def test_gradient_density_approximation(self):
"""Tests the function `gradient_density_approximation`.
A histogram is saved at
"tools/pseudo_visualization/gradient_density_approximation.png".
The test is successful if the histogram
absolute values are smaller than 1.e-9.
"""
nb_points_per_interval = 10
nb_intervals_per_side = 4
nb_points = 2*nb_intervals_per_side*nb_points_per_interval + 1
grid = numpy.linspace(-nb_intervals_per_side,
nb_intervals_per_side,
num=nb_points)
parameters = scipy.stats.distributions.norm.pdf(grid,
loc=0.,
scale=1.)
# There is an intentional mismatch between
# the probability density function for generating
# the samples and the probability density function
# for creating the parameters of the piecewise
# linear function.
samples = numpy.random.normal(loc=0.,
scale=0.6,
size=200)
gradients = tls.gradient_density_approximation(samples,
parameters,
nb_points_per_interval,
nb_intervals_per_side)
offset = 1.e-4
approx = numpy.zeros(nb_points)
for i in range(nb_points):
parameters_pos = parameters.copy()
parameters_pos[i] += offset
loss_pos = tls.loss_density_approximation(samples,
parameters_pos,
nb_points_per_interval,
nb_intervals_per_side)
parameters_neg = parameters.copy()
parameters_neg[i] -= offset
loss_neg = tls.loss_density_approximation(samples,
parameters_neg,
nb_points_per_interval,
nb_intervals_per_side)
approx[i] = 0.5*(loss_pos - loss_neg)/offset
tls.histogram(gradients - approx,
'Gradient checking for the opposite mean probability',
'tools/pseudo_visualization/gradient_density_approximation.png')
def test_noise(self):
"""Tests the function `noise`.
A histogram is saved at
"tools/pseudo_visualization/noise.png".
The test is successful if the histogram
looks like that of the uniform distribution
of support [-0.5, 0.5].
"""
samples = tls.noise(100, 200)
tls.histogram(samples.flatten(),
'Noise from the uniform distribution of support [-0.5, 0.5]',
'tools/pseudo_visualization/noise.png')
def test_histogram(self):
"""Tests the function `histogram`.
A histogram is saved at
"tools/pseudo_visualization/histogram.png".
The test is successful if the selected
number of bins (60) gives a good histogram
of 2000 data points.
"""
data = numpy.random.normal(loc=0., scale=1., size=2000)
tls.histogram(data,
'Standard normal distribution',
'tools/pseudo_visualization/histogram.png')
def checking_area_under_piecewise_linear_functions(self, sess, title,
path):
"""Creates the histogram of the areas under the piecewise linear functions and saves the histogram.
Parameters
----------
sess : Session
Session that runs the graph.
title : str
Title of the histogram.
path : str
Path to the saved histogram. The
path ends with ".png".
"""
area = sess.run(self.node_area)
tls.histogram(area, title, path)
def test_encode_mini_batches(self):
"""Tests the function `encode_mini_batches` in the file "eae/batching.py".
For i = 0 ... 3, an histogram is saved at
"eae/pseudo_visualization/encode_mini_batches/latent_variables_i.png".
The test is successful if, in the first histogram,
all the values are around 0. In the third histogram,
most of the values must be around 0.
"""
batch_size = 2
h_in = 64
w_in = 48
path_to_nb_itvs_per_side_load = ''
path_to_restore = ''
# 2 batches of luminance images will be created
# by the function `encode_mini_batches`.
luminances_uint8 = numpy.random.randint(0,
high=256,
size=(2*batch_size, h_in, w_in, 1),
dtype=numpy.uint8)
luminances_uint8[0, :, :, :] = 0
luminances_uint8[1, :, :, :] = 255
luminances_uint8[2, :, :, :] = 0
# Only a portion of the luminance image of index
# 2 is white.
luminances_uint8[2, 0:2, 0:2, :] = 255
entropy_ae = EntropyAutoencoder(batch_size,
h_in,
w_in,
1.,
12000.,
path_to_nb_itvs_per_side_load,
False)
with tf.Session() as sess:
entropy_ae.initialization(sess, path_to_restore)
y_float32 = eae.batching.encode_mini_batches(luminances_uint8,
sess,
entropy_ae,
batch_size)
for i in range(luminances_uint8.shape[0]):
tls.histogram(y_float32[i, :, :, :].flatten(),
'Latent variables distribution for the image of index {}'.format(i),
'eae/pseudo_visualization/encode_mini_batches/latent_variables_{}.png'.format(i))
def checking_p_1(self, str_scope, str_variable, title, path):
"""Creates the histogram of a variable and saves the histogram.
Parameters
----------
str_scope : str
Scope of the variable.
str_variable : str
Name of the variable.
title : str
Title of the histogram.
path : str
Path to the saved histogram. The
path ends with ".png".
"""
with tf.variable_scope(str_scope, reuse=True):
variable = tf.get_variable(str_variable, dtype=tf.float32).eval()
tls.histogram(variable.flatten(), title, path)
def test_decode_mini_batches(self):
"""Tests the function `decode_mini_batches` in the file "eae/batching.py".
For i = 0 ... 3, an histogram is saved at
"eae/pseudo_visualization/decode_mini_batches/reconstructed_pixels_i.png".
The test is successful if, in the first histogram,
all the values are the same.
"""
batch_size = 2
h_in = 64
w_in = 48
path_to_restore = ''
# 2 batches of quantized latent variables will be created
# by the function `decode_mini_batches`.
quantized_y_float32 = numpy.random.randint(
-6,
high=6,
size=(2*batch_size, h_in//csts.STRIDE_PROD, w_in//csts.STRIDE_PROD, csts.NB_MAPS_3)
).astype(numpy.float32)
quantized_y_float32[0, :, :, :] = 0.
isolated_decoder = IsolatedDecoder(batch_size,
h_in,
w_in,
False)
with tf.Session() as sess:
isolated_decoder.initialization(sess, path_to_restore)
reconstruction_uint8 = eae.batching.decode_mini_batches(quantized_y_float32,
sess,
isolated_decoder,
batch_size)
for i in range(reconstruction_uint8.shape[0]):
tls.histogram(reconstruction_uint8[i, :, :, :].flatten(),
'Pixel distribution for the reconstructed image of index {}'.format(i),
'eae/pseudo_visualization/decode_mini_batches/reconstructed_pixels_{}.png'.format(i))
def test_gradient_entropy(self):
"""Tests the function `gradient_entropy`.
A histogram is saved at
"tools/pseudo_visualization/gradient_entropy.png".
The test is successful if the histogram
absolute values are smaller than 1.e-9.
"""
nb_points_per_interval = 10
nb_intervals_per_side = 10
height_samples = 24
width_samples = 32
nb_points = 2*nb_intervals_per_side*nb_points_per_interval + 1
grid = numpy.linspace(-nb_intervals_per_side,
nb_intervals_per_side,
num=nb_points)
parameters = scipy.stats.distributions.norm.pdf(grid,
loc=0.,
scale=1.)
samples = numpy.random.normal(loc=0.,
scale=1.,
size=(height_samples, width_samples))
gradients = tls.gradient_entropy(samples,
parameters,
nb_points_per_interval,
nb_intervals_per_side)
# `idx_initial` stores the linear piece
# index of each sample before the gradient
# checking.
idx_initial = tls.index_linear_piece(samples.flatten(),
nb_points_per_interval,
nb_intervals_per_side)
offset = 1.e-4
approx = numpy.zeros((height_samples, width_samples))
# `is_non_diff_fct` becomes true if the
# non-differentiability of the piecewise
# linear function at the edges of pieces
# wrecks the gradient checking.
is_non_diff_fct = False
for i in range(height_samples):
for j in range(width_samples):
samples_pos = samples.copy()
samples_pos[i, j] += offset
# `idx_pos` stores the linear piece
# index of each sample after adding
# an offset.
idx_pos = tls.index_linear_piece(samples_pos.flatten(),
nb_points_per_interval,
nb_intervals_per_side)
diff_entropy_pos = tls.differential_entropy(samples_pos.flatten(),
parameters,
nb_points_per_interval,
nb_intervals_per_side)
samples_neg = samples.copy()
samples_neg[i, j] -= offset
# `idx_neg` stores the linear piece
# index of each sample after subtracting
# an offset.
idx_neg = tls.index_linear_piece(samples_neg.flatten(),
nb_points_per_interval,
nb_intervals_per_side)
diff_entropy_neg = tls.differential_entropy(samples_neg.flatten(),
parameters,
nb_points_per_interval,
nb_intervals_per_side)
approx[i, j] = 0.5*(diff_entropy_pos - diff_entropy_neg)/offset
is_idx_pos_changed = not numpy.array_equal(idx_initial, idx_pos)
is_idx_neg_changed = not numpy.array_equal(idx_initial, idx_neg)
if is_idx_pos_changed or is_idx_neg_changed:
is_non_diff_fct = True
diff = (gradients/height_samples) - approx
if is_non_diff_fct:
warnings.warn('The non-differentiability of the piecewise linear function wrecks the gradient checking. Re-run it.')
else:
tls.histogram(diff.flatten(),
'Gradient checking for the differential entropy',
'tools/pseudo_visualization/gradient_entropy.png')
args.nb_test,
paths_to_outputs)
# `training_uint8.dtype` is equal to `numpy.uint8`.
training_uint8 = numpy.load(paths_to_outputs[0])
mean_training = numpy.load(paths_to_outputs[3])
std_training = numpy.load(paths_to_outputs[4])
sample_uint8 = training_uint8[0:nb_display, :]
# The function `svhn.svhn.preprocess_svhn` checks
# that `sample_uint8.dtype` is equal to `numpy.uint8`
# and `sample_uint8.ndim` is equal to 2.
sample_float64 = svhn.svhn.preprocess_svhn(sample_uint8,
mean_training,
std_training)
tls.visualize_rows(sample_uint8,
32,
32,
10,
'svhn/visualization/sample_training.png')
mu = numpy.mean(sample_float64, axis=0)
sigma = numpy.sqrt(numpy.mean((sample_float64 - numpy.tile(mu, (nb_display, 1)))**2, axis=0))
tls.histogram(mu,
'Mean of each pixel over {} training images after preprocessing'.format(nb_display),
'svhn/visualization/mean_after_preprocessing.png')
tls.histogram(sigma,
'Std of each pixel over {} training images after preprocessing'.format(nb_display),
'svhn/visualization/std_after_preprocessing.png')
def fit_maps(y_float32, path_to_histogram_locations, path_to_histogram_scales, paths, idx_map_exception=None):
"""Fits a Laplace density to the normed histogram of each latent variable feature map.
Parameters
----------
y_float32 : numpy.ndarray
4D array with data-type `numpy.float32`.
Latent variables. `y_float32[i, :, :, j]`
is the jth latent variable feature map of
the ith example.
path_to_histogram_locations : str
Path to the histogram of the Laplace locations. The
path ends with ".png".
path_to_histogram_scales : str
Path to the histogram of the Laplace scales. The
path ends with ".png".
paths : list
`paths[i]` is the path to the fitted normed histogram
for the ith latent variable feature map. Each path ends
with ".png".
idx_map_exception : int, optional
Index of the latent variable feature map that is
not compressed as the other maps. The default value
is None.
Raises
------
ValueError
If `len(paths)` is not equal to `y_float32.shape[3]`.
"""
if len(paths) != y_float32.shape[3]:
raise ValueError('`len(paths)` is not equal to `y_float32.shape[3]`.')
locations = []
scales = []
for i in range(y_float32.shape[3]):
map_float32 = y_float32[:, :, :, i]
edge_left = numpy.floor(numpy.amin(map_float32)).item()
edge_right = numpy.ceil(numpy.amax(map_float32)).item()
# The grid below contains 50 points
# per unit interval.
grid = numpy.linspace(edge_left,
edge_right,
num=50*int(edge_right - edge_left) + 1)
# Let's assume that `map_float32` contains i.i.d samples
# from an unknown probability density function. The two
# equations below result from the minimization of the
# Kullback-Lieber divergence of the unknown probability
# density function from our statistical model (Laplace
# density of location `laplace_location` and scale
# `laplace_scale`). Note that this minimization is
# equivalent to the maximum likelihood estimator.
# To dive into the details, see:
# "Estimating distributions and densities". 36-402,
# advanced data analysis, CMU, 27 January 2011.
laplace_location = numpy.mean(map_float32).item()
laplace_scale = numpy.mean(numpy.absolute(map_float32 - laplace_location)).item()
laplace_pdf = scipy.stats.laplace.pdf(grid,
loc=laplace_location,
scale=laplace_scale)
handle = [plt.plot(grid, laplace_pdf, color='red')[0]]
hist, bin_edges = numpy.histogram(map_float32,
bins=60,
density=True)
plt.bar(bin_edges[0:60],
hist,
width=bin_edges[1] - bin_edges[0],
align='edge',
color='blue')
plt.title('Latent variable feature map {}'.format(i + 1))
plt.legend(handle,
[r'$f( . ; {0}, {1})$'.format(str(round(laplace_location, 2)), str(round(laplace_scale, 2)))],
prop={'size': 30},
loc=9)
plt.savefig(paths[i])
plt.clf()
if idx_map_exception is None:
locations.append(laplace_location)
scales.append(laplace_scale)
else:
if i != idx_map_exception:
locations.append(laplace_location)
scales.append(laplace_scale)
# `len(locations)` and `len(scales)` are equal.
tls.histogram(numpy.array(locations),
'Histogram of {} locations'.format(len(locations)),
path_to_histogram_locations)
tls.histogram(numpy.array(scales),
'Histogram of {} scales'.format(len(scales)),
path_to_histogram_scales)