def call(self, x, mask=None):
x = K.permute_dimensions(x, (0, 2, 1))
x = K.expand_dims(x, -1)
output = K.square(K.permute_dimensions(K.squeeze(K.conv2d(x, self.kernel), -1), (0, 2, 1)))
return output
def call(self, x):
assert(K.backend() == 'tensorflow')
temp = K.permute_dimensions(x, (0, 2, 1))
for i in range(0, self.attention_depth):
temp = K.sigmoid(K.dot(temp, self.Ws[i]) + self.bs[i])
temp = K.permute_dimensions(temp, (0, 2, 1))
estimated_weight = K.squeeze(K.dot(temp, K.expand_dims(self.Wf, -1)), -1)
biased_weight = estimated_weight + self.bias
non_linear_weight = K.tanh(biased_weight)
# For each hidded state calculate how much should it contribute
# to the context vector. This is the main part of attention.
# In order to convert weights to "probabilities" use a sigmoid
# based function: exp(x) / sum(exp(xi)).
prob = K.exp(non_linear_weight)
# Compute the total sum for each batch.
total_sum = K.sum(prob, axis=1, keepdims=True)
prob /= K.cast(total_sum, K.floatx())
# Enable this if you want access to internal probabilities.
# Should only be used for testing that Attention works as expected.
# return prob
# Multiply each hidden value by the corresponding probability.
prob = K.expand_dims(prob, -1)
new_hidden_values = x * prob
return K.sum(new_hidden_values, axis=1)
def get_output(self, train=False):
H = self.get_input(train)
X = K.permute_dimensions(H, (1, 0, 2))[-1]
def reshape(x, states):
h = K.dot(x, self.W_h) + self.b_h
return h, []
_, H, _ = K.rnn(reshape, H, [], mask=None)
if self.stateful or self.state_input or len(self.state_outputs) > 0:
initial_states = self.states
else:
initial_states = self.get_initial_states(X)
[outputs,hidden_states, cell_states], updates = theano.scan(
self._step,
n_steps = self.output_length,
outputs_info=[X] + initial_states,
non_sequences=[H, self.U_i, self.U_f, self.U_o, self.U_c,
self.W_i, self.W_f, self.W_c, self.W_o,
self.W_x, self.W_a, self.V_i, self.V_f, self.V_c,
self.V_o, self.b_i, self.b_f, self.b_c,
self.b_o, self.b_x, self.b_a])
states = [hidden_states[-1], cell_states[-1]]
if self.stateful and not self.state_input:
self.updates = []
for i in range(2):
self.updates.append((self.states[i], states[i]))
for o in self.state_outputs:
o.updates = []
for i in range(2):
o.updates.append((o.states[i], states[i]))
return K.permute_dimensions(outputs, (1, 0, 2))
def attend_function(self, inputs, mask=None):
# b,n,f -> b,f via b,n broadcasted
inputs = K.permute_dimensions(inputs, (1,0,2)) ### assuming it comes from an unroller
if mask:
mask = K.permute_dimensions(mask, (1,0,2))
output = super(Accumulator, self).call(inputs, mask)
return output
def call(self, x, mask=None):
if self.direction == 'Down':
X = K.permute_dimensions(x, (0, 3, 1, 2))
elif self.direction == 'Right':
X = K.permute_dimensions(x, (0, 2, 1, 3))
else:
raise Exception('ERROR: Unknown direction')
if self.stateful:
super(DiagLSTM, self).call(X, mask)
else:
if self.reverse:
X = X[:,::-1,:,:]
X = Utils.Skew(X)
res = super(DiagLSTM, self).call(X, mask)
unskew = Utils.Unskew(res)
if self.reverse:
unskew = unskew[:,::-1,:,:]
if self.direction == 'Down':
return K.permute_dimensions(unskew, (0, 2, 3, 1))
elif self.direction == 'Right':
return K.permute_dimensions(unskew, (0, 2, 1, 3))
else:
raise Exception('ERROR: Unknown direction')
def call(self, X, mask=None):
# 1D -> 2D
batch = K.shape(X)[0]
width = deconv_output_length(K.shape(X)[1],
self.filter_length,
self.padding,
self.strides[2])
print("Output width: ", width)
print("Input shape: ", K.shape(X))
X = K.expand_dims(X,2)
print("Input shape after expand: ", K.shape(X))
# X = K.permute_dimensions(X, (0, 2, 3, 1))
X = K.permute_dimensions(X, (0, 2, 1, 3))
print("Input shape after permute: ", K.shape(X))
deconv_shape = tf.pack([batch, 1, width, self.nb_filter])
print("Deconv shape: ", deconv_shape)
conv_out = tf.nn.conv2d_transpose(X, self.W, strides=self.strides,
padding=self.padding.upper(),
output_shape=deconv_shape)
output = conv_out + K.reshape(self.b, (1, 1, 1, self.W_shape[2]))
print("Output shape: ", K.shape(output))
# output = K.permute_dimensions(output, (0, 3, 1, 2))
output = K.permute_dimensions(output, (0, 2, 1, 3))
print("Output shape after permute: ", K.shape(output))
# 2D -> 1D
output = K.squeeze(output,2)
print("Output shape after squeeze: ", K.shape(output))
return output
def _step(self,
x_tm1,
h_tm1, c_tm1, H,
u_i, u_f, u_o, u_c, w_i, w_f, w_c, w_o, w_x, w_a, v_i, v_f, v_c, v_o, b_i, b_f, b_c, b_o, b_x, b_a):
s_tm1 = K.repeat(c_tm1, self.input_length)
e = H + s_tm1
def a(x, states):
output = K.dot(x, w_a) + b_a
return output, []
_, energy, _ = K.rnn(a, e, [], mask=None)
energy = activations.get('linear')(energy)
energy = K.permute_dimensions(energy, (2, 0, 1))
energy = energy[0]
alpha = K.softmax(energy)
alpha = K.repeat(alpha, self.hidden_dim)
alpha = K.permute_dimensions(alpha, (0, 2 , 1))
weighted_H = H * alpha
v = K.sum(weighted_H, axis=1)
xi_t = K.dot(x_tm1, w_i) + K.dot(v, v_i) + b_i
xf_t = K.dot(x_tm1, w_f) + K.dot(v, v_f) + b_f
xc_t = K.dot(x_tm1, w_c) + K.dot(v, v_c) + b_c
xo_t = K.dot(x_tm1, w_o) + K.dot(v, v_o) + b_o
i_t = self.inner_activation(xi_t + K.dot(h_tm1, u_i))
f_t = self.inner_activation(xf_t + K.dot(h_tm1, u_f))
c_t = f_t * c_tm1 + i_t * self.activation(xc_t + K.dot(h_tm1, u_c))
o_t = self.inner_activation(xo_t + K.dot(h_tm1, u_o))
h_t = o_t * self.activation(c_t)
x_t = K.dot(h_t, w_x) + b_x
return x_t, h_t, c_t
def call(self, inputs):
input_shape = K.int_shape(inputs)
if len(input_shape) != 4:
raise ValueError('Inputs should have rank ' +
str(4) +
'; Received input shape:', str(input_shape))
if self.data_format == 'channels_first':
batch_size, c, h, w = input_shape
if batch_size is None:
batch_size = -1
rh, rw = self.size
oh, ow = h * rh, w * rw
oc = c // (rh * rw)
out = K.reshape(inputs, (batch_size, rh, rw, oc, h, w))
out = K.permute_dimensions(out, (0, 3, 4, 1, 5, 2))
out = K.reshape(out, (batch_size, oc, oh, ow))
return out
elif self.data_format == 'channels_last':
batch_size, h, w, c = input_shape
if batch_size is None:
batch_size = -1
rh, rw = self.size
oh, ow = h * rh, w * rw
oc = c // (rh * rw)
out = K.reshape(inputs, (batch_size, h, w, rh, rw, oc))
out = K.permute_dimensions(out, (0, 1, 3, 2, 4, 5))
out = K.reshape(out, (batch_size, oh, ow, oc))
return out
def call(self, x, mask=None):
x = K.permute_dimensions(x, (0, 2, 1))
x = K.reshape(x, (-1, self.input_length))
x = K.expand_dims(x, 1)
x = K.expand_dims(x, -1)
if self.real_filts is not None:
conv_out_r = K.conv2d(x, self.W_r, strides=self.subsample,
border_mode=self.border_mode,
dim_ordering='th')
else:
conv_out_r = x
if self.complex_filts is not None:
conv_out_c1 = K.conv2d(x, self.W_c1, strides=self.subsample,
border_mode=self.border_mode,
dim_ordering='th')
conv_out_c2 = K.conv2d(x, self.W_c2, strides=self.subsample,
border_mode=self.border_mode,
dim_ordering='th')
conv_out_c = K.sqrt(K.square(conv_out_c1) + K.square(conv_out_c2) + K.epsilon())
output = K.concatenate((conv_out_r, conv_out_c), axis=1)
else:
output = conv_out_r
output_shape = self.get_output_shape_for((None, self.input_length, self.input_dim))
output = K.squeeze(output, 3) # remove the dummy 3rd dimension
output = K.permute_dimensions(output, (2, 1, 0))
output = K.reshape(output, (-1, output_shape[1], output.shape[1]*output.shape[2]))
return output
def reverse(x):
if K.ndim(x) == 2:
x = K.expand_dims(x, -1)
rev = K.permute_dimensions(x, (1, 0, 2))[::-1]
rev = K.squeeze(rev, -1)
else:
rev = K.permute_dimensions(x, (1, 0, 2))[::-1]
return K.permute_dimensions(rev, (1, 0, 2))
def semantic_matrix(argv): assert len(argv) == 2 q = argv[0] a = argv[1] q_sqrt = K.sqrt((q ** 2).sum(axis=2, keepdims=True)) a_sqrt = K.sqrt((a ** 2).sum(axis=2, keepdims=True)) denominator = K.batch_dot(q_sqrt, K.permute_dimensions(a_sqrt, [0,2,1])) return K.batch_dot(q, K.permute_dimensions(a, [0,2,1])) / (denominator + SAFE_EPSILON)
def call(self, X, mask=None):
#X = self.get_input(train)
X = K.permute_dimensions(X, (0, 2, 3, 1))
conv_out = tf.nn.conv2d_transpose(X, self.W, strides=self.strides,
padding=self.padding.upper(),
output_shape=self.deconv_shape)
output = conv_out + K.reshape(self.b, (1, 1, 1, self.W_shape[2]))
return K.permute_dimensions(output, (0, 3, 1, 2))
def call(self, x, mask=None):
stride_row, stride_col = self.subsample
_, feature_dim, nb_filter = self.W_shape
if self.dim_ordering == 'th':
if K._backend == 'theano':
output = []
for i in range(self.output_row):
for j in range(self.output_col):
slice_row = slice(i * stride_row,
i * stride_row + self.nb_row)
slice_col = slice(j * stride_col,
j * stride_col + self.nb_col)
x_flatten = K.reshape(x[:, :, slice_row, slice_col], (1, -1, feature_dim))
output.append(K.dot(x_flatten, self.W[i * self.output_col + j, :, :]))
output = K.concatenate(output, axis=0)
else:
xs = []
for i in range(self.output_row):
for j in range(self.output_col):
slice_row = slice(i * stride_row,
i * stride_row + self.nb_row)
slice_col = slice(j * stride_col,
j * stride_col + self.nb_col)
xs.append(K.reshape(x[:, :, slice_row, slice_col], (1, -1, feature_dim)))
x_aggregate = K.concatenate(xs, axis=0)
output = K.batch_dot(x_aggregate, self.W)
output = K.reshape(output, (self.output_row, self.output_col, -1, nb_filter))
output = K.permute_dimensions(output, (2, 3, 0, 1))
elif self.dim_ordering == 'tf':
xs = []
for i in range(self.output_row):
for j in range(self.output_col):
slice_row = slice(i * stride_row,
i * stride_row + self.nb_row)
slice_col = slice(j * stride_col,
j * stride_col + self.nb_col)
xs.append(K.reshape(x[:, slice_row, slice_col, :], (1, -1, feature_dim)))
x_aggregate = K.concatenate(xs, axis=0)
output = K.batch_dot(x_aggregate, self.W)
output = K.reshape(output, (self.output_row, self.output_col, -1, nb_filter))
output = K.permute_dimensions(output, (2, 0, 1, 3))
else:
raise Exception('Invalid dim_ordering: ' + self.dim_ordering)
if self.bias:
if self.dim_ordering == 'th':
output += K.reshape(self.b, (1, nb_filter, self.output_row, self.output_col))
elif self.dim_ordering == 'tf':
output += K.reshape(self.b, (1, self.output_row, self.output_col, nb_filter))
else:
raise Exception('Invalid dim_ordering: ' + self.dim_ordering)
output = self.activation(output)
return output
def f(X):
b, ch, r, c = X.shape # batch, channel, row, column
half = n // 2
square = K.square(X)
extra_channels = K.spatial_2d_padding(K.permute_dimensions(square, (0, 2, 3, 1)), (0, half))
extra_channels = K.permute_dimensions(extra_channels, (0, 3, 1, 2))
scale = k
for i in range(n):
scale += alpha * extra_channels[:, i:i + ch, :, :]
scale = scale ** beta
return X / scale
def Skew(inputs):
inputs_ = K.permute_dimensions(inputs, (3,0,1,2))
buffer_ = T.zeros((K.shape(inputs)[3], K.shape(inputs)[0], K.shape(inputs)[1]+K.shape(inputs)[3]-1, K.shape(inputs)[2]))
def fnc(buf, inp, i):
return T.set_subtensor(buf[:, i:i+K.shape(inputs)[1], :], inp[:,:,:])
res, _ = theano.scan(fn=fnc, sequences=[buffer_, inputs_, T.arange(K.shape(inputs)[3])])
res = K.permute_dimensions(res, (1,2,3,0))
return res
def call(self, x, mask=None):
if isinstance(x, list):
x,_ = x
if mask is not None and isinstance(mask, list):
mask,_ = mask
if 0. < self.dropout < 1.:
retain_p = 1. - self.dropout
dims = self.W._keras_shape[:-1]
B = K.random_binomial(dims, p=retain_p) * (1. / retain_p)
B = K.expand_dims(B)
W = K.in_train_phase(self.W * B, self.W)
else:
W = self.W
if self.mode == 'matrix':
return K.gather(W,x)
elif self.mode == 'tensor':
# quick and dirty: only allowing for 3dim inputs when it's tensor mode
assert K.ndim(x) == 3
# put sequence on first; gather; take diagonal across shared batch dimension
# in other words, W is (B, S, F)
# incoming x is (B, S, A)
inds = K.arange(self.W._keras_shape[0])
#out = K.gather(K.permute_dimensions(W, (1,0,2)), x).diagonal(axis1=0, axis2=3)
#return K.permute_dimensions(out, (3,0,1,2))
### method above doesn't do grads =.=
# tensor abc goes to bac, indexed onto with xyz, goes to xyzac,
# x == a, so shape to xayzc == xxyzc
# take diagonal on first two: xyzc
#out = K.colgather()
out = K.gather(K.permute_dimensions(W, (1,0,2)), x)
out = K.permute_dimensions(out, (0,3,1,2,4))
out = K.gather(out, (inds, inds))
return out
else:
raise Exception('sanity check. should not be here.')
#all_dims = T.arange(len(self.W._keras_shape))
#first_shuffle = [all_dims[self.embed_dim]] + all_dims[:self.embed_dim] + all_dims[self.embed_dim+1:]
## 1. take diagonal from 0th to
## chang eof tactics
## embed on time or embed on batch. that's all I'm supporting.
## if it's embed on time, then, x.ndim+1 is where batch will be, and is what
## i need to take the diagonal over.
## now dim shuffle the xdims + 1 to the front.
#todo: get second shuffle or maybe find diagonal calculations
#out = K.gather(W, x)
#return out
### reference
#A = S(np.arange(60).reshape(3,4,5))
#x = S(np.random.randint(0, 4, (3,4,10)))
#x_emb = A.dimshuffle(1,0,2)[x].dimshuffle(0,3,1,2,4)[T.arange(A.shape[0]), T.arange(A.shape[0])]
def call(self, x, mask=None):
x = K.permute_dimensions(x, (0, 2, 1))
x = K.expand_dims(x, -1)
conv_out = K.permute_dimensions(K.squeeze(K.conv2d(x, self.kernel), -1), (0, 2, 1))
conv_out_s = conv_out[:,:,:self.nb_simple]
conv_out_c = K.square(conv_out[:,:,self.nb_simple:])
output = K.concatenate((conv_out_s, conv_out_c), axis=-1)
return output
def get_initial_states(self, x): M = K.zeros_like(x[:, 0, 0]) # (nb_samples,) M = K.pack([M] * self.nb_slots) # (nb_slots, nb_samples) M = K.pack([M] * self.memory_size) # (memory_size, nb_slots, nb_samples) M = K.permute_dimensions(M, (2, 1, 0)) # (nb_samples, nb_slots, memory_size) h = K.zeros_like(x[:, 0, 0]) # (nb_samples,) h = K.pack([h] * self.memory_size) # (memory_size, nb_samples) h = K.permute_dimensions(h, (1, 0)) # (nb_samples, memory_size) w = K.zeros_like(x[:, 0, 0]) # (nb_samples,) w = K.pack([w] * self.nb_slots) # (nb_slots, nb_samples) w = K.permute_dimensions(w, (1, 0)) # (nb_samples, nb_slots) states = [M, h, w] return states
def call(self, X, mask=None):
# 1D -> 2D
X = K.expand_dims(X,2)
X = K.permute_dimensions(X, (0, 2, 3, 1))
conv_out = tf.nn.conv2d_transpose(X, self.W, strides=self.strides,
padding=self.padding.upper(),
output_shape=self.deconv_shape)
output = conv_out + K.reshape(self.b, (1, 1, 1, self.W_shape[2]))
output = K.permute_dimensions(output, (0, 3, 1, 2))
# 2D -> 1D
output = K.squeeze(output,2)
return output
def get_output(self, train=False):
X = train
X = K.expand_dims(X, -1) # add a dimension of the right
X = K.permute_dimensions(X, (0, 2, 1, 3))
conv_out = K.conv2d(X, self.W, strides=self.subsample,
border_mode=self.border_mode,
dim_ordering='th')
output = conv_out + K.reshape(self.b, (1, self.nb_filter, 1, 1))
output = self.activation(output)
output = K.squeeze(output, 3) # remove the dummy 3rd dimension
output = K.permute_dimensions(output, (0, 2, 1))
return output
def call(self, x, mask=None):
if self.direction == 'Down':
X = K.permute_dimensions(x, (0, 2, 1, 3))
elif self.direction == 'Right':
X = K.permute_dimensions(x, (0, 3, 1, 2))
else:
raise Exception('ERROR: Unknown direction')
if self.direction == 'Down':
return K.permute_dimensions(super(PyramidSTM, self).call(X, mask), (0, 2, 1, 3))
elif self.direction == 'Right':
return K.permute_dimensions(super(PyramidSTM, self).call(X, mask), (0, 2, 3, 1))
else:
raise Exception('ERROR: Unknown direction')
def recurrence(y_i, h):
h_permute = K.permute_dimensions(h, [0, 2, 1]) # (batch_size, encoding_dim, input_length)
e = K.l2_normalize(
K.batch_dot(h_permute, s, axes=1), # (batch_size, input_length)
axis=1) # (batch_size, input_length)
# eqn 6
alpha = K.softmax(e) # (batch_size, input_length)
# eqn 5
c = K.batch_dot(h, alpha, axes=1) # (batch_size, encoding_dim)
recurrence_result = K.expand_dims(
K.concatenate([c, y_i], axis=1),
dim=1) # (batch_size, 1, 2 * encoding_dim)
expanded_h = Input(shape=(1, 2 * encoding_dim),
name='expanded_h')
gru = Sequential([
GRU(output_dim,
return_sequences=False,
input_shape=(1, 2 * encoding_dim))
])
model = Model(input=[expanded_h],
output=[gru(expanded_h)]) # (batch_size, 1, output_dim)
return model(recurrence_result)
def get_output(self, train=False):
v = self.get_input(train)
if self.stateful or self.state_input or len(self.state_outputs) > 0:
initial_states = self.states
else:
initial_states = self.get_initial_states(v)
[outputs,hidden_states, cell_states], updates = theano.scan(
self._step,
n_steps = self.output_length,
outputs_info=[v] + initial_states,
non_sequences=[v, self.U_i, self.U_f, self.U_o, self.U_c,
self.W_i, self.W_f, self.W_c, self.W_o,
self.W_x, self.V_i, self.V_f, self.V_c,
self.V_o, self.b_i, self.b_f, self.b_c,
self.b_o, self.b_x])
states = [hidden_states[-1], cell_states[-1]]
if self.stateful and not self.state_input:
self.updates = []
for i in range(2):
self.updates.append((self.states[i], states[i]))
for o in self.state_outputs:
o.updates = []
for i in range(2):
o.updates.append((o.states[i], states[i]))
return K.permute_dimensions(outputs, (1, 0, 2))
def gram_matrix(x):
#change height,width,depth to depth, height, width, it could be 2,1,0 too
#maybe 2,0,1 is more efficient due to underlying memory layout
features = K.permute_dimensions(x, (2,0,1))
#batch flatten make features become 2D array
features = K.batch_flatten(features)
return K.dot(features, K.transpose(features)) / x.get_shape().num_elements()
def teacher_forced(h, states):
# switching from (batch_size, previous_layer_input|true_input, output_dim)
# to ( previous_layer_input|true_input, batch_size, output_dim)
axes = [1, 0] + list(range(2, K.ndim(h)))
h = K.permute_dimensions(h, axes)
prev_layer_input = h[0:1, :, :]
true_input = h[1:, :, :self.units]
# this should correspond to true input
prev_sampled_output = true_input
if self.implementation == 0:
x_z = prev_layer_input[0, :, :self.units]
x_r = prev_layer_input[0, :, self.units: 2 * self.units]
x_h = prev_layer_input[0, :, 2 * self.units:]
else:
raise ValueError('Implementation type ' + self.implementation + ' is invalid')
z = self.recurrent_activation(x_z + K.dot(h_tm1 * rec_dp_mask[0],
self.recurrent_kernel_z))
r = self.recurrent_activation(x_r + K.dot(h_tm1 * rec_dp_mask[1],
self.recurrent_kernel_r))
hh = self.activation(x_h +
K.dot(r * h_tm1 * rec_dp_mask[2],
self.recurrent_kernel_h) +
K.dot(r * prev_sampled_output, self.recurrent_kernel_y))
output = z * h_tm1 + (1. - z) * hh
return K.stack([output, output])
def make_patches_grid(x, patch_size, patch_stride):
'''Break image `x` up into a grid of patches.
input shape: (channels, rows, cols)
output shape: (rows, cols, channels, patch_rows, patch_cols)
'''
from theano.tensor.nnet.neighbours import images2neibs # TODO: all K, no T
x = K.expand_dims(x, 0)
xs = K.shape(x)
num_rows = 1 + (xs[-2] - patch_size) // patch_stride
num_cols = 1 + (xs[-1] - patch_size) // patch_stride
num_channels = xs[-3]
patches = images2neibs(
x, (patch_size, patch_size), (patch_stride, patch_stride),
mode='valid')
# neibs are sorted per-channel
patches = K.reshape(patches,
(num_channels, K.shape(patches)[0] // num_channels,
patch_size, patch_size))
patches = K.permute_dimensions(patches, (1, 0, 2, 3))
# arrange in a 2d-grid (rows, cols, channels, px, py)
patches = K.reshape(
patches, (num_rows, num_cols, num_channels, patch_size, patch_size))
patches_norm = K.sqrt(
K.sum(K.square(patches), axis=(2, 3, 4), keepdims=True))
return patches, patches_norm
def gram_matrix(x):
if K.image_dim_ordering() == "th":
features = K.batch_flatten(x)
else:
features = K.batch_flatten(K.permute_dimensions(x, (2, 0, 1)))
gram = K.dot(features, K.transpose(features))
return gram
def call(self, inputs, **kwargs):
"""Following the routing algorithm from Hinton's paper,
but replace b = b + <u,v> with b = <u,v>.
This change can improve the feature representation of the capsule.
However, you can replace
b = K.batch_dot(outputs, hat_inputs, [2, 3])
with
b += K.batch_dot(outputs, hat_inputs, [2, 3])
to get standard routing.
"""
if self.share_weights:
hat_inputs = K.conv1d(inputs, self.kernel)
else:
hat_inputs = K.local_conv1d(inputs, self.kernel, [1], [1])
batch_size = K.shape(inputs)[0]
input_num_capsule = K.shape(inputs)[1]
hat_inputs = K.reshape(hat_inputs,
(batch_size, input_num_capsule,
self.num_capsule, self.dim_capsule))
hat_inputs = K.permute_dimensions(hat_inputs, (0, 2, 1, 3))
b = K.zeros_like(hat_inputs[:, :, :, 0])
print(self.routings)
for i in range(self.routings):
c = K.softmax(b, 1)
o = self.activation(K.batch_dot(c, hat_inputs, [2, 2]))
if i < self.routings - 1:
b = K.batch_dot(o, hat_inputs, [2, 3])
if K.backend() == 'theano':
o = K.sum(o, axis=1)
return o
def call(self, x, mask=None):
print("AttentionDecoder.call")
H = x
x = K.permute_dimensions(H, (1, 0, 2))[-1, :, :]
if self.stateful or self.state_input or len(self.state_outputs) > 0:
initial_states = self.states[:]
else:
initial_states = self.get_initial_states(H)
constants = self.get_constants(H) + [H]
y_0 = x
x = K.repeat(x, self.output_length)
initial_states += [y_0]
last_output, outputs, states = K.rnn(
self.step,
x,
initial_states,
go_backwards=self.go_backwards,
mask=mask,
constants=constants,
unroll=self.unroll,
input_length=self.output_length)
if self.stateful and not self.state_input:
self.updates = zip(self.states, states)
self.states_to_transfer = states
return outputs
def free_running(h, states):
prev_generated_output = initial_states[0][1:, :, :]
prev_sampled_output = prev_generated_output
# switching from (batch_size, previous_layer_input|true_input, output_dim)
# to ( previous_layer_input|true_input, batch_size, output_dim)
axes = [1, 0] + list(range(2, K.ndim(h)))
h = K.permute_dimensions(h, axes)
prev_layer_input = h[0:1, :, :]
if self.implementation == 0:
x_z = prev_layer_input[0, :, :self.units]
x_r = prev_layer_input[0, :, self.units: 2 * self.units]
x_h = prev_layer_input[0, :, 2 * self.units:]
z = self.recurrent_activation(x_z + K.dot(h_tm1 * rec_dp_mask[0],
self.recurrent_kernel_z))
r = self.recurrent_activation(x_r + K.dot(h_tm1 * rec_dp_mask[1],
self.recurrent_kernel_r))
hh = self.activation(x_h +
K.dot(r * h_tm1 * rec_dp_mask[2],
self.recurrent_kernel_h) +
K.dot(r * prev_sampled_output, self.recurrent_kernel_y))
output = z * h_tm1 + (1. - z) * hh
final_output = self.output_sampling(output, random_cutoff_vec)
return K.stack([output, final_output])
def _outer(AB):
att_ji = K.batch_dot(AB[1], K.permute_dimensions(AB[0], (0, 2, 1)))
return K.permute_dimensions(att_ji, (0, 2, 1))
def call(self, x, mask=None):
assert (len(x) == 2)
img = x[0]
rois = x[1]
input_shape = K.shape(img)
outputs = []
for roi_idx in range(self.num_rois):
x = rois[0, roi_idx, 0]
y = rois[0, roi_idx, 1]
w = rois[0, roi_idx, 2]
h = rois[0, roi_idx, 3]
row_length = w / float(self.pool_size)
col_length = h / float(self.pool_size)
num_pool_regions = self.pool_size
#NOTE: the RoiPooling implementation differs between theano and tensorflow due to the lack of a resize op
# in theano. The theano implementation is much less efficient and leads to long compile times
if self.dim_ordering == 'channels_first':
for jy in range(num_pool_regions):
for ix in range(num_pool_regions):
x1 = x + ix * row_length
x2 = x1 + row_length
y1 = y + jy * col_length
y2 = y1 + col_length
x1 = K.cast(x1, 'int32')
x2 = K.cast(x2, 'int32')
y1 = K.cast(y1, 'int32')
y2 = K.cast(y2, 'int32')
x2 = x1 + K.maximum(1, x2 - x1)
y2 = y1 + K.maximum(1, y2 - y1)
new_shape = [
input_shape[0], input_shape[1], y2 - y1, x2 - x1
]
x_crop = img[:, :, y1:y2, x1:x2]
xm = K.reshape(x_crop, new_shape)
pooled_val = K.max(xm, axis=(2, 3))
outputs.append(pooled_val)
elif self.dim_ordering == 'channels_last':
x = K.cast(x, 'int32')
y = K.cast(y, 'int32')
w = K.cast(w, 'int32')
h = K.cast(h, 'int32')
rs = tf.image.resize(img[:, y:y + h, x:x + w, :],
size=(self.pool_size, self.pool_size))
outputs.append(rs)
final_output = K.concatenate(outputs, axis=0)
final_output = K.reshape(final_output,
(1, self.num_rois, self.pool_size,
self.pool_size, self.nb_channels))
if self.dim_ordering == 'channels_first':
final_output = K.permute_dimensions(final_output, (0, 1, 4, 2, 3))
else:
final_output = K.permute_dimensions(final_output, (0, 1, 2, 3, 4))
return final_output
def local_conv3d(self, inputs, kernel, kernel_size, strides, output_shape, data_format=None):
"""Apply 3D conv with un-shared weights.
# Arguments
inputs: 4D tensor with shape:
(batch_size, filters, new_rows, new_cols)
if data_format='channels_first'
or 4D tensor with shape:
(batch_size, new_rows, new_cols, filters)
if data_format='channels_last'.
kernel: the unshared weight for convolution,
with shape (output_items, feature_dim, filters)
kernel_size: a tuple of 2 integers, specifying the
width and height of the 3D convolution window.
strides: a tuple of 2 integers, specifying the strides
of the convolution along the width and height.
output_shape: a tuple with (output_row, output_col)
data_format: the data format, channels_first or channels_last
# Returns
A 4d tensor with shape:
(batch_size, filters, new_rows, new_cols)
if data_format='channels_first'
or 4D tensor with shape:
(batch_size, new_rows, new_cols, filters)
if data_format='channels_last'.
# Raises
ValueError: if `data_format` is neither
`channels_last` or `channels_first`.
"""
if data_format is None:
data_format = K.image_data_format()
if data_format not in {'channels_first', 'channels_last'}:
raise ValueError('Unknown data_format: ' + str(data_format))
stride_row, stride_col, stride_z = strides
output_row, output_col, output_z = output_shape
kernel_shape = K.int_shape(kernel)
_, feature_dim, filters = kernel_shape
xs = []
for i in range(output_row):
for j in range(output_col):
for k in range(output_z):
slice_row = slice(i * stride_row,
i * stride_row + kernel_size[0])
slice_col = slice(j * stride_col,
j * stride_col + kernel_size[1])
slice_z = slice(k * stride_z,
k * stride_z + kernel_size[2])
if data_format == 'channels_first':
xs.append(K.reshape(inputs[:, :, slice_row, slice_col, slice_z],
(1, -1, feature_dim)))
else:
xs.append(K.reshape(inputs[:, slice_row, slice_col, slice_z, :],
(1, -1, feature_dim)))
x_aggregate = K.concatenate(xs, axis=0)
output = K.batch_dot(x_aggregate, kernel)
output = K.reshape(output,
(output_row, output_col, output_z, -1, filters))
if data_format == 'channels_first':
output = K.permute_dimensions(output, (3, 4, 0, 1, 2))
else:
output = K.permute_dimensions(output, (3, 0, 1, 2, 4))
return output
def minibatch_discriminator(x):
""" Computes minibatch discrimination features from input tensor x"""
diffs = K.expand_dims(x, 3) - \
K.expand_dims(K.permute_dimensions(x, [1, 2, 0]), 0)
l1_norm = K.sum(K.abs(diffs), axis=2)
return K.sum(K.exp(-l1_norm), axis=2)
def call(self, inputs):
X = inputs[0] # Node features (batch x N x F)
A = inputs[1] # Adjacency matrix (batch x N x N)
assert K.ndim(X) == 3
assert K.ndim(A) == 3
outputs = []
for h in range(self.attn_heads):
kernel = self.kernels[h]
attn_kernel_self = self.attn_kernels_self[h]
attn_kernel_neighs = self.attn_kernels_neighs[h]
if self.use_bias:
bias = self.biases[h]
# Compute inputs to attention network
features = K.dot(X, kernel) # (batch x 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]
# broadcast the attention kernel across all batches and nodes
attn_for_self = K.dot(features, attn_kernel_self)
attn_for_neighs = K.dot(features, attn_kernel_neighs)
# Attention head a(Wh_i, Wh_j) = a^T [[Wh_i], [Wh_j]]
trans_attn_for_neighs = K.permute_dimensions(
attn_for_neighs, (0, 2, 1))
# add dimensions to compute additive attention with broadcasting
scores = attn_for_self + trans_attn_for_neighs # (batch x N x N) via broadcasting
# Add nonlinearty
scores = LeakyReLU(alpha=0.2)(scores)
# Mask values before activation (Vaswani et al., 2017)
mask = (1.0 - A) * -10e9
scores = scores + mask
# Feed masked values to softmax
attn_weights = K.softmax(
scores) # (batch x N x N), attention coefficients
dropout_attn_coeffs = Dropout(self.attn_dropout)(
attn_weights) # (batch x N x N)
dropout_features = Dropout(self.feature_dropout)(features)
# Linear combination with neighbors' features
# (batch x N x N) * (batch x N x F') = (batch x N x F')
node_features = K.batch_dot(dropout_attn_coeffs, dropout_features)
if self.use_bias:
node_features = K.bias_add(node_features, bias)
outputs.append(node_features)
# Reduce the attention heads output according to the reduction method
if self.attn_heads_reduction == 'concat':
output = K.concatenate(outputs, -1) # (batch x N x KF')
else:
output = K.mean(K.stack(outputs, axis=0),
axis=0) # (batch x N x F')
output = self.activation(output)
return output
def gram_matrix(x):
features = K.batch_flatten(K.permute_dimensions(x, (2, 0, 1)))
return K.dot(features, K.transpose(features)) / x.get_shape().num_elements()
def call(self, inputs):
channel_axis = 1 if self.data_format == 'channels_first' else -1
input_dim = K.shape(inputs)[channel_axis] // 2
if self.rank == 1:
f_real = self.kernel[:, :, :self.filters]
f_imag = self.kernel[:, :, self.filters:]
elif self.rank == 2:
f_real = self.kernel[:, :, :, :self.filters]
f_imag = self.kernel[:, :, :, self.filters:]
elif self.rank == 3:
f_real = self.kernel[:, :, :, :, :self.filters]
f_imag = self.kernel[:, :, :, :, self.filters:]
convArgs = {"strides": self.strides[0] if self.rank == 1 else self.strides,
"padding": self.padding,
"data_format": self.data_format,
"dilation_rate": self.dilation_rate[0] if self.rank == 1 else self.dilation_rate}
if self.transposed:
convFunc = {1: K.conv1d_transpose,
2: K.conv2d_transpose,
3: K.conv3d_transpose}[self.rank]
else:
convFunc = {1: K.conv1d,
2: K.conv2d,
3: K.conv3d}[self.rank]
# processing if the weights are assumed to be represented in the
# spectral domain
if self.spectral_parametrization:
if self.rank == 1:
f_real = K.permute_dimensions(f_real, (2,1,0))
f_imag = K.permute_dimensions(f_imag, (2,1,0))
f = K.concatenate([f_real, f_imag], axis=0)
fshape = K.shape(f)
f = K.reshape(f, (fshape[0] * fshape[1], fshape[2]))
f = ifft(f)
f = K.reshape(f, fshape)
f_real = f[:fshape[0]//2]
f_imag = f[fshape[0]//2:]
f_real = K.permute_dimensions(f_real, (2,1,0))
f_imag = K.permute_dimensions(f_imag, (2,1,0))
elif self.rank == 2:
f_real = K.permute_dimensions(f_real, (3,2,0,1))
f_imag = K.permute_dimensions(f_imag, (3,2,0,1))
f = K.concatenate([f_real, f_imag], axis=0)
fshape = K.shape(f)
f = K.reshape(f, (fshape[0] * fshape[1], fshape[2], fshape[3]))
f = ifft2(f)
f = K.reshape(f, fshape)
f_real = f[:fshape[0]//2]
f_imag = f[fshape[0]//2:]
f_real = K.permute_dimensions(f_real, (2,3,1,0))
f_imag = K.permute_dimensions(f_imag, (2,3,1,0))
# In case of weight normalization, real and imaginary weights are
# normalized
if self.normalize_weight:
ker_shape = self.kernel_shape
nb_kernels = ker_shape[-2] * ker_shape[-1]
kernel_shape_4_norm = (np.prod(self.kernel_size), nb_kernels)
reshaped_f_real = K.reshape(f_real, kernel_shape_4_norm)
reshaped_f_imag = K.reshape(f_imag, kernel_shape_4_norm)
reduction_axes = list(range(2))
del reduction_axes[-1]
mu_real = K.mean(reshaped_f_real, axis=reduction_axes)
mu_imag = K.mean(reshaped_f_imag, axis=reduction_axes)
broadcast_mu_shape = [1] * 2
broadcast_mu_shape[-1] = nb_kernels
broadcast_mu_real = K.reshape(mu_real, broadcast_mu_shape)
broadcast_mu_imag = K.reshape(mu_imag, broadcast_mu_shape)
reshaped_f_real_centred = reshaped_f_real - broadcast_mu_real
reshaped_f_imag_centred = reshaped_f_imag - broadcast_mu_imag
Vrr = K.mean(reshaped_f_real_centred ** 2, axis=reduction_axes) + self.epsilon
Vii = K.mean(reshaped_f_imag_centred ** 2, axis=reduction_axes) + self.epsilon
Vri = K.mean(reshaped_f_real_centred * reshaped_f_imag_centred,
axis=reduction_axes) + self.epsilon
normalized_weight = complex_normalization(
K.concatenate([reshaped_f_real, reshaped_f_imag], axis=-1),
Vrr, Vii, Vri,
beta = None,
gamma_rr = self.gamma_rr,
gamma_ri = self.gamma_ri,
gamma_ii = self.gamma_ii,
scale=True,
center=False,
axis=-1
)
normalized_real = normalized_weight[:, :nb_kernels]
normalized_imag = normalized_weight[:, nb_kernels:]
f_real = K.reshape(normalized_real, self.kernel_shape)
f_imag = K.reshape(normalized_imag, self.kernel_shape)
# Performing complex convolution
f_real._keras_shape = self.kernel_shape
f_imag._keras_shape = self.kernel_shape
cat_kernels_4_real = K.concatenate([f_real, -f_imag], axis=-2)
cat_kernels_4_imag = K.concatenate([f_imag, f_real], axis=-2)
cat_kernels_4_complex = K.concatenate([cat_kernels_4_real, cat_kernels_4_imag], axis=-1)
cat_kernels_4_complex._keras_shape = self.kernel_size + (2 * input_dim, 2 * self.filters)
output = convFunc(inputs, cat_kernels_4_complex, **convArgs)
if self.use_bias:
output = K.bias_add(
output,
self.bias,
data_format=self.data_format
)
if self.activation is not None:
output = self.activation(output)
return output
def gram_matrix(x):
features = backend.batch_flatten(backend.permute_dimensions(x, (2, 0, 1)))
gram = backend.dot(features, backend.transpose(features))
return gram
def _interpolate(image, sampled_grids, output_size):
image = K.permute_dimensions(image, (0, 2, 3, 1))
batch_size = K.shape(image)[0]
height = K.shape(image)[1]
width = K.shape(image)[2]
num_channels = K.shape(image)[3]
x = K.cast(K.flatten(sampled_grids[:, 0:1, :]), dtype='float32')
y = K.cast(K.flatten(sampled_grids[:, 1:2, :]), dtype='float32')
x = .5 * (x + 1.0) * K.cast(width, dtype='float32')
y = .5 * (y + 1.0) * K.cast(height, dtype='float32')
x0 = K.cast(x, 'int32')
x1 = x0 + 1
y0 = K.cast(y, 'int32')
y1 = y0 + 1
max_x = int(K.int_shape(image)[2] - 1)
max_y = int(K.int_shape(image)[1] - 1)
x0 = K.clip(x0, 0, max_x)
x1 = K.clip(x1, 0, max_x)
y0 = K.clip(y0, 0, max_y)
y1 = K.clip(y1, 0, max_y)
pixels_batch = K.arange(0, batch_size) * (height * width)
pixels_batch = K.expand_dims(pixels_batch, axis=-1)
flat_output_size = output_size[0] * output_size[1]
base = K.repeat_elements(pixels_batch, flat_output_size, axis=1)
base = K.flatten(base)
# base_y0 = base + (y0 * width)
base_y0 = y0 * width
base_y0 = base + base_y0
# base_y1 = base + (y1 * width)
base_y1 = y1 * width
base_y1 = base_y1 + base
indices_a = base_y0 + x0
indices_b = base_y1 + x0
indices_c = base_y0 + x1
indices_d = base_y1 + x1
flat_image = K.reshape(image, shape=(-1, num_channels))
flat_image = K.cast(flat_image, dtype='float32')
pixel_values_a = K.gather(flat_image, indices_a)
pixel_values_b = K.gather(flat_image, indices_b)
pixel_values_c = K.gather(flat_image, indices_c)
pixel_values_d = K.gather(flat_image, indices_d)
x0 = K.cast(x0, 'float32')
x1 = K.cast(x1, 'float32')
y0 = K.cast(y0, 'float32')
y1 = K.cast(y1, 'float32')
area_a = K.expand_dims(((x1 - x) * (y1 - y)), 1)
area_b = K.expand_dims(((x1 - x) * (y - y0)), 1)
area_c = K.expand_dims(((x - x0) * (y1 - y)), 1)
area_d = K.expand_dims(((x - x0) * (y - y0)), 1)
values_a = area_a * pixel_values_a
values_b = area_b * pixel_values_b
values_c = area_c * pixel_values_c
values_d = area_d * pixel_values_d
return values_a + values_b + values_c + values_d
def stack_and_transpose(x):
# x is a list of length T, each element is a batch_size x output_vocab_size tensor
x = K.stack(x) # is now T x batch_size x output_vocab_size tensor
x = K.permute_dimensions(
x, pattern=(1, 0, 2)) # is now batch_size x T x output_vocab_size
return x
def NN_model(args, training=True):
global N_COL
global N_ROW
if args.model == 'densenet121':
from keras.applications.densenet import DenseNet121
input_tensor = Input(shape=(N_COL, N_ROW, 3))
base_model = DenseNet121(input_shape=(N_COL, N_ROW, 3),
include_top=False,
weights='imagenet',
input_tensor=input_tensor,
pooling=None)
elif args.model == 'resnet18':
import resnet
NOT_CARE = 1
base_model = resnet.ResnetBuilder.build_resnet_18(input_shape=(N_COL,
N_ROW,
3),
num_outputs=NOT_CARE,
include_top=False)
elif args.model == 'resnet18_2222':
import resnet
NOT_CARE = 1
base_model = resnet.ResnetBuilder.build_resnet_18_2222(
input_shape=(N_COL, N_ROW, 3),
num_outputs=NOT_CARE,
include_top=False)
elif args.model == 'resnet34':
import resnet
NOT_CARE = 1
base_model = resnet.ResnetBuilder.build_resnet_34(input_shape=(N_COL,
N_ROW,
3),
num_outputs=NOT_CARE,
include_top=False)
elif args.model == 'resnet50':
import resnet
NOT_CARE = 1
base_model = resnet.ResnetBuilder.build_resnet_50(input_shape=(N_COL,
N_ROW,
3),
num_outputs=NOT_CARE,
include_top=False)
elif args.model == 'resnet101':
import resnet
NOT_CARE = 1
base_model = resnet.ResnetBuilder.build_resnet_101(
input_shape=(N_COL, N_ROW, 3),
num_outputs=NOT_CARE,
include_top=False)
else:
raise TypeError('model should be in the list of the supported model!')
print('Input col: ', N_COL)
print('Input row: ', N_ROW)
x = base_model.output
#CNN to RNN
x = Lambda(lambda x: K.permute_dimensions(x, (0, 2, 1, 3)))(
x) # switchaxes from [b,h,w,c] to [b,w,h,c]
conv_shape = x.get_shape() # b, h,w,c resnet 18 -> (?, 16, 32, 256)
print('conv_shape', conv_shape)
x = Reshape(target_shape=(int(conv_shape[1]),
int(conv_shape[2] * conv_shape[3])),
name='reshape')(x)
x = Dense(para.dense_size,
activation='relu',
kernel_initializer='he_normal',
name='dense1')(x)
#x = BatchNormalization()(x)
# GRU RNN
gru_1 = GRU(para.rnn_size,
return_sequences=True,
init='he_normal',
name='gru1')(x)
gru_1b = GRU(para.rnn_size,
return_sequences=True,
go_backwards=True,
init='he_normal',
name='gru1_b')(x)
gru1_merged = add([gru_1, gru_1b])
gru1_merged = BatchNormalization()(gru1_merged)
gru_2 = GRU(para.rnn_size,
return_sequences=True,
init='he_normal',
name='gru2')(gru1_merged)
gru_2b = GRU(para.rnn_size,
return_sequences=True,
go_backwards=True,
init='he_normal',
name='gru2_b')(gru1_merged)
gru2_merged = concatenate([gru_2, gru_2b])
gru2_merged = BatchNormalization()(gru2_merged)
inner = Dense(para.num_classes,
kernel_initializer='he_normal',
name='dense2')(gru2_merged)
y_pred = Activation('softmax', name='softmax')(inner)
labels = Input(name='the_labels',
shape=[para.max_text_len],
dtype='float32') # (None ,7)
input_length = Input(name='input_length', shape=[1],
dtype='int64') # (None, 1)
label_length = Input(name='label_length', shape=[1],
dtype='int64') # (None, 1)
# Keras doesn't currently support loss funcs with extra parameters
# so CTC loss is implemented in a lambda layer
loss_out = Lambda(ctc_lambda_func, output_shape=(1, ),
name='ctc')([y_pred, labels, input_length,
label_length]) #(None, 1)
if training:
return Model(
inputs=[base_model.input, labels, input_length, label_length],
outputs=loss_out), conv_shape[1]
else:
return Model(inputs=[base_model.input], outputs=y_pred)
def merge_heads(x):
new_x = K.permute_dimensions(x, [0, 2, 1, 3])
x_shape = shape_list(new_x)
new_x_shape = x_shape[:-2] + [np.prod(x_shape[-2:])]
return K.reshape(new_x, new_x_shape)
def split_heads(x, n: int, k: bool = False): # B, L, C
x_shape = shape_list(x)
m = x_shape[-1]
new_x_shape = x_shape[:-1] + [n, m // n]
new_x = K.reshape(x, new_x_shape)
return K.permute_dimensions(new_x, [0, 2, 3, 1] if k else [0, 2, 1, 3])
def correlation_layer(x):
lbranch, rbranch = squeeze(x[0], 1), squeeze(x[1], 1)
rbranch = permute_dimensions(rbranch, (0, 2, 1))
out_tensor = squeeze(batch_dot(lbranch, rbranch), 1)
return out_tensor
def _call(self, features, edges):
return K.batch_dot(K.permute_dimensions(edges, (0, 2, 1)), features) \
/ (K.sum(edges, axis=2, keepdims=True) + K.epsilon())
def gram_matrix(x):
features = K.batch_flatten(K.permute_dimensions(x, (2, 0, 1)))
gram = K.dot(features, K.transpose(features))
return gram
def attention(self,
pre_q,
pre_v,
pre_k,
out_seq_len: int,
d_model: int,
training=None):
"""
Calculates the output of the attention once the affine transformations
of the inputs are done. Here's the shapes of the arguments:
:param pre_q: (batch_size, q_seq_len, num_heads, d_model // num_heads)
:param pre_v: (batch_size, v_seq_len, num_heads, d_model // num_heads)
:param pre_k: (batch_size, k_seq_len, num_heads, d_model // num_heads)
:param out_seq_len: the length of the output sequence
:param d_model: dimensionality of the model (by the paper)
:param training: Passed by Keras. Should not be defined manually.
Optional scalar tensor indicating if we're in training
or inference phase.
"""
# shaping Q and V into (batch_size, num_heads, seq_len, d_model//heads)
q = K.permute_dimensions(pre_q, [0, 2, 1, 3])
v = K.permute_dimensions(pre_v, [0, 2, 1, 3])
if self.compression_window_size is None:
k_transposed = K.permute_dimensions(pre_k, [0, 2, 3, 1])
else:
# Memory-compressed attention described in paper
# "Generating Wikipedia by Summarizing Long Sequences"
# (https://arxiv.org/pdf/1801.10198.pdf)
# It compresses keys and values using 1D-convolution which reduces
# the size of Q * K_transposed from roughly seq_len^2
# to convoluted_seq_len^2. If we use strided convolution with
# window size = 3 and stride = 3, memory requirements of such
# memory-compressed attention will be 9 times smaller than
# that of the original version.
if self.use_masking:
raise NotImplementedError(
"Masked memory-compressed attention has not "
"been implemented yet")
k = K.permute_dimensions(pre_k, [0, 2, 1, 3])
k, v = [
K.reshape(
# Step 3: Return the result to its original dimensions
# (batch_size, num_heads, seq_len, d_model//heads)
K.bias_add(
# Step 3: ... and add bias
K.conv1d(
# Step 2: we "compress" K and V using strided conv
K.reshape(
# Step 1: we reshape K and V to
# (batch + num_heads, seq_len, d_model//heads)
item,
(-1, K.int_shape(item)[-2],
d_model // self.num_heads)),
kernel,
strides=self.compression_window_size,
padding='valid',
data_format='channels_last'),
bias,
data_format='channels_last'),
# new shape
K.concatenate(
[K.shape(item)[:2], [-1, d_model // self.num_heads]]))
for item, kernel, bias in ((k, self.k_conv_kernel,
self.k_conv_bias),
(v, self.v_conv_kernel,
self.v_conv_bias))
]
k_transposed = K.permute_dimensions(k, [0, 1, 3, 2])
# shaping K into (batch_size, num_heads, d_model//heads, seq_len)
# for further matrix multiplication
sqrt_d = K.constant(np.sqrt(d_model // self.num_heads),
dtype=K.floatx())
q_shape = K.int_shape(q)
k_t_shape = K.int_shape(k_transposed)
v_shape = K.int_shape(v)
# before performing batch_dot all tensors are being converted to 3D
# shape (batch_size * num_heads, rows, cols) to make sure batch_dot
# performs identically on all backends
attention_heads = K.reshape(
K.batch_dot(
self.apply_dropout_if_needed(K.softmax(
self.mask_attention_if_needed(
K.batch_dot(
K.reshape(q, (-1, ) + q_shape[-2:]),
K.reshape(k_transposed,
(-1, ) + k_t_shape[-2:])) / sqrt_d)),
training=training),
K.reshape(v, (-1, ) + v_shape[-2:])),
(-1, self.num_heads, q_shape[-2], v_shape[-1]))
attention_heads_merged = K.reshape(
K.permute_dimensions(attention_heads, [0, 2, 1, 3]), (-1, d_model))
attention_out = K.reshape(
K.dot(attention_heads_merged, self.output_weights),
(-1, out_seq_len, d_model))
return attention_out
def get_gru_baseline(self):
lstm_qo = GRU(100, return_sequences=False)
get_diag = Lambda(
lambda xin: K.sum(xin * T.eye(self.max_opt_count), axis=2),
output_shape=(self.max_opt_count, ))
transp_out = Lambda(lambda xin: K.permute_dimensions(xin, (0, 2, 1)),
output_shape=(self.max_opt_count, 100))
apply_weights = Lambda(lambda xin: (K.expand_dims(xin[
0], axis=-1) * K.expand_dims(xin[1], axis=2)).sum(axis=1),
output_shape=(100, self.max_opt_count))
tile_q = Lambda(lambda xin: K.tile(xin, (1, self.max_opt_count, 1, 1)),
output_shape=(self.max_opt_count, self.max_q_length,
self.word_vec_size))
exp_dims = Lambda(lambda xin: K.expand_dims(xin, 1),
output_shape=(1, self.max_q_length,
self.word_vec_size))
exp_layer = Lambda(lambda xin: K.exp(xin),
output_shape=(self.max_sent_para,
self.max_opt_count))
mask_weights = Lambda(lambda xin: T.switch(T.eq(xin, 0), np.NINF, xin),
output_shape=(self.max_sent_para,
self.max_opt_count))
final_weights = Lambda(lambda xin: xin / K.cast(
K.sum(xin, axis=1, keepdims=True), K.floatx()),
output_shape=(self.max_sent_para,
self.max_opt_count))
q_input = Input(shape=(self.max_q_length, self.word_vec_size),
name='question_input')
q_exp = exp_dims(q_input)
q_rep = tile_q(q_exp)
option_input = Input(shape=(self.max_opt_count, self.max_option_length,
self.word_vec_size),
name='option_input')
opt_q = Concatenate(axis=2)([q_rep, option_input])
lstm_input = Input(shape=(None, self.word_vec_size), name='lstm_input')
lstm_mask = Masking(mask_value=0.)(lstm_input)
lstm_out = lstm_qo(lstm_mask)
lstm_model = Model(inputs=lstm_input, outputs=lstm_out)
lstm_td_opt = TimeDistributed(lstm_model)(opt_q)
doc_input = Input(shape=(self.max_sent_para, self.max_words_sent,
self.word_vec_size),
name='doc_input')
lstm_doc = TimeDistributed(lstm_model)(doc_input)
att_wts = Dot(axes=2, normalize=True)([lstm_doc, lstm_td_opt])
att_wts = mask_weights(att_wts)
att_wts = exp_layer(att_wts)
att_wts = final_weights(att_wts)
out = apply_weights([lstm_doc, att_wts])
out = transp_out(out)
dp = Dot(axes=2, normalize=True)([out, lstm_td_opt])
out = get_diag(dp)
probs = MaskedSoftmax()([out, option_input])
main_model = Model(inputs=[q_input, doc_input, option_input],
outputs=probs)
sgd = SGD(lr=0.1, decay=0., momentum=0., nesterov=False)
main_model.compile(loss='categorical_crossentropy',
optimizer=sgd,
metrics=['accuracy'])
main_model.summary()
return main_model
conv_4 = Conv1D(300,
4,
padding='same',
activation='relu',
strides=1)(input)
shared = Model(input, conv_4)
input_1 = Input(shape=(None, 300), dtype='float32')
input_2 = Input(shape=(None, 300), dtype='float32')
out_1 = shared(input_1)
out_2 = shared(input_2)
attention = AttentionLayer()([out_1,out_2])
# out_1 column wise
att_1 = GlobalMaxPooling1D()(attention)
att_1 = Activation('softmax')(att_1)
out_1 = dot([att_1, out_1], axes=1)
# out_2 row wise
attention_transposed = Lambda(lambda x: K.permute_dimensions(x, (0,2,1)))(attention)
att_2 = GlobalMaxPooling1D()(attention_transposed)
att_2 = Activation('softmax')(att_2)
out_2 = dot([att_2, out_2], axes=1)
distance = Lambda(euclidean_distance,
output_shape=eucl_dist_output_shape)([out_1, out_2])
model = Model(input=[input_1, input_2], output=distance)
def call(self, inputs):
num_axis = K.ndim(inputs)
inputs = K.permute_dimensions(inputs, range(num_axis)[::-1])
x_outs = K.gather(inputs, self.idxs)
x_outs = K.permute_dimensions(x_outs, range(num_axis)[::-1])
return x_outs
def _call(self, inputs, **kwargs):
if self.proto_number == self.capsule_number:
return inputs
else:
signals = inputs[0]
diss = inputs[1]
signal_shape = mixed_shape(signals)
if self.use_for_loop:
diss_stack = []
signals_stack = []
sub_idx = None
with K.name_scope('for_loop'):
for p in self._proto_distrib:
with K.name_scope('compute_slices'):
diss_ = diss[:, p[0]:(p[-1] + 1)]
signals_ = K.reshape(
signals[:, p[0]:(p[-1] + 1), :],
[signal_shape[0] * len(p)] +
list(signal_shape[2:]))
with K.name_scope('competition'):
if len(p) > 1:
with K.name_scope('competition_indices'):
argmin_idx = K.argmin(diss_, axis=-1)
if sub_idx is None:
sub_idx = K.arange(
0,
signal_shape[0],
dtype=argmin_idx.dtype)
argmin_idx = argmin_idx + len(p) * sub_idx
with K.name_scope('dissimilarity_competition'):
diss_stack.append(
K.expand_dims(
K.gather(K.flatten(diss_),
argmin_idx), -1))
with K.name_scope('signal_competition'):
signals_stack.append(
K.gather(signals_, argmin_idx))
else:
diss_stack.append(diss_)
signals_stack.append(signals_)
diss = K.concatenate(diss_stack, 1)
with K.name_scope('signal_concatenation'):
signals = K.concatenate(signals_stack, 1)
signals = K.reshape(
signals, [signal_shape[0], self.capsule_number] +
list(signal_shape[2:]))
else:
with K.name_scope('dissimilarity_preprocessing'):
# extend if it is not equally distributed
if not self._equally_distributed:
# permute to first dimension is prototype (protos x batch)
diss = K.permute_dimensions(diss, [1, 0])
# gather regarding extension (preparing for reshape to block)
diss = K.gather(diss, self._proto_extension)
# permute back (max_proto_number x (max_proto_number * batch))
diss = K.permute_dimensions(diss, [1, 0])
# reshape to block form
diss = K.reshape(diss, [
signal_shape[0] * self.capsule_number,
self._max_proto_number_in_capsule
])
with K.name_scope('competition_indices'):
# get minimal idx in each class and batch for element selection in diss and signals
argmin_idx = K.argmin(diss, axis=-1)
argmin_idx = argmin_idx + self._max_proto_number_in_capsule * \
K.arange(0, signal_shape[0] * self.capsule_number, dtype=argmin_idx.dtype)
with K.name_scope('dissimilarity_competition'):
# get minimal values in the form (batch x capsule)
diss = K.gather(K.flatten(diss), argmin_idx)
diss = K.reshape(diss,
[signal_shape[0], self.capsule_number])
with K.name_scope('signal_preprocessing'):
# apply the same steps as above for signals
# get signals in: (batch x protos x dim1 x ... x dimN) --> out: (batch x capsule x dim1 x ... x dimN)
# extend if is not equally distributed
if not self._equally_distributed:
signals = K.permute_dimensions(
signals,
[1, 0] + list(range(2, len(signal_shape))))
signals = K.gather(signals, self._proto_extension)
signals = K.permute_dimensions(
signals,
[1, 0] + list(range(2, len(signal_shape))))
signals = K.reshape(signals, [
signal_shape[0] * self.capsule_number *
self._max_proto_number_in_capsule
] + list(signal_shape[2:]))
with K.name_scope('signal_competition'):
signals = K.gather(signals, argmin_idx)
signals = K.reshape(
signals, [signal_shape[0], self.capsule_number] +
list(signal_shape[2:]))
return {0: signals, 1: diss}
def integrate_vec(vec, time_dep=False, method='ss', **kwargs):
"""
Integrate (stationary of time-dependent) vector field (N-D Tensor) in tensorflow
Aside from directly using tensorflow's numerical integration odeint(), also implements
"scaling and squaring", and quadrature. Note that the diff. equation given to odeint
is the one used in quadrature.
Parameters:
vec: the Tensor field to integrate.
If vol_size is the size of the intrinsic volume, and vol_ndim = len(vol_size),
then vector shape (vec_shape) should be
[vol_size, vol_ndim] (if stationary)
[vol_size, vol_ndim, nb_time_steps] (if time dependent)
time_dep: bool whether vector is time dependent
method: 'scaling_and_squaring' or 'ss' or 'ode' or 'quadrature'
if using 'scaling_and_squaring': currently only supports integrating to time point 1.
nb_steps: int number of steps. Note that this means the vec field gets broken
down to 2**nb_steps. so nb_steps of 0 means integral = vec.
if using 'ode':
out_time_pt (optional): a time point or list of time points at which to evaluate
Default: 1
init (optional): if using 'ode', the initialization method.
Currently only supporting 'zero'. Default: 'zero'
ode_args (optional): dictionary of all other parameters for
tf.contrib.integrate.odeint()
Returns:
int_vec: integral of vector field.
Same shape as the input if method is 'scaling_and_squaring', 'ss', 'quadrature',
or 'ode' with out_time_pt not a list. Will have shape [*vec_shape, len(out_time_pt)]
if method is 'ode' with out_time_pt being a list.
Todo:
quadrature for more than just intrinsically out_time_pt = 1
"""
if method not in ['ss', 'scaling_and_squaring', 'ode', 'quadrature']:
raise ValueError(
"method has to be 'scaling_and_squaring' or 'ode'. found: %s" %
method)
if method in ['ss', 'scaling_and_squaring']:
nb_steps = kwargs['nb_steps']
assert nb_steps >= 0, 'nb_steps should be >= 0, found: %d' % nb_steps
if time_dep:
svec = K.permute_dimensions(vec,
[-1, *range(0, vec.shape[-1] - 1)])
assert 2**nb_steps == svec.shape[
0], "2**nb_steps and vector shape don't match"
svec = svec / (2**nb_steps)
for _ in range(nb_steps):
svec = svec[0::2] + tf.map_fn(transform, svec[1::2, :],
svec[0::2, :])
disp = svec[0, :]
else:
vec = vec / (2**nb_steps)
for _ in range(nb_steps):
vec += transform(vec, vec)
disp = vec
elif method == 'quadrature':
# TODO: could output more than a single timepoint!
nb_steps = kwargs['nb_steps']
assert nb_steps >= 1, 'nb_steps should be >= 1, found: %d' % nb_steps
vec = vec / nb_steps
if time_dep:
disp = vec[..., 0]
for si in range(nb_steps - 1):
disp += transform(vec[..., si + 1], disp)
else:
disp = vec
for _ in range(nb_steps - 1):
disp += transform(vec, disp)
else:
assert not time_dep, "odeint not implemented with time-dependent vector field"
fn = lambda disp, _: transform(vec, disp)
# process time point.
out_time_pt = kwargs['out_time_pt'] if 'out_time_pt' in kwargs.keys(
) else 1
single_out_time_pt = not isinstance(out_time_pt, (list, tuple))
if single_out_time_pt: out_time_pt = [out_time_pt]
K_out_time_pt = K.variable([0, *out_time_pt])
# process initialization
if 'init' not in kwargs.keys() or kwargs['init'] == 'zero':
disp0 = vec * 0
else:
raise ValueError('non-zero init for ode method not implemented')
# compute integration with tf.contrib.integrate.odeint
if 'ode_args' not in kwargs.keys(): kwargs['ode_args'] = {}
disp = tf.contrib.integrate.odeint(fn, disp0, K_out_time_pt,
**kwargs['ode_args'])
disp = K.permute_dimensions(disp[1:len(out_time_pt) + 1, :],
[*range(1, len(disp.shape)), 0])
# return
if single_out_time_pt:
disp = disp[..., 0]
return disp
def get_cnn_model2(self):
get_diag = Lambda(
lambda xin: K.sum(xin * T.eye(self.max_opt_count), axis=2),
output_shape=(self.max_opt_count, ))
transp_out = Lambda(lambda xin: K.permute_dimensions(xin, (0, 2, 1)),
output_shape=(self.max_opt_count,
self.word_vec_size))
apply_weights = Lambda(lambda xin: (K.expand_dims(xin[
0], axis=-1) * K.expand_dims(xin[1], axis=2)).sum(axis=1),
output_shape=(self.word_vec_size,
self.max_opt_count))
tile_q = Lambda(lambda xin: K.tile(xin, (1, self.max_opt_count, 1, 1)),
output_shape=(self.max_opt_count, self.max_q_length,
self.word_vec_size))
exp_dims = Lambda(lambda xin: K.expand_dims(xin, 1),
output_shape=(1, self.max_q_length,
self.word_vec_size))
exp_dims2 = Lambda(lambda xin: K.expand_dims(xin, 3),
output_shape=(None, self.word_vec_size, 1))
exp_layer = Lambda(lambda xin: K.exp(xin),
output_shape=(self.max_sent_para,
self.max_opt_count))
final_weights = Lambda(lambda xin: xin / K.cast(
K.sum(xin, axis=1, keepdims=True), K.floatx()),
output_shape=(self.max_sent_para,
self.max_opt_count))
mask_weights = Lambda(lambda xin: T.switch(T.eq(xin, 0), np.NINF, xin),
output_shape=(self.max_sent_para,
self.max_opt_count))
glob_pool = Lambda(lambda xin: K.mean(xin, axis=[1, 2]),
output_shape=(100, ))
filter_sizes = [2, 3, 4]
num_filters = 100
q_input = Input(shape=(self.max_q_length, self.word_vec_size),
name='question_input')
q_exp = exp_dims(q_input)
q_rep = tile_q(q_exp)
option_input = Input(shape=(self.max_opt_count, self.max_option_length,
self.word_vec_size),
name='option_input')
opt_q = Concatenate(axis=2)([q_rep, option_input])
cnn_input = Input(shape=(None, self.word_vec_size), name='cnn_input')
cnn_reshape = exp_dims2(cnn_input)
conv_0 = Conv2D(num_filters,
kernel_size=(filter_sizes[0], self.word_vec_size),
padding='valid',
kernel_initializer='normal',
activation='linear')(cnn_reshape)
conv_1 = Conv2D(num_filters,
kernel_size=(filter_sizes[1], self.word_vec_size),
padding='valid',
kernel_initializer='normal',
activation='linear')(cnn_reshape)
conv_2 = Conv2D(num_filters,
kernel_size=(filter_sizes[2], self.word_vec_size),
padding='valid',
kernel_initializer='normal',
activation='linear')(cnn_reshape)
meanpool_0 = glob_pool(conv_0)
meanpool_1 = glob_pool(conv_1)
meanpool_2 = glob_pool(conv_2)
concatenated_tensor = Concatenate(axis=1)(
[meanpool_0, meanpool_1, meanpool_2])
cnn_model = Model(inputs=cnn_input, outputs=concatenated_tensor)
cnn_td_opt = TimeDistributed(cnn_model)(opt_q)
doc_input = Input(shape=(self.max_sent_para, self.max_words_sent,
self.word_vec_size),
name='doc_input')
cnn_doc = TimeDistributed(cnn_model)(doc_input)
att_wts = Dot(axes=2, normalize=True)([cnn_doc, cnn_td_opt])
att_wts = mask_weights(att_wts)
att_wts = exp_layer(att_wts)
att_wts = final_weights(att_wts)
out = apply_weights([cnn_doc, att_wts])
out = transp_out(out)
dp = Dot(axes=2, normalize=True)([out, cnn_td_opt])
out = get_diag(dp)
probs = MaskedSoftmax()([out, option_input])
main_model = Model(inputs=[q_input, doc_input, option_input],
outputs=probs)
sgd = SGD(lr=0.1, decay=0., momentum=0., nesterov=False)
main_model.compile(loss='categorical_crossentropy',
optimizer=sgd,
metrics=['accuracy'])
main_model.summary()
return main_model
def ext_start(inputs):
m = inputs[0]
s = inputs[1]
w = K.one_hot(s[:, 0] + l_s * s[:, 1], l_s * l_s) # (None, l_s * l_s)
return K.transpose(
K.sum(w * K.permute_dimensions(m, (1, 0, 2)), axis=2))
def T(x):
return K.permute_dimensions(x, [0, 2, 1])
def call(self, x, mask=None):
mask = K.cast(mask, 'float32')
mask = K.repeat(mask, self.repeat_dim)
mask = K.permute_dimensions(mask, (0, 2, 1))
return x * mask
def _call(self, inputs, **kwargs):
if self.proto_number == self.capsule_number:
return inputs
else:
signals = inputs[0]
diss = inputs[1]
signal_shape = None
# signal.shape: (batch, proto_num, caps_dim1, ..., caps_dimN)
if self.input_spec[0].ndim > 3:
signal_shape = mixed_shape(signals)
signals = K.reshape(signals, signal_shape[0:2] + (-1, ))
if not self._equally_distributed:
if self.use_for_loop:
signals_stack = []
diss_stack = []
with K.name_scope('for_loop'):
for i, p in enumerate(self._proto_distrib):
with K.name_scope('compute_slices'):
diss_ = diss[:, p[0]:(p[-1] + 1)]
signals_ = signals[:, p[0]:(p[-1] + 1), :]
if len(p) > 1:
with K.name_scope('competition_probabilities'):
coefficients = prob_trans.neg_softmax(
diss_ * self.beta[i],
axis=-1,
max_stabilization=True)
with K.name_scope('signal_competition'):
signals_stack.append(
K.expand_dims(
K.batch_dot(
coefficients, signals_,
[1, 1]), 1))
with K.name_scope('dissimilarity_competition'):
diss_stack.append(
K.batch_dot(coefficients, diss_,
[1, 1]))
else:
signals_stack.append(signals_)
diss_stack.append(diss_)
signals = K.concatenate(signals_stack, axis=1)
diss = K.concatenate(diss_stack, axis=-1)
else:
extension_idx = []
for i in self._proto_extension:
if i not in extension_idx:
extension_idx.append(i)
else:
extension_idx.append(
max(self._proto_extension) + 1)
batch_size = K.shape(
signals
)[0] if signal_shape is None else signal_shape[0]
# reshape to block
with K.name_scope('competition_probabilities'):
with K.name_scope('neg_softmax'):
with K.name_scope('coefficients'):
beta = K.gather(self.beta,
self._capsule_extension)
coefficients = -diss * beta
# max stabilization
coefficients = coefficients - K.max(
coefficients, axis=-1, keepdims=True)
coefficients = K.exp(coefficients)
coefficients = K.concatenate([
coefficients,
K.zeros_like(coefficients[:, 0:1])
],
axis=-1)
coefficients = K.transpose(coefficients)
coefficients = K.gather(
coefficients, extension_idx)
coefficients = K.transpose(coefficients)
coefficients = K.reshape(
coefficients, [
batch_size, self.capsule_number,
self._max_proto_number_in_capsule
])
# could never be a zero division
with K.name_scope('normalization_constant'):
constant = K.sum(coefficients,
axis=-1,
keepdims=True)
probs = coefficients / constant
with K.name_scope('dissimilarity_preprocessing'):
diss = K.transpose(diss)
diss = K.gather(diss, self._proto_extension)
diss = K.transpose(diss)
diss = K.reshape(diss, [
batch_size, self.capsule_number,
self._max_proto_number_in_capsule
])
with K.name_scope('dissimilarity_competition'):
diss = K.squeeze(
K.batch_dot(probs, K.expand_dims(diss), [2, 2]),
-1)
with K.name_scope('signal_preprocessing'):
signals = K.permute_dimensions(signals, [1, 0, 2])
signals = K.gather(signals, self._proto_extension)
signals = K.permute_dimensions(signals, [1, 0, 2])
signals = K.reshape(signals, [
batch_size, self.capsule_number,
self._max_proto_number_in_capsule, -1
])
with K.name_scope('signal_competition'):
signals = K.batch_dot(probs, signals, [2, 2])
else:
batch_size = K.shape(
signals)[0] if signal_shape is None else signal_shape[0]
diss = K.reshape(diss, [
batch_size, self.capsule_number,
self._max_proto_number_in_capsule
])
with K.name_scope('competition_probabilities'):
coefficients = prob_trans.neg_softmax(
diss * K.expand_dims(self.beta, -1),
axis=-1,
max_stabilization=True)
with K.name_scope('signal_competition'):
signals = K.reshape(signals, [
batch_size, self.capsule_number,
self._max_proto_number_in_capsule, -1
])
signals = K.batch_dot(coefficients, signals, [2, 2])
with K.name_scope('dissimilarity_competition'):
diss = K.squeeze(
K.batch_dot(coefficients, K.expand_dims(diss), [2, 2]),
-1)
if self.input_spec[0].ndim > 3:
signals = K.reshape(signals,
[signal_shape[0], self.capsule_number] +
list(signal_shape[2:]))
return {0: signals, 1: diss}
def call(self, inputs, mask=None, training=None):
(inputs, content, memories, segment_mat, segment_embed, relatives,
bias_context, bias_relative, bias_segment, permutation) = inputs
full = K.concatenate([memories, content],
axis=1) # (batch, prev_len + seq_len, units)
kernel_q = self.kernel[:, :self.units]
kernel_kv = self.kernel[:, self.units:self.units * 3]
kernel_r = self.kernel[:, self.units * 3:self.units * 4]
kernel_o = self.kernel[:, self.units * 4:self.units * 5]
bias_q, bias_kv, bias_r, bias_o = (None, ) * 4
if self.use_bias:
bias_q = self.bias[:self.units]
bias_kv = self.bias[self.units:self.units * 3]
bias_r = self.bias[self.units * 3:self.units * 4]
bias_o = self.bias[self.units * 4:self.units * 5]
w_q = K.dot(inputs, kernel_q) # (batch, seq_len, units)
w_kv = K.dot(full, kernel_kv) # (batch, prev_len + seq_len, units * 2)
w_r = K.dot(relatives, kernel_r) # (batch, prev_len + seq_len, units)
if self.use_bias:
w_q = K.bias_add(w_q, bias_q)
w_kv = K.bias_add(w_kv, bias_kv)
w_r = K.bias_add(w_r, bias_r)
if self.activation is not None:
w_q = self.activation(w_q)
w_kv = self.activation(w_kv)
w_r = self.activation(w_r)
w_k = w_kv[:, :, :self.units] # (batch, prev_len + seq_len, units)
w_v = w_kv[:, :, self.units:] # (batch, prev_len + seq_len, units)
batch_size, q_len, k_len = K.shape(inputs)[0], K.shape(
w_q)[1], K.shape(w_k)[1]
w_qc = K.bias_add(w_q, bias_context)
w_qc = self._reshape_to_batches(
w_qc) # (batch * n_head, seq_len, units_head)
w_k = self._reshape_to_batches(
w_k) # (batch * n_head, prev_len + seq_len, units_head)
a_context = K.batch_dot(
w_qc, w_k, axes=2) # (batch * n_head, seq_len, prev_len + seq_len)
w_qr = K.bias_add(w_q, bias_relative)
w_qr = self._reshape_to_batches(
w_qr) # (batch * n_head, seq_len, units_head)
w_r = self._reshape_to_batches(
w_r) # (batch * n_head, prev_len + seq_len, units_head)
a_relative = K.batch_dot(
w_qr, w_r, axes=2) # (batch * n_head, seq_len, prev_len + seq_len)
a_relative = self._relative_shift( # (batch * n_head, seq_len, prev_len + seq_len)
a_relative,
key_len_expected=K.shape(a_context)[-1],
)
w_qs = K.bias_add(w_q, bias_segment)
w_qs = K.reshape(w_qs, (-1, q_len, self.num_head, self.units_head))
w_qs = K.permute_dimensions(
w_qs, (2, 0, 1, 3)) # (n_head, batch, seq_len, units_head)
segment_embed = K.reshape(K.transpose(segment_embed),
(self.num_head, 1, self.units_head, 2))
segment_embed = K.tile(segment_embed, (1, batch_size, 1, 1))
w_qs = K.reshape(w_qs, (-1, q_len, self.units_head))
segment_embed = K.reshape(segment_embed, (-1, self.units_head, 2))
a_segment = K.batch_dot(w_qs, segment_embed,
axes=(2, 1)) # (n_head * batch, seq_len, 2)
a_segment = K.reshape(a_segment, (self.num_head, batch_size, q_len, 2))
a_segment = K.permute_dimensions(
a_segment, (1, 2, 3, 0)) # (batch, seq_len, 2, n_head)
segment_mat = K.reshape(
segment_mat,
(-1, k_len, 2)) # (batch * seq_len, prev_len + seq_len, 2)
a_segment = K.reshape(
a_segment, (-1, 2, self.num_head)) # (batch * seq_len, 2, n_head)
a_segment = K.batch_dot(
segment_mat, a_segment,
axes=(2, 1)) # (batch * seq_len, prev_len + seq_len, n_head)
a_segment = K.reshape(a_segment, (-1, q_len, k_len, self.num_head))
a_segment = K.reshape(K.permute_dimensions(a_segment, (0, 3, 1, 2)),
(-1, q_len, k_len))
att = (a_context + a_relative + a_segment) / K.sqrt(
K.constant(self.units_head, dtype=K.floatx()))
exp = K.exp(att - K.max(att, axis=-1, keepdims=True))
permutation = K.tile(K.expand_dims(permutation, axis=1),
[1, self.num_head, 1, 1])
permutation = K.reshape(permutation, (-1, q_len, k_len))
exp *= permutation
if mask is not None and mask[0] is not None:
mask = K.cast(mask[0], K.floatx())
mask = K.concatenate([K.ones_like(memories[:, :, 0]), mask],
axis=1)
exp *= K.expand_dims(self._reshape_mask(mask), axis=1)
att = exp / (K.sum(exp, axis=-1, keepdims=True) + K.epsilon())
if self.att_drop_layer is not None:
att = self.att_drop_layer(att, training=training)
w_v = self._reshape_to_batches(
w_v) # (batch * n_head, prev_len + seq_len, units_head)
w_o = K.batch_dot(att, w_v) # (batch * n_head, seq_len, units_head)
w_o = self._reshape_from_batches(w_o) # (batch, seq_len, units)
w_o = K.dot(w_o, kernel_o) # (batch, seq_len, units)
if self.use_bias:
w_o = K.bias_add(w_o, bias_o)
if self.activation is not None:
w_o = self.activation(w_o)
if TF_KERAS:
# Add shape information to tensor when using `tf.keras`
input_shape = K.int_shape(inputs)
if input_shape[1] is not None:
w_o = K.reshape(w_o, (-1, ) + input_shape[1:])
return w_o
def transpose_3tensor(t):
'''
Lambda function to switch dimensions of input in order to properly
take the dot product and return the necessary relationships
'''
return K.permute_dimensions(t, (0, 2, 1))
from keras.datasets import mnist
(x_train, y_train), (x_test, y_test) = mnist.load_data()
x_train, x_test = x_train / 255., x_test / 255.
print('X_train shape: {}'.format(x_train.shape))
print('X_test shape: {}'.format(x_test.shape))
print('y_train shape: {}'.format(y_train.shape))
print('y_test shape: {}'.format(y_test.shape))
D = 28
M = 15
inputs = Input(shape=(D, D))
x1 = Bidirectional(LSTM(M, return_sequences=True))(inputs)
x1 = GlobalMaxPooling1D()(x1)
permutor = Lambda(lambda t: K.permute_dimensions(t, pattern=(0, 2, 1)))
x2 = permutor(inputs)
x2 = Bidirectional(LSTM(M, return_sequences=True))(x2)
x2 = GlobalMaxPooling1D()(x2)
x = Concatenate(axis=1)([x1, x2])
outputs = Dense(10, activation='softmax')(x)
model = Model(inputs=inputs, outputs=outputs)
model.compile(optimizer='Adam',
loss='sparse_categorical_crossentropy',
metrics=['accuracy'])
print(model.summary())
history = model.fit(x_train,
y_train,
batch_size=256,
epochs=5,