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# Copyright 2018 Google, Inc. All Rights Reserved. | |
# | |
# Licensed under the Apache License, Version 2.0 (the "License"); | |
# you may not use this file except in compliance with the License. | |
# You may obtain a copy of the License at | |
# | |
# http://www.apache.org/licenses/LICENSE-2.0 | |
# | |
# Unless required by applicable law or agreed to in writing, software | |
# distributed under the License is distributed on an "AS IS" BASIS, | |
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
# See the License for the specific language governing permissions and | |
# limitations under the License. | |
# ============================================================================== | |
from __future__ import absolute_import | |
from __future__ import division | |
from __future__ import print_function | |
import sonnet as snt | |
import tensorflow as tf | |
import numpy as np | |
import collections | |
from learning_unsupervised_learning import utils | |
from tensorflow.python.util import nest | |
from learning_unsupervised_learning import variable_replace | |
class LinearBatchNorm(snt.AbstractModule): | |
"""Module that does a Linear layer then a BatchNorm followed by an activation fn""" | |
def __init__(self, size, activation_fn=tf.nn.relu, name="LinearBatchNorm"): | |
self.size = size | |
self.activation_fn = activation_fn | |
super(LinearBatchNorm, self).__init__(name=name) | |
def _build(self, x): | |
x = tf.to_float(x) | |
initializers={"w": tf.truncated_normal_initializer(stddev=0.01)} | |
lin = snt.Linear(self.size, use_bias=False, initializers=initializers) | |
z = lin(x) | |
scale = tf.constant(1., dtype=tf.float32) | |
offset = tf.get_variable( | |
"b", | |
shape=[1, z.shape.as_list()[1]], | |
initializer=tf.truncated_normal_initializer(stddev=0.1), | |
dtype=tf.float32 | |
) | |
mean, var = tf.nn.moments(z, [0], keep_dims=True) | |
z = ((z - mean) * tf.rsqrt(var + 1e-6)) * scale + offset | |
x_p = self.activation_fn(z) | |
return z, x_p | |
# This needs to work by string name sadly due to how the variable replace | |
# works and would also work even if the custom getter approuch was used. | |
# This is verbose, but it should atleast be clear as to what is going on. | |
# TODO(lmetz) a better way to do this (the next 3 functions: | |
# _raw_name, w(), b() ) | |
def _raw_name(self, var_name): | |
"""Return just the name of the variable, not the scopes.""" | |
return var_name.split("/")[-1].split(":")[0] | |
def w(self): | |
var_list = snt.get_variables_in_module(self) | |
w = [x for x in var_list if self._raw_name(x.name) == "w"] | |
assert len(w) == 1 | |
return w[0] | |
def b(self): | |
var_list = snt.get_variables_in_module(self) | |
b = [x for x in var_list if self._raw_name(x.name) == "b"] | |
assert len(b) == 1 | |
return b[0] | |
class Linear(snt.AbstractModule): | |
def __init__(self, size, use_bias=True, init_const_mag=True): | |
self.size = size | |
self.use_bias = use_bias | |
self.init_const_mag = init_const_mag | |
super(Linear, self).__init__(name="commonLinear") | |
def _build(self, x): | |
if self.init_const_mag: | |
initializers={"w": tf.truncated_normal_initializer(stddev=0.01)} | |
else: | |
initializers={} | |
lin = snt.Linear(self.size, use_bias=self.use_bias, initializers=initializers) | |
z = lin(x) | |
return z | |
# This needs to work by string name sadly due to how the variable replace | |
# works and would also work even if the custom getter approuch was used. | |
# This is verbose, but it should atleast be clear as to what is going on. | |
# TODO(lmetz) a better way to do this (the next 3 functions: | |
# _raw_name, w(), b() ) | |
def _raw_name(self, var_name): | |
"""Return just the name of the variable, not the scopes.""" | |
return var_name.split("/")[-1].split(":")[0] | |
def w(self): | |
var_list = snt.get_variables_in_module(self) | |
if self.use_bias: | |
assert len(var_list) == 2, "Found not 2 but %d" % len(var_list) | |
else: | |
assert len(var_list) == 1, "Found not 1 but %d" % len(var_list) | |
w = [x for x in var_list if self._raw_name(x.name) == "w"] | |
assert len(w) == 1 | |
return w[0] | |
def b(self): | |
var_list = snt.get_variables_in_module(self) | |
assert len(var_list) == 2, "Found not 2 but %d" % len(var_list) | |
b = [x for x in var_list if self._raw_name(x.name) == "b"] | |
assert len(b) == 1 | |
return b[0] | |
def transformer_at_state(base_model, new_variables): | |
"""Get the base_model that has been transformed to use the variables | |
in final_state. | |
Args: | |
base_model: snt.Module | |
Goes from batch to features | |
new_variables: list | |
New list of variables to use | |
Returns: | |
func: callable of same api as base_model. | |
""" | |
assert not variable_replace.in_variable_replace_scope() | |
def _feature_transformer(input_data): | |
"""Feature transformer at the end of training.""" | |
initial_variables = base_model.get_variables() | |
replacement = collections.OrderedDict( | |
utils.eqzip(initial_variables, new_variables)) | |
with variable_replace.variable_replace(replacement): | |
features = base_model(input_data) | |
return features | |
return _feature_transformer | |