def reverse_pixel_cnn_28_binary(x,
masks,
context=None,
nr_logistic_mix=10,
nr_resnet=1,
nr_filters=100,
dropout_p=0.0,
nonlinearity=None,
bn=True,
kernel_initializer=None,
kernel_regularizer=None,
is_training=False,
counters={}):
name = get_name("reverse_pixel_cnn_28_binary", counters)
x = x * broadcast_masks_tf(masks, num_channels=3)
x = tf.concat([x, broadcast_masks_tf(masks, num_channels=1)], axis=-1)
print("construct", name, "...")
print(" * nr_resnet: ", nr_resnet)
print(" * nr_filters: ", nr_filters)
print(" * nr_logistic_mix: ", nr_logistic_mix)
assert not bn, "auto-reggressive model should not use batch normalization"
with tf.variable_scope(name):
with arg_scope([gated_resnet],
gh=None,
sh=context,
nonlinearity=nonlinearity,
dropout_p=dropout_p):
with arg_scope([
gated_resnet, up_shifted_conv2d, up_left_shifted_conv2d,
up_shifted_deconv2d, up_left_shifted_deconv2d
],
bn=bn,
kernel_initializer=kernel_initializer,
kernel_regularizer=kernel_regularizer,
is_training=is_training,
counters=counters):
xs = int_shape(x)
x_pad = tf.concat(
[x, tf.ones(xs[:-1] + [1])], 3
) # add channel of ones to distinguish image from padding later on
u_list = [
up_shift(
up_shifted_conv2d(x_pad,
num_filters=nr_filters,
filter_size=[2, 3]))
] # stream for pixels above
ul_list = [up_shift(up_shifted_conv2d(x_pad, num_filters=nr_filters, filter_size=[1,3])) + \
left_shift(up_left_shifted_conv2d(x_pad, num_filters=nr_filters, filter_size=[2,1]))] # stream for up and to the left
for rep in range(nr_resnet):
u_list.append(
gated_resnet(u_list[-1], conv=up_shifted_conv2d))
ul_list.append(
gated_resnet(ul_list[-1],
u_list[-1],
conv=up_left_shifted_conv2d))
x_out = nin(tf.nn.elu(ul_list[-1]), nr_filters)
return x_out
def conditioning_network_28(x,
masks,
nr_filters,
is_training=True,
nonlinearity=None,
bn=True,
kernel_initializer=None,
kernel_regularizer=None,
counters={}):
name = get_name("conditioning_network_28", counters)
x = x * broadcast_masks_tf(masks, num_channels=3)
x = tf.concat([x, broadcast_masks_tf(masks, num_channels=1)], axis=-1)
xs = int_shape(x)
x = tf.concat([x, tf.ones(xs[:-1] + [1])], 3)
with tf.variable_scope(name):
with arg_scope([conv2d, residual_block, dense],
nonlinearity=nonlinearity,
bn=bn,
kernel_initializer=kernel_initializer,
kernel_regularizer=kernel_regularizer,
is_training=is_training,
counters=counters):
outputs = conv2d(x, nr_filters, 4, 1, "SAME")
for l in range(4):
outputs = conv2d(outputs, nr_filters, 4, 1, "SAME")
outputs = conv2d(outputs,
nr_filters,
1,
1,
"SAME",
nonlinearity=None,
bn=False)
return outputs
def context_encoder(contexts,
masks,
is_training,
nr_resnet=5,
nr_filters=100,
nonlinearity=None,
bn=False,
kernel_initializer=None,
kernel_regularizer=None,
counters={}):
name = get_name("context_encoder", counters)
print("construct", name, "...")
x = contexts * broadcast_masks_tf(masks, num_channels=3)
x = tf.concat([x, broadcast_masks_tf(masks, num_channels=1)], axis=-1)
if bn:
print("*** Attention *** using bn in the context encoder\n")
with tf.variable_scope(name):
with arg_scope([gated_resnet],
nonlinearity=nonlinearity,
counters=counters):
with arg_scope(
[gated_resnet, up_shifted_conv2d, up_left_shifted_conv2d],
bn=bn,
kernel_initializer=kernel_initializer,
kernel_regularizer=kernel_regularizer,
is_training=is_training):
xs = int_shape(x)
x_pad = tf.concat(
[x, tf.ones(xs[:-1] + [1])], 3
) # add channel of ones to distinguish image from padding later on
u_list = [
up_shift(
up_shifted_conv2d(x_pad,
num_filters=nr_filters,
filter_size=[2, 3]))
] # stream for pixels above
ul_list = [up_shift(up_shifted_conv2d(x_pad, num_filters=nr_filters, filter_size=[1,3])) + \
left_shift(up_left_shifted_conv2d(x_pad, num_filters=nr_filters, filter_size=[2,1]))] # stream for up and to the left
receptive_field = (2, 3)
for rep in range(nr_resnet):
u_list.append(
gated_resnet(u_list[-1], conv=up_shifted_conv2d))
ul_list.append(
gated_resnet(ul_list[-1],
u_list[-1],
conv=up_left_shifted_conv2d))
receptive_field = (receptive_field[0] + 1,
receptive_field[1] + 2)
x_out = nin(tf.nn.elu(ul_list[-1]), nr_filters)
print(" * receptive_field", receptive_field)
return x_out
def __model(self, network_type="large"):
print("****** Building Graph ******")
# placeholders
if self.network_type == 'binary':
num_channels = 1
else:
num_channels = 3
self.x = tf.placeholder(tf.float32,
shape=(self.batch_size, self.img_size,
self.img_size, num_channels))
self.x_bar = tf.placeholder(tf.float32,
shape=(self.batch_size, self.img_size,
self.img_size, num_channels))
self.is_training = tf.placeholder(tf.bool, shape=())
self.dropout_p = tf.placeholder(tf.float32, shape=())
self.masks = tf.placeholder(tf.float32,
shape=(self.batch_size, self.img_size,
self.img_size))
self.input_masks = tf.placeholder(tf.float32,
shape=(self.batch_size,
self.img_size, self.img_size))
self.use_prior = tf.placeholder_with_default(False, shape=())
# choose network size
if self.img_size == 32:
if self.network_type == 'large':
encoder = conv_encoder_32_large
decoder = conv_decoder_32_large
else:
encoder = conv_encoder_32
decoder = conv_decoder_32
forward_pixelcnn = forward_pixel_cnn_32_small
reverse_pixelcnn = reverse_pixel_cnn_32_small
kwargs = {
"nonlinearity": self.nonlinearity,
"bn": self.bn,
"kernel_initializer": self.kernel_initializer,
"kernel_regularizer": self.kernel_regularizer,
"is_training": self.is_training,
"counters": self.counters,
}
with arg_scope([forward_pixelcnn, reverse_pixelcnn, encoder, decoder],
**kwargs):
kwargs_pixelcnn = {
"nr_resnet": self.nr_resnet,
"nr_filters": self.nr_filters,
"nr_logistic_mix": self.nr_logistic_mix,
"dropout_p": self.dropout_p,
"bn": False,
}
with arg_scope([forward_pixelcnn, reverse_pixelcnn],
**kwargs_pixelcnn):
inputs = self.x
if self.input_masks is not None:
inputs = inputs * broadcast_masks_tf(self.input_masks,
num_channels=3)
inputs += tf.random_uniform(int_shape(inputs), -1, 1) * (
1 -
broadcast_masks_tf(self.input_masks, num_channels=3))
inputs = tf.concat([
inputs,
broadcast_masks_tf(self.input_masks, num_channels=1)
],
axis=-1)
self.z_mu, self.z_log_sigma_sq = encoder(inputs, self.z_dim)
sigma = tf.exp(self.z_log_sigma_sq / 2.)
self.z = gaussian_sampler(self.z_mu, sigma)
self.z_pr = gaussian_sampler(tf.zeros_like(self.z_mu),
tf.ones_like(sigma))
self.z_ph = tf.placeholder_with_default(
tf.zeros_like(self.z_mu), shape=int_shape(self.z_mu))
self.use_z_ph = tf.placeholder_with_default(False, shape=())
use_prior = tf.cast(tf.cast(self.use_prior, tf.int32),
tf.float32)
use_z_ph = tf.cast(tf.cast(self.use_z_ph, tf.int32),
tf.float32)
z = (use_prior * self.z_pr + (1 - use_prior) * self.z) * (
1 - use_z_ph) + use_z_ph * self.z_ph
decoded_features = decoder(z, output_features=True)
r_outputs = reverse_pixelcnn(self.x_bar, self.masks, bn=False)
cond_features = tf.concat([r_outputs, decoded_features],
axis=-1)
self.mix_logistic_params = forward_pixelcnn(self.x_bar,
cond_features,
bn=False)
self.x_hat = mix_logistic_sampler(
self.mix_logistic_params,
nr_logistic_mix=self.nr_logistic_mix,
sample_range=self.sample_range,
counters=self.counters)
def __model(self,
x,
x_bar,
is_training,
dropout_p,
masks,
input_masks,
network_size="medium"):
print("****** Building Graph ******")
self.x = x
self.x_bar = x_bar
self.is_training = is_training
self.dropout_p = dropout_p
self.masks = masks
self.input_masks = input_masks
if int_shape(x)[1] == 64:
conv_encoder = conv_encoder_64_medium
conv_decoder = conv_decoder_64_medium
elif int_shape(x)[1] == 32:
if network_size == 'medium':
conv_encoder = conv_encoder_32_medium
conv_decoder = conv_decoder_32_medium
elif network_size == 'large':
conv_encoder = conv_encoder_32_large
conv_decoder = conv_decoder_32_large
elif network_size == 'large1':
conv_encoder = conv_encoder_32_large1
conv_decoder = conv_decoder_32_large1
else:
raise Exception("unknown network type")
with arg_scope(
[conv_encoder, conv_decoder, context_encoder, cond_pixel_cnn],
nonlinearity=self.nonlinearity,
bn=self.bn,
kernel_initializer=self.kernel_initializer,
kernel_regularizer=self.kernel_regularizer,
is_training=self.is_training,
counters=self.counters):
inputs = self.x
if self.input_masks is not None:
inputs = inputs * broadcast_masks_tf(self.input_masks,
num_channels=3)
inputs += tf.random_uniform(int_shape(inputs), -1, 1) * (
1 - broadcast_masks_tf(self.input_masks, num_channels=3))
inputs = tf.concat([
inputs,
broadcast_masks_tf(self.input_masks, num_channels=1)
],
axis=-1)
self.z_mu, self.z_log_sigma_sq = conv_encoder(inputs, self.z_dim)
sigma = tf.exp(self.z_log_sigma_sq / 2.)
if self.use_mode == 'train':
self.z = gaussian_sampler(self.z_mu, sigma)
elif self.use_mode == 'test':
self.z = tf.placeholder(tf.float32, shape=int_shape(self.z_mu))
print("use mode:{0}".format(self.use_mode))
self.decoded_features = conv_decoder(self.z, output_features=True)
if self.masks is None:
sh = self.decoded_features
else:
self.encoded_context = context_encoder(
self.x,
self.masks,
bn=False,
nr_resnet=self.nr_resnet,
nr_filters=self.nr_filters)
sh = tf.concat([self.decoded_features, self.encoded_context],
axis=-1)
if self.input_masks is not None:
sh = tf.concat([
broadcast_masks_tf(self.input_masks, num_channels=1),
sh
],
axis=-1)
self.mix_logistic_params = cond_pixel_cnn(
self.x_bar,
sh=sh,
bn=False,
dropout_p=self.dropout_p,
nr_resnet=self.nr_resnet,
nr_filters=self.nr_filters,
nr_logistic_mix=self.nr_logistic_mix)
self.x_hat = mix_logistic_sampler(
self.mix_logistic_params,
nr_logistic_mix=self.nr_logistic_mix,
sample_range=self.sample_range,
counters=self.counters)
def __model(self):
print("****** Building Graph ******")
# placeholders
if self.network_type == 'binary':
self.num_channels = 1
else:
self.num_channels = 3
self.x = tf.placeholder(tf.float32,
shape=(self.batch_size, self.img_size,
self.img_size, self.num_channels))
self.x_bar = tf.placeholder(tf.float32,
shape=(self.batch_size, self.img_size,
self.img_size, self.num_channels))
self.is_training = tf.placeholder(tf.bool, shape=())
self.dropout_p = tf.placeholder(tf.float32, shape=())
self.masks = tf.placeholder(tf.float32,
shape=(self.batch_size, self.img_size,
self.img_size))
self.input_masks = tf.placeholder(tf.float32,
shape=(self.batch_size,
self.img_size, self.img_size))
# choose network size
if self.img_size == 32:
if self.network_type == 'large':
encoder = conv_encoder_32_large_bn
decoder = conv_decoder_32_large_mixture_logistic
encoder_q = conv_encoder_32_q
else:
raise Exception("unknown network type")
elif self.img_size == 28:
if self.network_type == 'binary':
encoder = conv_encoder_28_binary
decoder = conv_decoder_28_binary
encoder_q = conv_encoder_28_binary_q
else:
raise Exception("unknown network type")
kwargs = {
"nonlinearity": self.nonlinearity,
"bn": self.bn,
"kernel_initializer": self.kernel_initializer,
"kernel_regularizer": self.kernel_regularizer,
"is_training": self.is_training,
"counters": self.counters,
}
with arg_scope([encoder, decoder, encoder_q], **kwargs):
inputs = self.x
self.num_particles = 16
inputs = inputs * broadcast_masks_tf(
self.masks, num_channels=self.num_channels)
inputs = tf.concat(
[inputs,
broadcast_masks_tf(self.masks, num_channels=1)],
axis=-1)
inputs_pos = tf.concat(
[self.x,
broadcast_masks_tf(self.masks, num_channels=1)],
axis=-1)
inputs = tf.concat([inputs, inputs_pos], axis=0)
z_mu, z_log_sigma_sq = encoder(inputs, self.z_dim)
self.z_mu_pr, self.z_mu = z_mu[:self.batch_size], z_mu[self.
batch_size:]
self.z_log_sigma_sq_pr, self.z_log_sigma_sq = z_log_sigma_sq[:self.batch_size], z_log_sigma_sq[
self.batch_size:]
self.z_mu, self.z_log_sigma_sq = self.z_mu_pr, self.z_log_sigma_sq_pr
x = tf.tile(self.x, [self.num_particles, 1, 1, 1])
masks = tf.tile(self.masks, [self.num_particles, 1, 1])
self.z_mu = tf.tile(self.z_mu, [self.num_particles, 1])
self.z_mu_pr = tf.tile(self.z_mu_pr, [self.num_particles, 1])
self.z_log_sigma_sq = tf.tile(self.z_log_sigma_sq,
[self.num_particles, 1])
self.z_log_sigma_sq_pr = tf.tile(self.z_log_sigma_sq_pr,
[self.num_particles, 1])
sigma = tf.exp(self.z_log_sigma_sq / 2.)
self.params = get_trainable_variables(["inference"])
dist = tf.distributions.Normal(loc=0., scale=1.)
epsilon = dist.sample(sample_shape=[
self.batch_size * self.num_particles, self.z_dim
],
seed=None)
z = self.z_mu + tf.multiply(epsilon, sigma)
if self.network_type == 'binary':
self.pixel_params = decoder(z)
else:
self.pixel_params = decoder(
z, nr_logistic_mix=self.nr_logistic_mix)
if self.network_type == 'binary':
nll = bernoulli_loss(x,
self.pixel_params,
masks=masks,
output_mean=False)
else:
nll = mix_logistic_loss(x,
self.pixel_params,
masks=masks,
output_mean=False)
log_prob_pos = dist.log_prob(epsilon)
epsilon_pr = (z - self.z_mu_pr) / tf.exp(
self.z_log_sigma_sq_pr / 2.)
log_prob_pr = dist.log_prob(epsilon_pr)
# convert back
log_prob_pr = tf.stack([
log_prob_pr[self.batch_size * i:self.batch_size * (i + 1)]
for i in range(self.num_particles)
],
axis=0)
log_prob_pos = tf.stack([
log_prob_pos[self.batch_size * i:self.batch_size * (i + 1)]
for i in range(self.num_particles)
],
axis=0)
log_prob_pr = tf.reduce_sum(log_prob_pr, axis=2)
log_prob_pos = tf.reduce_sum(log_prob_pos, axis=2)
nll = tf.stack([
nll[self.batch_size * i:self.batch_size * (i + 1)]
for i in range(self.num_particles)
],
axis=0)
log_likelihood = -nll
# log_weights = log_prob_pr + log_likelihood - log_prob_pos
log_weights = log_likelihood
log_sum_weight = tf.reduce_logsumexp(log_weights, axis=0)
log_avg_weight = log_sum_weight - tf.log(
tf.to_float(self.num_particles))
self.log_avg_weight = log_avg_weight
normalized_weights = tf.stop_gradient(
tf.nn.softmax(log_weights, axis=0))
sq_normalized_weights = tf.square(normalized_weights)
self.gradients = tf.gradients(
-tf.reduce_sum(sq_normalized_weights * log_weights, axis=0),
self.params,
colocate_gradients_with_ops=True)
def __model(self):
print("****** Building Graph ******")
# placeholders
if self.network_type == 'binary':
self.num_channels = 1
else:
self.num_channels = 3
self.x = tf.placeholder(tf.float32,
shape=(self.batch_size, self.img_size,
self.img_size, self.num_channels))
self.x_bar = tf.placeholder(tf.float32,
shape=(self.batch_size, self.img_size,
self.img_size, self.num_channels))
self.is_training = tf.placeholder(tf.bool, shape=())
self.dropout_p = tf.placeholder(tf.float32, shape=())
self.masks = tf.placeholder(tf.float32,
shape=(self.batch_size, self.img_size,
self.img_size))
self.input_masks = tf.placeholder(tf.float32,
shape=(self.batch_size,
self.img_size, self.img_size))
# choose network size
if self.img_size == 32:
if self.network_type == 'large':
encoder = conv_encoder_32_large_bn
decoder = conv_decoder_32_large_mixture_logistic
else:
raise Exception("unknown network type")
elif self.img_size == 28:
if self.network_type == 'binary':
encoder = conv_encoder_28_binary
decoder = conv_decoder_28_binary
else:
raise Exception("unknown network type")
kwargs = {
"nonlinearity": self.nonlinearity,
"bn": self.bn,
"kernel_initializer": self.kernel_initializer,
"kernel_regularizer": self.kernel_regularizer,
"is_training": self.is_training,
"counters": self.counters,
}
with arg_scope([encoder, decoder], **kwargs):
inputs = self.x
inputs = inputs * broadcast_masks_tf(
self.masks, num_channels=self.num_channels)
inputs = tf.concat(
[inputs,
broadcast_masks_tf(self.masks, num_channels=1)],
axis=-1)
self.z_mu, self.z_log_sigma_sq = encoder(inputs, self.z_dim)
sigma = tf.exp(self.z_log_sigma_sq / 2.)
self.z = gaussian_sampler(self.z_mu, sigma)
self.z_ph = tf.placeholder_with_default(tf.zeros_like(self.z_mu),
shape=int_shape(self.z_mu))
self.use_z_ph = tf.placeholder_with_default(False, shape=())
use_z_ph = tf.cast(tf.cast(self.use_z_ph, tf.int32), tf.float32)
z = self.z * (1 - use_z_ph) + use_z_ph * self.z_ph
if self.network_type == 'binary':
self.pixel_params = decoder(z)
self.x_hat = bernoulli_sampler(self.pixel_params,
counters=self.counters)
else:
self.pixel_params = decoder(
z, nr_logistic_mix=self.nr_logistic_mix)
self.x_hat = mix_logistic_sampler(
self.pixel_params,
nr_logistic_mix=self.nr_logistic_mix,
sample_range=self.sample_range,
counters=self.counters)
def __model(self):
print("****** Building Graph ******")
# placeholders
if self.network_type == 'binary':
self.num_channels = 1
else:
self.num_channels = 3
self.x = tf.placeholder(tf.float32,
shape=(self.batch_size, self.img_size,
self.img_size, self.num_channels))
self.x_bar = tf.placeholder(tf.float32,
shape=(self.batch_size, self.img_size,
self.img_size, self.num_channels))
self.is_training = tf.placeholder(tf.bool, shape=())
self.dropout_p = tf.placeholder(tf.float32, shape=())
self.masks = tf.placeholder(tf.float32,
shape=(self.batch_size, self.img_size,
self.img_size))
self.input_masks = tf.placeholder(tf.float32,
shape=(self.batch_size,
self.img_size, self.img_size))
# choose network size
if self.img_size == 32:
if self.network_type == 'large':
encoder = conv_encoder_32_large_bn
decoder = conv_decoder_32_large
encoder_q = conv_encoder_32_q
else:
encoder = conv_encoder_32
decoder = conv_decoder_32
forward_pixelcnn = forward_pixel_cnn_32_small
reverse_pixelcnn = reverse_pixel_cnn_32_small
elif self.img_size == 28:
if self.network_type == 'binary':
encoder = conv_encoder_28_binary
decoder = conv_decoder_28_binary
forward_pixelcnn = forward_pixel_cnn_28_binary
reverse_pixelcnn = reverse_pixel_cnn_28_binary
encoder_q = conv_encoder_28_binary_q
kwargs = {
"nonlinearity": self.nonlinearity,
"bn": self.bn,
"kernel_initializer": self.kernel_initializer,
"kernel_regularizer": self.kernel_regularizer,
"is_training": self.is_training,
"counters": self.counters,
}
with arg_scope(
[forward_pixelcnn, reverse_pixelcnn, encoder, decoder, encoder_q],
**kwargs):
kwargs_pixelcnn = {
"nr_resnet": self.nr_resnet,
"nr_filters": self.nr_filters,
"nr_logistic_mix": self.nr_logistic_mix,
"dropout_p": self.dropout_p,
"bn": False,
}
with arg_scope([forward_pixelcnn, reverse_pixelcnn],
**kwargs_pixelcnn):
self.num_particles = 16
inp = self.x * broadcast_masks_tf(
self.input_masks, num_channels=self.num_channels)
inp += tf.random_uniform(
int_shape(inp), -1, 1) * (1 - broadcast_masks_tf(
self.input_masks, num_channels=self.num_channels))
inp = tf.concat([
inp,
broadcast_masks_tf(self.input_masks, num_channels=1)
],
axis=-1)
inputs_pos = tf.concat([
self.x,
broadcast_masks_tf(tf.ones_like(self.input_masks),
num_channels=1)
],
axis=-1)
inp = tf.concat([inp, inputs_pos], axis=0)
z_mu, z_log_sigma_sq = encoder(inp, self.z_dim)
self.z_mu_pr, self.z_mu = z_mu[:self.batch_size], z_mu[
self.batch_size:]
self.z_log_sigma_sq_pr, self.z_log_sigma_sq = z_log_sigma_sq[:self.batch_size], z_log_sigma_sq[
self.batch_size:]
x = tf.tile(self.x, [self.num_particles, 1, 1, 1])
x_bar = tf.tile(self.x_bar, [self.num_particles, 1, 1, 1])
input_masks = tf.tile(self.input_masks,
[self.num_particles, 1, 1])
masks = tf.tile(self.masks, [self.num_particles, 1, 1])
self.z_mu_pr = tf.tile(self.z_mu_pr, [self.num_particles, 1])
self.z_log_sigma_sq_pr = tf.tile(self.z_log_sigma_sq_pr,
[self.num_particles, 1])
self.z_mu = tf.tile(self.z_mu, [self.num_particles, 1])
self.z_log_sigma_sq = tf.tile(self.z_log_sigma_sq,
[self.num_particles, 1])
self.z_mu, self.z_log_sigma_sq = self.z_mu_pr, self.z_log_sigma_sq_pr
sigma = tf.exp(self.z_log_sigma_sq / 2.)
self.params = get_trainable_variables(["inference"])
dist = tf.distributions.Normal(loc=0., scale=1.)
epsilon = dist.sample(sample_shape=[
self.batch_size * self.num_particles, self.z_dim
],
seed=None)
z = self.z_mu + tf.multiply(epsilon, sigma)
decoded_features = decoder(z, output_features=True)
r_outputs = reverse_pixelcnn(x, masks, context=None, bn=False)
cond_features = tf.concat([r_outputs, decoded_features],
axis=-1)
cond_features = tf.concat([
broadcast_masks_tf(input_masks, num_channels=1),
cond_features
],
axis=-1)
self.pixel_params = forward_pixelcnn(x_bar,
cond_features,
bn=False)
if self.network_type == 'binary':
nll = bernoulli_loss(x,
self.pixel_params,
masks=masks,
output_mean=False)
else:
nll = mix_logistic_loss(x,
self.pixel_params,
masks=masks,
output_mean=False)
log_prob_pos = dist.log_prob(epsilon)
epsilon_pr = (z - self.z_mu_pr) / tf.exp(
self.z_log_sigma_sq_pr / 2.)
log_prob_pr = dist.log_prob(epsilon_pr)
# convert back
log_prob_pr = tf.stack([
log_prob_pr[self.batch_size * i:self.batch_size * (i + 1)]
for i in range(self.num_particles)
],
axis=0)
log_prob_pos = tf.stack([
log_prob_pos[self.batch_size * i:self.batch_size * (i + 1)]
for i in range(self.num_particles)
],
axis=0)
log_prob_pr = tf.reduce_sum(log_prob_pr, axis=2)
log_prob_pos = tf.reduce_sum(log_prob_pos, axis=2)
nll = tf.stack([
nll[self.batch_size * i:self.batch_size * (i + 1)]
for i in range(self.num_particles)
],
axis=0)
log_likelihood = -nll
# log_weights = log_prob_pr + log_likelihood - log_prob_pos
log_weights = log_likelihood
log_sum_weight = tf.reduce_logsumexp(log_weights, axis=0)
log_avg_weight = log_sum_weight - tf.log(
tf.to_float(self.num_particles))
self.log_avg_weight = log_avg_weight
normalized_weights = tf.stop_gradient(
tf.nn.softmax(log_weights, axis=0))
sq_normalized_weights = tf.square(normalized_weights)
self.gradients = tf.gradients(-tf.reduce_sum(
sq_normalized_weights * log_weights, axis=0),
self.params,
colocate_gradients_with_ops=True)