def gram_matrix(input_tensor):
assert K.ndim(input_tensor) == 3
features = K.batch_flatten(K.permute_dimensions(input_tensor, (2, 0, 1)))
gram = K.dot(features, K.transpose(features))
return gram
def call(self, x, mask=None):
# TODO: validate input shape
assert (len(x) == 3)
L_flat = x[0]
mu = x[1]
a = x[2]
if self.mode == 'full':
# Create L and L^T matrix, which we use to construct the positive-definite matrix P.
L = None
LT = None
if K.backend() == 'theano':
import theano.tensor as T
import theano
def fn(x, L_acc, LT_acc):
x_ = K.zeros((self.nb_actions, self.nb_actions))
x_ = T.set_subtensor(x_[np.tril_indices(self.nb_actions)], x)
diag = K.exp(T.diag(x_)) + K.epsilon()
x_ = T.set_subtensor(x_[np.diag_indices(self.nb_actions)], diag)
return x_, x_.T
outputs_info = [
K.zeros((self.nb_actions, self.nb_actions)),
K.zeros((self.nb_actions, self.nb_actions)),
]
results, _ = theano.scan(fn=fn, sequences=L_flat, outputs_info=outputs_info)
L, LT = results
elif K.backend() == 'tensorflow':
import tensorflow as tf
# Number of elements in a triangular matrix.
nb_elems = (self.nb_actions * self.nb_actions + self.nb_actions) // 2
# Create mask for the diagonal elements in L_flat. This is used to exponentiate
# only the diagonal elements, which is done before gathering.
diag_indeces = [0]
for row in range(1, self.nb_actions):
diag_indeces.append(diag_indeces[-1] + (row + 1))
diag_mask = np.zeros(1 + nb_elems) # +1 for the leading zero
diag_mask[np.array(diag_indeces) + 1] = 1
diag_mask = K.variable(diag_mask)
# Add leading zero element to each element in the L_flat. We use this zero
# element when gathering L_flat into a lower triangular matrix L.
nb_rows = tf.shape(L_flat)[0]
zeros = tf.expand_dims(tf.tile(K.zeros((1,)), [nb_rows]), 1)
try:
# Old TF behavior.
L_flat = tf.concat(1, [zeros, L_flat])
except (TypeError, ValueError):
# New TF behavior
L_flat = tf.concat([zeros, L_flat], 1)
# Create mask that can be used to gather elements from L_flat and put them
# into a lower triangular matrix.
tril_mask = np.zeros((self.nb_actions, self.nb_actions), dtype='int32')
tril_mask[np.tril_indices(self.nb_actions)] = range(1, nb_elems + 1)
# Finally, process each element of the batch.
init = [
K.zeros((self.nb_actions, self.nb_actions)),
K.zeros((self.nb_actions, self.nb_actions)),
]
def fn(a, x):
# Exponentiate everything. This is much easier than only exponentiating
# the diagonal elements, and, usually, the action space is relatively low.
x_ = K.exp(x) + K.epsilon()
# Only keep the diagonal elements.
x_ *= diag_mask
# Add the original, non-diagonal elements.
x_ += x * (1. - diag_mask)
# Finally, gather everything into a lower triangular matrix.
L_ = tf.gather(x_, tril_mask)
return [L_, tf.transpose(L_)]
tmp = tf.scan(fn, L_flat, initializer=init)
if isinstance(tmp, (list, tuple)):
# TensorFlow 0.10 now returns a tuple of tensors.
L, LT = tmp
else:
# Old TensorFlow < 0.10 returns a shared tensor.
L = tmp[:, 0, :, :]
LT = tmp[:, 1, :, :]
else:
raise RuntimeError('Unknown Keras backend "{}".'.format(K.backend()))
assert L is not None
assert LT is not None
P = K.batch_dot(L, LT)
elif self.mode == 'diag':
if K.backend() == 'theano':
import theano.tensor as T
import theano
def fn(x, P_acc):
x_ = K.zeros((self.nb_actions, self.nb_actions))
x_ = T.set_subtensor(x_[np.diag_indices(self.nb_actions)], x)
return x_
outputs_info = [
K.zeros((self.nb_actions, self.nb_actions)),
]
P, _ = theano.scan(fn=fn, sequences=L_flat, outputs_info=outputs_info)
elif K.backend() == 'tensorflow':
import tensorflow as tf
# Create mask that can be used to gather elements from L_flat and put them
# into a diagonal matrix.
diag_mask = np.zeros((self.nb_actions, self.nb_actions), dtype='int32')
diag_mask[np.diag_indices(self.nb_actions)] = range(1, self.nb_actions + 1)
# Add leading zero element to each element in the L_flat. We use this zero
# element when gathering L_flat into a lower triangular matrix L.
nb_rows = tf.shape(L_flat)[0]
zeros = tf.expand_dims(tf.tile(K.zeros((1,)), [nb_rows]), 1)
try:
# Old TF behavior.
L_flat = tf.concat(1, [zeros, L_flat])
except (TypeError, ValueError):
# New TF behavior
L_flat = tf.concat([zeros, L_flat], 1)
# Finally, process each element of the batch.
def fn(a, x):
x_ = tf.gather(x, diag_mask)
return x_
P = tf.scan(fn, L_flat, initializer=K.zeros((self.nb_actions, self.nb_actions)))
else:
raise RuntimeError('Unknown Keras backend "{}".'.format(K.backend()))
assert P is not None
assert K.ndim(P) == 3
# Combine a, mu and P into a scalar (over the batches). What we compute here is
# -.5 * (a - mu)^T * P * (a - mu), where * denotes the dot-product. Unfortunately
# TensorFlow handles vector * P slightly suboptimal, hence we convert the vectors to
# 1xd/dx1 matrices and finally flatten the resulting 1x1 matrix into a scalar. All
# operations happen over the batch size, which is dimension 0.
prod = K.batch_dot(K.expand_dims(a - mu, 1), P)
prod = K.batch_dot(prod, K.expand_dims(a - mu, -1))
A = -.5 * K.batch_flatten(prod)
assert K.ndim(A) == 2
return A
def complex_standardization(input_centred, Vrr, Vii, Vri, layernorm = False, axis = -1):
"""Complex Standardization of input
Arguments:
input_centred -- Input Tensor
Vrr -- Real component of covariance matrix V
Vii -- Imaginary component of covariance matrix V
Vri -- Non-diagonal component of covariance matrix V
Keyword Arguments:
layernorm {bool} -- Normalization (default: {False})
axis {int} -- Axis for Standardization (default: {-1})
Raises:
ValueError: Mismatched dimensoins
Returns:
Complex standardized input
We require the covariance matrix's inverse square root. That first
requires square rooting, followed by inversion (I do this in that order
because during the computation of square root we compute the determinant
we'll need for inversion as well).
The square root matrix could now be explicitly formed as
[ Vrr+s Vri ]
(1/t) [ Vir Vii+s ]
https://en.wikipedia.org/wiki/Square_root_of_a_2_by_2_matrix
but we don't need to do this immediately since we can also simultaneously
invert. We can do this because we've already computed the determinant of
the square root matrix, and can thus invert it using the analytical
solution for 2x2 matrices
[ A B ] [ D -B ]
inv( [ C D ] ) = (1/det) [ -C A ]
http://mathworld.wolfram.com/MatrixInverse.html
Thus giving us
[ Vii+s -Vri ]
(1/s)(1/t)[ -Vir Vrr+s ]
So we proceed as follows:
And we have computed the inverse square root matrix W = sqrt(V)!
Normalization. We multiply, x_normalized = W.x.
The returned result will be a complex standardized input
where the real and imaginary parts are obtained as follows:
x_real_normed = Wrr * x_real_centred + Wri * x_imag_centred
x_imag_normed = Wri * x_real_centred + Wii * x_imag_centred
Wrr * x_real_centered | Wii * x_imag_centered
+ Wri * x_imag_centered | Wri * x_real_centered
-----------------------------------------------
= output
"""
"""
[Batch_size, height, width, channels]
ndim(input_centred) == 4
shape(input_centred) == [2, 256, 32, 16] --> [2, 256, 32, 8] is real, [2, 256, 32, 8] is imag
shape(input_centred)[axis = -1] == 16
variances_broadcast는 채널의 갯수에 의존
"""
ndim = K.ndim(input_centred)
input_dim = K.shape(input_centred)[axis] // 2
variances_broadcast = [1] * ndim
variances_broadcast[axis] = input_dim
if layernorm:
variances_broadcast[0] = K.shape(input_centred)[0]
tau = Vrr + Vii
delta = (Vrr * Vii) - (Vri ** 2)
s = K.sqrt(delta)
t = K.sqrt(tau + 2 * s)
inverse_st = 1.0 / (s * t)
Wrr = (Vii + s) * inverse_st
Wii = (Vrr + s) * inverse_st
Wri = -Vri * inverse_st
broadcast_Wrr = K.reshape(Wrr, variances_broadcast)
broadcast_Wri = K.reshape(Wri, variances_broadcast)
broadcast_Wii = K.reshape(Wii, variances_broadcast)
cat_W_4_real = K.concatenate([broadcast_Wrr, broadcast_Wii], axis=axis)
cat_W_4_imag = K.concatenate([broadcast_Wri, broadcast_Wri], axis=axis)
'for Conv2D'
centred_real = input_centred[:, :, :, :input_dim]
centred_imag = input_centred[:, :, :, input_dim:]
rolled_input = K.concatenate([centred_imag, centred_real], axis=axis)
# wrr real + wri imag, wri real + wii imag
output = cat_W_4_real * input_centred + cat_W_4_imag * rolled_input
return output
def modal_dot(a, b, transpose_a=False, transpose_b=False):
"""
Computes the matrix multiplication of a and b, handling the data modes
automatically.
This is a wrapper to standard matmul operations, for a and b with rank 2
or 3, that:
- Supports automatic broadcasting of the "batch" dimension if the two inputs
have different ranks.
- Supports any combination of dense and sparse inputs.
This op is useful for multiplying matrices that represent batches of graphs
in the different modes, for which the adjacency matrices may or may not be
sparse and have different ranks from the node attributes.
Additionally, it can also support the case where we have many adjacency
matrices and only one graph signal (which is uncommon, but may still happen).
If you know a-priori the type and shape of the inputs, it may be faster to
use the built-in functions of TensorFlow directly instead.
Examples:
- `a` rank 2, `b` rank 2 -> `a @ b`
- `a` rank 3, `b` rank 3 -> `[a[i] @ b[i] for i in range(len(a))]`
- `a` rank 2, `b` rank 3 -> `[a @ b[i] for i in range(len(b))]`
- `a` rank 3, `b` rank 2 -> `[a[i] @ b for i in range(len(a))]`
:param a: Tensor or SparseTensor with rank 2 or 3;
:param b: Tensor or SparseTensor with rank 2 or 3;
:param transpose_a: transpose the innermost 2 dimensions of `a`;
:param transpose_b: transpose the innermost 2 dimensions of `b`;
:return: Tensor or SparseTensor with rank = max(rank(a), rank(b)).
"""
a_ndim = K.ndim(a)
b_ndim = K.ndim(b)
assert a_ndim in (2, 3), "Expected a of rank 2 or 3, got {}".format(a_ndim)
assert b_ndim in (2, 3), "Expected b of rank 2 or 3, got {}".format(b_ndim)
if transpose_a:
perm = None if a_ndim == 2 else (0, 2, 1)
a = ops.transpose(a, perm)
if transpose_b:
perm = None if b_ndim == 2 else (0, 2, 1)
b = ops.transpose(b, perm)
if a_ndim == b_ndim:
# ...ij,...jk->...ik
return dot(a, b)
elif a_ndim == 2:
# ij,bjk->bik
return mixed_mode_dot(a, b)
else: # a_ndim == 3
# bij,jk->bik
if not K.is_sparse(a) and not K.is_sparse(b):
# Immediately fallback to standard dense matmul, no need to reshape
return tf.matmul(a, b)
# If either input is sparse, we use dot(a, b)
# This implementation is faster than using rank 3 sparse matmul with tfsp
a_shape = tf.shape(a)
b_shape = tf.shape(b)
a_flat = ops.reshape(a, (-1, a_shape[2]))
output = dot(a_flat, b)
return ops.reshape(output, (-1, a_shape[1], b_shape[1]))
def ComplexBN(input_centred, Vrr, Vii, Vri, beta,
gamma_rr, gamma_ri, gamma_ii, scale=True,
center=True, layernorm=False, axis=-1):
ndim = K.ndim(input_centred)
input_dim = tf.shape(input_centred)[axis] // 2
if scale:
gamma_broadcast_shape = [1] * ndim
gamma_broadcast_shape[axis] = input_dim
if center:
broadcast_beta_shape = [1] * ndim
broadcast_beta_shape[axis] = input_dim * 2
if scale:
standardized_output = complex_standardization(
input_centred, Vrr, Vii, Vri,
layernorm,
axis=axis
)
# Now we perform th scaling and Shifting of the normalized x using
# the scaling parameter
# [ gamma_rr gamma_ri ]
# Gamma = [ gamma_ri gamma_ii ]
# and the shifting parameter
# Beta = [beta_real beta_imag].T
# where:
# x_real_BN = gamma_rr * x_real_normed + gamma_ri * x_imag_normed + beta_real
# x_imag_BN = gamma_ri * x_real_normed + gamma_ii * x_imag_normed + beta_imag
broadcast_gamma_rr = tf.reshape(gamma_rr, gamma_broadcast_shape)
broadcast_gamma_ri = tf.reshape(gamma_ri, gamma_broadcast_shape)
broadcast_gamma_ii = tf.reshape(gamma_ii, gamma_broadcast_shape)
cat_gamma_4_real = tf.concat([broadcast_gamma_rr, broadcast_gamma_ii], axis=axis)
cat_gamma_4_imag = tf.concat([broadcast_gamma_ri, broadcast_gamma_ri], axis=axis)
if (axis == 1 and ndim != 3) or ndim == 2:
centred_real = standardized_output[:, :input_dim]
centred_imag = standardized_output[:, input_dim:]
elif ndim == 3:
centred_real = standardized_output[:, :, :input_dim]
centred_imag = standardized_output[:, :, input_dim:]
elif axis == -1 and ndim == 4:
centred_real = standardized_output[:, :, :, :input_dim]
centred_imag = standardized_output[:, :, :, input_dim:]
elif axis == -1 and ndim == 5:
centred_real = standardized_output[:, :, :, :, :input_dim]
centred_imag = standardized_output[:, :, :, :, input_dim:]
else:
raise ValueError(
'Incorrect Batchnorm combination of axis and dimensions. axis should be either 1 or -1. '
'axis: ' + str(self.axis) + '; ndim: ' + str(ndim) + '.'
)
rolled_standardized_output = tf.concat([centred_imag, centred_real], axis=axis)
if center:
broadcast_beta = tf.reshape(beta, broadcast_beta_shape)
return cat_gamma_4_real * standardized_output + cat_gamma_4_imag * rolled_standardized_output + broadcast_beta
else:
return cat_gamma_4_real * standardized_output + cat_gamma_4_imag * rolled_standardized_output
else:
if center:
broadcast_beta = tf.reshape(beta, broadcast_beta_shape)
return input_centred + broadcast_beta
else:
return input_centred
def compile_backprop(self, proj_type='l2'):
self.proj_type = proj_type
layers = [layer for layer in self.model.layers if layer.get_weights()]
A = [Input(layer.output_shape[1:]) for layer in layers[:-1]]
# Store the constraint gradients and biases for each layer.
grads, biases = [], []
prev_grad, prev_bias = None, None
for i, layer in enumerate(layers):
W, b = layer.weights
if isinstance(layer, Dense):
if i > 0 and K.ndim(A[i - 1]) == 4 and (K.image_data_format()
== 'channels_first'):
# The `Flatten` layer doesn't respect the channels-first
# dimension ordering, so it mixes up our dimensions. We need
# to correct for that here.
_, ch, h, w = K.int_shape(A[i - 1])
_, n_out = K.int_shape(W)
W = K.reshape(
K.permute_dimensions(K.reshape(W, (h, w, ch, n_out)),
(2, 0, 1, 3)),
(ch * h * w, n_out))
if len(grads) == 0:
grad = K.transpose(W)
bias = b
# Expand to batch shape.
grad = grad[None] * K.ones_like(A[i])[:, :, None]
bias = bias[None] * K.ones_like(A[i])
else:
A_i = K.reshape(
A[i - 1], [-1, np.prod(K.int_shape(A[i - 1])[1:])])
grad = (K.transpose(W)[None] * A_i[:, None]) @ grads[-1]
bias = (biases[-1] * A_i) @ W + b[None]
grads.append(grad)
biases.append(bias)
else:
if K.image_data_format() == 'channels_first':
_, ch_in, h_in, w_in = layer.input_shape
_, ch_out, h_out, w_out = layer.output_shape
else:
_, h_in, w_in, ch_in = layer.input_shape
_, h_out, w_out, ch_out = layer.output_shape
if len(grads) == 0:
if K.image_data_format() == 'channels_first':
grad = K.conv2d(K.reshape(
K.eye(ch_in * h_in * w_in),
[ch_in * h_in * w_in, ch_in, h_in, w_in]),
W,
padding=layer.padding,
strides=layer.strides)
bias = K.tile(b[:, None, None], [1, h_out, w_out])
else:
grad = K.conv2d(K.reshape(
K.eye(ch_in * h_in * w_in),
[ch_in * h_in * w_in, h_in, w_in, ch_in]),
W,
padding=layer.padding,
strides=layer.strides)
bias = K.tile(b[None, None], [h_out, w_out, 1])
# Expand to batch shape.
grad = grad[None] * K.ones_like(A[i])[:, None]
bias = bias[None] * K.ones_like(A[i])
else:
n = np.prod(self.input_shape)
if K.image_data_format() == 'channels_first':
grad = K.reshape(
K.conv2d(K.reshape(grad * A[i - 1][:, None],
(-1, ch_in, h_in, w_in)),
W,
padding=layer.padding,
strides=layer.strides),
(-1, n, ch_out, h_out, w_out))
bias = K.conv2d(bias * A[i - 1],
W,
padding=layer.padding,
strides=layer.strides) + b[None, :,
None, None]
else:
grad = K.reshape(
K.conv2d(K.reshape(grad * A[i - 1][:, None],
(-1, h_in, h_in, ch_in)),
W,
padding=layer.padding,
strides=layer.strides),
(-1, n, h_out, h_out, ch_out))
bias = K.conv2d(bias * A[i - 1],
W,
padding=layer.padding,
strides=layer.strides) + b[None, None,
None]
grads.append(
K.permute_dimensions(
K.reshape(grad, (-1, n, ch_out * h_out * w_out)),
(0, 2, 1)))
biases.append(K.batch_flatten(bias))
# Handle the softmax constraints.
c = K.placeholder((1, ), dtype='int32')
softmax_grads = grads[-1]
softmax_biases = biases[-1]
c_grad = K.permute_dimensions(
K.gather(K.permute_dimensions(softmax_grads, (1, 0, 2)), c),
(1, 0, 2))
c_bias = K.transpose(K.gather(K.transpose(softmax_biases), c))
grads[-1] = softmax_grads - c_grad
biases[-1] = softmax_biases - c_bias
grads_no_first_layer = K.concatenate(grads[1:], axis=1)
biases_no_first_layer = K.concatenate(biases[1:], axis=1)
grads = K.concatenate(grads, axis=1)
biases = K.concatenate(biases, axis=1)
# Calculate distances.
x = K.placeholder(self.input_shape)
distances = proj_dist(proj_type, K.reshape(x, (1, -1)), grads, biases)
distances_no_first_layer = proj_dist(proj_type, K.reshape(x, (1, -1)),
grads_no_first_layer,
biases_no_first_layer)
self._grad_f = K.function(A + [c], [grads])
self._bias_f = K.function(A + [c], [biases])
self._dist_f = K.function(A + [c, x], [distances])
self._all_f = K.function(A + [c, x], [
distances, grads[:, -self.n_classes:], biases[:, -self.n_classes:]
])
self._all_except_first_f = K.function(A + [c, x], [
distances_no_first_layer, grads_no_first_layer[:,
-self.n_classes:],
biases_no_first_layer[:, -self.n_classes:]
])
self.compiled = True
return self
def call(self, inputs, **kwargs):
input_shape = K.shape(inputs)
ndim = K.ndim(inputs)
reduction_axes = list(range(ndim))
del reduction_axes[self.axis]
del reduction_axes[0]
input_dim = input_shape[self.axis] // 2
mu = K.mean(inputs, axis=reduction_axes)
broadcast_mu_shape = [1] * ndim
broadcast_mu_shape[self.axis] = input_shape[self.axis]
broadcast_mu_shape[0] = K.shape(inputs)[0]
broadcast_mu = K.reshape(mu, broadcast_mu_shape)
if self.center:
input_centred = inputs - broadcast_mu
else:
input_centred = inputs
centred_squared = input_centred**2
if (self.axis == 1 and ndim != 3) or ndim == 2:
centred_squared_real = centred_squared[:, :input_dim]
centred_squared_imag = centred_squared[:, input_dim:]
centred_real = input_centred[:, :input_dim]
centred_imag = input_centred[:, input_dim:]
elif ndim == 3:
centred_squared_real = centred_squared[:, :, :input_dim]
centred_squared_imag = centred_squared[:, :, input_dim:]
centred_real = input_centred[:, :, :input_dim]
centred_imag = input_centred[:, :, input_dim:]
elif self.axis == -1 and ndim == 4:
centred_squared_real = centred_squared[:, :, :, :input_dim]
centred_squared_imag = centred_squared[:, :, :, input_dim:]
centred_real = input_centred[:, :, :, :input_dim]
centred_imag = input_centred[:, :, :, input_dim:]
elif self.axis == -1 and ndim == 5:
centred_squared_real = centred_squared[:, :, :, :, :input_dim]
centred_squared_imag = centred_squared[:, :, :, :, input_dim:]
centred_real = input_centred[:, :, :, :, :input_dim]
centred_imag = input_centred[:, :, :, :, input_dim:]
else:
raise ValueError(
'Incorrect Layernorm combination of axis and dimensions. axis should be either 1 or -1. '
'axis: ' + str(self.axis) + '; ndim: ' + str(ndim) + '.')
if self.scale:
Vrr = K.mean(centred_squared_real,
axis=reduction_axes) + self.epsilon
Vii = K.mean(centred_squared_imag,
axis=reduction_axes) + self.epsilon
# Vri contains the real and imaginary covariance for each feature map.
Vri = K.mean(
centred_real * centred_imag,
axis=reduction_axes,
)
elif self.center:
Vrr = None
Vii = None
Vri = None
else:
raise ValueError(
'Error. Both scale and center in batchnorm are set to False.')
return complex_normalization(input_centred,
Vrr,
Vii,
Vri,
self.beta,
self.gamma_rr,
self.gamma_ri,
self.gamma_ii,
self.scale,
self.center,
layernorm=True,
axis=self.axis)
def call(self, inputs, **kwargs):
"""Constructs the NMS graph.
Args:
inputs: List of
``[boxes, classification, other[0], other[1], ...]`` tensors.
"""
boxes = inputs[0]
classification = inputs[1]
other = inputs[2:]
time_distributed = K.ndim(boxes) == 4
if time_distributed:
boxes_shape = K.shape(boxes)
# classification_shape = classification.get_shape()
classification_shape = K.shape(classification)
other_shape = [K.shape(o) for o in other]
new_boxes_shape = [-1] + [boxes_shape[i] for i in range(2, K.ndim(boxes))]
new_classification_shape = [-1] + \
[classification_shape[i] for i in range(2, K.ndim(classification) - 1)] + \
[classification.get_shape()[-1]]
new_other_shape = [[-1] + [o_s[i] for i in range(2, K.ndim(o))]
for o, o_s in zip(other, other_shape)]
boxes = K.reshape(boxes, new_boxes_shape)
classification = K.reshape(classification, new_classification_shape)
other = [K.reshape(o, o_s) for o, o_s in zip(other, new_other_shape)]
# wrap nms with our parameters
def _filter_detections(args):
boxes = args[0]
classification = args[1]
other = args[2]
return filter_detections(
boxes,
classification,
other,
nms=self.nms,
class_specific_filter=self.class_specific_filter,
score_threshold=self.score_threshold,
max_detections=self.max_detections,
nms_threshold=self.nms_threshold,
)
# call filter_detections on each batch
outputs = tf.map_fn(
_filter_detections,
elems=[boxes, classification, other],
dtype=[K.floatx(), K.floatx(), 'int32'] + [o.dtype for o in other],
parallel_iterations=self.parallel_iterations
)
if time_distributed:
filtered_boxes = outputs[0]
filtered_scores = outputs[1]
filtered_labels = outputs[2]
filtered_other = outputs[3:]
final_boxes_shape = [boxes_shape[0], boxes_shape[1], self.max_detections, 4]
final_scores_shape = [
classification_shape[0],
classification_shape[1],
self.max_detections
]
final_labels_shape = [
classification_shape[0],
classification_shape[1],
self.max_detections
]
final_others_shape = [[o[0], o[1], self.max_detections] +
[o[i] for i in range(3, K.ndim(o))]
for o in other_shape]
filtered_boxes = K.reshape(filtered_boxes, final_boxes_shape)
filtered_scores = K.reshape(filtered_scores, final_scores_shape)
filtered_labels = K.reshape(filtered_labels, final_labels_shape)
filtered_other = [K.reshape(o, o_s) for o, o_s in zip(filtered_other,
final_others_shape)]
outputs = [filtered_boxes, filtered_scores, filtered_labels] + filtered_other
return outputs
def filter_detections(boxes,
classification,
other=[],
class_specific_filter=True,
nms=True,
score_threshold=0.05,
max_detections=300,
nms_threshold=0.5):
"""Filter detections using the boxes and classification values.
Args:
boxes (numpy.array): Tensor of shape ``(num_boxes, 4)`` containing the
boxes in ``(x1, y1, x2, y2)`` format.
classification (numpy.array): Tensor of shape
``(num_boxes, num_classes)`` containing the classification scores.
other (list): List of tensors of shape ``(num_boxes, ...)`` to filter
along with the boxes and classification scores.
class_specific_filter (bool): Whether to perform filtering per class,
or take the best scoring class and filter those.
nms (bool): Whether to enable non maximum suppression.
score_threshold (float): Threshold used to prefilter the boxes with.
max_detections (int): Maximum number of detections to keep.
nms_threshold (float): Threshold for the IoU value to determine when a
box should be suppressed.
Returns:
list: A list of [``boxes, scores, labels, other[0], other[1], ...]``.
``boxes`` is shaped ``(max_detections, 4)`` and contains the
``(x1, y1, x2, y2)`` of the non-suppressed boxes.
``scores`` is shaped ``(max_detections,)`` and contains the scores
of the predicted class.
``labels`` is shaped ``(max_detections,)`` and contains the
predicted label.
``other[i]`` is shaped ``(max_detections, ...)`` and contains the
filtered ``other[i]`` data.
In case there are less than ``max_detections`` detections,
the tensors are padded with -1's.
"""
def _filter_detections(scores, labels):
# threshold based on score
indices = tf.where(K.greater(scores, score_threshold))
if nms:
filtered_boxes = tf.gather_nd(boxes, indices)
filtered_scores = K.gather(scores, indices)[:, 0]
# perform NMS
nms_indices = tf.image.non_max_suppression(
filtered_boxes,
filtered_scores,
max_output_size=max_detections,
iou_threshold=nms_threshold)
# filter indices based on NMS
indices = K.gather(indices, nms_indices)
# add indices to list of all indices
labels = tf.gather_nd(labels, indices)
indices = K.stack([indices[:, 0], labels], axis=1)
return indices
if class_specific_filter:
all_indices = []
# perform per class filtering
for c in range(K.int_shape(classification)[1]):
scores = classification[:, c]
labels = c * tf.ones((K.shape(scores)[0],), dtype='int64')
all_indices.append(_filter_detections(scores, labels))
# concatenate indices to single tensor
indices = K.concatenate(all_indices, axis=0)
else:
scores = K.max(classification, axis=1)
labels = K.argmax(classification, axis=1)
indices = _filter_detections(scores, labels)
# select top k
scores = tf.gather_nd(classification, indices)
labels = indices[:, 1]
scores, top_indices = tf.nn.top_k(
scores, k=K.minimum(max_detections, K.shape(scores)[0]))
# filter input using the final set of indices
indices = K.gather(indices[:, 0], top_indices)
boxes = K.gather(boxes, indices)
labels = K.gather(labels, top_indices)
other_ = [K.gather(o, indices) for o in other]
# zero pad the outputs
pad_size = K.maximum(0, max_detections - K.shape(scores)[0])
boxes = tf.pad(boxes, [[0, pad_size], [0, 0]], constant_values=-1)
scores = tf.pad(scores, [[0, pad_size]], constant_values=-1)
labels = tf.pad(labels, [[0, pad_size]], constant_values=-1)
labels = K.cast(labels, 'int32')
pads = lambda x: [[0, pad_size]] + [[0, 0] for _ in range(1, K.ndim(x))]
other_ = [tf.pad(o, pads(o), constant_values=-1) for o in other_]
# set shapes, since we know what they are
boxes.set_shape([max_detections, 4])
scores.set_shape([max_detections])
labels.set_shape([max_detections])
for o, s in zip(other_, [list(K.int_shape(o)) for o in other]):
o.set_shape([max_detections] + s[1:])
return [boxes, scores, labels] + other_
def call(self, inputs):
z, beta, gamma = inputs
for i in range(K.ndim(z) - 2):
beta = K.expand_dims(beta, 1)
gamma = K.expand_dims(gamma, 1)
return z * (gamma + 1) + beta
def content_loss(img1, img2):
assert K.int_shape(img1) == K.int_shape(img2)
assert K.ndim(img1) == 4
batch, height, width, channels = K.int_shape(img1)
return K.sum(
(img1 - img2)**2, axis=(1, 2, 3)) / height / width / channels / 2
def _mask_batch(y_true,
y_pred,
iou_threshold=0.5,
mask_size=(28, 28),
parallel_iterations=32):
if K.ndim(y_pred) == 4:
y_pred_shape = tf.shape(y_pred)
new_y_pred_shape = [
y_pred_shape[0] * y_pred_shape[1], y_pred_shape[2],
y_pred_shape[3]
]
y_pred = tf.reshape(y_pred, new_y_pred_shape)
y_true_shape = tf.shape(y_true)
new_y_true_shape = [
y_true_shape[0] * y_true_shape[1], y_true_shape[2],
y_true_shape[3]
]
y_true = tf.reshape(y_true, new_y_true_shape)
# split up the different predicted blobs
boxes = y_pred[:, :, :4]
masks = y_pred[:, :, 4:]
# split up the different blobs
annotations = y_true[:, :, :5]
width = K.cast(y_true[0, 0, 5], dtype='int32')
height = K.cast(y_true[0, 0, 6], dtype='int32')
masks_target = y_true[:, :, 7:]
# reshape the masks back to their original size
masks_target = K.reshape(masks_target,
(K.shape(masks_target)[0],
K.shape(masks_target)[1], height, width))
masks = K.reshape(masks, (K.shape(masks)[0], K.shape(masks)[1],
mask_size[0], mask_size[1], -1))
def _mask(args):
boxes = args[0]
masks = args[1]
annotations = args[2]
masks_target = args[3]
return compute_mask_loss(
boxes,
masks,
annotations,
masks_target,
width,
height,
iou_threshold=iou_threshold,
mask_size=mask_size,
)
mask_batch_loss = tf.map_fn(
_mask,
elems=[boxes, masks, annotations, masks_target],
dtype=K.floatx(),
parallel_iterations=parallel_iterations)
return K.mean(mask_batch_loss)
def temp_norm(ten, axis=None):
if axis is None:
axis = 1 if K.image_data_format(
) == 'channels_first' else K.ndim(ten) - 1
return K.sqrt(K.epsilon() + K.sum(K.square(ten), axis=axis))
def call(self, x, mask=None):
if self.mode == 0 or self.mode == 2:
assert self.built, 'Layer must be built before being called'
input_shape = K.int_shape(x)
reduction_axes = list(range(len(input_shape)))
del reduction_axes[self.axis]
broadcast_shape = [1] * len(input_shape)
broadcast_shape[self.axis] = input_shape[self.axis]
# mean_batch, var_batch = K.moments(x, reduction_axes, shift=None, keep_dims=False)
normed, mean_batch, var_batch = K.normalize_batch_in_training(
x, self.gamma, self.beta, reduction_axes, epsilon=self.epsilon)
std_batch = (K.sqrt(var_batch + self.epsilon))
r_max_value = K.get_value(self.r_max)
r = std_batch / (K.sqrt(self.running_std + self.epsilon))
r = K.stop_gradient(K.clip(r, 1 / r_max_value, r_max_value))
d_max_value = K.get_value(self.d_max)
d = (mean_batch - self.running_mean) / K.sqrt(self.running_std +
self.epsilon)
d = K.stop_gradient(K.clip(d, -d_max_value, d_max_value))
if sorted(reduction_axes) == range(K.ndim(x))[:-1]:
x_normed_batch = (x - mean_batch) / std_batch
x_normed = (x_normed_batch * r + d) * self.gamma + self.beta
else:
# need broadcasting
broadcast_mean = K.reshape(mean_batch, broadcast_shape)
broadcast_std = K.reshape(std_batch, broadcast_shape)
broadcast_r = K.reshape(r, broadcast_shape)
broadcast_d = K.reshape(d, broadcast_shape)
broadcast_beta = K.reshape(self.beta, broadcast_shape)
broadcast_gamma = K.reshape(self.gamma, broadcast_shape)
x_normed_batch = (x - broadcast_mean) / broadcast_std
x_normed = (x_normed_batch * broadcast_r +
broadcast_d) * broadcast_gamma + broadcast_beta
# explicit update to moving mean and standard deviation
self.add_update([
K.moving_average_update(self.running_mean, mean_batch,
self.momentum),
K.moving_average_update(self.running_std, std_batch**2,
self.momentum)
], x)
# update r_max and d_max
t_val = K.get_value(self.t)
r_val = self.r_max_value / (
1 + (self.r_max_value - 1) * np.exp(-t_val))
d_val = self.d_max_value / (1 + (
(self.d_max_value / 1e-3) - 1) * np.exp(-(2 * t_val)))
t_val += float(self.t_delta)
self.add_update([
K.update(self.r_max, r_val),
K.update(self.d_max, d_val),
K.update(self.t, t_val)
], x)
if self.mode == 0:
if sorted(reduction_axes) == range(K.ndim(x))[:-1]:
x_normed_running = K.batch_normalization(
x,
self.running_mean,
self.running_std,
self.beta,
self.gamma,
epsilon=self.epsilon)
else:
# need broadcasting
broadcast_running_mean = K.reshape(self.running_mean,
broadcast_shape)
broadcast_running_std = K.reshape(self.running_std,
broadcast_shape)
broadcast_beta = K.reshape(self.beta, broadcast_shape)
broadcast_gamma = K.reshape(self.gamma, broadcast_shape)
x_normed_running = K.batch_normalization(
x,
broadcast_running_mean,
broadcast_running_std,
broadcast_beta,
broadcast_gamma,
epsilon=self.epsilon)
# pick the normalized form of x corresponding to the training phase
# for batch renormalization, inference time remains same as batchnorm
x_normed = K.in_train_phase(x_normed, x_normed_running)
elif self.mode == 1:
# sample-wise normalization
m = K.mean(x, axis=self.axis, keepdims=True)
std = K.sqrt(
K.var(x, axis=self.axis, keepdims=True) + self.epsilon)
x_normed_batch = (x - m) / (std + self.epsilon)
r_max_value = K.get_value(self.r_max)
r = std / (self.running_std + self.epsilon)
r = K.stop_gradient(K.clip(r, 1 / r_max_value, r_max_value))
d_max_value = K.get_value(self.d_max)
d = (m - self.running_mean) / (self.running_std + self.epsilon)
d = K.stop_gradient(K.clip(d, -d_max_value, d_max_value))
x_normed = ((x_normed_batch * r) + d) * self.gamma + self.beta
# update r_max and d_max
t_val = K.get_value(self.t)
r_val = self.r_max_value / (
1 + (self.r_max_value - 1) * np.exp(-t_val))
d_val = self.d_max_value / (1 + (
(self.d_max_value / 1e-3) - 1) * np.exp(-(2 * t_val)))
t_val += float(self.t_delta)
self.add_update([
K.update(self.r_max, r_val),
K.update(self.d_max, d_val),
K.update(self.t, t_val)
], x)
return x_normed
def to_vector(x):
if K.ndim(x) == 1 and K.dtype(x).startswith('int'):
x = K.one_hot(x, self.env.observation_space.n)
elif K.ndim(S) > 2:
x = keras.layers.Flatten()(x)
return x
def call(self, inputs, training=None):
assert self.built, 'Layer must be built before being called'
input_shape = K.int_shape(inputs)
reduction_axes = list(range(len(input_shape)))
del reduction_axes[self.axis]
broadcast_shape = [1] * len(input_shape)
broadcast_shape[self.axis] = input_shape[self.axis]
mean_batch, var_batch = K.moments(inputs,
reduction_axes,
shift=None,
keep_dims=False)
std_batch = (K.sqrt(var_batch + self.epsilon))
r_max_value = K.get_value(self.r_max)
r = std_batch / (K.sqrt(self.running_variance + self.epsilon))
r = K.stop_gradient(K.clip(r, 1 / r_max_value, r_max_value))
d_max_value = K.get_value(self.d_max)
d = (mean_batch - self.running_mean) / K.sqrt(self.running_variance +
self.epsilon)
d = K.stop_gradient(K.clip(d, -d_max_value, d_max_value))
if sorted(reduction_axes) == range(K.ndim(inputs))[:-1]:
x_normed_batch = (inputs - mean_batch) / std_batch
x_normed = (x_normed_batch * r + d) * self.gamma + self.beta
else:
# need broadcasting
broadcast_mean = K.reshape(mean_batch, broadcast_shape)
broadcast_std = K.reshape(std_batch, broadcast_shape)
broadcast_r = K.reshape(r, broadcast_shape)
broadcast_d = K.reshape(d, broadcast_shape)
broadcast_beta = K.reshape(self.beta, broadcast_shape)
broadcast_gamma = K.reshape(self.gamma, broadcast_shape)
x_normed_batch = (inputs - broadcast_mean) / broadcast_std
x_normed = (x_normed_batch * broadcast_r +
broadcast_d) * broadcast_gamma + broadcast_beta
# explicit update to moving mean and standard deviation
self.add_update([
K.moving_average_update(self.running_mean, mean_batch,
self.momentum),
K.moving_average_update(self.running_variance, std_batch**2,
self.momentum)
], inputs)
# update r_max and d_max
t_val = K.get_value(self.t)
r_val = self.r_max_value / (1 +
(self.r_max_value - 1) * np.exp(-t_val))
d_val = self.d_max_value / (1 + (
(self.d_max_value / 1e-3) - 1) * np.exp(-(2 * t_val)))
t_val += float(self.t_delta)
self.add_update([
K.update(self.r_max, r_val),
K.update(self.d_max, d_val),
K.update(self.t, t_val)
], inputs)
if training in {0, False}:
return x_normed
else:
def normalize_inference():
if sorted(reduction_axes) == range(K.ndim(inputs))[:-1]:
x_normed_running = K.batch_normalization(
inputs,
self.running_mean,
self.running_variance,
self.beta,
self.gamma,
epsilon=self.epsilon)
return x_normed_running
else:
# need broadcasting
broadcast_running_mean = K.reshape(self.running_mean,
broadcast_shape)
broadcast_running_std = K.reshape(self.running_variance,
broadcast_shape)
broadcast_beta = K.reshape(self.beta, broadcast_shape)
broadcast_gamma = K.reshape(self.gamma, broadcast_shape)
x_normed_running = K.batch_normalization(
inputs,
broadcast_running_mean,
broadcast_running_std,
broadcast_beta,
broadcast_gamma,
epsilon=self.epsilon)
return x_normed_running
# pick the normalized form of inputs corresponding to the training phase
# for batch renormalization, inference time remains same as batchnorm
x_normed = K.in_train_phase(x_normed,
normalize_inference,
training=training)
return x_normed
def call(self, x, **kwargs):
if K.ndim(x) != 3:
raise ValueError(
f'Wrong dimensions of inputs, expected 3 but input {K.ndim(x)}.'
)
dim = int(x.get_shape()[-1])
hidden_nn_layers = [x]
final_result = []
split_tensor0 = tf.split(hidden_nn_layers[0], dim * [1], 2)
for idx, layer_size in enumerate(self.cross_layer_size):
split_tensor = tf.split(hidden_nn_layers[-1], dim * [1], 2)
dot_result_m = tf.matmul(split_tensor0,
split_tensor,
transpose_b=True)
dot_result_o = tf.reshape(
dot_result_m,
shape=[dim, -1, self.field_nums[0] * self.field_nums[idx]])
dot_result = tf.transpose(dot_result_o, perm=[1, 0, 2])
if self.reduce_D:
f0_ = self.f0_[idx]
f__ = self.f__[idx]
f_m = tf.matmul(f0_, f__)
f_o = tf.reshape(f_m,
shape=[
1, layer_size,
self.field_nums[0] * self.field_nums[idx]
])
filters = tf.transpose(f_o, perm=[0, 2, 1])
else:
filters = self.f_[idx]
curr_out = tf.nn.conv1d(dot_result,
filters=filters,
stride=1,
padding='VALID')
if self.use_bias:
curr_out = tf.nn.bias_add(curr_out, self.bias[idx])
curr_out = self.activation_layers[idx](curr_out)
curr_out = tf.transpose(curr_out, perm=[0, 2, 1])
if self.direct:
direct_connect = curr_out
next_hidden = curr_out
else:
if idx != len(self.cross_layer_size) - 1:
next_hidden, direct_connect = tf.split(
curr_out, 2 * [layer_size // 2], 1)
else:
direct_connect = curr_out
next_hidden = 0
final_result.append(direct_connect)
hidden_nn_layers.append(next_hidden)
result = tf.concat(final_result, axis=1)
result = tf.reduce_sum(result, -1)
if self.use_residual:
exFM_out0 = self.exFM_out0(result)
exFM_in = tf.concat([exFM_out0, result], axis=1)
exFM_out = self.exFM_out(exFM_in)
else:
exFM_out = self.exFM_out(result)
return exFM_out
def predict(predict_var,
x_unlabeled,
inputs,
y_true,
batch_sizes,
x_labeled=None,
y_labeled=None):
"""Evaluates predict_var, batchwise, over all points in x_unlabeled and x_labeled.
Args:
predict_var: list of tensors to evaluate and return
x_unlabeled: unlabeled input data
inputs: dictionary containing input_types and input_placeholders
as key, value pairs, respectively
y_true: true labels tensorflow placeholder
batch_sizes: dictionary containing input_types and batch_sizes as
key, value pairs, respectively
x_labeled: labeled input data
y_labeled: labeled input labels
Returns:
a list of length n containing the result of all tensors
in return_var, where n = len(x_unlabeled) + len(x_labeled)
"""
x_unlabeled, x_labeled, y_labeled = check_inputs(x_unlabeled, x_labeled,
y_labeled, y_true)
# combined data
x = np.concatenate((x_unlabeled, x_labeled), 0)
# get shape of y_true
y_shape = y_true.get_shape()[1:K.ndim(y_true)].as_list()
# calculate batches for predict loop
unlabeled_batch_size = batch_sizes.get('Unlabeled', 0)
labeled_batch_size = batch_sizes.get('Labeled', 0)
if 'Labeled' in batch_sizes and 'Unlabeled' in batch_sizes:
assert unlabeled_batch_size == labeled_batch_size
batch_size = min(len(x), max(unlabeled_batch_size, labeled_batch_size))
batches = make_batches(len(x), batch_size)
y_preds = []
# predict over all points
for _, (batch_start, batch_end) in enumerate(batches):
feed_dict = {K.learning_phase(): 0}
# feed corresponding input for each input_type
for input_type, input_placeholder in inputs.items():
if input_type == 'Unlabeled':
feed_dict[input_placeholder] = x[batch_start:batch_end]
elif input_type == 'Labeled':
if x_labeled:
batch_ids = np.random.choice(
len(x_labeled),
size=min(batch_sizes[input_type], len(x_labeled)),
replace=False)
feed_dict[input_placeholder] = x_labeled[batch_ids]
feed_dict[y_true] = y_labeled[batch_ids]
else:
# we have no labeled points, so feed an empty array
feed_dict[input_placeholder] = x[0:0]
feed_dict[y_true] = np.empty([0] + y_shape)
# evaluate the batch
y_pred_batch = np.asarray(K.get_session().run(
predict_var, feed_dict=feed_dict))
y_preds.append(y_pred_batch)
if y_preds[0].shape:
return np.concatenate(y_preds)
else:
return np.sum(y_preds)
def policy_loss_with_metrics(self, Adv, A):
"""
This method constructs the policy loss as a scalar-valued Tensor,
together with a dictionary of metrics (also scalars).
This method may be overridden to construct a custom policy loss and/or
to change the accompanying metrics.
Parameters
----------
Adv : 1d Tensor, shape: [batch_size]
A batch of advantages.
A : nd Tensor, shape: [batch_size, ...]
A batch of actions taken under the behavior policy.
Returns
-------
loss, metrics : (Tensor, dict of Tensors)
The policy loss along with some metrics, which is a dict of type
``{name <str>: metric <Tensor>}``. The loss and each of the metrics
(dict values) are scalar Tensors, i.e. Tensors with ``ndim=0``.
The ``loss`` is passed to a keras Model using
``train_model.add_loss(loss)``. Similarly, each metric in the
metric dict is passed to the model using
``train_model.add_metric(metric, name=name, aggregation='mean')``.
"""
Adv = K.stop_gradient(Adv)
if K.ndim(Adv) == 2:
Adv = K.squeeze(Adv, axis=1)
check_tensor(Adv, ndim=1)
if self.update_strategy == 'vanilla':
log_pi = self.dist.log_proba(A)
check_tensor(log_pi, same_as=Adv)
entropy = K.mean(self.dist.entropy())
# flip sign to get loss from objective
loss = -K.mean(Adv * log_pi) + self.entropy_beta * entropy
# no metrics related to behavior_dist since its not used in loss
metrics = {'policy/entropy': entropy}
elif self.update_strategy == 'ppo':
log_pi = self.dist.log_proba(A)
log_pi_old = K.stop_gradient(self.target_dist.log_proba(A))
check_tensor(log_pi, same_as=Adv)
check_tensor(log_pi_old, same_as=Adv)
eps = self.ppo_clip_eps
ratio = K.exp(log_pi - log_pi_old)
ratio_clip = K.clip(ratio, 1 - eps, 1 + eps)
check_tensor(log_pi, same_as=Adv)
check_tensor(log_pi_old, same_as=Adv)
clip_objective = K.mean(K.minimum(Adv * ratio, Adv * ratio_clip))
entropy = K.mean(self.dist.entropy())
kl_div = K.mean(self.target_dist.kl_divergence(self.dist))
# flip sign to get loss from objective
loss = -(clip_objective + self.entropy_beta * entropy)
metrics = {'policy/entropy': entropy, 'policy/kl_div': kl_div}
elif self.update_strategy == 'cross_entropy':
raise NotImplementedError('cross_entropy')
else:
raise ValueError("unknown update_strategy '{}'".format(
self.update_strategy))
# rename
loss = tf.identity(loss, name='policy_loss')
return loss, metrics
def train_step(return_vars,
updates,
x_unlabeled,
inputs,
y_true,
batch_sizes,
x_labeled=None,
y_labeled=None,
batches_per_epoch=100):
"""Performs one training step.
Evaluates the tensors in return_vars and updates, then returns the values of
the tensors in return_vars.
Args:
return_vars: list of tensors to evaluate and return
updates: list of tensors to evaluate only
x_unlabeled: unlabeled input data
inputs: dictionary containing input_types and input_placeholders as key,
value pairs, respectively
y_true: true labels placeholder
batch_sizes: dictionary containing input_types and batch_sizes as key, value
pairs, respectively
x_labeled: labeled input data
y_labeled: labeled input labels
batches_per_epoch: parameter updates per epoch*
Returns:
the evaluated result of all tensors in return_vars, summed
across all epochs
*note: the term epoch is used loosely here, it does not necessarily
refer to one iteration over the entire dataset. instead, it
is just batches_per_epoch parameter updates.
"""
x_unlabeled, x_labeled, y_labeled = check_inputs(x_unlabeled, x_labeled,
y_labeled, y_true)
# combine data
x = np.concatenate((x_unlabeled, x_labeled), 0)
# get shape of y_true
y_shape = y_true.get_shape()[1:K.ndim(y_true)].as_list()
return_vars_ = np.zeros(shape=(len(return_vars)))
# train batches_per_epoch batches
for _ in range(0, batches_per_epoch):
feed_dict = {K.learning_phase(): 1}
# feed corresponding input for each input_type
for input_type, input_placeholder in inputs.items():
if input_type == 'Labeled':
if x_labeled:
batch_ids = np.random.choice(
len(x_labeled),
size=min(batch_sizes[input_type], len(x_labeled)),
replace=False)
feed_dict[input_placeholder] = x_labeled[batch_ids]
feed_dict[y_true] = y_labeled[batch_ids]
else:
# we have no labeled points, so feed an empty array
feed_dict[input_placeholder] = x[0:0]
feed_dict[y_true] = np.empty([0] + y_shape)
elif input_type == 'Unlabeled':
if x_unlabeled:
batch_ids = np.random.choice(
len(x_unlabeled), size=batch_sizes[input_type], replace=False)
feed_dict[input_placeholder] = x_unlabeled[batch_ids]
else:
# we have no unlabeled points, so feed an empty array
feed_dict[input_placeholder] = x[0:0]
all_vars = return_vars + updates
return_vars_ += np.asarray(K.get_session().run(
all_vars, feed_dict=feed_dict)[:len(return_vars)])
return return_vars_
def softmax_over_time(self, x):
assert (K.ndim(x) > 2), "x dims too small"
e = K.exp(x - K.max(x, axis=1, keepdims=True))
s = K.sum(e, axis=1, keepdims=True)
return e / s
def _to_vector(X, space):
if K.ndim(X) == 1 and K.dtype(X).startswith('int'):
X = K.one_hot(X, space.n)
elif K.ndim(X) > 2:
X = keras.layers.Flatten()(X)
return X
def loss_per_pixel(mask, y_true, y_pred):
"""Pixel L1 loss outside the hole / mask"""
assert K.ndim(y_true) == 4, 'Input tensor should be 4D (B, H, W, C).'
return K.mean(K.abs(mask * (y_pred - y_true)), axis=[1, 2, 3])
def call(self, inputs):
if len(inputs) == 3:
X, A, I = inputs
if K.ndim(I) == 2:
I = I[:, 0]
else:
X, A = inputs
I = None
N = K.shape(A)[-1]
# Check if the layer is operating in mixed or batch mode
mode = ops.autodetect_mode(A, X)
self.reduce_loss = mode in (modes.MIXED, modes.BATCH)
# Get normalized adjacency
if K.is_sparse(A):
I_ = tf.sparse.eye(N, dtype=A.dtype)
A_ = tf.sparse.add(A, I_)
else:
I_ = tf.eye(N, dtype=A.dtype)
A_ = A + I_
fltr = ops.normalize_A(A_)
# Node embeddings
Z = K.dot(X, self.kernel_emb)
Z = ops.filter_dot(fltr, Z)
if self.activation is not None:
Z = self.activation(Z)
# Compute cluster assignment matrix
S = K.dot(X, self.kernel_pool)
S = ops.filter_dot(fltr, S)
S = activations.softmax(S, axis=-1) # softmax applied row-wise
# Link prediction loss
S_gram = ops.matmul_A_BT(S, S)
if mode == modes.MIXED:
A = tf.sparse.to_dense(A)[None, ...]
if K.is_sparse(A):
LP_loss = tf.sparse.add(
A, -S_gram) # A/tf.norm(A) - S_gram/tf.norm(S_gram)
else:
LP_loss = A - S_gram
LP_loss = tf.norm(LP_loss, axis=(-1, -2))
if self.reduce_loss:
LP_loss = K.mean(LP_loss)
self.add_loss(LP_loss)
# Entropy loss
entr = tf.negative(
tf.reduce_sum(tf.multiply(S, K.log(S + K.epsilon())), axis=-1))
entr_loss = K.mean(entr, axis=-1)
if self.reduce_loss:
entr_loss = K.mean(entr_loss)
self.add_loss(entr_loss)
# Pooling
X_pooled = ops.matmul_AT_B(S, Z)
A_pooled = ops.matmul_AT_B_A(S, A)
output = [X_pooled, A_pooled]
if I is not None:
I_mean = tf.math.segment_mean(I, I)
I_pooled = ops.repeat(I_mean, tf.ones_like(I_mean) * self.k)
output.append(I_pooled)
if self.return_mask:
output.append(S)
return output
def complex_standardization(input_centred, Vrr, Vii, Vri,
layernorm=False, axis=-1):
ndim = K.ndim(input_centred)
input_dim = tf.shape(input_centred)[axis] // 2
variances_broadcast = [1] * ndim
variances_broadcast[axis] = input_dim
if layernorm:
variances_broadcast[0] = tf.shape(input_centred)[0]
# We require the covariance matrix's inverse square root. That first requires
# square rooting, followed by inversion (I do this in that order because during
# the computation of square root we compute the determinant we'll need for
# inversion as well).
# tau = Vrr + Vii = Trace. Guaranteed >= 0 because SPD
tau = Vrr + Vii
# delta = (Vrr * Vii) - (Vri ** 2) = Determinant. Guaranteed >= 0 because SPD
delta = (Vrr * Vii) - (Vri ** 2)
s = tf.sqrt(delta) # Determinant of square root matrix
t = tf.sqrt(tau + 2 * s)
# The square root matrix could now be explicitly formed as
# [ Vrr+s Vri ]
# (1/t) [ Vir Vii+s ]
# https://en.wikipedia.org/wiki/Square_root_of_a_2_by_2_matrix
# but we don't need to do this immediately since we can also simultaneously
# invert. We can do this because we've already computed the determinant of
# the square root matrix, and can thus invert it using the analytical
# solution for 2x2 matrices
# [ A B ] [ D -B ]
# inv( [ C D ] ) = (1/det) [ -C A ]
# http://mathworld.wolfram.com/MatrixInverse.html
# Thus giving us
# [ Vii+s -Vri ]
# (1/delta)(1/t)[ -Vir Vrr+s ]
# So we proceed as follows:
inverse_st = 1.0 / (s * t)
Wrr = (Vii + s) * inverse_st
Wii = (Vrr + s) * inverse_st
Wri = -Vri * inverse_st
# And we have computed the inverse square root matrix W = sqrt(V)!
# Normalization. We multiply, x_normalized = W.x.
# The returned result will be a complex standardized input
# where the real and imaginary parts are obtained as follows:
# x_real_normed = Wrr * x_real_centred + Wri * x_imag_centred
# x_imag_normed = Wri * x_real_centred + Wii * x_imag_centred
broadcast_Wrr = tf.reshape(Wrr, variances_broadcast)
broadcast_Wri = tf.reshape(Wri, variances_broadcast)
broadcast_Wii = tf.reshape(Wii, variances_broadcast)
cat_W_4_real = tf.concat([broadcast_Wrr, broadcast_Wii], axis=axis)
cat_W_4_imag = tf.concat([broadcast_Wri, broadcast_Wri], axis=axis)
if (axis == 1 and ndim != 3) or ndim == 2:
centred_real = input_centred[:, :input_dim]
centred_imag = input_centred[:, input_dim:]
elif ndim == 3:
centred_real = input_centred[:, :, :input_dim]
centred_imag = input_centred[:, :, input_dim:]
elif axis == -1 and ndim == 4:
centred_real = input_centred[:, :, :, :input_dim]
centred_imag = input_centred[:, :, :, input_dim:]
elif axis == -1 and ndim == 5:
centred_real = input_centred[:, :, :, :, :input_dim]
centred_imag = input_centred[:, :, :, :, input_dim:]
else:
raise ValueError(
'Incorrect Batchnorm combination of axis and dimensions. axis should be either 1 or -1. '
'axis: ' + str(self.axis) + '; ndim: ' + str(ndim) + '.'
)
rolled_input = tf.concat([centred_imag, centred_real], axis=axis)
output = cat_W_4_real * input_centred + cat_W_4_imag * rolled_input
# Wrr * x_real_centered | Wii * x_imag_centered
# + Wri * x_imag_centered | Wri * x_real_centered
# -----------------------------------------------
# = output
return output
def body(self, S):
if K.ndim(S) > 2:
S = keras.layers.Flatten(name='flatten')(S)
if self.interaction_layer is not None:
S = self.interaction_layer(S)
return S
def repeat_(x, k):
tile_factor = [1, k] + [1] * (K.ndim(x) - 1)
return K.tile(x[:, None, :], tile_factor)
def call(self, inputs, **kwargs):
image_shape = K.cast(inputs[0], K.floatx())
boxes = K.stop_gradient(inputs[1])
scores = K.stop_gradient(inputs[2])
fpn = [K.stop_gradient(i) for i in inputs[3:]]
time_distributed = K.ndim(boxes) == 4
if time_distributed:
image_shape = image_shape[1:]
boxes_shape = tf.shape(boxes)
scores_shape = tf.shape(scores)
fpn_shape = [tf.shape(f) for f in fpn]
new_boxes_shape = [-1] + [
boxes_shape[i] for i in range(2, K.ndim(boxes))
]
new_scores_shape = [-1] + [
scores_shape[i] for i in range(2, K.ndim(scores))
]
new_fpn_shape = [[-1] + [f_s[i] for i in range(2, K.ndim(f))]
for f, f_s in zip(fpn, fpn_shape)]
boxes = tf.reshape(boxes, new_boxes_shape)
scores = tf.reshape(scores, new_scores_shape)
fpn = [tf.reshape(f, f_s) for f, f_s in zip(fpn, new_fpn_shape)]
def _roi_align(args):
boxes = args[0]
scores = args[1]
fpn = args[2]
# compute from which level to get features from
target_levels = self.map_to_level(boxes)
# process each pyramid independently
rois, ordered_indices = [], []
for i in range(len(fpn)):
# select the boxes and classification from this pyramid level
indices = tf.where(K.equal(target_levels, i))
ordered_indices.append(indices)
level_boxes = tf.gather_nd(boxes, indices)
fpn_shape = K.cast(K.shape(fpn[i]), dtype=K.floatx())
# convert to expected format for crop_and_resize
x1 = level_boxes[:, 0]
y1 = level_boxes[:, 1]
x2 = level_boxes[:, 2]
y2 = level_boxes[:, 3]
level_boxes = K.stack([
(y1 / image_shape[1] * fpn_shape[0]) / (fpn_shape[0] - 1),
(x1 / image_shape[2] * fpn_shape[1]) / (fpn_shape[1] - 1),
(y2 / image_shape[1] * fpn_shape[0] - 1) /
(fpn_shape[0] - 1),
(x2 / image_shape[2] * fpn_shape[1] - 1) /
(fpn_shape[1] - 1),
],
axis=1)
# append the rois to the list of rois
rois.append(
tf.image.crop_and_resize(
K.expand_dims(fpn[i], axis=0), level_boxes,
tf.zeros((K.shape(level_boxes)[0], ), dtype='int32'),
self.crop_size))
# concatenate rois to one blob
rois = K.concatenate(rois, axis=0)
# reorder rois back to original order
indices = K.concatenate(ordered_indices, axis=0)
rois = tf.scatter_nd(indices, rois, K.cast(K.shape(rois), 'int64'))
return rois
roi_batch = tf.map_fn(_roi_align,
elems=[boxes, scores, fpn],
dtype=K.floatx(),
parallel_iterations=self.parallel_iterations)
if time_distributed:
roi_shape = tf.shape(roi_batch)
new_roi_shape = [boxes_shape[0], boxes_shape[1]] + \
[roi_shape[i] for i in range(1, K.ndim(roi_batch))]
roi_batch = tf.reshape(roi_batch, new_roi_shape)
return roi_batch
def ComplexBN(input_centred,
Vrr,
Vii,
Vri,
beta,
gamma_rr,
gamma_ri,
gamma_ii,
scale=True,
center=True,
layernorm=False,
axis=-1):
"""Complex Batch Normalization
Arguments:
input_centred -- input data
Vrr -- Real component of covariance matrix V
Vii -- Imaginary component of covariance matrix V
Vri -- Non-diagonal component of covariance matrix V
beta -- Lernable shift parameter beta
gamma_rr -- Scaling parameter gamma - rr component of 2x2 matrix
gamma_ri -- Scaling parameter gamma - ri component of 2x2 matrix
gamma_ii -- Scaling parameter gamma - ii component of 2x2 matrix
Keyword Arguments:
scale {bool} {bool} -- Standardization of input (default: {True})
center {bool} -- Mean-shift correction (default: {True})
layernorm {bool} -- Normalization (default: {False})
axis {int} -- Axis for Standardization (default: {-1})
Raises:
ValueError: Dimonsional mismatch
Returns:
Batch-Normalized Input
"""
ndim = K.ndim(input_centred)
input_dim = K.shape(input_centred)[axis] // 2
if scale:
gamma_broadcast_shape = [1] * ndim
gamma_broadcast_shape[axis] = input_dim
if center:
broadcast_beta_shape = [1] * ndim
broadcast_beta_shape[axis] = input_dim * 2
if scale:
standardized_output = complex_standardization(input_centred,
Vrr,
Vii,
Vri,
layernorm,
axis=axis)
# Now we perform th scaling and Shifting of the normalized x using
# the scaling parameter
# [ gamma_rr gamma_ri ]
# Gamma = [ gamma_ri gamma_ii ]
# and the shifting parameter
# Beta = [beta_real beta_imag].T
# where:
# x_real_BN = gamma_rr * x_real_normed +
# gamma_ri * x_imag_normed + beta_real
# x_imag_BN = gamma_ri * x_real_normed +
# gamma_ii * x_imag_normed + beta_imag
broadcast_gamma_rr = K.reshape(gamma_rr, gamma_broadcast_shape)
broadcast_gamma_ri = K.reshape(gamma_ri, gamma_broadcast_shape)
broadcast_gamma_ii = K.reshape(gamma_ii, gamma_broadcast_shape)
cat_gamma_4_real = K.concatenate(
[broadcast_gamma_rr, broadcast_gamma_ii], axis=axis)
cat_gamma_4_imag = K.concatenate(
[broadcast_gamma_ri, broadcast_gamma_ri], axis=axis)
if (axis == 1 and ndim != 3) or ndim == 2:
centred_real = standardized_output[:, :input_dim]
centred_imag = standardized_output[:, input_dim:]
elif ndim == 3:
centred_real = standardized_output[:, :, :input_dim]
centred_imag = standardized_output[:, :, input_dim:]
elif axis == -1 and ndim == 4:
centred_real = standardized_output[:, :, :, :input_dim]
centred_imag = standardized_output[:, :, :, input_dim:]
elif axis == -1 and ndim == 5:
centred_real = standardized_output[:, :, :, :, :input_dim]
centred_imag = standardized_output[:, :, :, :, input_dim:]
else:
raise ValueError(
'Incorrect Batchnorm combination of axis and dimensions. axis'
' should be either 1 or -1. '
'axis: ' + str(axis) + '; ndim: ' + str(ndim) + '.')
rolled_standardized_output = K.concatenate(
[centred_imag, centred_real], axis=axis)
if center:
broadcast_beta = K.reshape(beta, broadcast_beta_shape)
return cat_gamma_4_real * standardized_output + cat_gamma_4_imag * rolled_standardized_output + broadcast_beta
else:
return cat_gamma_4_real * standardized_output + cat_gamma_4_imag * rolled_standardized_output
else:
if center:
broadcast_beta = K.reshape(beta, broadcast_beta_shape)
return input_centred + broadcast_beta
else:
return input_centred
def call(self,
inputs,
initial_state=None,
initial_readout=None,
ground_truth=None,
mask=None,
training=None):
# input shape: `(samples, time (padded with zeros), input_dim)`
# note that the .build() method of subclasses MUST define
# self.input_spec and self.state_spec with complete input shapes.
if type(mask) is list:
mask = mask[0]
if self.model is None:
raise Exception('Empty RecurrentModel.')
num_req_states = self.num_states
if self.readout:
num_actual_states = num_req_states - 1
else:
num_actual_states = num_req_states
if type(inputs) is list:
inputs_list = inputs[:]
inputs = inputs_list.pop(0)
initial_states = inputs_list[:num_actual_states]
if len(initial_states) > 0:
if self._is_optional_input_placeholder(initial_states[0]):
initial_states = self.get_initial_state(inputs)
inputs_list = inputs_list[num_actual_states:]
if self.readout:
initial_readout = inputs_list.pop(0)
if self.teacher_force:
ground_truth = inputs_list.pop()
else:
if initial_state is not None:
if not isinstance(initial_state, (list, tuple)):
initial_states = [initial_state]
else:
initial_states = list(initial_state)
if self._is_optional_input_placeholder(initial_states[0]):
initial_states = self.get_initial_state(inputs)
elif self.stateful:
initial_states = self.states
else:
initial_states = self.get_initial_state(inputs)
if self.readout:
if initial_readout is None or self._is_optional_input_placeholder(
initial_readout):
output_shape = K.int_shape(_to_list((self.model.output))[0])
output_ndim = len(output_shape)
input_ndim = K.ndim(inputs)
initial_readout = K.zeros_like(inputs)
slices = [slice(None)] + [0] * (input_ndim - 1)
initial_readout = initial_readout[slices] # (batch_size,)
initial_readout = K.reshape(initial_readout,
(-1, ) + (1, ) * (output_ndim - 1))
initial_readout = K.tile(initial_readout,
(1, ) + tuple(output_shape[1:]))
initial_states.append(initial_readout)
if self.teacher_force:
if ground_truth is None or self._is_optional_input_placeholder(
ground_truth):
raise Exception(
'ground_truth must be provided for RecurrentModel with teacher_force=True.'
)
if K.backend() == 'tensorflow':
with tf.control_dependencies(None):
counter = K.zeros((1, ))
else:
counter = K.zeros((1, ))
counter = K.cast(counter, 'int32')
initial_states.insert(-1, counter)
initial_states[-2]
initial_states.insert(-1, ground_truth)
num_req_states += 2
if len(initial_states) != num_req_states:
raise ValueError('Layer requires ' + str(num_req_states) +
' states but was passed ' +
str(len(initial_states)) + ' initial states.')
input_shape = K.int_shape(inputs)
if self.unroll and input_shape[1] is None:
raise ValueError('Cannot unroll a RNN if the '
'time dimension is undefined. \n'
'- If using a Sequential model, '
'specify the time dimension by passing '
'an `input_shape` or `batch_input_shape` '
'argument to your first layer. If your '
'first layer is an Embedding, you can '
'also use the `input_length` argument.\n'
'- If using the functional API, specify '
'the time dimension by passing a `shape` '
'or `batch_shape` argument to your Input layer.')
preprocessed_input = self.preprocess_input(inputs, training=None)
constants = self.get_constants(inputs, training=None)
if self.decode:
initial_states.insert(0, inputs)
preprocessed_input = K.zeros((1, self.output_length, 1))
input_length = self.output_length
else:
input_length = input_shape[1]
if self.uses_learning_phase:
with learning_phase_scope(0):
last_output_test, outputs_test, states_test, updates = rnn(
self.step,
preprocessed_input,
initial_states,
go_backwards=self.go_backwards,
mask=mask,
constants=constants,
unroll=self.unroll,
input_length=input_length)
with learning_phase_scope(1):
last_output_train, outputs_train, states_train, updates = rnn(
self.step,
preprocessed_input,
initial_states,
go_backwards=self.go_backwards,
mask=mask,
constants=constants,
unroll=self.unroll,
input_length=input_length)
last_output = K.in_train_phase(last_output_train,
last_output_test,
training=training)
outputs = K.in_train_phase(outputs_train,
outputs_test,
training=training)
states = []
for state_train, state_test in zip(states_train, states_test):
states.append(
K.in_train_phase(state_train,
state_test,
training=training))
else:
last_output, outputs, states, updates = rnn(
self.step,
preprocessed_input,
initial_states,
go_backwards=self.go_backwards,
mask=mask,
constants=constants,
unroll=self.unroll,
input_length=input_length)
states = list(states)
if self.decode:
states.pop(0)
if self.readout:
states.pop()
if self.teacher_force:
states.pop()
states.pop()
if len(updates) > 0:
self.add_update(updates)
if self.stateful:
updates = []
for i in range(len(states)):
updates.append((self.states[i], states[i]))
self.add_update(updates, inputs)
# Properly set learning phase
if 0 < self.dropout + self.recurrent_dropout:
last_output._uses_learning_phase = True
outputs._uses_learning_phase = True
if self.return_sequences:
y = outputs
else:
y = last_output
if self.return_states:
return [y] + states
else:
return y