def get_label_scores(params, replay):
serp_len = params['serp_len']
batch_size = tf.shape(replay['serp'])[0]
hidden_state_size = params['hidden_state_size']
doc_col = mu._shared_doc_embeddings(replay['docs'], params,
'/label/doc_emb',
inference=True,
label_network=True,
reuse_variable_scope=False)
doc_emb = mu._shared_doc_embeddings(replay['serp'], params,
'/label/doc_emb',
inference=True,
label_network=True,
reuse_variable_scope=True)
init_scores = tf.zeros([batch_size, 1])
init_hidden = tf.zeros([batch_size, hidden_state_size])
serp_emb = tf.transpose(doc_emb, [1, 0, 2])
gru = ru.get_gru_score_layer(params, '/label/gru',
label_network=True,
inference=True,
reuse_variable_scope=False)
hidden_states, _ = tf.scan(gru, serp_emb, (init_hidden, init_scores))
hidden_states = tf.transpose(hidden_states, [1, 0, 2])
hidden_states = hidden_states[:, :-1, None, :]
max_col = tf.expand_dims(doc_col, axis=1)
label_scores = tf.squeeze(gru((hidden_states, None), max_col)[1], axis=3)
return tf.stop_gradient(label_scores)
def pbow_model(params, examples, labels, epsilon):
serp_len = params['serp_len']
doc_emb_size = params['doc_emb'][-1]
hidden_state_size = params['hidden_state_size']
docs = mu._get_doc_tensors(examples, params, 'main')
result = {}
n_docs = tf.shape(docs)[0]
result['docs_per_query'] = n_docs
score_filter = tf.zeros([n_docs, 1], dtype=tf.float32)
neginf = tf.add(score_filter,np.NINF)
ind_range = tf.cast(tf.range(n_docs), dtype=tf.int64)
doc_emb = mu._shared_doc_embeddings(docs, params,
'/main/doc_emb',
inference=True)
pbow = tf.zeros([1, hidden_state_size])
doc_i = tf.zeros([n_docs,1])
doc_pos = tf.concat([doc_i, docs], axis=1)
doc_emb = mu._shared_doc_embeddings(doc_pos, params,
'/main/doc_emb',
inference=True)
doc_input = doc_emb
for i in range(serp_len):
scores = mu._create_subnetwork(doc_input, params, '/main/score',
reuse_variable_scope=i>0,
inference=True)
tf.summary.scalar('policy/scores/pos_%d' % i, tf.reduce_mean(scores))
action, max_ind = mu.select_eps_greedy_action(scores,
epsilon,
score_filter)
select_doc = tf.gather(docs, action)
select_doc_input = tf.gather(doc_emb, action)
result['label_%d' % i] = tf.cond(
tf.less(i, n_docs),
lambda: tf.gather(labels, action, axis=0),
lambda: tf.constant([[0]], dtype=tf.int64),
)
result['doc_%d' % i] = select_doc
if i > 0:
result['max_doc_%d' % i] = tf.gather(docs, max_ind)
if i < serp_len-1:
score_filter = tf.where(tf.equal(ind_range, action),
neginf,
score_filter)
pbow += select_doc_input
doc_i += 1
doc_pos = tf.concat([doc_i, docs], axis=1)
doc_emb = mu._shared_doc_embeddings(doc_pos, params,
'/main/doc_emb', reuse_variable_scope=True,
inference=True)
doc_input = pbow + doc_emb
return result
def get_label_scores(params, replay):
serp_len = params['serp_len']
all_docs = replay['docs']
batch_docs = replay['serp']
batch_pos = replay['pos_order']
max_n_docs = params['max_docs']
n_docs = batch_docs.shape[0]
hidden_state_size = params['hidden_state_size']
init_hidden = tf.zeros([n_docs, hidden_state_size])
doc_col = mu._shared_doc_embeddings(all_docs,
params,
'/label/doc_emb',
label_network=True,
inference=True,
reuse_variable_scope=False)
doc_emb = mu._shared_doc_embeddings(batch_docs[:, :-1, :],
params,
'/label/doc_emb',
label_network=True,
inference=True,
reuse_variable_scope=True)
serp_emb = tf.transpose(doc_emb, [1, 0, 2])
gru = ru.get_gru_layer(params,
'/label/gru',
label_network=True,
inference=True,
reuse_variable_scope=False)
pos = tf.cast(batch_pos, tf.float32)[:, :-1, None]
pos = tf.transpose(pos, [1, 0, 2])
gru_input = tf.concat([serp_emb, pos], axis=2)
hidden_states = tf.scan(gru, gru_input, init_hidden)
hidden_states = tf.transpose(hidden_states, [1, 0, 2])
tiled_states = tf.tile(hidden_states[:, :, None, :], [1, 1, max_n_docs, 1])
tiled_docs = tf.tile(doc_col[:, None, :, :], [1, serp_len - 1, 1, 1])
score_input = tf.concat([tiled_states, tiled_docs], axis=3)
return mu._create_subnetwork(score_input,
params,
subnetwork_name='/label/scoring',
label_network=True,
inference=True,
reuse_variable_scope=False)
def naive_model(params, examples, labels, epsilon):
serp_len = params['serp_len']
doc_emb_size = params['doc_emb'][-1]
docs = mu._get_doc_tensors(examples, params, 'main')
result = {}
n_docs = tf.shape(docs)[0]
ind_range = tf.cast(tf.range(n_docs), dtype=tf.int64)
result['docs_per_query'] = n_docs
score_filter = tf.zeros([n_docs, 1], dtype=tf.float32)
neginf = tf.add(score_filter,np.NINF)
doc_emb = mu._shared_doc_embeddings(docs, params,
'/main/doc_emb',
inference=True)
serp_docs = []
serp_labels = []
doc_input = doc_emb
for i in range(serp_len):
scores = mu._create_subnetwork(doc_input, params,
'/main/score/pos_%d' % i,
reuse_variable_scope=False,
inference=True)
tf.summary.scalar('policy/scores/pos_%d' % i, tf.reduce_mean(scores))
action, max_ind = mu.select_eps_greedy_action(scores,
epsilon,
score_filter)
select_doc = tf.gather(docs, action)
serp_labels.append(
tf.cond(
tf.less(i, n_docs),
lambda: tf.gather(labels, action, axis=0),
lambda: tf.constant([[0]], dtype=tf.int64),
)
)
serp_docs.append(select_doc)
if i > 0:
result['max_doc_%d' % i] = tf.gather(docs, max_ind)
if i < serp_len-1:
score_filter = tf.where(tf.equal(ind_range, action),
neginf,
score_filter)
select_doc_input = tf.gather(doc_emb, action)
tiled = tf.tile(select_doc_input, [n_docs, 1])
doc_input = tf.concat([tiled, doc_input], axis=1)
result['serp'] = tf.stack(serp_docs, axis=1)
# result['max_docs'] = tf.stack(max_docs, axis=1)
result['labels'] = tf.concat(serp_labels, axis=1)
tf.summary.histogram("label/output", result['labels'])
return result
def calculate_naive_loss(params, replay, rewards):
serp_len = params['serp_len']
visible_dropout = params['visible_dropout']
docs_in_query = replay['docs_per_query']
batch_docs = replay['serp']
n_docs = tf.shape(batch_docs)[0]
drop_docs = tf.nn.dropout(batch_docs, visible_dropout)
doc_emb = mu._shared_doc_embeddings(drop_docs, params,
'/main/doc_emb',
inference=True,
reuse_variable_scope=True)
main_serp = tf.gather(doc_emb, 1, axis=1)
main_scores = []
for i in range(serp_len):
main_scores.append(mu._create_subnetwork(main_serp, params,
'/main/score/pos_%d' % i,
reuse_variable_scope=True,
label_network=False,
inference=False))
if i < serp_len - 1:
main_serp = tf.concat([
main_serp,
tf.gather(doc_emb, 1, axis=1),
], axis=1)
scores = tf.concat(main_scores, axis=1)
unfiltered_mc_loss = (rewards-scores)**2
ind = tf.expand_dims(tf.range(serp_len),0)
mask = tf.less(ind, docs_in_query)
filtered_mc_loss = tf.where(mask,
unfiltered_mc_loss,
tf.zeros_like(unfiltered_mc_loss))
mc_loss = tf.reduce_mean(filtered_mc_loss)
# tf.summary.scalar('q_loss/loss', mean_losses[1])
tf.summary.scalar('monte_carlo/loss', mc_loss)
tf.summary.scalar('loss', mc_loss)
return (mc_loss, mc_loss, mc_loss)
def model(params, examples, labels):
serp_len = params['serp_len']
doc_emb_size = params['doc_emb'][-1]
hidden_state_size = params['hidden_state_size']
docs = examples['doc_tensors']
batch_size = docs.shape[0].value
batch_max_docs = tf.shape(docs)[1]
docs_per_query = examples['n_docs']
result = {
'docs_per_query': docs_per_query,
}
doc_emb = mu._shared_doc_embeddings(docs, params,
'/main/doc_emb')
hidden_init = tf.zeros([batch_size, hidden_state_size])
rnn_fn = get_sigmoid_layer(params, '/main/gru',
label_network=False,
inference=False,
reuse_variable_scope=False)
batch_ind = tf.range(batch_size, dtype=tf.int64)[:, None]
hidden_state = hidden_init
n_doc_filter = tf.sequence_mask(docs_per_query[:, 0], batch_max_docs)
doc_filter = tf.where(n_doc_filter,
tf.zeros([batch_size, batch_max_docs]),
tf.fill([batch_size, batch_max_docs], np.NINF))
#tf.zeros([n_docs, hidden_state_size])
serp_labels = []
serp_ind = []
probs = []
for i in range(serp_len):
hidden_states = tf.tile(hidden_state[:, None, :], [1, batch_max_docs, 1])
score_input = tf.concat([hidden_states, doc_emb], axis=2)
scores = mu._create_subnetwork(score_input,
params,
subnetwork_name='/main/scoring',
label_network=False,
reuse_variable_scope=i>0,
inference=False)[:, :, 0]
seq_mask = tf.less(i, docs_per_query[:,0])
if params['evaluation']:
sampled = tf.argmax(scores + doc_filter, axis=1)[:, None]
else:
sampled = tf.multinomial((scores + doc_filter), 1)
sampled = tf.where(seq_mask,
sampled,
tf.zeros_like(sampled))
serp_ind.append(sampled[:, 0])
# sampled = tf.Print(sampled, [tf.shape(scores + doc_filter)], 'shape: ')
# sampled = tf.Print(sampled, [tf.reduce_sum(scores, axis=1)], 'scores: ')
# sampled = tf.Print(sampled, [tf.reduce_sum(doc_filter, axis=1)], 'filter: ')
# sampled = tf.Print(sampled, [tf.reduce_sum(scores + doc_filter, axis=1)], 'sum: ')
# sampled = tf.Print(sampled, [docs_per_query[:,0]], 'docs_per_query: ')
# sampled = tf.Print(sampled, [sampled[:,0]], 'sampled: ')
gather_ind = tf.concat([batch_ind, sampled], axis=1)
sampled_scores = tf.gather_nd(scores, gather_ind)
exp_scores = tf.exp(scores + doc_filter)
exp_scores = tf.where(tf.less(exp_scores, 0.001),
exp_scores + 0.001,
exp_scores)
denom = tf.reduce_sum(exp_scores, axis=1)
doc_filter += tf.one_hot(sampled[:, 0], batch_max_docs,
on_value=np.NINF, off_value=0.)
select_doc = tf.gather_nd(doc_emb, gather_ind)
hidden_state = rnn_fn(hidden_state, select_doc)
select_labels = tf.gather_nd(labels, gather_ind)
serp_labels.append(tf.where(
seq_mask,
select_labels,
tf.zeros([batch_size], dtype=tf.int32),
))
probs.append(tf.where(
seq_mask,
sampled_scores - tf.log(denom),
tf.zeros([batch_size]),
))
# probs[-1] = tf.Print(probs[-1], [denom], 'denom %d:' % i)
# probs[-1] = tf.Print(probs[-1], [tf.exp(np.NINF)], 'test %d:' % i)
# probs[-1] = tf.Print(probs[-1], [sampled], 'sampled %d:' % i)
# probs[-1] = tf.Print(probs[-1], [serp_labels[-1]], 'labels %d:' % i)
# probs[-1] = tf.Print(probs[-1], [probs[-1]], 'probs %d:' % i)
result['labels'] = tf.stack(serp_labels, axis=1)
result['probs'] = tf.stack(probs, axis=1)
result['serp_ind'] = tf.stack(serp_ind, axis=1)
# result['probs'] = tf.Print(result['probs'], [result['serp_ind']], 'serp_ind: ')
# result['probs'] = tf.Print(result['probs'], [tf.exp(result['probs'])], 'prob: ')
return result
def model(params, examples, labels, epsilon, stats_ops):
serp_len = params['serp_len']
doc_emb_size = params['doc_emb'][-1]
hidden_state_size = params['hidden_state_size']
docs = mu._get_doc_tensors(examples, params, 'main')
result = {}
n_docs = tf.shape(docs)[0]
result['docs_per_query'] = n_docs
doc_emb = mu._shared_doc_embeddings(docs,
params,
'/main/doc_emb',
inference=True)
hidden_init = tf.zeros([1, hidden_state_size])
gru_fn = ru.get_gru_layer(params,
'/main/gru',
label_network=False,
inference=True,
reuse_variable_scope=False)
policy = PositionEpsilonGreedy(serp_len, epsilon, n_docs)
hidden_state = hidden_init #tf.zeros([n_docs, hidden_state_size])
serp = []
serp_pos = []
serp_labels = []
serp_ind = []
for i in range(serp_len):
hidden_states = tf.tile(hidden_state, [n_docs, 1])
score_input = tf.concat([hidden_states, doc_emb], axis=1)
scores = mu._create_subnetwork(score_input,
params,
subnetwork_name='/main/scoring',
label_network=False,
reuse_variable_scope=i > 0,
inference=True)
for j in range(serp_len):
mean_summary(params, 'policy_%d/pos_%d' % (i, j), scores[:, j],
stats_ops)
action_ind, action_pos = policy.choose(scores)
select_doc = tf.gather(docs, action_ind)
serp.append(select_doc)
serp_ind.append(action_ind)
in_doc = tf.less(i, n_docs)
serp_labels.append(
tf.cond(
in_doc,
lambda: tf.gather(labels, action_ind, axis=0),
lambda: tf.constant([[0]], dtype=tf.int64),
))
serp_labels[-1].set_shape([1, 1])
serp_pos.append(
tf.cond(
in_doc,
lambda: tf.expand_dims(action_pos, axis=1),
lambda: tf.constant([[serp_len]], dtype=tf.int32),
))
serp_pos[-1].set_shape([1, 1])
if i < serp_len - 1:
a_pos = tf.expand_dims(tf.cast(action_pos, tf.float32), axis=1)
a_doc = tf.gather(doc_emb, action_ind)
gru_input = tf.concat([a_doc, a_pos], axis=1)
hidden_state = gru_fn(hidden_state, gru_input)
pos_order = tf.concat(serp_pos, axis=1)
order_ind = tf.nn.top_k(-pos_order, serp_len)[1]
# order_ind.set_shape()
unordered_labels = tf.squeeze(tf.concat(serp_labels, axis=1), axis=0)
ordered_labels = tf.gather(unordered_labels, order_ind)
result['serp'] = tf.stack(serp, axis=1)
result['serp_ind'] = tf.stack(serp_ind, axis=1)
result['serp_doc'] = tf.stack(serp_ind, axis=1)
result['labels'] = ordered_labels
result['select_order_labels'] = unordered_labels[None, :]
# pos_order = tf.Print(pos_order, [unordered_labels[i] for i in range(10)], 'unordered: ')
# pos_order = tf.Print(pos_order, [pos_order[0, i] for i in range(10)], 'reranking: ')
# pos_order = tf.Print(pos_order, [result['labels'][0, i] for i in range(10)], 'ordered: ')
# pos_order = tf.Print(pos_order, [n_docs], ' ')
result['pos_order'] = pos_order
# tf.summary.histogram("label/output", result['labels'])
# if params['context_input']:
max_docs = params['max_docs']
padding = tf.convert_to_tensor([[0, max_docs - n_docs], [0, 0]])
padded_docs = tf.pad(docs, padding, "CONSTANT")
padded_docs = tf.reshape(padded_docs, [1, max_docs, docs.shape[1].value])
result['docs'] = padded_docs
return result
def loss(params, replay, rewards):
serp_len = params['serp_len']
visible_dropout = params['visible_dropout']
docs_in_query = replay['docs_per_query']
batch_docs = replay['serp']
batch_pos = replay['pos_order']
max_n_docs = params['max_docs']
n_docs = batch_docs.shape[0]
hidden_state_size = params['hidden_state_size']
drop_col = tf.nn.dropout(replay['docs'], visible_dropout)
doc_col = mu._shared_doc_embeddings(drop_col,
params,
'/main/doc_emb',
inference=False,
reuse_variable_scope=True)
init_hidden = tf.zeros([n_docs, hidden_state_size])
drop_docs = tf.nn.dropout(batch_docs, visible_dropout)
doc_emb = mu._shared_doc_embeddings(drop_docs,
params,
'/main/doc_emb',
inference=False,
reuse_variable_scope=True)
serp_emb = tf.transpose(doc_emb, [1, 0, 2])
gru = ru.get_gru_layer(params,
'/main/gru',
label_network=False,
inference=False,
reuse_variable_scope=True)
pos = tf.expand_dims(tf.cast(batch_pos, tf.float32), axis=2)
pos = tf.transpose(pos, [1, 0, 2])
gru_input = tf.concat([serp_emb, pos], axis=2)
hidden_states = tf.scan(gru, gru_input, init_hidden)
score_states = tf.concat(
[init_hidden[None, :, :], hidden_states[:-1, :, :]], axis=0)
score_input = tf.concat([score_states, serp_emb], axis=2)
pos_scores = mu._create_subnetwork(score_input,
params,
subnetwork_name='/main/scoring',
label_network=False,
reuse_variable_scope=True,
inference=False)
pos_scores = tf.transpose(pos_scores, [1, 0, 2])
pos_filter = tf.one_hot(batch_pos, serp_len)
scores = tf.reduce_sum(pos_scores * pos_filter, axis=2)
unfiltered_mc_loss = (rewards - scores)**2
max_filter = max_train_filter(params, hidden_states, serp_len, doc_col,
replay['serp_ind'], batch_pos, docs_in_query,
max_n_docs)
label_scores = get_label_scores(params, replay)
double_max_scores = tf.reduce_sum(max_filter * label_scores, axis=[2, 3])
q_values = tf.concat([double_max_scores, rewards], axis=1)
end_mask = tf.equal(docs_in_query - 1, tf.range(serp_len)[None, :])
reward_tile = tf.tile(rewards, [1, serp_len])
q_values = tf.where(end_mask, reward_tile, q_values)
unfiltered_dqn_loss = (scores - q_values)**2
doc_denom = tf.cast(tf.reduce_sum(docs_in_query), tf.float32)
mask = tf.squeeze(tf.sequence_mask(docs_in_query, serp_len), axis=1)
filtered_mc_loss = tf.where(mask, unfiltered_mc_loss,
tf.zeros_like(unfiltered_mc_loss))
mc_loss = tf.reduce_sum(filtered_mc_loss) / doc_denom
filtered_dqn_loss = tf.where(mask, unfiltered_dqn_loss,
tf.zeros_like(unfiltered_dqn_loss))
dqn_loss = tf.reduce_sum(filtered_dqn_loss) / doc_denom
# dqn_loss = tf.Print(dqn_loss, [scores[0,i] for i in range(10)], 'Scores:')
# dqn_loss = tf.Print(dqn_loss, [q_values[0,i] for i in range(10)], 'Q_values:')
# dqn_loss = tf.Print(dqn_loss, [unfiltered_dqn_loss[0,i] for i in range(10)], 'Loss:')
# dqn_loss = tf.Print(dqn_loss, [n_docs], 'DQN:')
# mc_loss = tf.Print(mc_loss, [n_docs], 'MC:')
tf.summary.scalar('monte_carlo/loss', mc_loss)
tf.summary.scalar('DQN/loss', dqn_loss)
tf.summary.scalar('DQN/double_max_scores',
tf.reduce_mean(double_max_scores))
return mc_loss, dqn_loss
def calculate_gru_loss(params, replay, rewards):
serp_len = params['serp_len']
visible_dropout = params['visible_dropout']
docs_in_query = replay['docs_per_query']
batch_docs = replay['serp']
max_n_docs = params['max_docs']
n_docs = tf.shape(batch_docs)[0]
hidden_state_size = params['hidden_state_size']
drop_col = tf.nn.dropout(replay['docs'], visible_dropout)
doc_col = mu._shared_doc_embeddings(drop_col, params,
'/main/doc_emb',
inference=False,
reuse_variable_scope=True)
# if params['context_input']:
# gru = ru.get_gru_layer(params, '/main/gru/collection/',
# label_network=False,
# inference=False,
# reuse_variable_scope=False)
# input_col = tf.transpose(doc_col, [1, 0, 2])
# hidden_col = tf.scan(gru, input_col, init_hidden)
# hidden_col = tf.transpose(hidden_col, [1, 0, 2])
# indices = tf.stack([tf.range(n_docs), tf.squeeze(docs_in_query-1 ,axis=1)], axis=1)
# init_hidden = tf.gather_nd(hidden_col, indices)
# else:
init_hidden = tf.zeros([n_docs, hidden_state_size])
drop_docs = tf.nn.dropout(batch_docs, visible_dropout)
doc_emb = mu._shared_doc_embeddings(drop_docs, params,
'/main/doc_emb',
label_network=False,
inference=False,
reuse_variable_scope=True)
serp_emb = tf.transpose(doc_emb, [1, 0, 2])
gru = ru.get_gru_layer(params, '/main/gru',
label_network=False,
inference=False,
reuse_variable_scope=True)
init_scores = tf.zeros([n_docs, 1])
hidden_states = tf.scan(gru, serp_emb[:-1, :, :], init_hidden)
hidden_states = tf.concat([init_hidden[None, :, :], hidden_states], axis=0)
scores = mu._create_subnetwork(score_input,
params,
subnetwork_name='/main/scoring',
label_network=False,
reuse_variable_scope=i>0,
inference=True)
scores = tf.squeeze(tf.transpose(scores, [1,0,2]), axis=2)
unfiltered_mc_loss = (rewards-scores)**2.
max_filter = max_train_filter(gru, hidden_states, serp_len,
doc_col, replay['serp_ind'],
docs_in_query, max_n_docs)
label_scores = get_label_scores(params, replay)
double_max_scores = tf.reduce_sum(max_filter*label_scores, axis=2)
q_values = tf.concat([double_max_scores, rewards], axis=1)
end_mask = tf.equal(docs_in_query-1,
tf.expand_dims(tf.range(serp_len), axis=0))
reward_tile = tf.tile(rewards, [1, serp_len])
q_values = tf.where(end_mask, reward_tile, q_values)
unfiltered_dqn_loss = (scores - q_values)**2.
doc_denom = tf.cast(tf.reduce_sum(tf.minimum(docs_in_query, serp_len)), tf.float32)
mask = tf.squeeze(tf.sequence_mask(docs_in_query, serp_len), axis=1)
filtered_mc_loss = tf.where(mask,
unfiltered_mc_loss,
tf.zeros_like(unfiltered_mc_loss))
mc_loss = tf.reduce_sum(filtered_mc_loss)/doc_denom
filtered_dqn_loss = tf.where(mask,
unfiltered_dqn_loss,
tf.zeros_like(unfiltered_dqn_loss))
dqn_loss = tf.reduce_sum(filtered_dqn_loss)/doc_denom
# tf.summary.scalar('q_loss/loss', mean_losses[1])
tf.summary.scalar('monte_carlo/loss', mc_loss)
tf.summary.scalar('DQN/loss', dqn_loss)
filtered_double_max = tf.where(mask[:,:-1],
double_max_scores,
tf.zeros_like(double_max_scores))
double_max_denom = doc_denom - tf.cast(n_docs, tf.float32)
double_max_mean = tf.reduce_sum(filtered_double_max)/double_max_denom
tf.summary.scalar('DQN/double_max_scores', double_max_mean)
return mc_loss, dqn_loss
def calculate_pbow_loss(params, replay, rewards):
serp_len = params['serp_len']
visible_dropout = params['visible_dropout']
batch_size = tf.shape(replay['doc_0'])[0]
docs_in_query = replay['docs_per_query']
# Gather documents from replay.
docs = [replay['doc_%d' % i] for i in range(serp_len)]
drop_docs = [tf.nn.dropout(x, visible_dropout) for x in docs]
max_docs = [replay['max_doc_%d' % i] for i in range(1, serp_len)]
# Create embeddings from documents.
doc_i = tf.zeros([batch_size, 1])
main_emb = []
label_emb = []
max_emb = []
for i in range(serp_len):
main_pos_doc = tf.concat([doc_i, drop_docs[i]], axis=1)
main_emb.append(mu._shared_doc_embeddings(
main_pos_doc,
params, '/main/doc_emb',
reuse_variable_scope=True,
inference=False))
label_pos_doc = tf.concat([doc_i, docs[i]], axis=1)
label_emb.append(mu._shared_doc_embeddings(label_pos_doc,
params, '/label/doc_emb',
reuse_variable_scope=i>0,
label_network=True,
inference=True))
doc_i += 1
# Documents for max choices, index is one behind.
if i < serp_len - 1:
max_pos_doc = tf.concat([doc_i, max_docs[i]], axis=1)
max_emb.append(mu._shared_doc_embeddings(max_pos_doc,
params, '/label/doc_emb',
reuse_variable_scope=True,
label_network=True,
inference=True))
serp_pbow = main_emb[0]
label_pbow = label_emb[0]
losses = None
for i in range(serp_len-1):
scores = mu._create_subnetwork(serp_pbow, params, '/main/score',
reuse_variable_scope=True,
label_network=False,
inference=False)
max_scores = mu._create_subnetwork(label_pbow + max_emb[i],
params,
'/label/score',
reuse_variable_scope=i>0,
label_network=True,
inference=False)
losses = get_pos_loss(params, losses, i, docs_in_query,
scores, max_scores, rewards)
serp_pbow += main_emb[i+1]
if i < serp_len - 2:
label_pbow += label_emb[i+1]
scores = mu._create_subnetwork(serp_pbow, params,
'/main/score',
reuse_variable_scope=True,
label_network=False,
inference=False)
losses = get_pos_loss(params, losses,
serp_len-1, docs_in_query,
scores, rewards, rewards)
mean_losses = [tf.reduce_mean(loss) for loss in losses]
tf.summary.scalar('q_loss/loss', mean_losses[1])
tf.summary.scalar('monte_carlo/loss', mean_losses[2])
tf.summary.scalar('loss', mean_losses[0])
return mean_losses
def gru_model(params, examples, labels, epsilon):
serp_len = params['serp_len']
doc_emb_size = params['doc_emb'][-1]
hidden_state_size = params['hidden_state_size']
# docs = mu._get_doc_tensors(examples, params, 'main')
docs = examples['doc_tensors']
batch_size = docs.shape[0].value
batch_max_docs = tf.shape(docs)[1]
docs_per_query = examples['n_docs']
# if params['context_input']:
# to_shuffle = tf.concat([tf.cast(labels, tf.float32), docs], axis=1)
# shuffled = tf.random_shuffle(to_shuffle)
# labels = tf.cast(tf.slice(shuffled, [0, 0], [-1, 1]), tf.int64)
# docs = tf.slice(shuffled, [0, 1], [-1, -1])
assert not params['context_input'], 'Context not supported for GRU.'
result = {
'docs_per_query': docs_per_query,
}
doc_emb = mu._shared_doc_embeddings(docs, params,
'/main/doc_emb',
inference=True)
hidden_init = tf.zeros([batch_size, hidden_state_size])
# if params['context_input']:
# context_gru_fn = ru.get_gru_layer(params, '/main/gru/context',
# label_network=False,
# inference=True,
# reuse_variable_scope=False)
# context_init = hidden_init
# context = tf.scan(context_gru_fn,
# tf.expand_dims(doc_emb, axis=1), context_init)
# hidden_init = tf.gather(context, n_docs-1)
gru_fn = ru.get_gru_layer(params, '/main/gru',
label_network=False,
inference=True,
reuse_variable_scope=False)
policy = mu.EpsilonGreedy(epsilon, batch_size, batch_max_docs, docs_per_query)
hidden_state = hidden_init
#tf.zeros([n_docs, hidden_state_size])
serp = []
serp_labels = []
serp_ind = []
for i in range(serp_len):
hidden_states = tf.tile(hidden_state[:, None, :], [1, batch_max_docs, 1])
score_input = tf.concat([hidden_states, doc_emb], axis=2)
scores = mu._create_subnetwork(score_input,
params,
subnetwork_name='/main/scoring',
label_network=False,
reuse_variable_scope=i>0,
inference=True)
tf.summary.scalar('policy/scores/pos_%d' % i, tf.reduce_mean(scores))
action = policy.choose(scores)
serp_ind.append(action)
nd_ind = tf.stack([tf.range(batch_size, dtype=tf.int64), action], axis=1)
select_doc = tf.gather_nd(docs, nd_ind)
select_labels = tf.gather_nd(labels, nd_ind)[:, None]
serp_labels.append(tf.where(
tf.less(i, docs_per_query),
select_labels,
tf.zeros([batch_size, 1], dtype=tf.int32),
))
serp.append(select_doc)
if i < serp_len-1:
select_emb = tf.gather_nd(doc_emb, nd_ind)
hidden_state = gru_fn(hidden_state, select_emb)
result['serp'] = tf.stack(serp, axis=1)
result['serp_ind'] = tf.stack(serp_ind, axis=1)
result['serp_ind'] = tf.Print(result['serp_ind'], serp_ind, 'serp_ind: ')
result['labels'] = tf.concat(serp_labels, axis=1)
tf.summary.histogram("label/output", result['labels'])
# if params['context_input']:
max_docs = params['max_docs']
padding = tf.convert_to_tensor([[0, 0], [0, max_docs-batch_max_docs], [0, 0]])
padded_docs = tf.pad(docs, padding, "CONSTANT")
padded_docs = tf.reshape(padded_docs, [batch_size, max_docs, docs.shape[2].value])
result['docs'] = padded_docs
return result
def model(params, examples, labels, epsilon, stats_ops):
serp_len = params['serp_len']
doc_emb_size = params['doc_emb'][-1]
hidden_state_size = params['hidden_state_size']
docs = examples['doc_tensors']
batch_size = docs.shape[0].value
batch_max_docs = tf.shape(docs)[1]
docs_per_query = examples['n_docs']
result = {
'docs_per_query': docs_per_query,
}
doc_emb = mu._shared_doc_embeddings(docs, params,
'/main/doc_emb',
inference=True)
hidden_init = tf.zeros([batch_size, hidden_state_size])
gru_fn = ru.get_gru_layer(params, '/main/gru',
label_network=False,
inference=True,
reuse_variable_scope=False)
policy = PositionEpsilonGreedy(serp_len, epsilon, batch_size,
batch_max_docs, docs_per_query)
hidden_state = hidden_init
serp = []
serp_pos = []
serp_labels = []
serp_ind = []
for i in range(serp_len):
hidden_states = tf.tile(hidden_state[:, None, :], [1, batch_max_docs, 1])
score_input = tf.concat([hidden_states, doc_emb], axis=2)
doc_scores = mu._create_subnetwork(score_input,
params,
subnetwork_name='/main/scoring/doc',
label_network=False,
reuse_variable_scope=i>0,
inference=True,
n_output=1)
action_ind = policy.choose_doc(doc_scores)
ind_nd = tf.stack([tf.range(batch_size, dtype=tf.int64), action_ind],
axis=1)
select_doc = tf.gather_nd(docs, ind_nd)
serp.append(select_doc)
serp_ind.append(action_ind)
select_emb = tf.gather_nd(doc_emb, ind_nd)
pos_input = tf.concat([hidden_state, select_emb], axis=1)
pos_scores = mu._create_subnetwork(pos_input,
params,
subnetwork_name='/main/scoring/pos',
label_network=False,
reuse_variable_scope=i>0,
inference=True,
n_output=10)
# pos_scores = tf.Print(pos_scores, [pos_scores[0,x] for x in range(10)], 'scores %d: ' % i)
mean_summary(params, 'policy_%d/doc' % i,
tf.gather_nd(doc_scores, ind_nd), stats_ops)
for j in range(serp_len):
mean_summary(params, 'policy_%d/pos_%d' % (i, j),
pos_scores[:, j], stats_ops)
action_pos = policy.choose_pos(pos_scores)
# if i == 0:
# action_pos = tf.Print(action_pos, [pos_scores[0,x] for x in range(10)], 'pos_scores: ')
# action_pos = tf.Print(action_pos, [action_pos], 'pos: ')
in_doc = tf.less(i, docs_per_query[:, 0])
serp_labels.append(tf.where(
in_doc,
tf.gather_nd(labels, ind_nd),
tf.zeros([batch_size], dtype=tf.int32),
))
serp_pos.append(tf.where(
in_doc,
action_pos,
tf.fill([batch_size], tf.cast(serp_len, dtype=tf.int64)),
))
if i < serp_len-1:
a_pos = tf.cast(action_pos, tf.float32)[:, None]
gru_input = tf.concat([select_emb, a_pos], axis=1)
hidden_state = gru_fn(hidden_state, gru_input)
pos_order = tf.stack(serp_pos, axis=1)
_, order_ind = tf.nn.top_k(-pos_order, serp_len)
unordered_labels = tf.stack(serp_labels, axis=1)
batch_ind_nd = tf.tile(tf.range(batch_size)[:, None], [1, serp_len])
order_ind_nd = tf.stack([tf.reshape(batch_ind_nd, [-1]),
tf.reshape(order_ind, [-1])],
axis=1)
ordered_labels = tf.gather_nd(unordered_labels, order_ind_nd)
ordered_labels = tf.reshape(ordered_labels, [batch_size, serp_len])
result['serp'] = tf.stack(serp, axis=1)
result['serp_ind'] = tf.stack(serp_ind, axis=1)
result['labels'] = ordered_labels
result['select_order_labels'] = unordered_labels
result['pos_order'] = pos_order
max_docs = params['max_docs']
padding = tf.convert_to_tensor([[0, 0], [0, max_docs-batch_max_docs], [0, 0]])
padded_docs = tf.pad(docs, padding, "CONSTANT")
padded_docs = tf.reshape(padded_docs, [batch_size, max_docs, docs.shape[2].value])
result['docs'] = padded_docs
return result
def loss(params, replay, rewards, doc_rewards):
serp_len = params['serp_len']
visible_dropout = params['visible_dropout']
docs_per_query = replay['docs_per_query']
batch_docs = replay['serp']
batch_pos = replay['pos_order']
max_n_docs = params['max_docs']
batch_size = batch_docs.shape[0]
hidden_state_size = params['hidden_state_size']
doc_level_rewards = params['doc_rewards']
mask = tf.squeeze(tf.sequence_mask(docs_per_query, serp_len), axis=1)
init_hidden = tf.zeros([batch_size, hidden_state_size])
drop_col = tf.nn.dropout(replay['docs'], visible_dropout)
doc_col = mu._shared_doc_embeddings(drop_col, params,
'/main/doc_emb',
inference=False,
reuse_variable_scope=True)
drop_docs = tf.nn.dropout(batch_docs, visible_dropout)
doc_emb = mu._shared_doc_embeddings(drop_docs, params,
'/main/doc_emb',
inference=False,
reuse_variable_scope=True)
serp_emb = tf.transpose(doc_emb, [1, 0, 2])
gru = ru.get_gru_layer(params, '/main/gru',
label_network=False,
inference=False,
reuse_variable_scope=True)
pos = tf.cast(batch_pos, tf.float32)[:, :, None]
pos = tf.transpose(pos, [1, 0, 2])
gru_input = tf.concat([serp_emb, pos], axis=2)
hidden_states = tf.scan(gru, gru_input, init_hidden)
hidden_states = tf.concat([init_hidden[None, :, :],
hidden_states[:-1, :, :]], axis=0)
hidden_states = tf.transpose(hidden_states, [1, 0, 2])
score_input = tf.concat([hidden_states, doc_emb], axis=2)
doc_scores = mu._create_subnetwork(score_input,
params,
subnetwork_name='/main/scoring/doc',
label_network=False,
reuse_variable_scope=True,
inference=False)[:, :, 0]
pos_scores = mu._create_subnetwork(score_input,
params,
subnetwork_name='/main/scoring/pos',
label_network=False,
reuse_variable_scope=True,
inference=False,
n_output=serp_len)
batch_pos_filtered = tf.where(mask,
batch_pos,
tf.zeros_like(batch_pos))
batch_ind_nd = tf.tile(tf.range(batch_size, dtype=tf.int64)[:, None], [1, serp_len])
serp_ind_nd = tf.tile(tf.range(serp_len, dtype=tf.int64)[:, None], [batch_size, 1])
pos_ind_nd = tf.stack([tf.reshape(batch_ind_nd, [-1]),
tf.reshape(serp_ind_nd, [-1]),
tf.reshape(batch_pos_filtered, [-1]),
], axis=1)
pos_scores = tf.gather_nd(pos_scores, pos_ind_nd)
pos_scores = tf.reshape(pos_scores, [batch_size, serp_len])
if not doc_level_rewards:
unfiltered_mc_loss = (rewards-pos_scores)**2 + (rewards-doc_scores)**2
else:
cum_rewards = tf.cumsum(doc_rewards, axis=1, reverse=True)
unfiltered_mc_loss = (cum_rewards-pos_scores)**2 + (cum_rewards-doc_scores)**2
max_doc_ind, max_pos = max_train_doc_pos(params, hidden_states,
doc_emb, serp_len, doc_col,
replay['serp_ind'], batch_pos,
docs_per_query, max_n_docs)
label_doc_scores, q_pos_values = get_label_scores(params, replay, max_doc_ind, max_pos)
if not doc_level_rewards:
q_doc_values = tf.concat([label_doc_scores, rewards], axis=1)
end_mask = tf.equal(docs_per_query-1,
tf.range(serp_len)[None, :])
reward_tile = tf.tile(rewards, [1, serp_len])
q_doc_values = tf.where(end_mask, reward_tile, q_doc_values)
else:
zero_end = tf.zeros([batch_size, 1])
q_doc_values = tf.concat([label_doc_scores, zero_end], axis=1)
end_mask = tf.equal(docs_per_query-1,
tf.range(serp_len)[None, :])
q_doc_values = tf.where(end_mask, tf.zeros_like(q_doc_values), q_doc_values)
q_doc_values += doc_rewards
# q_doc_values = tf.Print(q_doc_values, [batch_pos[0,x] for x in range(10)], 'pos: ')
# q_doc_values = tf.Print(q_doc_values, [pos_scores[0,x] for x in range(10)], 'pos_scores: ')
# q_doc_values = tf.Print(q_doc_values, [q_doc_values[0,x] for x in range(10)], 'q-values: ')
# q_doc_values = tf.Print(q_doc_values, [doc_rewards[0,x] for x in range(10)], 'doc_rewards: ')
unfiltered_doc_loss = (doc_scores - q_pos_values)**2
unfiltered_pos_loss = (pos_scores - q_doc_values)**2
unfiltered_dqn_loss = unfiltered_doc_loss + unfiltered_pos_loss
query_denom = tf.cast(docs_per_query[:, 0], tf.float32)
query_denom = tf.minimum(query_denom, serp_len)
query_denom = tf.maximum(query_denom, tf.ones_like(query_denom))
filtered_mc_loss = tf.where(mask,
unfiltered_mc_loss,
tf.zeros_like(unfiltered_mc_loss))
mc_loss = tf.reduce_mean(tf.reduce_sum(filtered_mc_loss, axis=1)/query_denom)
filtered_dqn_loss = tf.where(mask,
unfiltered_dqn_loss,
tf.zeros_like(unfiltered_dqn_loss))
dqn_loss = tf.reduce_mean(tf.reduce_sum(filtered_dqn_loss, axis=1)/query_denom)
tf.summary.scalar('monte_carlo/loss', mc_loss)
tf.summary.scalar('DQN/loss', dqn_loss)
tf.summary.scalar('DQN/max_doc_scores', tf.reduce_mean(label_doc_scores))
tf.summary.scalar('DQN/max_pos_scores', tf.reduce_mean(q_pos_values))
return mc_loss, dqn_loss
def get_label_scores(params, replay, max_doc_ind, max_pos):
serp_len = params['serp_len']
all_docs = replay['docs']
batch_docs = replay['serp']
batch_pos = replay['pos_order']
max_n_docs = params['max_docs']
batch_size = all_docs.shape[0]
hidden_state_size = params['hidden_state_size']
init_hidden = tf.zeros([batch_size, hidden_state_size])
doc_emb = mu._shared_doc_embeddings(batch_docs, params,
'/label/doc_emb',
label_network=True,
inference=True,
reuse_variable_scope=False)
batch_ind_nd = tf.tile(tf.range(batch_size, dtype=tf.int64)[:, None], [1, serp_len-1])
doc_ind_nd = tf.stack([tf.reshape(batch_ind_nd, [-1]),
tf.reshape(max_doc_ind, [-1]),
], axis=1)
max_docs = tf.gather_nd(all_docs, doc_ind_nd)
max_docs = tf.reshape(max_docs, [batch_size, serp_len-1, all_docs.shape[2]])
max_emb = mu._shared_doc_embeddings(max_docs, params,
'/label/doc_emb',
label_network=True,
inference=True,
reuse_variable_scope=True)
serp_emb = tf.transpose(doc_emb, [1, 0, 2])
gru = ru.get_gru_layer(params, '/label/gru',
label_network=True,
inference=True,
reuse_variable_scope=False)
pos = tf.cast(batch_pos, tf.float32)[:, :-1, None]
pos = tf.transpose(pos, [1, 0, 2])
gru_input = tf.concat([serp_emb[:-1, :, :], pos], axis=2)
hidden_states = tf.scan(gru, gru_input, init_hidden)
hidden_states = tf.transpose(hidden_states, [1, 0, 2])
score_input = tf.concat([hidden_states, max_emb], axis=2)
doc_scores = mu._create_subnetwork(score_input,
params,
subnetwork_name='/label/scoring/doc',
label_network=True,
inference=True,
reuse_variable_scope=False)[:,:,0]
pos_states = tf.concat([init_hidden[:, None, :], hidden_states], axis=1)
pos_input = tf.concat([pos_states, doc_emb], axis=2)
pos_scores = mu._create_subnetwork(pos_input,
params,
subnetwork_name='/label/scoring/pos',
label_network=True,
inference=True,
reuse_variable_scope=False,
n_output=10)
batch_ind_nd = tf.tile(tf.range(batch_size, dtype=tf.int64)[:, None], [1, serp_len])
serp_ind_nd = tf.tile(tf.range(serp_len, dtype=tf.int64)[None, :], [batch_size, 1])
pos_ind_nd = tf.stack([tf.reshape(batch_ind_nd, [-1]),
tf.reshape(serp_ind_nd, [-1]),
tf.reshape(max_pos, [-1]),
],axis=1)
pos_scores = tf.gather_nd(pos_scores, pos_ind_nd)
pos_scores = tf.reshape(pos_scores, [batch_size, serp_len])
return doc_scores, pos_scores
def loss(params, replay, rewards, doc_rewards):
serp_len = params['serp_len']
visible_dropout = params['visible_dropout']
docs_per_query = replay['docs_per_query']
batch_docs = replay['serp']
max_n_docs = params['max_docs']
batch_size = params['replay_batch']
hidden_state_size = params['hidden_state_size']
doc_level_rewards = params['doc_rewards']
drop_col = tf.nn.dropout(replay['docs'], visible_dropout)
doc_col = mu._shared_doc_embeddings(drop_col,
params,
'/main/doc_emb',
inference=False,
reuse_variable_scope=True)
init_hidden = tf.zeros([batch_size, hidden_state_size])
if params['context_input']:
context_gru_fn = ru.get_gru_layer(params,
'/main/gru/context',
label_network=False,
inference=False,
reuse_variable_scope=True)
scan_input = tf.transpose(doc_col, [1, 0, 2])
context = tf.scan(context_gru_fn, scan_input, init_hidden)
ind_nd = tf.concat([docs_per_query - 1,
tf.range(batch_size)[:, None]],
axis=1)
init_hidden = tf.gather_nd(context, ind_nd)
drop_docs = tf.nn.dropout(batch_docs, visible_dropout)
doc_emb = mu._shared_doc_embeddings(drop_docs,
params,
'/main/doc_emb',
label_network=False,
inference=False,
reuse_variable_scope=True)
serp_emb = tf.transpose(doc_emb, [1, 0, 2])
gru = ru.get_gru_layer(params,
'/main/gru',
label_network=False,
inference=False,
reuse_variable_scope=True)
hidden_states = tf.scan(gru, serp_emb[:-1, :, :], init_hidden)
hidden_states = tf.concat([init_hidden[None, :, :], hidden_states], axis=0)
score_input = tf.concat([hidden_states, serp_emb], axis=2)
scores = mu._create_subnetwork(score_input,
params,
subnetwork_name='/main/scoring',
label_network=False,
reuse_variable_scope=True,
inference=False)
scores = tf.transpose(scores, [1, 0, 2])[:, :, 0]
if not doc_level_rewards:
unfiltered_mc_loss = (rewards - scores)**2.
else:
cum_rewards = tf.cumsum(doc_rewards, axis=1, reverse=True)
unfiltered_mc_loss = (rewards - scores)**2.
max_train_ind = max_train_docs(params, replay, hidden_states, doc_col)
label_scores = get_label_scores(params, replay, max_train_ind)
if not doc_level_rewards:
q_values = tf.concat([label_scores, rewards], axis=1)
end_mask = tf.equal(docs_per_query - 1, tf.range(serp_len)[None, :])
reward_tile = tf.tile(rewards, [1, serp_len])
q_values = tf.where(end_mask, reward_tile, q_values)
unfiltered_dqn_loss = (scores - q_values)**2.
else:
zero_end = tf.zeros([batch_size, 1])
q_values = tf.concat([label_scores, zero_end], axis=1)
end_mask = tf.equal(docs_per_query - 1, tf.range(serp_len)[None, :])
q_values = tf.where(end_mask, tf.zeros_like(q_values), q_values)
q_values += doc_rewards
unfiltered_dqn_loss = (scores - q_values)**2.
mask = tf.squeeze(tf.sequence_mask(docs_per_query, serp_len), axis=1)
query_denom = tf.cast(docs_per_query[:, 0], tf.float32)
query_denom = tf.minimum(query_denom, serp_len)
query_denom = tf.maximum(query_denom, tf.ones_like(query_denom))
filtered_mc_loss = tf.where(mask, unfiltered_mc_loss,
tf.zeros_like(unfiltered_mc_loss))
mc_loss = tf.reduce_mean(
tf.reduce_sum(filtered_mc_loss, axis=1) / query_denom)
filtered_dqn_loss = tf.where(mask, unfiltered_dqn_loss,
tf.zeros_like(unfiltered_dqn_loss))
dqn_loss = tf.reduce_mean(
tf.reduce_sum(filtered_dqn_loss, axis=1) / query_denom)
# dqn_loss = tf.Print(dqn_loss, [filtered_dqn_loss[0, j] for j in range(10)], 'dqn loss: ')
# dqn_loss = tf.Print(dqn_loss, [query_denom[0]], 'denom: ')
# dqn_loss = tf.Print(dqn_loss, [dqn_loss], 'total loss: ')
tf.summary.scalar('monte_carlo/loss', mc_loss)
tf.summary.scalar('DQN/loss', dqn_loss)
tf.summary.scalar('DQN/double_max_scores', tf.reduce_mean(label_scores))
return mc_loss, dqn_loss
def get_label_scores(params, replay, max_train_ind):
serp_len = params['serp_len']
batch_size = replay['serp'].shape[0]
hidden_state_size = params['hidden_state_size']
docs_per_query = replay['docs_per_query']
doc_col = replay['docs']
batch_ind = tf.tile(
tf.range(batch_size, dtype=tf.int64)[:, None], [1, serp_len - 1])
max_ind = tf.stack(
[tf.reshape(batch_ind, [-1]),
tf.reshape(max_train_ind, [-1])], axis=1)
max_docs = tf.gather_nd(doc_col, max_ind)
max_docs = tf.reshape(max_docs, [batch_size, serp_len - 1, -1])
max_emb = mu._shared_doc_embeddings(max_docs,
params,
'/label/doc_emb',
inference=True,
label_network=True,
reuse_variable_scope=False)
doc_emb = mu._shared_doc_embeddings(replay['serp'][:, :-1],
params,
'/label/doc_emb',
inference=True,
label_network=True,
reuse_variable_scope=True)
gru = ru.get_gru_layer(params,
'/label/gru',
label_network=True,
inference=True,
reuse_variable_scope=False)
init_hidden = tf.zeros([batch_size, hidden_state_size])
if params['context_input']:
emb_col = mu._shared_doc_embeddings(doc_col,
params,
'/label/doc_emb',
inference=True,
label_network=True,
reuse_variable_scope=True)
context_gru_fn = ru.get_gru_layer(params,
'/label/gru/context',
label_network=True,
inference=True,
reuse_variable_scope=False)
scan_input = tf.transpose(emb_col, [1, 0, 2])
context = tf.scan(context_gru_fn, scan_input, init_hidden)
ind_nd = tf.concat([docs_per_query - 1,
tf.range(batch_size)[:, None]],
axis=1)
init_hidden = tf.gather_nd(context, ind_nd)
serp_emb = tf.transpose(doc_emb, [1, 0, 2])
hidden_states = tf.scan(gru, serp_emb, init_hidden)
hidden_states = tf.transpose(hidden_states, [1, 0, 2])
score_input = tf.concat([hidden_states, max_emb], axis=2)
scores = mu._create_subnetwork(score_input,
params,
subnetwork_name='/label/scoring',
label_network=True,
reuse_variable_scope=False,
inference=True)
return tf.stop_gradient(scores)[:, :, 0]