# Copyright 2016 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
# limitations under the License.
# ==============================================================================

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

import numpy as np

from tensorflow.contrib import linalg as linalg_lib
from tensorflow.contrib.linalg.python.ops import linear_operator_test_util
from tensorflow.python.framework import dtypes
from tensorflow.python.framework import ops
from tensorflow.python.framework import random_seed
from tensorflow.python.ops import array_ops
from tensorflow.python.ops import math_ops
from tensorflow.python.platform import test

linalg = linalg_lib
random_seed.set_random_seed(23)


class SquareLinearOperatorFullMatrixTest(
    linear_operator_test_util.SquareLinearOperatorDerivedClassTest):
  """Most tests done in the base class LinearOperatorDerivedClassTest."""

  def _operator_and_mat_and_feed_dict(self, shape, dtype, use_placeholder):
    shape = list(shape)

    matrix = linear_operator_test_util.random_positive_definite_matrix(shape,
                                                                       dtype)

    if use_placeholder:
      matrix_ph = array_ops.placeholder(dtype=dtype)
      # Evaluate here because (i) you cannot feed a tensor, and (ii)
      # values are random and we want the same value used for both mat and
      # feed_dict.
      matrix = matrix.eval()
      operator = linalg.LinearOperatorFullMatrix(matrix_ph, is_square=True)
      feed_dict = {matrix_ph: matrix}
    else:
      # is_square should be auto-detected here.
      operator = linalg.LinearOperatorFullMatrix(matrix)
      feed_dict = None

    # Convert back to Tensor.  Needed if use_placeholder, since then we have
    # already evaluated matrix to a numpy array.
    mat = ops.convert_to_tensor(matrix)

    return operator, mat, feed_dict

  def test_is_x_flags(self):
    # Matrix with two positive eigenvalues.
    matrix = [[1., 0.], [1., 11.]]
    operator = linalg.LinearOperatorFullMatrix(
        matrix,
        is_positive_definite=True,
        is_non_singular=True,
        is_self_adjoint=False)
    self.assertTrue(operator.is_positive_definite)
    self.assertTrue(operator.is_non_singular)
    self.assertFalse(operator.is_self_adjoint)
    # Auto-detected.
    self.assertTrue(operator.is_square)

  def test_assert_non_singular_raises_if_cond_too_big_but_finite(self):
    with self.test_session():
      tril = linear_operator_test_util.random_tril_matrix(
          shape=(50, 50), dtype=np.float32)
      diag = np.logspace(-2, 2, 50).astype(np.float32)
      tril = array_ops.matrix_set_diag(tril, diag)
      matrix = math_ops.matmul(tril, tril, transpose_b=True).eval()
      operator = linalg.LinearOperatorFullMatrix(matrix)
      with self.assertRaisesOpError("Singular matrix"):
        # Ensure that we have finite condition number...just HUGE.
        cond = np.linalg.cond(matrix)
        self.assertTrue(np.isfinite(cond))
        self.assertGreater(cond, 1e12)
        operator.assert_non_singular().run()

  def test_assert_non_singular_raises_if_cond_infinite(self):
    with self.test_session():
      matrix = [[1., 1.], [1., 1.]]
      # We don't pass the is_self_adjoint hint here, which means we take the
      # generic code path.
      operator = linalg.LinearOperatorFullMatrix(matrix)
      with self.assertRaisesOpError("Singular matrix"):
        operator.assert_non_singular().run()

  def test_assert_self_adjoint(self):
    matrix = [[0., 1.], [0., 1.]]
    operator = linalg.LinearOperatorFullMatrix(matrix)
    with self.test_session():
      with self.assertRaisesOpError("not equal to its adjoint"):
        operator.assert_self_adjoint().run()

  def test_assert_positive_definite(self):
    matrix = [[1., 1.], [1., 1.]]
    operator = linalg.LinearOperatorFullMatrix(matrix, is_self_adjoint=True)
    with self.test_session():
      with self.assertRaisesOpError("Cholesky decomposition was not success"):
        operator.assert_positive_definite().run()


class SquareLinearOperatorFullMatrixSymmetricPositiveDefiniteTest(
    linear_operator_test_util.SquareLinearOperatorDerivedClassTest):
  """Most tests done in the base class LinearOperatorDerivedClassTest.

  In this test, the operator is constructed with hints that invoke the use of
  a Cholesky decomposition for solves/determinant.
  """

  def setUp(self):
    # Increase from 1e-6 to 1e-5.  This reduction in tolerance happens,
    # presumably, because we are taking a different code path in the operator
    # and the matrix.  The operator uses a Choleksy, the matrix uses standard
    # solve.
    self._atol[dtypes.float32] = 1e-5
    self._rtol[dtypes.float32] = 1e-5
    self._atol[dtypes.float64] = 1e-10
    self._rtol[dtypes.float64] = 1e-10

  @property
  def _dtypes_to_test(self):
    return [dtypes.float32, dtypes.float64]

  def _operator_and_mat_and_feed_dict(self, shape, dtype, use_placeholder):
    shape = list(shape)

    matrix = linear_operator_test_util.random_positive_definite_matrix(
        shape, dtype, force_well_conditioned=True)

    if use_placeholder:
      matrix_ph = array_ops.placeholder(dtype=dtype)
      # Evaluate here because (i) you cannot feed a tensor, and (ii)
      # values are random and we want the same value used for both mat and
      # feed_dict.
      matrix = matrix.eval()
      # is_square is auto-set because of self_adjoint/pd.
      operator = linalg.LinearOperatorFullMatrix(
          matrix_ph, is_self_adjoint=True, is_positive_definite=True)
      feed_dict = {matrix_ph: matrix}
    else:
      operator = linalg.LinearOperatorFullMatrix(
          matrix, is_self_adjoint=True, is_positive_definite=True)
      feed_dict = None

    # Convert back to Tensor.  Needed if use_placeholder, since then we have
    # already evaluated matrix to a numpy array.
    mat = ops.convert_to_tensor(matrix)

    return operator, mat, feed_dict

  def test_is_x_flags(self):
    # Matrix with two positive eigenvalues.
    matrix = [[1., 0.], [0., 7.]]
    operator = linalg.LinearOperatorFullMatrix(
        matrix, is_positive_definite=True, is_self_adjoint=True)

    self.assertTrue(operator.is_positive_definite)
    self.assertTrue(operator.is_self_adjoint)

    # Should be auto-set
    self.assertTrue(operator.is_non_singular)
    self.assertTrue(operator._can_use_cholesky)
    self.assertTrue(operator.is_square)

  def test_assert_non_singular(self):
    matrix = [[1., 1.], [1., 1.]]
    operator = linalg.LinearOperatorFullMatrix(
        matrix, is_self_adjoint=True, is_positive_definite=True)
    with self.test_session():
      # Cholesky decomposition may fail, so the error is not specific to
      # non-singular.
      with self.assertRaisesOpError(""):
        operator.assert_non_singular().run()

  def test_assert_self_adjoint(self):
    matrix = [[0., 1.], [0., 1.]]
    operator = linalg.LinearOperatorFullMatrix(
        matrix, is_self_adjoint=True, is_positive_definite=True)
    with self.test_session():
      with self.assertRaisesOpError("not equal to its adjoint"):
        operator.assert_self_adjoint().run()

  def test_assert_positive_definite(self):
    matrix = [[1., 1.], [1., 1.]]
    operator = linalg.LinearOperatorFullMatrix(
        matrix, is_self_adjoint=True, is_positive_definite=True)
    with self.test_session():
      # Cholesky decomposition may fail, so the error is not specific to
      # non-singular.
      with self.assertRaisesOpError(""):
        operator.assert_positive_definite().run()


class NonSquareLinearOperatorFullMatrixTest(
    linear_operator_test_util.NonSquareLinearOperatorDerivedClassTest):
  """Most tests done in the base class LinearOperatorDerivedClassTest."""

  def _operator_and_mat_and_feed_dict(self, shape, dtype, use_placeholder):
    matrix = linear_operator_test_util.random_normal(shape, dtype=dtype)
    if use_placeholder:
      matrix_ph = array_ops.placeholder(dtype=dtype)
      # Evaluate here because (i) you cannot feed a tensor, and (ii)
      # values are random and we want the same value used for both mat and
      # feed_dict.
      matrix = matrix.eval()
      operator = linalg.LinearOperatorFullMatrix(matrix_ph)
      feed_dict = {matrix_ph: matrix}
    else:
      operator = linalg.LinearOperatorFullMatrix(matrix)
      feed_dict = None

    # Convert back to Tensor.  Needed if use_placeholder, since then we have
    # already evaluated matrix to a numpy array.
    mat = ops.convert_to_tensor(matrix)

    return operator, mat, feed_dict

  def test_is_x_flags(self):
    matrix = [[3., 2., 1.], [1., 1., 1.]]
    operator = linalg.LinearOperatorFullMatrix(
        matrix,
        is_self_adjoint=False)
    self.assertEqual(operator.is_positive_definite, None)
    self.assertEqual(operator.is_non_singular, None)
    self.assertFalse(operator.is_self_adjoint)
    self.assertFalse(operator.is_square)

  def test_matrix_must_have_at_least_two_dims_or_raises(self):
    with self.assertRaisesRegexp(ValueError, "at least 2 dimensions"):
      linalg.LinearOperatorFullMatrix([1.])


if __name__ == "__main__":
  test.main()
