def normalize_func(mean_batch, variance_batch):
mean_batch = K.reshape(mean_batch, broadcast_shape)
variance_batch = K.reshape(variance_batch, broadcast_shape)
mean_weights = K.softmax(self.mean_weights, axis=0)
variance_weights = K.softmax(self.variance_weights, axis=0)
mean = (mean_weights[0] * mean_instance +
mean_weights[1] * mean_layer +
mean_weights[2] * mean_batch)
variance = (variance_weights[0] * variance_instance +
variance_weights[1] * variance_layer +
variance_weights[2] * variance_batch)
outputs = (inputs - mean) / (K.sqrt(variance + self.epsilon))
if self.scale:
broadcast_gamma = K.reshape(self.gamma, broadcast_shape)
outputs = outputs * broadcast_gamma
if self.center:
broadcast_beta = K.reshape(self.beta, broadcast_shape)
outputs = outputs + broadcast_beta
return outputs
def call(self, x, mask=None):
features_dim = self.features_dim
step_dim = self.step_dim
#xw = K.reshape(K.dot(x[0], K.reshape(self.W, (features_dim, features_dim))), (-1, features_dim))
#yavg=K.reshape(K.mean(K.mean(x[1], axis=1, keepdims=True),axis=0, keepdims=True), (features_dim,-1))
xw1 = K.dot(x[0], K.reshape(self.W1, (features_dim, features_dim)))
xw2 = K.dot(x[1], K.reshape(self.W2, (features_dim, features_dim)))
xw1t = K.permute_dimensions(xw1, [0, 2, 1])
xw2t = K.permute_dimensions(xw2, [0, 2, 1])
xw11 = K.batch_dot(xw1, xw1t) / (step_dim**0.5)
xw12 = K.batch_dot(xw1, xw2t) / (step_dim**0.5)
s11 = self.ll * K.softmax(xw11)
s12 = (1 - self.ll) * K.softmax(xw12)
eij = s11 + s12
print(eij.get_shape())
V = x[0] * K.mean(eij, axis=2, keepdims=True)
if self.get_alpha:
return eij
else:
if self.get_sequence:
return V
else:
return K.sum(V, axis=1)
def modified_kd_targets_from_logits(train_logits, test_logits, temp=1):
# create soft targets from loaded logits
if temp <= 0:
temp = 1
train_logits_t = train_logits / temp
test_logits_t = test_logits / temp
Y_train_soft = K.softmax(train_logits_t)
Y_test_soft = K.softmax(test_logits_t)
sess = K.get_session()
Y_train_soft = sess.run(Y_train_soft)
Y_test_soft = sess.run(Y_test_soft)
return Y_train_soft, Y_test_soft
def modified_kd_targets_from_logits(Y_train, Y_test, train_logits, test_logits,
temp):
# create soft targets from loaded logits
train_logits_t = train_logits / temp
test_logits_t = test_logits / temp
Y_train_soft = K.softmax(train_logits_t)
Y_test_soft = K.softmax(test_logits_t)
sess = K.get_session()
Y_train_soft = sess.run(Y_train_soft)
Y_test_soft = sess.run(Y_test_soft)
# concatenate hard and soft targets to create the knowledge distillation targets
Y_train_new = np.concatenate([Y_train, Y_train_soft], axis=1)
Y_test_new = np.concatenate([Y_test, Y_test_soft], axis=1)
return Y_train_new, Y_test_new
def call(self, inputs, mask=None):
if mask is not None:
adder = (math_ops.cast(mask, inputs.dtype)) * (
_large_compatible_negative(inputs.dtype))
inputs += adder
if isinstance(self.axis, (tuple, list)):
if len(self.axis) > 1:
return math_ops.exp(inputs - math_ops.reduce_logsumexp(
inputs, axis=self.axis, keepdims=True))
else:
return K.softmax(inputs, axis=self.axis[0])
return K.softmax(inputs, axis=self.axis)
def energy_step(inputs, states):
assert_msg = "States must be a list. However states {} is of type {}".format(
states, type(states))
assert isinstance(states, list) or isinstance(states,
tuple), assert_msg
en_seq_len, en_hidden = encoder_out_seq.shape[
1], encoder_out_seq.shape[2]
de_hidden = inputs.shape[-1]
reshaped_enc_outputs = K.reshape(encoder_out_seq, (-1, en_hidden))
W_a_dot_s = K.reshape(K.dot(reshaped_enc_outputs, self.W_a),
(-1, en_seq_len, en_hidden))
if verbose:
print('wa.s > ', W_a_dot_s.shape)
U_a_dot_h = K.expand_dims(K.dot(inputs, self.U_a),
1) # (batch_size, 1, latent_dim)
if verbose:
print('Ua.h > ', U_a_dot_h.shape)
reshaped_Ws_plus_Uh = K.tanh(
K.reshape(W_a_dot_s + U_a_dot_h, (-1, en_hidden)))
if verbose:
print('Ws+Uh > ', reshaped_Ws_plus_Uh.shape)
e_i = K.reshape(K.dot(reshaped_Ws_plus_Uh, self.V_a),
(-1, en_seq_len))
e_i = K.softmax(e_i)
if verbose:
print('ei > ', e_i.shape)
return e_i, [e_i]
def energy_step(inputs, states):
""" Step function for computing energy for a single decoder state
inputs: (batchsize * 1 * de_in_dim)
states: (batchsize * 1 * de_latent_dim)
"""
""" Some parameters required for shaping tensors"""
en_seq_len, en_hidden = encoder_out_seq.shape[
1], encoder_out_seq.shape[2]
de_hidden = inputs.shape[-1]
""" Computing S.Wa where S=[s0, s1, ..., si]"""
# <= batch size * en_seq_len * latent_dim
W_a_dot_s = K.dot(encoder_out_seq, self.W_a)
""" Computing hj.Ua """
U_a_dot_h = K.expand_dims(K.dot(inputs, self.U_a),
1) # <= batch_size, 1, latent_dim
""" tanh(S.Wa + hj.Ua) """
# <= batch_size*en_seq_len, latent_dim
Ws_plus_Uh = K.tanh(W_a_dot_s + U_a_dot_h)
""" softmax(va.tanh(S.Wa + hj.Ua)) """
# <= batch_size, en_seq_len
e_i = K.squeeze(K.dot(Ws_plus_Uh, self.V_a), axis=-1)
# <= batch_size, en_seq_len
e_i = K.softmax(e_i)
return e_i, [e_i]
def simple_context(X, mask):
"""
Simple context calculation layer logic
X = (batch_size, time_steps, units)
time_steps are nothing but number of words in our case.
"""
# segregrate heading and desc
desc, head = X[:, :parameters.max_len_desc, :], X[:, parameters.max_len_desc:, :]
# segregrate activation and context part
head_activations, head_words = head[:, :, :parameters.activation_rnn_size], head[:, :, parameters.activation_rnn_size:]
desc_activations, desc_words = desc[:, :, :parameters.activation_rnn_size], desc[:, :, parameters.activation_rnn_size:]
# p=(bacth_size, length_desc_words, rnn_units)
# q=(bacth_size, length_headline_words, rnn_units)
# K.dot(p,q) = (bacth_size, length_desc_words,length_headline_words)
activation_energies = K.batch_dot(head_activations, desc_activations, axes=(2, 2))
# make sure we dont use description words that are masked out
activation_energies = activation_energies + -1e20 * K.expand_dims(1. - K.cast(mask[:, :parameters.max_len_desc], 'float32'), 1)
# for every head word compute weights for every desc word
activation_energies = K.reshape(activation_energies, (-1, parameters.max_len_desc))
activation_weights = K.softmax(activation_energies)
activation_weights = K.reshape(activation_weights, (-1, parameters.max_len_head, parameters.max_len_desc))
# for every head word compute weighted average of desc words
desc_avg_word = K.batch_dot(activation_weights, desc_words, axes=(2, 1))
return K.concatenate((desc_avg_word, head_words))
def energy_step(decode_outs, states): # decode_outs(batch,dim)
# decoder_seq [N,30,512] 30是字符串长度
en_seq_len, en_hidden = encoder_out_seq.shape[
1], encoder_out_seq.shape[2] # 30, 512
de_hidden = decode_outs.shape[-1]
# W * h_j
reshaped_enc_outputs = K.reshape(
encoder_out_seq, (-1, en_hidden)) #[b,64,512]=> [b*64,512]
# W_a[512x512],reshaped_enc_outputs[b*64,512] => [b*64,512] => [b,64,512]
W_a_dot_s = K.reshape(K.dot(reshaped_enc_outputs, self.W_a),
(-1, en_seq_len, en_hidden))
# U * S_t - 1,decode_outs[b,512],U_a[512,512] => [b,512] => [b,1,512]
U_a_dot_h = K.expand_dims(K.dot(decode_outs, self.U_a),
axis=1) # <= batch_size, 1, latent_dim
# 这个细节很变态，其实就是完成了decoder的输出复制time(64)个，和encoder的输出【64,512】，相加的过程
# tanh ( W * h_j + U * S_t-1 + b ),[b,64,512] = [b*64,512]
reshaped_Ws_plus_Uh = K.tanh(
K.reshape(W_a_dot_s + U_a_dot_h, (-1, en_hidden)))
# V * tanh ( W * h_j + U * S_t-1 + b ), [b*64,512]*[512,1] => [b*64,1] => [b,64]
e_i = K.reshape(K.dot(reshaped_Ws_plus_Uh, self.V_a),
(-1, en_seq_len))
e_i = K.softmax(e_i)
return e_i, [e_i]
def call(self, inputs, mask=None):
# output = softmax(score)
k, q = inputs
if len(q.shape) == 2:
q = K.expand_dims(q, axis=1)
# k: (?, K_LEN, EMBED_DIM,)
# q: (?, Q_LEN, EMBED_DIM,)
# score: (?, Q_LEN, K_LEN,)
if self.score_function == 'scaled_dot_product':
kt = K.permute_dimensions(k, (0, 2, 1))
qkt = K.batch_dot(q, kt)
score = qkt / self.EMBED_DIM
elif self.score_function == 'mlp':
kq = K.concatenate([k, q], axis=1)
kqw2 = K.tanh(K.dot(kq, self.W2))
score = K.permute_dimensions(K.dot(self.W1, kqw2), (1, 0, 2))
elif self.score_function == 'bi_linear':
qw = K.dot(q, self.W)
kt = K.permute_dimensions(k, (0, 2, 1))
score = K.batch_dot(qw, kt)
else:
raise RuntimeError('invalid score_function')
score = K.softmax(score)
# if mask is not None:
# score *= K.cast(mask[0], K.floatx())
# output: (?, Q_LEN, EMBED_DIM,)
output = K.batch_dot(score, k)
return output
def call(self, inputs, **kwargs):
inputs = inputs if isinstance(inputs, list) else [inputs]
if len(inputs) < 1 or len(inputs) > 2:
raise ValueError("AttentionLayer expect one or two inputs.")
actual_input = inputs[0]
mask = inputs[1] if len(inputs) > 1 else None
if mask is not None and not (
((len(mask.shape) == 3 and mask.shape[2] == 1)
or len(mask.shape) == 2) and mask.shape[1] == self.input_length):
raise ValueError(
"`mask` should be of shape (batch, input_length) or (batch, input_length, 1) "
"when calling an AttentionLayer.")
assert actual_input.shape[-1] == self.attention_param.shape[0]
# (batch, input_length, input_dim) * (input_dim, 1) ==> (batch, input_length, 1)
attention_weights = K.dot(actual_input, self.attention_param)
if mask is not None:
if len(mask.shape) == 2:
mask = K.expand_dims(mask, axis=2) # (batch, input_length, 1)
mask = K.log(mask)
attention_weights += mask
attention_weights = K.softmax(attention_weights,
axis=1) # (batch, input_length, 1)
result = K.sum(
actual_input * attention_weights,
axis=1) # (batch, input_length) [multiplication uses broadcast]
return result, attention_weights
def energy_step(inputs, states):
""" Step function for computing energy for a single decoder state """
# input: (batch_size, latent_dim)
assert_msg = "States must be a list. However states {} is of type {}".format(
states, type(states))
assert isinstance(states, list) or isinstance(states,
tuple), assert_msg
""" Computing sj.Ua """
# (batch_size, 1, d3)
U_a_dot_s = K.expand_dims(K.dot(inputs, self.U_a), 1)
if verbose:
print('Ua.h>', K.int_shape(U_a_dot_s))
""" tanh(h.Wa + s.Ua) """
# (batch_size, h1*h2*...*hn, d3) = (batch_size, h1*h2*...*hn, d3) + (batch_size, 1, d3)
Wh_plus_Us = K.tanh(W_hi + U_a_dot_s)
# (batch_size, d3, h1*h2*...*hn)
Wh_plus_Us = K.permute_dimensions(Wh_plus_Us, (0, 2, 1))
if verbose:
print('Wh+Us>', K.int_shape(Wh_plus_Us))
""" softmax(va.tanh(S.Wa + hj.Ua)) """
# (1, batch_size, h1*h2*...*hn) = (1, d3) . (batch_size, d3, h1*h2*...*hn)
Wh_plus_Us_dot_Va = K.dot(self.V_a, Wh_plus_Us)
# (batch_size, h1*h2*...*hn)
e_i = K.squeeze(Wh_plus_Us_dot_Va, 0)
e_i = K.softmax(e_i)
if verbose:
print('ei>', K.int_shape(e_i))
# (batch_size, h1*h2*...*hn)
return e_i, states
def simple_context(X, mask):
desc, head = X[:, :parameters.max_len_desc, :], X[:, parameters.
max_len_desc:, :]
head_activations, head_words = head[:, :, :parameters.
activation_rnn_size], head[:, :,
parameters.
activation_rnn_size:]
desc_activations, desc_words = desc[:, :, :parameters.
activation_rnn_size], desc[:, :,
parameters.
activation_rnn_size:]
activation_energies = K.batch_dot(head_activations,
desc_activations,
axes=(2, 2))
activation_energies = activation_energies + -1e20 * K.expand_dims(
1. - K.cast(mask[:, :parameters.max_len_desc], 'float32'), 1)
activation_energies = K.reshape(activation_energies,
(-1, parameters.max_len_desc))
activation_weights = K.softmax(activation_energies)
activation_weights = K.reshape(
activation_weights,
(-1, parameters.max_len_head, parameters.max_len_desc))
desc_avg_word = K.batch_dot(activation_weights, desc_words, axes=(2, 1))
return K.concatenate((desc_avg_word, head_words))
def call(self, inputs):
X = inputs[0] # Node features (N x F)
A = inputs[1] # Adjacency matrix (N x N)
outputs = []
for head in range(self.attn_heads):
kernel = self.kernels[head] # W in the paper (F x F")
attention_kernel = self.attn_kernels[
head] # Attention kernel a in the paper (2F" x 1)
# Compute inputs to attention network
features = K.dot(X, kernel) # (N x F")
# Compute feature combinations
# Note: [[a_1], [a_2]]^T [[Wh_i], [Wh_2]] = [a_1]^T [Wh_i] + [a_2]^T [Wh_j]
attn_for_self = K.dot(
features, attention_kernel[0]) # (N x 1), [a_1]^T [Wh_i]
attn_for_neighs = K.dot(
features, attention_kernel[1]) # (N x 1), [a_2]^T [Wh_j]
# Attention head a(Wh_i, Wh_j) = a^T [[Wh_i], [Wh_j]]
dense = attn_for_self + K.transpose(
attn_for_neighs) # (N x N) via broadcasting
# Add nonlinearty
dense = LeakyReLU(alpha=0.2)(dense)
# Mask values before activation (Vaswani et al., 2017)
mask = -10e9 * (1.0 - A)
dense += mask
# Apply softmax to get attention coefficients
dense = K.softmax(dense) # (N x N)
# Apply dropout to features and attention coefficients
dropout_attn = Dropout(self.dropout_rate)(dense) # (N x N)
dropout_feat = Dropout(self.dropout_rate)(features) # (N x F")
# Linear combination with neighbors" features
node_features = K.dot(dropout_attn, dropout_feat) # (N x F")
if self.use_bias:
node_features = K.bias_add(node_features, self.biases[head])
if self.attn_heads_reduction == "concat":
# If "concat", compute the activation here (Eq. 5)
node_features = self.activation(node_features)
# Add output of attention head to final output
outputs.append(node_features)
# Aggregate the heads" output according to the reduction method
if self.attn_heads_reduction == "concat":
output = K.concatenate(outputs) # (N x KF")
else:
output = K.mean(K.stack(outputs), axis=0) # N x F")
output = self.activation(output)
return output
def call(self, x, mask=None):
energy = self.activation(K.dot(x, self.W0) + self.b0)
#energy=self.activation(K.dot(energy, self.W) + self.b)
energy = K.dot(energy, self.W) + self.b
energy = K.reshape(energy, (-1, self.input_length))
energy = K.softmax(energy)
xx = K.batch_dot(energy, x, axes=(1, 1))
all = K.concatenate([xx, energy])
return all
def call(self, inputs, mask=None):
x = K.permute_dimensions(inputs, (0, 2, 1))
a = K.softmax(K.tanh(K.dot(x, self.W)))
a = K.permute_dimensions(a, (0, 2, 1))
outputs = a * inputs
outputs = K.sum(outputs, axis=1)
return outputs
def call(self, inputs, mask=None):
if mask is not None:
# Since mask is 1.0 for positions we want to keep and 0.0 for
# masked positions, this operation will create a tensor which is 0.0 for
# positions we want to attend and -1e.9 for masked positions.
adder = (1.0 - math_ops.cast(mask, inputs.dtype)) * (
_large_compatible_negative(inputs.dtype))
# Since we are adding it to the raw scores before the softmax, this is
# effectively the same as removing these entirely.
inputs += adder
if isinstance(self.axis, (tuple, list)):
if len(self.axis) > 1:
return math_ops.exp(inputs - math_ops.reduce_logsumexp(
inputs, axis=self.axis, keepdims=True))
else:
return K.softmax(inputs, axis=self.axis[0])
return K.softmax(inputs, axis=self.axis)
def softmax(x, axis=1):
ndim = K.ndim(x)
if ndim == 2:
return K.softmax(x)
elif ndim > 2:
e = K.exp(x - K.max(x, axis=axis, keepdims=True))
s = K.sum(e, axis=axis, keepdims=True)
return e / s
else:
raise ValueError('Cannot apply softmax to a tensor that is 1D')
def call(self, inputs, training=None, mask=None):
q = inputs[0]
k = inputs[1]
v = inputs[2]
qkTensor = K.math_ops.matmul(q,k,transpose_b=True)
scaleTensor = K.math_ops.multiply(K.stop_gradient(1. / K.math_ops.sqrt(self.dk)) , qkTensor)
softMaxTensor = K.softmax(scaleTensor)
drT = self.dropout(softMaxTensor,training = training)
vTensor = K.math_ops.matmul(drT,v)
return vTensor
def loss(y_true, y_pred):
loss_val = -1 * K.sum(
K.log(K.softmax(y_pred[:, :-1])) * y_true[:, :-1], axis=-1)
return K.mean(
K.switch(
K.equal(task, 1005), loss_weights[task] * loss_val,
K.switch(K.equal(y_true[:, -1], task), loss_val,
loss_weights[task] * loss_val)))
def call(self, inputs, mask=None):
# inputs.shape = (batch_size, time_steps, seq_len)
x = K.permute_dimensions(inputs, (0, 2, 1))
# x.shape = (batch_size, seq_len, time_steps)
# general
a = K.softmax(K.tanh(K.dot(x, self.W)))
a = K.permute_dimensions(a, (0, 2, 1))
outputs = a * inputs
outputs = K.sum(outputs, axis=1)
return outputs
def call(self, inputs, **kwargs):
query, values, keys = inputs
hidden_with_time_axis = K.expand_dims(query, 1)
score = self.attention_variable(
K.tanh(keys + self.query_layer(hidden_with_time_axis))
) # TODO Mask option for score with infinity
alignment = K.softmax(score, axis=1)
attention = alignment * values
alignment = K.squeeze(alignment, axis=2)
attention = K.sum(attention, axis=1)
return attention, alignment
def convert_logits_to_soft_targets(temp, teacher_train_logits,
teacher_test_logits, Y_train, Y_test):
# softmax at raised temperature
train_logits_T = teacher_train_logits / temp
test_logits_T = teacher_test_logits / temp
Y_train_soft = K.softmax(train_logits_T)
Y_test_soft = K.softmax(test_logits_T)
sess = K.get_session()
Y_train_soft = sess.run(Y_train_soft)
Y_test_soft = sess.run(Y_test_soft)
# # TODO remove if negative test feedback!
# Y_train_soft, Y_test_soft = normalizeStudentSoftTargets(Y_train_soft, Y_test_soft)
# for i in range(0, len(Y_train_soft)):
# Y_train_soft[i] = (1 / find_largest_value(Y_train_soft[i])) * Y_train_soft[i]
# for i in range(0, len(Y_test_soft)):
# Y_test_soft[i] = (1 / find_largest_value(Y_test_soft[i])) * Y_test_soft[i]
# Concatenate so that this becomes a (num_classes + num_classes) dimensional vector
Y_train_new = np.concatenate([Y_train, Y_train_soft], axis=1)
Y_test_new = np.concatenate([Y_test, Y_test_soft], axis=1)
return Y_train_new, Y_test_new
def FCN(input_shape):
vgg16_model = VGG16(weights = 'imagenet', include_top = False, input_shape = input_shape);
#Sq_net = squeezenet(float(input_shape));
fire8 = extract_layer_from_model(vgg16_model, layer_name = 'block4_pool');
pool8 = MaxPooling2D((3,3), strides = (2,2), name = 'pool8')(fire8.output);
fc1 = Conv2D(64, (6,6), strides= (1, 1), padding = 'same', name = 'fc1')(pool8);
fc1 = Dropout(rate = 0.5)(fc1);
if SEPERATE_CONFIDENCE:
fc2 = Conv2D(4 , (1, 1), strides = (1, 1), padding = 'same', activation = 'relu', name = 'fc2')(fc1);
rgb = K.l2_normalize(fc2[:, :, :, 0:3], axis = 3);
w, h = map(int, fc2.get_shape()[1:3]);
confidence = fc2[:, :, :, 3:4];
confidence = np.reshape(confidence, [-1, w*h]);
confidence = K.softmax(confidence);
confidence = np.reshape(confidence, shape=[-1, w, h, 1]);
fc2 = rgb * confidence;
else:
fc2 = Conv2D(3, (1, 1), strides = (1, 1), padding = 'same', name = 'fc2')(fc1);
fc2 = Activation('relu')(fc2);
fc2 = Conv2D(3, (15, 15), padding = 'valid', name = 'fc_pooling')(fc2);
def norm(fc2):
fc2_norm = K.l2_normalize(fc2, axis = 3);
illum_est = K.tf.reduce_sum(fc2_norm, axis = (1, 2));
illum_est = K.l2_normalize(illum_est);
return illum_est;
#illum_est = Dense(3)(fc2);
illum_est = Lambda(norm)(fc2);
FCN_model = Model(inputs = vgg16_model.input, outputs = illum_est, name = 'FC4');
return FCN_model;
def selfattoptions(args):
q = args[0]
k = args[1]
v = args[2]
q = tf.expand_dims(q, -1)
k = tf.expand_dims(k, -1)
v = tf.expand_dims(v, -1)
QK = K.batch_dot(q, K.permute_dimensions(k, [0, 2, 1]))
QK = QK / (20**0.5)
QK = K.softmax(QK)
MV = K.batch_dot(QK, v)
MV = tf.squeeze(MV, -1)
return MV
def energy_step(inputs, states):
""" Step function for computing energy for a single decoder state """
assert_msg = "States must be a list. However states {} is of type {}".format(
states, type(states))
assert isinstance(states, list) or isinstance(states,
tuple), assert_msg
""" Some parameters required for shaping tensors"""
en_seq_len, en_hidden = encoder_out_seq.shape[
1], encoder_out_seq.shape[2]
de_hidden = inputs.shape[-1]
""" Computing S.Wa where S=[s0, s1, ..., si]"""
# <= batch_size*en_seq_len, latent_dim
reshaped_enc_outputs = K.reshape(encoder_out_seq, (-1, en_hidden))
# <= batch_size*en_seq_len, latent_dim
W_a_dot_s = K.reshape(K.dot(reshaped_enc_outputs, self.W_a),
(-1, en_seq_len, en_hidden))
if verbose:
print('wa.s>', W_a_dot_s.shape)
""" Computing hj.Ua """
U_a_dot_h = K.expand_dims(K.dot(inputs, self.U_a),
1) # <= batch_size, 1, latent_dim
if verbose:
print('Ua.h >', U_a_dot_h.shape)
print('U_a >', self.U_a.shape)
print('inputs.shape >', inputs.shape)
""" tanh(S.Wa + hj.Ua) """
# <= batch_size*en_seq_len, latent_dim
reshaped_Ws_plus_Uh = K.tanh(
K.reshape(W_a_dot_s + U_a_dot_h, (-1, en_hidden)))
if verbose:
print('Ws+Uh>', reshaped_Ws_plus_Uh.shape)
""" softmax(va.tanh(S.Wa + hj.Ua)) """
# <= batch_size, en_seq_len
e_i = K.reshape(K.dot(reshaped_Ws_plus_Uh, K.tanh(self.V_a)),
(-1, en_seq_len))
# <= batch_size, en_seq_len
e_i = K.softmax(e_i)
if verbose:
print('ei>', e_i.shape)
K.print_tensor(reshaped_Ws_plus_Uh,
message='reshaped_Ws_plus_Uh')
K.print_tensor(self.V_a, message='V_a')
K.print_tensor(e_i, message='e_i')
return e_i, [e_i]
def _body(i, logits, activations):
"""Routing while loop."""
# route: [batch, input_dim, output_dim, ...]
# route = tf.nn.softmax(logits, dim=-1)
route = K.softmax(logits)
preactivate_unrolled = route * votes_trans
preact_trans = tf.transpose(preactivate_unrolled, r_t_shape)
preactivate = tf.reduce_sum(preact_trans, axis=1) + biases
activation = _squash(preactivate)
activations = activations.write(i, activation)
act_3d = K.expand_dims(activation, 1)
tile_shape = np.ones(num_dims, dtype=np.int32).tolist()
tile_shape[1] = input_dim
act_replicated = tf.tile(act_3d, tile_shape)
distances = tf.reduce_sum(votes * act_replicated, axis=-1)
logits += distances
return (i + 1, logits, activations)
def call(self, x):
row = []
col = []
# 对特征进行两两组合
for r, c in combinations(x, 2): # [field * (field - 1)] / 2
row.append(r)
col.append(c)
p = K.concatenate(
row,
axis=1) # [batch_size, [field * (field - 1)] / 2, embedding_size]
q = K.concatenate(col, axis=1)
inner_product = p * q # 对应元素相乘
# 添加非线性, 进行激活
attention_tmp = K.relu(
K.bias_add(K.dot(inner_product, self.attention_W),
self.attention_b))
# [batch_size, [field * (field - 1)] / 2, embedding_size] * [embedding_size, attention_units] = > [batch_size, [field * (field - 1)] / 2, attention_units]
# context 向量
attention_tmp_dot = K.dot(
attention_tmp,
self.projection_h) # [batch_size, [field * (field - 1)] / 2, 1]
# 计算的是一个样本的sofmax， sum的是一个样本的所有特征
attention_weight = K.softmax(
attention_tmp_dot, axis=1
) # 等价于 K.exp(attention_tmp_dot) / K.sum(attention_tmp_dot, axis=1, keepdims=True)
# [batch_size, [field * (field - 1)] / 2, 1]
# 权重乘以内积
attention_output = K.sum(inner_product * attention_weight,
axis=1) # [batch_size, embedding_size]
# 经过dropout操作
attention_output = K.dropout(
attention_output,
self.dropout_rate) # [batch_size, embedding_size]
# 等价于dense层
afm_out = K.dot(attention_output, self.projection_p) # [batch_size, 1]
return afm_out
def call(self, inputs, mask=None):
'''
:param inputs: a list of tensor of length not larger than 2, or a memory tensor of size BxTXD1.
If a list, the first entry is memory, and the second one is query tensor of size BxD2 if any
:param mask: the masking entry will be directly discarded
:return: a tensor of size BxD1, weighted summing along the sequence dimension
'''
if isinstance(inputs, list) and len(inputs) == 2:
memory, query = inputs
if self.method is None:
return memory[:, -1, :]
elif self.method == 'cba':
hidden = K.dot(memory, self.Wh) + K.expand_dims(K.dot(query, self.Wq), 1)
hidden = K.tanh(hidden)
s = K.squeeze(K.dot(hidden, self.v), -1)
elif self.method == 'ga':
s = K.sum(K.expand_dims(K.dot(query, self.Wq), 1) * memory, axis=-1)
else:
s = K.squeeze(K.dot(memory, self.v), -1)
if mask is not None:
mask = mask[0]
else:
if isinstance(inputs, list):
if len(inputs) != 1:
raise ValueError('inputs length should not be larger than 2')
memory = inputs[0]
else:
memory = inputs
if self.method is None:
return memory[:, -1, :]
elif self.method == 'cba':
hidden = K.dot(memory, self.Wh)
hidden = K.tanh(hidden)
s = K.squeeze(K.dot(hidden, self.v), -1)
elif self.method == 'ga':
raise ValueError('general attention needs the second input')
else:
s = K.squeeze(K.dot(memory, self.v), -1)
s = K.softmax(s)
if mask is not None:
s *= K.cast(mask, dtype='float32')
sum_by_time = K.sum(s, axis=-1, keepdims=True)
s = s / (sum_by_time + K.epsilon())
return K.sum(memory * K.expand_dims(s), axis=1)
def call(self, x, mask=None):
'''
i_emb: [Batch_size, Hidden_units]
hist_emb: [Batch_size, max_len, Hidden_units]
hist_len: [Batch_size]
'''
assert len(x) == 3
i_emb, hist_emb, hist_len = x[0], x[1], x[2]
hidden_units = K.int_shape(hist_emb)[-1]
max_len = tf.shape(hist_emb)[1]
i_emb = tf.tile(i_emb,
[1, max_len]) # (batch_size, max_len * hidden_units)
i_emb = tf.reshape(
i_emb,
[-1, max_len, hidden_units]) # (batch_size, max_len, hidden_units)
concat = K.concatenate(
[i_emb, hist_emb, i_emb - hist_emb, i_emb * hist_emb],
axis=2) # (batch_size, max_len, hidden_units * 4)
for i in range(len(self.attention_hidden_units)):
activation = None if i == 2 else self.attention_activation
outputs = keras.layers.Dense(self.attention_hidden_units[i],
activation=activation)(concat)
concat = outputs
outputs = tf.reshape(outputs,
[-1, 1, max_len]) # (batch_size, 1, max_len)
if self.supports_masking:
mask = tf.sequence_mask(hist_len,
max_len) # (batch_size, 1, max_len)
padding = tf.ones_like(outputs) * (-1e12)
outputs = tf.where(mask, outputs, padding)
# 对outputs进行scale
outputs = outputs / (hidden_units**0.5)
outputs = K.softmax(outputs)
outputs = tf.matmul(outputs, hist_emb) # batch_size, 1, hidden_units)
outputs = tf.squeeze(outputs) # (batch_size, hidden_units)
return outputs
def call(self, inputs): return K.softmax(inputs, axis=self.axis)
