def _apply_blur(image):
image_ = tf.expand_dims(image, axis=0)
kernel_ = tf.expand_dims(tf.expand_dims(tf.eye(3), 0), 0)
# Horizontal blur with distance sampled from beta distribution
horizontal_blur_ = tf.random_gamma([], horizontal_blur_alpha_)
horizontal_blur_ = horizontal_blur_ / (
horizontal_blur_ + tf.random_gamma([], horizontal_blur_beta_))
horizontal_blur_ = tf.cast(horizontal_blur_ * horizontal_blur_max_,
tf.int32) + 1
horizontal_blur_kernel_ = tf.tile(kernel_, (1, horizontal_blur_, 1, 1))
horizontal_blur_kernel_ = horizontal_blur_kernel_ / tf.cast(
horizontal_blur_, tf.float32)
image_ = tf.nn.conv2d(image_, horizontal_blur_kernel_, [1, 1, 1, 1],
'SAME')
# Vertical blur with distance sampled from beta distribution
vertical_blur_ = tf.random_gamma([], vertical_blur_alpha_)
vertical_blur_ = vertical_blur_ / (
vertical_blur_ + tf.random_gamma([], vertical_blur_beta_))
vertical_blur_ = tf.cast(vertical_blur_ * vertical_blur_max_, tf.int32) + 1
vertical_blur_kernel_ = tf.tile(kernel_, (vertical_blur_, 1, 1, 1))
vertical_blur_kernel_ = vertical_blur_kernel_ / tf.cast(
vertical_blur_, tf.float32)
image_ = tf.nn.conv2d(image_, vertical_blur_kernel_, [1, 1, 1, 1], 'SAME')
return image_[0]
def test_conv1d_weighted_gram(self,
input_size,
kernel_size,
output_size,
padding,
strides,
dtype=tf.float64,
atol=1.e-9,
block_size=0):
num_targets = 3
batch_size = 2
input_channels = 13
output_channels = 11
w = tf.random_normal(
dtype=dtype, shape=[kernel_size, input_channels, output_channels])
d = tf.random_gamma(
alpha=1,
dtype=dtype,
shape=[num_targets, batch_size, output_size, output_channels])
beta = tf.random_gamma(
alpha=1,
dtype=dtype,
shape=[num_targets, batch_size, input_size, input_channels])
proj = gram_calcs.conv_weighted_gram_abs_projection(
w, d, beta, padding, strides, block_size=block_size)
proj_slow = conv_weighted_gram_abs_projection_slow(
w, d, beta, padding, strides)
with tf.Session() as session:
proj_val, proj_slow_val = session.run((proj, proj_slow))
self.assertAllClose(proj_val, proj_slow_val, atol=atol)
def sample(self):
alpha_sample = tf.random_gamma(shape=(), alpha=self.alpha)
beta_sample = tf.random_gamma(shape=(), alpha=self.beta)
sample = alpha_sample / tf.maximum(x=(alpha_sample + beta_sample),
y=1e-6)
return self.min_value + sample * (self.max_value - self.min_value)
def q_theta_x(name, lay, x, reuse=False):
with tf.variable_scope('q_theta_x' + name, reuse=reuse):
# if lay == 1:
# bb = sio.loadmat('C:/Users/yulai/Dropbox/[201709]Variance Reduction/Python Code/data/tmpmat5111.mat')
# theta1 = tf.constant(bb['theta1'], dtype=tf.float32)
# theta_alpha1 = tf.constant(bb['theta_alpha1'], dtype=tf.float32)
# theta_beta1 = tf.constant(bb['theta_beta1'], dtype=tf.float32)
# else:
# h1 = x
h1 = tf.layers.batch_normalization(x)
h1 = tf.nn.relu(
tf.layers.dense(h1, units=h_dim[lay], kernel_initializer=tf.random_normal_initializer(0, 0.001)))
h1 = tf.nn.relu(
tf.layers.dense(h1, units=h_dim[lay], kernel_initializer=tf.random_normal_initializer(0, 0.001)))
theta_Ralpha1 = tf.layers.dense(h1, units=K[lay], kernel_initializer=tf.random_normal_initializer(0, 0.001))
theta_Ralpha1 = max_m_grad(min_theta_alpha_rate, theta_Ralpha1)
theta_alpha1 = tf.nn.softplus(theta_Ralpha1)
theta_Rbeta1 = tf.layers.dense(h1, units=K[lay], kernel_initializer=tf.random_normal_initializer(0, 0.001))
theta_Rbeta1 = max_m_grad(min_theta_beta_rate, theta_Rbeta1)
theta_beta1 = tf.nn.softplus(theta_Rbeta1)
theta_hat1s = tf.random_gamma([1], tf.stop_gradient(theta_alpha1), 1.)
theta_hat1s = tf.minimum(theta_hat1s,
theta_alpha1 + tf.maximum(3., 2. * tf.log(theta_alpha1)) * tf.sqrt(theta_alpha1))
theta_hat1s = tf.maximum(min_theta, tf.squeeze(theta_hat1s, 0))
Grad_theta_alpha1 = GO_Gamma_v2(tf.stop_gradient(theta_hat1s), tf.stop_gradient(theta_alpha1))
theta_hat1 = theta_alpha1 * tf.stop_gradient(Grad_theta_alpha1) - \
tf.stop_gradient(theta_alpha1 * Grad_theta_alpha1) + \
tf.stop_gradient(theta_hat1s)
theta1 = theta_hat1 / theta_beta1
# Next Layer - c_j
# h2 = theta1
h2 = tf.layers.batch_normalization(theta1)
# h2 = tf.nn.relu(tf.layers.dense(h2, units=128, kernel_initializer=tf.random_normal_initializer(0, 0.001)))
c_alpha2 = tf.layers.dense(h2, units=1, kernel_initializer=tf.random_normal_initializer(0, 0.001))
c_alpha2 = tf.nn.softplus(max_m_grad(min_theta_alpha_rate, c_alpha2))
c_beta2 = tf.layers.dense(h2, units=1, kernel_initializer=tf.random_normal_initializer(0, 0.001))
c_beta2 = tf.nn.softplus(max_m_grad(min_theta_beta_rate, c_beta2))
c_hat2s = tf.random_gamma([1], tf.stop_gradient(c_alpha2), 1.)
c_hat2s = tf.minimum(c_hat2s, c_alpha2 + tf.maximum(3., 2. * tf.log(c_alpha2)) * tf.sqrt(c_alpha2))
c_hat2s = tf.maximum(min_theta, tf.squeeze(c_hat2s, 0))
Grad_c_alpha2 = GO_Gamma_v2(tf.stop_gradient(c_hat2s), tf.stop_gradient(c_alpha2))
c_hat2 = c_alpha2 * tf.stop_gradient(Grad_c_alpha2) - \
tf.stop_gradient(c_alpha2 * Grad_c_alpha2) + \
tf.stop_gradient(c_hat2s)
c2 = 0.1 + c_hat2 / c_beta2
# c2 = max_m_grad(0.3, c2)
return theta1, theta_alpha1, theta_beta1, c2, c_alpha2, c_beta2
def sample(self):
# Non-deterministic: sample action using gamma distribution
alpha_sample = tf.random_gamma(shape=(), alpha=self.alpha)
beta_sample = tf.random_gamma(shape=(), alpha=self.beta)
sampled = beta_sample / tf.maximum(x=(alpha_sample + beta_sample),
y=1e-6)
return sampled
def testShape(self):
# Fully known shape.
rnd = tf.random_gamma([150], 2.0)
self.assertEqual([150], rnd.get_shape().as_list())
rnd = tf.random_gamma([150], 2.0, beta=[3.0, 4.0])
self.assertEqual([150, 2], rnd.get_shape().as_list())
rnd = tf.random_gamma([150], tf.ones([1, 2, 3]))
self.assertEqual([150, 1, 2, 3], rnd.get_shape().as_list())
rnd = tf.random_gamma([20, 30], tf.ones([1, 2, 3]))
self.assertEqual([20, 30, 1, 2, 3], rnd.get_shape().as_list())
rnd = tf.random_gamma([123], tf.placeholder(tf.float32, shape=(2, )))
self.assertEqual([123, 2], rnd.get_shape().as_list())
# Partially known shape.
rnd = tf.random_gamma(tf.placeholder(tf.int32, shape=(1, )),
tf.ones([7, 3]))
self.assertEqual([None, 7, 3], rnd.get_shape().as_list())
rnd = tf.random_gamma(tf.placeholder(tf.int32, shape=(3, )),
tf.ones([9, 6]))
self.assertEqual([None, None, None, 9, 6], rnd.get_shape().as_list())
# Unknown shape.
rnd = tf.random_gamma(tf.placeholder(tf.int32),
tf.placeholder(tf.float32))
self.assertIs(None, rnd.get_shape().ndims)
rnd = tf.random_gamma([50], tf.placeholder(tf.float32))
self.assertIs(None, rnd.get_shape().ndims)
def sample(self):
deterministic = self.mean
alpha_sample = tf.random_gamma(shape=(), alpha=self.alpha)
beta_sample = tf.random_gamma(shape=(), alpha=self.beta)
sample = beta_sample / tf.maximum(x=(alpha_sample + beta_sample),
y=util.epsilon)
return self.min_value + tf.where(condition=self.deterministic, x=deterministic, y=sample) * \
(self.max_value - self.min_value)
def _sample_n(self, n, seed=None):
seed = seed_stream.SeedStream(seed, "gamma_gamma")
rate = tf.random_gamma(shape=[n],
alpha=self.mixing_concentration,
beta=self.mixing_rate,
dtype=self.dtype,
seed=seed())
return tf.random_gamma(shape=[],
alpha=self.concentration,
beta=rate,
dtype=self.dtype,
seed=seed())
def testNoCSE(self):
"""CSE = constant subexpression eliminator.
SetIsStateful() should prevent two identical random ops from getting
merged.
"""
for dtype in tf.float16, tf.float32, tf.float64:
for use_gpu in [False, True]:
with self.test_session(use_gpu=use_gpu):
rnd1 = tf.random_gamma([24], 2.0, dtype=dtype)
rnd2 = tf.random_gamma([24], 2.0, dtype=dtype)
diff = rnd2 - rnd1
self.assertGreater(np.linalg.norm(diff.eval()), 0.1)
def _sample_n(self, n, seed=None):
seed = seed_stream.SeedStream(seed, "gamma_gamma")
rate = tf.random_gamma(
shape=[n],
alpha=self.mixing_concentration,
beta=self.mixing_rate,
dtype=self.dtype,
seed=seed())
return tf.random_gamma(
shape=[],
alpha=self.concentration,
beta=rate,
dtype=self.dtype,
seed=seed())
def tf_sample(self, distr_params, deterministic):
alpha, beta, alpha_beta, _ = distr_params
# Deterministic: mean as action
definite = beta / alpha_beta
# Non-deterministic: sample action using gamma distribution
alpha_sample = tf.random_gamma(shape=(), alpha=alpha)
beta_sample = tf.random_gamma(shape=(), alpha=beta)
sampled = beta_sample / tf.maximum(x=(alpha_sample + beta_sample), y=util.epsilon)
return self.min_value + (self.max_value - self.min_value) * \
tf.where(condition=deterministic, x=definite, y=sampled)
def _sample_n(self, n, seed=None):
expanded_concentration1 = tf.ones_like(
self.total_concentration, dtype=self.dtype) * self.concentration1
expanded_concentration0 = tf.ones_like(
self.total_concentration, dtype=self.dtype) * self.concentration0
gamma1_sample = tf.random_gamma(shape=[n],
alpha=expanded_concentration1,
dtype=self.dtype,
seed=seed)
gamma2_sample = tf.random_gamma(shape=[n],
alpha=expanded_concentration0,
dtype=self.dtype,
seed=util.gen_new_seed(seed, "beta"))
beta_sample = gamma1_sample / (gamma1_sample + gamma2_sample)
return beta_sample
def q_W(name, V, K, reuse=False):
with tf.variable_scope('q_W' + name, reuse=reuse):
W_aW = tf.get_variable("W_aW", [V, K], tf.float32,
tf.random_uniform_initializer(0.1, 10))
RW_aW = max_m_grad(min_W_alpha_rate, W_aW)
# RW_aW = tf.maximum(min_W_alpha_rate, W_aW)
W_alpha = tf.nn.softplus(RW_aW)
W_bW = tf.get_variable("W_bW", [V, K], tf.float32,
tf.random_uniform_initializer(0.1, 10))
RW_bW = max_m_grad(min_W_beta_rate, W_bW)
# RW_bW = tf.maximum(min_W_beta_rate, W_bW)
W_beta = tf.nn.softplus(RW_bW)
# W_beta = tf.nn.softplus(W_bW)
# W_beta = min_m_grad(W_alpha / min_mean, W_beta)
if MethodName == 'GO':
W_hat1s = tf.random_gamma([1], tf.stop_gradient(W_alpha), 1.)
W_hat1s = tf.maximum(min_W, tf.squeeze(W_hat1s, 0))
Grad_W_alpha1 = GO_Gamma_v2(tf.stop_gradient(W_hat1s), tf.stop_gradient(W_alpha))
W_hat1 = W_alpha * tf.stop_gradient(Grad_W_alpha1) - \
tf.stop_gradient(W_alpha * Grad_W_alpha1) + \
tf.stop_gradient(W_hat1s)
W1_Fcorr = tf.zeros([1])
if MethodName == 'GRep':
posi0 = tf.polygamma(tf.constant(0,dtype=tf.float32),W_alpha)
posi1 = tf.polygamma(tf.constant(1,dtype=tf.float32),W_alpha)
W_hat1s = tf.random_gamma([1], tf.stop_gradient(W_alpha), 1.)
W_hat1s = tf.maximum(min_W, tf.squeeze(W_hat1s, 0))
epsilo = tf.stop_gradient( (tf.log(W_hat1s)-posi0)/tf.maximum((tf.pow(posi1,0.5)),1e-8) )
log_W_hat1 = epsilo*tf.pow(posi1,0.5)+posi0
W_hat1 = tf.exp( log_W_hat1 )
W1_Fcorr = tf.reduce_sum(
- tf.lgamma(W_alpha) + (W_alpha-1.)*log_W_hat1 - W_hat1
+ log_W_hat1 + 0.5 * tf.log( posi1 )
)
if MethodName == 'RSVI':
lambda_W1 = tf.squeeze(tf.random_gamma([1], W_alpha + Bf, 1.), 0)
lambda_W1 = tf.stop_gradient(tf.maximum(min_W, lambda_W1))
W_hat1, W1_Fcorr = reject_h_boosted(lambda_W1, W_alpha)
W = W_hat1 / W_beta
# W = tf.maximum(min_W, W)
W = max_m_grad(min_W, W)
return W, W_alpha, W_beta, W1_Fcorr
def q_z_x(name, x, K, reuse=False):
with tf.variable_scope('q_z_x' + name, reuse=reuse):
# h1 = tf.nn.relu(tf.layers.dense(x, units=h_dim[1]))
h1 = x
z_Ralpha1 = tf.layers.dense(h1, units=K, kernel_initializer=tf.random_normal_initializer(0, 0.01))
z_Ralpha1 = max_m_grad(min_z_alpha_rate, z_Ralpha1)
# z_Ralpha1 = tf.maximum(min_z_alpha_rate, z_Ralpha1)
z_alpha1 = tf.nn.softplus(z_Ralpha1)
z_Rbeta1 = tf.layers.dense(h1, units=K, kernel_initializer=tf.random_normal_initializer(0, 0.01))
z_Rbeta1 = max_m_grad(min_z_beta_rate, z_Rbeta1)
# z_Rbeta1 = tf.maximum(min_z_beta_rate, z_Rbeta1)
z_beta1 = tf.nn.softplus(z_Rbeta1)
# z_beta1 = min_m_grad(z_alpha1 / min_mean, z_beta1)
if MethodName == 'GO':
z_hat1s = tf.random_gamma([1], tf.stop_gradient(z_alpha1), 1.)
z_hat1s = tf.maximum(min_z, tf.squeeze(z_hat1s, 0))
Grad_z_alpha1 = GO_Gamma_v2(tf.stop_gradient(z_hat1s), tf.stop_gradient(z_alpha1))
z_hat1 = z_alpha1 * tf.stop_gradient(Grad_z_alpha1) - \
tf.stop_gradient(z_alpha1 * Grad_z_alpha1) + \
tf.stop_gradient(z_hat1s)
z1_Fcorr = tf.zeros([1])
if MethodName == 'GRep':
posi0 = tf.polygamma(tf.constant(0,dtype=tf.float32),z_alpha1)
posi1 = tf.polygamma(tf.constant(1,dtype=tf.float32),z_alpha1)
z_hat1s = tf.random_gamma([1], tf.stop_gradient(z_alpha1), 1.)
z_hat1s = tf.maximum(min_z, tf.squeeze(z_hat1s, 0))
epsilo = tf.stop_gradient( (tf.log(z_hat1s)-posi0)/tf.maximum((tf.pow(posi1,0.5)),1e-5) )
log_z_hat1 = epsilo*tf.pow(posi1,0.5)+posi0
z_hat1 = tf.exp( log_z_hat1 )
z1_Fcorr = tf.reduce_sum(
- tf.lgamma(z_alpha1) + (z_alpha1-1.)*log_z_hat1 - z_hat1
+ log_z_hat1 + 0.5 * tf.log( posi1 )
)
if MethodName == 'RSVI':
lambda_z1 = tf.squeeze(tf.random_gamma([1], z_alpha1 + Bf, 1.), 0)
lambda_z1 = tf.stop_gradient(tf.maximum(min_z, lambda_z1))
z_hat1, z1_Fcorr = reject_h_boosted(lambda_z1, z_alpha1)
z1 = z_hat1 / z_beta1
# z1 = tf.maximum(min_z, z1)
z1 = max_m_grad(min_z, z1)
return z1, z_alpha1, z_beta1, z1_Fcorr
def func():
with self.test_session(use_gpu=use_gpu, graph=tf.Graph()) as sess:
rng = tf.random_gamma([num], alpha, beta=beta, dtype=dtype, seed=seed)
ret = np.empty([10, num])
for i in xrange(10):
ret[i, :] = sess.run(rng)
return ret
def _sample_n(self, n, seed=None):
# This implementation is equivalent to the one in tf.contrib.distributions.Wishart
batch_shape = self.batch_shape_tensor()
event_shape = self.event_shape_tensor()
stream = seed_stream.SeedStream(seed=seed, salt="Wishart")
shape = tf.concat([[n], batch_shape, event_shape], 0)
# Sample a normal full matrix
x = tf.random_normal(shape=shape, dtype=self.dtype, seed=stream())
# Sample the diagonal
g = tf.random_gamma(shape=[n],
alpha=self._multi_gamma_sequence(
0.5 * self.df, self.p),
beta=0.5,
dtype=self.dtype,
seed=stream())
# Discard the upper triangular part
x = tf.matrix_band_part(x, -1, 0)
# Set the diagonal
x = tf.matrix_set_diag(x, tf.sqrt(g))
# Scale with the Scale matrix, equivalent to matmul(sqrt(diag_scale), x)
x *= tf.sqrt(tf.exp(self.log_diag_scale[tf.newaxis, :, :, tf.newaxis]))
return x
def random():
"""
求随机值
:return:
"""
tf.set_random_seed(100)
# 均值（默认值=0.0）和标准差（默认值=1.0）、形状为 [M，N] 的正态分布随机数组：
n = tf.random_normal(shape=(3, 3), mean=0.0, stddev=1.0)
tn = tf.truncated_normal(shape=(3, 3), mean=0.0, stddev=1.0)
# 要在种子的[minval（default = 0），maxval] 范围内创建形状为[M，N] 的给定伽马分布随机数组
u = tf.random_uniform(shape=(3, 3), minval=1, maxval=10)
g = tf.random_gamma(shape=(3, 3), alpha=1)
# 数据截取
corp = tf.random_crop(g, size=(3, 2))
# 对数据进行混洗
sg = tf.random_shuffle(g)
with tf.Session() as sess:
logger.info("random_normal\n %s" % sess.run(n))
logger.info("truncated_normal\n %s" % sess.run(tn))
logger.info("random_uniform\n %s" % sess.run(u))
logger.info("random_gamma\n %s" % sess.run(g))
logger.info("random_crop\n %s" % sess.run(corp))
logger.info("random_shuffle\n %s" % sess.run(sg))
def _sample_n(self, n, seed):
batch_shape = self.batch_shape_tensor()
event_shape = self.event_shape_tensor()
batch_ndims = tf.shape(batch_shape)[0]
ndims = batch_ndims + 3 # sample_ndims=1, event_ndims=2
shape = tf.concat([[n], batch_shape, event_shape], 0)
stream = seed_stream.SeedStream(seed, salt="Wishart")
# Complexity: O(nbk**2)
x = tf.random_normal(shape=shape,
mean=0.,
stddev=1.,
dtype=self.dtype,
seed=stream())
# Complexity: O(nbk)
# This parametrization is equivalent to Chi2, i.e.,
# ChiSquared(k) == Gamma(alpha=k/2, beta=1/2)
expanded_df = self.df * tf.ones(
self.scale_operator.batch_shape_tensor(),
dtype=self.df.dtype.base_dtype)
g = tf.random_gamma(shape=[n],
alpha=self._multi_gamma_sequence(
0.5 * expanded_df, self.dimension),
beta=0.5,
dtype=self.dtype,
seed=stream())
# Complexity: O(nbk**2)
x = tf.matrix_band_part(x, -1, 0) # Tri-lower.
# Complexity: O(nbk)
x = tf.matrix_set_diag(x, tf.sqrt(g))
# Make batch-op ready.
# Complexity: O(nbk**2)
perm = tf.concat([tf.range(1, ndims), [0]], 0)
x = tf.transpose(x, perm)
shape = tf.concat([batch_shape, [event_shape[0]], [-1]], 0)
x = tf.reshape(x, shape)
# Complexity: O(nbM) where M is the complexity of the operator solving a
# vector system. For LinearOperatorLowerTriangular, each matmul is O(k^3) so
# this step has complexity O(nbk^3).
x = self.scale_operator.matmul(x)
# Undo make batch-op ready.
# Complexity: O(nbk**2)
shape = tf.concat([batch_shape, event_shape, [n]], 0)
x = tf.reshape(x, shape)
perm = tf.concat([[ndims - 1], tf.range(0, ndims - 1)], 0)
x = tf.transpose(x, perm)
if not self.input_output_cholesky:
# Complexity: O(nbk**3)
x = tf.matmul(x, x, adjoint_b=True)
return x
def _sample_n(self, n, seed=None):
gamma_sample = tf.random_gamma(
shape=[n],
alpha=self.concentration,
dtype=self.dtype,
seed=seed)
return gamma_sample / tf.reduce_sum(gamma_sample, -1, keepdims=True)
def _sample_n(self, n, seed=None):
return 1. / tf.random_gamma(
shape=[n],
alpha=self.concentration,
beta=self.rate,
dtype=self.dtype,
seed=seed)
def _sample_n(self, n, seed=None):
gamma_sample = tf.random_gamma(
shape=[n],
alpha=self.concentration,
dtype=self.dtype,
seed=seed)
return gamma_sample / tf.reduce_sum(gamma_sample, -1, keepdims=True)
def _get_histogram_var_by_type(self,
histogram_type,
shape,
name=None,
**kwargs):
with tf.name_scope(name, "get_hist_{}".format(histogram_type)):
if histogram_type == "normal":
# Make a normal distribution, with a shifting mean
mean = tf.Variable(kwargs['mean'])
stddev = tf.Variable(kwargs['stddev'])
return tf.random_normal(
shape=shape, mean=mean, stddev=stddev), [mean, stddev]
elif histogram_type == "gamma":
# Add a gamma distribution
alpha = tf.Variable(kwargs['alpha'])
return tf.random_gamma(shape=shape, alpha=alpha), [alpha]
elif histogram_type == "poisson":
lam = tf.Variable(kwargs['lam'])
return tf.random_poisson(shape=shape, lam=lam), [lam]
elif histogram_type == "uniform":
# Add a uniform distribution
maxval = tf.Variable(kwargs['maxval'])
return tf.random_uniform(shape=shape, maxval=maxval), [maxval]
raise Exception('histogram type error %s' % histogram_type,
'builtin type', self._histogram_distribute_list)
def sample_pi(self, alpha, beta):
Gam = tf.random_gamma([1],
alpha=alpha,
beta=beta,
name='Gam',
seed=None)[0]
return self.G_inv(Gam, alpha, beta)
def _sample_n(self, n, seed=None):
return 1. / tf.random_gamma(
shape=[n],
alpha=self.concentration,
beta=self.rate,
dtype=self.dtype,
seed=seed)
def sample_tf(self, x, training=None):
alphas = self.__call__(x, training)
alphas_sample = tf.random_gamma(shape=(), alpha=alphas)
alphas_sample_sum = utils.sum_keep_shape(alphas_sample, axis=-1)
alphas_sample_sum = tf.maximum(x=alphas_sample_sum, y=utils.epsilon)
sampled = alphas_sample / alphas_sample_sum
return self.min_value + (self.max_value - self.min_value) * sampled
def norm_posterior(dim, std0):
"""Initialise a posterior (diagonal) Normal distribution.
Parameters
----------
dim : tuple or list
the dimension of this distribution.
std0 : float
the initial (unoptimized) standard deviation of this distribution.
Returns
-------
Q : tf.distributions.Normal
the initialised posterior Normal object.
Note
----
This will make tf.Variables on the randomly initialised mean and standard
deviation of the posterior. The initialisation of the mean is from a Normal
with zero mean, and ``std0`` standard deviation, and the initialisation of
the standard deviation is from a gamma distribution with an alpha of
``std0`` and a beta of 1.
"""
mu_0 = tf.random_normal(dim, stddev=std0, seed=next(seedgen))
mu = tf.Variable(mu_0, name="W_mu_q")
std_0 = tf.random_gamma(alpha=std0, shape=dim, seed=next(seedgen))
std = pos(tf.Variable(std_0, name="W_std_q"))
Q = tf.distributions.Normal(loc=mu, scale=std)
return Q
def ApplyDepthImageDistortions(depth_images,
random_noise_level=0.05,
random_noise_apply_probability=0.5,
scaling_noise=True,
gamma_shape=1000.0,
gamma_scale_inverse=1000.0,
min_depth_allowed=0.25,
max_depth_allowed=2.5):
"""Apply photometric distortions to the input depth images.
Args:
depth_images: Tensor of shape [batch_size, h, w, 1] containing a batch of
depth images to apply the random photometric distortions to.
random_noise_level: The standard deviation of the Gaussian distribution for
the noise that is applied to the depth image. When 0.0, then no noise is
applied.
random_noise_apply_probability: Probability of applying additive random
noise to the images.
scaling_noise: If True; sample a random variable from a Gamma distribution
to scale the depth image.
gamma_shape: Float; shape parameter of a Gamma distribution.
gamma_scale_inverse: Float; inverse of scale parameter of a Gamma
distribution.
min_depth_allowed: Float; minimum clip value for depth.
max_depth_allowed: Float; max clip value for depth.
Returns:
depth_images: Tensor of shape [batch_size, h, w, 1] containing a
batch of images resulting from applying random photometric distortions to
the inputs.
"""
assert depth_images[0].get_shape().as_list()[-1] == 1
with tf.variable_scope('distortions_depth_images'):
# Add random Gaussian noise.
if random_noise_level:
for i, image in enumerate(depth_images):
img_shape = tf.shape(image)
rnd_noise = tf.random_normal(img_shape,
stddev=random_noise_level)
def ReturnImageTensor(value):
return lambda: value
if scaling_noise:
alpha = tf.random_gamma([], gamma_shape,
gamma_scale_inverse)
image = tf.cond(
tf.reduce_all(
tf.greater(tf.random.uniform([1]),
random_noise_apply_probability)),
ReturnImageTensor(image),
ReturnImageTensor(alpha * image + rnd_noise))
depth_images[i] = tf.reshape(image, img_shape)
# Clip to valid range.
for i, image in enumerate(depth_images):
depth_images[i] = tf.clip_by_value(image, min_depth_allowed,
max_depth_allowed)
return depth_images
def restore():
v = tf.Variable(tf.random_gamma(shape=(3, 3), alpha=10))
initial_op = tf.global_variables_initializer()
with tf.Session() as sess:
sess.run(initial_op)
logger.info(v)
saver = tf.train.Saver()
saver.restore(sess, save_path="./saver")
def _sample(self, alpha):
# broadcast alpha from scalar to vector, if necessary
alpha = alpha * tf.ones(shape=(self.shape[0]), dtype=self.dtype)
gammas = tf.squeeze(tf.random_gamma(shape=(1, ), alpha=alpha, beta=1))
sample = Normalize.transform(gammas)
return sample
def appx_remain_mass_mean_rate(n_samp, q_omega, q_beta, ii_tot_mass_m, q_w, su,
tu, a, b, K):
"""
Monte carlo approximation for expectation of the leftover mass rate.
E[leftover mass] = (mass_mean_rate)*size
"""
theta_rem_samp = tf.random_gamma([n_samp, K], a, b)
# we also need to draw samples from the total item mass
# this is potentially quite expensive, so we just approximate the sum as a Gamma
#compute the variance of the total item mass
ii_tot_mass_v = tf.reduce_sum(
q_beta.variance() * q_omega.variance() +
q_beta.variance() * tf.square(q_omega.mean()) +
tf.square(q_beta.mean()) * q_omega.variance(),
axis=0,
keep_dims=True)
ii_tot_mass_v = tf.transpose(ii_tot_mass_v)
# params for gamma dist approximation
ii_tot_mass_beta = ii_tot_mass_m / ii_tot_mass_v
ii_tot_mass_alpha = ii_tot_mass_m * ii_tot_mass_beta
# sample total item mass
i_tot_mass_sample = tf.squeeze(
tf.random_gamma(
[n_samp], alpha=ii_tot_mass_alpha, beta=ii_tot_mass_beta) +
q_w.sample([n_samp]))
# compute the estimate
denom = tf.pow(
tu + tf.reduce_sum(
theta_rem_samp * i_tot_mass_sample, axis=1, keep_dims=True),
1 - su)
leftover_samps = theta_rem_samp / denom
estimated_expect = tf.reduce_mean(leftover_samps, 0,
keep_dims=True) # monte carlo average
# can also compute variance... but it'll turn out to be really tiny
# var_samps = (1.-su) * tf.square(theta_rem_samp) / tf.pow(tu + tf.reduce_sum(theta_rem_samp*i_tot_mass_sample, axis=1, keep_dims=True), 2-su)
# estimated_var = tf.reduce_mean(var_samps, 0, keep_dims=True)
return tf.transpose(estimated_expect)
def assert_random_gamma_has_gradients():
"""Check that TensorFlow supports tf.random_gamma gradients."""
a = tf.constant(1.0)
gradient = tf.gradients(tf.random_gamma([], a), a)[0]
message = (
"This example requires tf.random_gamma gradients, introduced in"
" TensorFlow 1.10 RC0, to work correctly."
" Please upgrade TensorFlow to a newer version, e.g. tf-nightly.")
assert gradient is not None, message
def _sample_n(self, n, seed=None):
seed = seed_stream.SeedStream(seed, "beta")
expanded_concentration1 = tf.ones_like(
self.total_concentration, dtype=self.dtype) * self.concentration1
expanded_concentration0 = tf.ones_like(
self.total_concentration, dtype=self.dtype) * self.concentration0
gamma1_sample = tf.random_gamma(
shape=[n],
alpha=expanded_concentration1,
dtype=self.dtype,
seed=seed())
gamma2_sample = tf.random_gamma(
shape=[n],
alpha=expanded_concentration0,
dtype=self.dtype,
seed=seed())
beta_sample = gamma1_sample / (gamma1_sample + gamma2_sample)
return beta_sample
def _sample_n(self, n, seed):
batch_shape = self.batch_shape_tensor()
event_shape = self.event_shape_tensor()
batch_ndims = tf.shape(batch_shape)[0]
ndims = batch_ndims + 3 # sample_ndims=1, event_ndims=2
shape = tf.concat([[n], batch_shape, event_shape], 0)
stream = seed_stream.SeedStream(seed, salt="Wishart")
# Complexity: O(nbk**2)
x = tf.random_normal(
shape=shape, mean=0., stddev=1., dtype=self.dtype, seed=stream())
# Complexity: O(nbk)
# This parametrization is equivalent to Chi2, i.e.,
# ChiSquared(k) == Gamma(alpha=k/2, beta=1/2)
expanded_df = self.df * tf.ones(
self.scale_operator.batch_shape_tensor(),
dtype=self.df.dtype.base_dtype)
g = tf.random_gamma(
shape=[n],
alpha=self._multi_gamma_sequence(0.5 * expanded_df, self.dimension),
beta=0.5,
dtype=self.dtype,
seed=stream())
# Complexity: O(nbk**2)
x = tf.matrix_band_part(x, -1, 0) # Tri-lower.
# Complexity: O(nbk)
x = tf.matrix_set_diag(x, tf.sqrt(g))
# Make batch-op ready.
# Complexity: O(nbk**2)
perm = tf.concat([tf.range(1, ndims), [0]], 0)
x = tf.transpose(x, perm)
shape = tf.concat([batch_shape, [event_shape[0]], [-1]], 0)
x = tf.reshape(x, shape)
# Complexity: O(nbM) where M is the complexity of the operator solving a
# vector system. For LinearOperatorLowerTriangular, each matmul is O(k^3) so
# this step has complexity O(nbk^3).
x = self.scale_operator.matmul(x)
# Undo make batch-op ready.
# Complexity: O(nbk**2)
shape = tf.concat([batch_shape, event_shape, [n]], 0)
x = tf.reshape(x, shape)
perm = tf.concat([[ndims - 1], tf.range(0, ndims - 1)], 0)
x = tf.transpose(x, perm)
if not self.input_output_cholesky:
# Complexity: O(nbk**3)
x = tf.matmul(x, x, adjoint_b=True)
return x
def elbo_sample(self): """Unconditional, unboosted sample to get estimate of ELBO. This is a separate function to avoid stepping on freeze/thaw cycle.""" alpha = self.get_alpha() mean = self.get_mean() gamma_draw = tf.squeeze(tf.random_gamma([1], alpha, 1.0), [0]) * (mean / alpha) gamma_draw = tf.maximum(1e-300, gamma_draw) return gamma_draw
def random_exponential(shape, rate=1.0, dtype=tf.float32, seed=None):
"""
Helper function to sample from the exponential distribution, which is not
included in core TensorFlow.
"""
return tf.random_gamma(shape,
alpha=1,
beta=1. / rate,
dtype=dtype,
seed=seed)
def slice_sampler_one_dim(target_log_prob, x_initial, step_size=0.01,
max_doublings=30, seed=None, name=None):
"""For a given x position in each Markov chain, returns the next x.
Applies the one dimensional slice sampling algorithm as defined in Neal (2003)
to an input tensor x of shape (num_chains,) where num_chains is the number of
simulataneous Markov chains, and returns the next tensor x of shape
(num_chains,) when these chains are evolved by the slice sampling algorithm.
Args:
target_log_prob: Callable accepting a tensor like `x_initial` and returning
a tensor containing the log density at that point of the same shape.
x_initial: A tensor of any shape. The initial positions of the chains. This
function assumes that all the dimensions of `x_initial` are batch
dimensions (i.e. the event shape is `[]`).
step_size: A tensor of shape and dtype compatible with `x_initial`. The min
interval size in the doubling algorithm.
max_doublings: Scalar tensor of dtype `tf.int32`. The maximum number of
doublings to try to find the slice bounds.
seed: (Optional) positive int. The random seed. If None, no seed is set.
name: Python `str` name prefixed to Ops created by this function.
Default value: `None` (i.e., 'find_slice_bounds').
Returns:
retval: A tensor of the same shape and dtype as `x_initial`. The next state
of the Markov chain.
next_target_log_prob: The target log density evaluated at `retval`.
bounds_satisfied: A tensor of bool dtype and shape batch dimensions.
upper_bounds: Tensor of the same shape and dtype as `x_initial`. The upper
bounds for the slice found.
lower_bounds: Tensor of the same shape and dtype as `x_initial`. The lower
bounds for the slice found.
"""
with tf.name_scope(name, 'slice_sampler_one_dim',
[x_initial, step_size, max_doublings]):
x_initial = tf.convert_to_tensor(x_initial)
# Obtain the input dtype of the array.
dtype = x_initial.dtype.base_dtype
# Select the height of the slice. Tensor of shape x_initial.shape.
log_slice_heights = target_log_prob(x_initial) - tf.random_gamma(
tf.shape(x_initial), alpha=1, dtype=dtype, seed=seed)
# Given the above x and slice heights, compute the bounds of the slice for
# each chain.
upper_bounds, lower_bounds, bounds_satisfied = slice_bounds_by_doubling(
x_initial, target_log_prob, log_slice_heights, max_doublings, step_size,
seed=seed)
retval = _sample_with_shrinkage(x_initial, target_log_prob=target_log_prob,
log_slice_heights=log_slice_heights,
step_size=step_size,
lower_bounds=lower_bounds,
upper_bounds=upper_bounds, seed=seed)
return (retval, target_log_prob(retval), bounds_satisfied,
upper_bounds, lower_bounds)
def _sample_n(self, n, seed=None):
# Here we use the fact that if:
# lam ~ Gamma(concentration=total_count, rate=(1-probs)/probs)
# then X ~ Poisson(lam) is Negative Binomially distributed.
rate = tf.random_gamma(
shape=[n],
alpha=self.total_count,
beta=tf.exp(-self.logits),
dtype=self.dtype,
seed=seed)
return tf.random_poisson(
rate,
shape=[],
dtype=self.dtype,
seed=distribution_util.gen_new_seed(seed, "negative_binom"))
def _sample_n(self, n, seed=None):
# Here we use the fact that if:
# lam ~ Gamma(concentration=total_count, rate=(1-probs)/probs)
# then X ~ Poisson(lam) is Negative Binomially distributed.
stream = seed_stream.SeedStream(seed, salt="NegativeBinomial")
rate = tf.random_gamma(
shape=[n],
alpha=self.total_count,
beta=tf.exp(-self.logits),
dtype=self.dtype,
seed=stream())
return tf.random_poisson(
rate,
shape=[],
dtype=self.dtype,
seed=stream())
def testShape(self): # Fully known shape. rnd = tf.random_gamma([150], 2.0) self.assertEqual([150], rnd.get_shape().as_list()) rnd = tf.random_gamma([150], 2.0, beta=[3.0, 4.0]) self.assertEqual([150, 2], rnd.get_shape().as_list()) rnd = tf.random_gamma([150], tf.ones([1, 2, 3])) self.assertEqual([150, 1, 2, 3], rnd.get_shape().as_list()) rnd = tf.random_gamma([20, 30], tf.ones([1, 2, 3])) self.assertEqual([20, 30, 1, 2, 3], rnd.get_shape().as_list()) rnd = tf.random_gamma([123], tf.placeholder(tf.float32, shape=(2,))) self.assertEqual([123, 2], rnd.get_shape().as_list()) # Partially known shape. rnd = tf.random_gamma(tf.placeholder(tf.int32, shape=(1,)), tf.ones([7, 3])) self.assertEqual([None, 7, 3], rnd.get_shape().as_list()) rnd = tf.random_gamma(tf.placeholder(tf.int32, shape=(3,)), tf.ones([9, 6])) self.assertEqual([None, None, None, 9, 6], rnd.get_shape().as_list()) # Unknown shape. rnd = tf.random_gamma(tf.placeholder(tf.int32), tf.placeholder(tf.float32)) self.assertIs(None, rnd.get_shape().ndims) rnd = tf.random_gamma([50], tf.placeholder(tf.float32)) self.assertIs(None, rnd.get_shape().ndims)
def _sample_n(self, n, seed=None):
seed = seed_stream.SeedStream(seed, "normal_gamma")
shape = tf.concat([[n], self.batch_shape_tensor()], 0)
precision = tf.random_gamma(
shape=shape,
alpha=self.concentration,
beta=self.rate,
dtype=self.dtype,
seed=seed())
scale = tf.sqrt(1 / (self._lambda * precision))
mean = tf.random_normal(
shape=shape, mean=0., stddev=1., dtype=self.loc.dtype, seed=seed())
mean = mean * scale + self.loc
return tf.concat((tf.expand_dims(mean, axis=-1),
tf.expand_dims(precision, axis=-1)), axis=-1)
def _sample_n(self, n, seed=None):
# The sampling method comes from the fact that if:
# X ~ Normal(0, 1)
# Z ~ Chi2(df)
# Y = X / sqrt(Z / df)
# then:
# Y ~ StudentT(df).
seed = seed_stream.SeedStream(seed, "student_t")
shape = tf.concat([[n], self.batch_shape_tensor()], 0)
normal_sample = tf.random_normal(shape, dtype=self.dtype, seed=seed())
df = self.df * tf.ones(self.batch_shape_tensor(), dtype=self.dtype)
gamma_sample = tf.random_gamma(
[n],
0.5 * df,
beta=0.5,
dtype=self.dtype,
seed=seed())
samples = normal_sample * tf.rsqrt(gamma_sample / df)
return samples * self.scale + self.loc # Abs(scale) not wanted.
def run_all(logdir, verbose=False):
"""Generate a bunch of histogram data, and write it to logdir."""
del verbose
tf.set_random_seed(0)
k = tf.placeholder(tf.float32)
# Make a normal distribution, with a shifting mean
mean_moving_normal = tf.random_normal(shape=[1000], mean=(5*k), stddev=1)
# Record that distribution into a histogram summary
histogram_summary.op("normal/moving_mean",
mean_moving_normal,
description="A normal distribution whose mean changes "
"over time.")
# Make a normal distribution with shrinking variance
shrinking_normal = tf.random_normal(shape=[1000], mean=0, stddev=1-(k))
# Record that distribution too
histogram_summary.op("normal/shrinking_variance", shrinking_normal,
description="A normal distribution whose variance "
"shrinks over time.")
# Let's combine both of those distributions into one dataset
normal_combined = tf.concat([mean_moving_normal, shrinking_normal], 0)
# We add another histogram summary to record the combined distribution
histogram_summary.op("normal/bimodal", normal_combined,
description="A combination of two normal distributions, "
"one with a moving mean and one with "
"shrinking variance. The result is a "
"distribution that starts as unimodal and "
"becomes more and more bimodal over time.")
# Add a gamma distribution
gamma = tf.random_gamma(shape=[1000], alpha=k)
histogram_summary.op("gamma", gamma,
description="A gamma distribution whose shape "
"parameter, α, changes over time.")
# And a poisson distribution
poisson = tf.random_poisson(shape=[1000], lam=k)
histogram_summary.op("poisson", poisson,
description="A Poisson distribution, which only "
"takes on integer values.")
# And a uniform distribution
uniform = tf.random_uniform(shape=[1000], maxval=k*10)
histogram_summary.op("uniform", uniform,
description="A simple uniform distribution.")
# Finally, combine everything together!
all_distributions = [mean_moving_normal, shrinking_normal,
gamma, poisson, uniform]
all_combined = tf.concat(all_distributions, 0)
histogram_summary.op("all_combined", all_combined,
description="An amalgamation of five distributions: a "
"uniform distribution, a gamma "
"distribution, a Poisson distribution, and "
"two normal distributions.")
summaries = tf.summary.merge_all()
# Setup a session and summary writer
sess = tf.Session()
writer = tf.summary.FileWriter(logdir)
# Setup a loop and write the summaries to disk
N = 400
for step in xrange(N):
k_val = step/float(N)
summ = sess.run(summaries, feed_dict={k: k_val})
writer.add_summary(summ, global_step=step)
def log_dirichlet(self, size, scale=1.0):
mu = tf.random_gamma([1], scale * np.ones(size).astype(np.float32))
mu = tf.log(mu / tf.reduce_sum(mu))
return mu
