# Copyright 2015 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.
# ==============================================================================
"""Tests for initializers."""

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import math

import tensorflow as tf

distributions = tf.contrib.distributions


class GaussianTest(tf.test.TestCase):

  def testGaussianConjugateKnownSigmaPosterior(self):
    with tf.Session():
      mu0 = tf.constant([3.0])
      sigma0 = tf.constant([math.sqrt(10.0)])
      sigma = tf.constant([math.sqrt(2.0)])
      x = tf.constant([-2.5, 2.5, 4.0, 0.0, -1.0, 2.0])
      s = tf.reduce_sum(x)
      n = tf.size(x)
      prior = distributions.Gaussian(mu=mu0, sigma=sigma0)
      posterior = distributions.gaussian_conjugates_known_sigma_posterior(
          prior=prior, sigma=sigma, s=s, n=n)

      # Smoke test
      self.assertTrue(isinstance(posterior, distributions.Gaussian))
      posterior_log_pdf = posterior.log_pdf(x).eval()
      self.assertEqual(posterior_log_pdf.shape, (6,))

  def testGaussianConjugateKnownSigmaPosteriorND(self):
    with tf.Session():
      batch_size = 6
      mu0 = tf.constant([[3.0, -3.0]] * batch_size)
      sigma0 = tf.constant([[math.sqrt(10.0), math.sqrt(15.0)]] * batch_size)
      sigma = tf.constant([[math.sqrt(2.0)]] * batch_size)
      x = tf.transpose(
          tf.constant([[-2.5, 2.5, 4.0, 0.0, -1.0, 2.0]], dtype=tf.float32))
      s = tf.reduce_sum(x)
      n = tf.size(x)
      prior = distributions.Gaussian(mu=mu0, sigma=sigma0)
      posterior = distributions.gaussian_conjugates_known_sigma_posterior(
          prior=prior, sigma=sigma, s=s, n=n)

      # Smoke test
      self.assertTrue(isinstance(posterior, distributions.Gaussian))
      posterior_log_pdf = posterior.log_pdf(x).eval()
      self.assertEqual(posterior_log_pdf.shape, (6, 2))

  def testGaussianConjugateKnownSigmaNDPosteriorND(self):
    with tf.Session():
      batch_size = 6
      mu0 = tf.constant([[3.0, -3.0]] * batch_size)
      sigma0 = tf.constant([[math.sqrt(10.0), math.sqrt(15.0)]] * batch_size)
      sigma = tf.constant([[math.sqrt(2.0), math.sqrt(4.0)]] * batch_size)
      x = tf.constant([
          [-2.5, 2.5, 4.0, 0.0, -1.0, 2.0],
          [2.5, -2.5, -4.0, 0.0, 1.0, -2.0]], dtype=tf.float32)
      s = tf.reduce_sum(x, reduction_indices=[1])
      x = tf.transpose(x)  # Reshape to shape (6, 2)
      n = tf.constant([6] * 2)
      prior = distributions.Gaussian(mu=mu0, sigma=sigma0)
      posterior = distributions.gaussian_conjugates_known_sigma_posterior(
          prior=prior, sigma=sigma, s=s, n=n)

      # Smoke test
      self.assertTrue(isinstance(posterior, distributions.Gaussian))

      # Calculate log_pdf under the 2 models
      posterior_log_pdf = posterior.log_pdf(x)
      self.assertEqual(posterior_log_pdf.get_shape(), (6, 2))
      self.assertEqual(posterior_log_pdf.eval().shape, (6, 2))

  def testGaussianConjugateKnownSigmaPredictive(self):
    with tf.Session():
      batch_size = 6
      mu0 = tf.constant([3.0] * batch_size)
      sigma0 = tf.constant([math.sqrt(10.0)] * batch_size)
      sigma = tf.constant([math.sqrt(2.0)] * batch_size)
      x = tf.constant([-2.5, 2.5, 4.0, 0.0, -1.0, 2.0])
      s = tf.reduce_sum(x)
      n = tf.size(x)
      prior = distributions.Gaussian(mu=mu0, sigma=sigma0)
      predictive = distributions.gaussian_congugates_known_sigma_predictive(
          prior=prior, sigma=sigma, s=s, n=n)

      # Smoke test
      self.assertTrue(isinstance(predictive, distributions.Gaussian))
      predictive_log_pdf = predictive.log_pdf(x).eval()
      self.assertEqual(predictive_log_pdf.shape, (6,))


if __name__ == '__main__':
  tf.test.main()
