(input=q_vec,
size=decoder_size,
act=None) + random_attn
U = layers.tanh(U)
logits = layers.fc(input=U,
size=1,
act=None)
scores = layers.sequence_softmax(input=logits)
pooled_vec = layers.elementwise_mul(x=q_vec, y=scores, axis=0)
pooled_vec = layers.sequence_pool(input=pooled_vec, pool_type='sum')
init_state = layers.fc(input=pooled_vec,
size=decoder_size,
act=None)
def custom_dynamic_rnn(p_vec, init_state, decoder_size):
context = layers.fc(input=p_vec,
size=decoder_size,
act=None)
drnn = layers.DynamicRNN()
with drnn.block():
H_s = drnn.step_input(p_vec)
ctx = drnn.static_input(context)
c_prev = drnn.memory(init=init_state, need_reorder=True)
m_prev = drnn.memory(init=init_state, need_reorder=True)
m_prev1 = layers.fc(input=m_prev, size=decoder_size, act=None)
m_prev1 = layers.sequence_expand(x=m_prev1, y=ctx)
Fk = ctx + m_prev1
Fk = layers.fc(input=Fk, size=decoder_size, act='tanh')
logits = layers.fc(input=Fk, size=1, act=None)
scores = layers.sequence_softmax(input=logits)
attn_ctx = layers.elementwise_mul(x=ctx, y=scores, axis=0)
attn_ctx = layers.sequence_pool(input=attn_ctx, pool_type='sum')
hidden_t, cell_t = lstm_step(attn_ctx, hidden_t_prev=m_prev1, cell_t_prev=c_prev, size=decoder_size)
drnn.update_memory(ex_mem=m_prev, new_mem=hidden_t)
drnn.update_memory(ex_mem=c_prev, new_mem=cell_t)
drnn.output(scores)
beta = drnn()
return beta
fw_outputs = custom_dynamic_rnn(p_vec, init_state, decoder_size)
bw_outputs = custom_dynamic_rnn(p_vec, init_state, decoder_size)
def sequence_slice(x, index):
#offset = layers.fill_constant(shape=[1, args.batch_size], value=index, dtype='float32')
#length = layers.fill_constant(shape=[1, args.batch_size], value=1, dtype='float32')
#return layers.sequence_slice(x, offset, length)
idx = layers.fill_constant(shape=[1], value=1, dtype='int32')
idx.stop_gradient = True
from paddle.fluid.layers.control_flow import lod_rank_table
from paddle.fluid.layers.control_flow import lod_tensor_to_array
from paddle.fluid.layers.control_flow import array_read
from paddle.fluid.layers.control_flow import array_to_lod_tensor
table = lod_rank_table(x, level=0)
table.stop_gradient = True
array = lod_tensor_to_array(x, table)
slice_array = array_read(array=array, i=idx)
return array_to_lod_tensor(slice_array, table)
start_prob = layers.elementwise_mul(x=sequence_slice(fw_outputs, 0), y=sequence_slice(bw_outputs, 1), axis=0) / 2
end_prob = layers.elementwise_mul(x=sequence_slice(fw_outputs, 1), y=sequence_slice(bw_outputs, 0), axis=0) / 2
return start_prob, end_prob
