# Copyright 2017 The TensorFlow Authors 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
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# ==============================================================================

"""Activation and weight binarizer implementations."""

import math

import numpy as np
import tensorflow as tf


def ConvertSignCodeToZeroOneCode(x):
  """Conversion from codes {-1, +1} to codes {0, 1}."""
  return 0.5 * (x + 1.0)


def ConvertZeroOneCodeToSignCode(x):
  """Convert from codes {0, 1} to codes {-1, +1}."""
  return 2.0 * x - 1.0


def CheckZeroOneCode(x):
  return tf.reduce_all(tf.equal(x * (x - 1.0), 0))