STT-tensorflow/tensorflow/python/ops/linalg/matmul_registrations.py
A. Unique TensorFlower e301dda113 Register matmuls and solves between ScaledIdentity LinearOperators.
Also register `linop.solve(identity_linop) = linop.inverse()`. This is useful
for families like ScaledIdentity that are closed under inversion.

PiperOrigin-RevId: 272530839
2019-10-02 18:00:47 -07:00

219 lines
8.7 KiB
Python

# Copyright 2018 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.
# ==============================================================================
"""Registrations for LinearOperator.matmul."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from tensorflow.python.ops.linalg import linear_operator
from tensorflow.python.ops.linalg import linear_operator_algebra
from tensorflow.python.ops.linalg import linear_operator_circulant
from tensorflow.python.ops.linalg import linear_operator_composition
from tensorflow.python.ops.linalg import linear_operator_diag
from tensorflow.python.ops.linalg import linear_operator_identity
from tensorflow.python.ops.linalg import linear_operator_lower_triangular
from tensorflow.python.ops.linalg import linear_operator_zeros
from tensorflow.python.ops.linalg import registrations_util
# By default, use a LinearOperatorComposition to delay the computation.
@linear_operator_algebra.RegisterMatmul(
linear_operator.LinearOperator, linear_operator.LinearOperator)
def _matmul_linear_operator(linop_a, linop_b):
"""Generic matmul of two `LinearOperator`s."""
is_square = registrations_util.is_square(linop_a, linop_b)
is_non_singular = None
is_self_adjoint = None
is_positive_definite = None
if is_square:
is_non_singular = registrations_util.combined_non_singular_hint(
linop_a, linop_b)
elif is_square is False: # pylint:disable=g-bool-id-comparison
is_non_singular = False
is_self_adjoint = False
is_positive_definite = False
return linear_operator_composition.LinearOperatorComposition(
operators=[linop_a, linop_b],
is_non_singular=is_non_singular,
is_self_adjoint=is_self_adjoint,
is_positive_definite=is_positive_definite,
is_square=is_square,
)
# Identity
@linear_operator_algebra.RegisterMatmul(
linear_operator_identity.LinearOperatorIdentity,
linear_operator.LinearOperator)
def _matmul_linear_operator_identity_left(identity, linop):
del identity
return linop
@linear_operator_algebra.RegisterMatmul(
linear_operator.LinearOperator,
linear_operator_identity.LinearOperatorIdentity)
def _matmul_linear_operator_identity_right(linop, identity):
del identity
return linop
@linear_operator_algebra.RegisterMatmul(
linear_operator_identity.LinearOperatorScaledIdentity,
linear_operator_identity.LinearOperatorScaledIdentity)
def _matmul_linear_operator_scaled_identity(linop_a, linop_b):
"""Matmul of two ScaledIdentity `LinearOperators`."""
return linear_operator_identity.LinearOperatorScaledIdentity(
num_rows=linop_a.domain_dimension_tensor(),
multiplier=linop_a.multiplier * linop_b.multiplier,
is_non_singular=registrations_util.combined_non_singular_hint(
linop_a, linop_b),
is_self_adjoint=registrations_util.combined_commuting_self_adjoint_hint(
linop_a, linop_b),
is_positive_definite=(
registrations_util.combined_commuting_positive_definite_hint(
linop_a, linop_b)),
is_square=True)
# Zeros
@linear_operator_algebra.RegisterMatmul(
linear_operator.LinearOperator,
linear_operator_zeros.LinearOperatorZeros)
def _matmul_linear_operator_zeros_right(linop, zeros):
if not zeros.is_square or not linop.is_square:
raise ValueError("Matmul with non-square `LinearOperator`s or non-square "
"`LinearOperatorZeros` not supported at this time.")
return zeros
@linear_operator_algebra.RegisterMatmul(
linear_operator_zeros.LinearOperatorZeros,
linear_operator.LinearOperator)
def _matmul_linear_operator_zeros_left(zeros, linop):
if not zeros.is_square or not linop.is_square:
raise ValueError("Matmul with non-square `LinearOperator`s or non-square "
"`LinearOperatorZeros` not supported at this time.")
return zeros
# Diag.
@linear_operator_algebra.RegisterMatmul(
linear_operator_diag.LinearOperatorDiag,
linear_operator_diag.LinearOperatorDiag)
def _matmul_linear_operator_diag(linop_a, linop_b):
return linear_operator_diag.LinearOperatorDiag(
diag=linop_a.diag * linop_b.diag,
is_non_singular=registrations_util.combined_non_singular_hint(
linop_a, linop_b),
is_self_adjoint=registrations_util.combined_commuting_self_adjoint_hint(
linop_a, linop_b),
is_positive_definite=(
registrations_util.combined_commuting_positive_definite_hint(
linop_a, linop_b)),
is_square=True)
@linear_operator_algebra.RegisterMatmul(
linear_operator_diag.LinearOperatorDiag,
linear_operator_identity.LinearOperatorScaledIdentity)
def _matmul_linear_operator_diag_scaled_identity_right(
linop_diag, linop_scaled_identity):
return linear_operator_diag.LinearOperatorDiag(
diag=linop_diag.diag * linop_scaled_identity.multiplier,
is_non_singular=registrations_util.combined_non_singular_hint(
linop_diag, linop_scaled_identity),
is_self_adjoint=registrations_util.combined_commuting_self_adjoint_hint(
linop_diag, linop_scaled_identity),
is_positive_definite=(
registrations_util.combined_commuting_positive_definite_hint(
linop_diag, linop_scaled_identity)),
is_square=True)
@linear_operator_algebra.RegisterMatmul(
linear_operator_identity.LinearOperatorScaledIdentity,
linear_operator_diag.LinearOperatorDiag)
def _matmul_linear_operator_diag_scaled_identity_left(
linop_scaled_identity, linop_diag):
return linear_operator_diag.LinearOperatorDiag(
diag=linop_diag.diag * linop_scaled_identity.multiplier,
is_non_singular=registrations_util.combined_non_singular_hint(
linop_diag, linop_scaled_identity),
is_self_adjoint=registrations_util.combined_commuting_self_adjoint_hint(
linop_diag, linop_scaled_identity),
is_positive_definite=(
registrations_util.combined_commuting_positive_definite_hint(
linop_diag, linop_scaled_identity)),
is_square=True)
@linear_operator_algebra.RegisterMatmul(
linear_operator_diag.LinearOperatorDiag,
linear_operator_lower_triangular.LinearOperatorLowerTriangular)
def _matmul_linear_operator_diag_tril(linop_diag, linop_triangular):
return linear_operator_lower_triangular.LinearOperatorLowerTriangular(
tril=linop_diag.diag[..., None] * linop_triangular.to_dense(),
is_non_singular=registrations_util.combined_non_singular_hint(
linop_diag, linop_triangular),
# This is safe to do since the Triangular matrix is only self-adjoint
# when it is a diagonal matrix, and hence commutes.
is_self_adjoint=registrations_util.combined_commuting_self_adjoint_hint(
linop_diag, linop_triangular),
is_positive_definite=None,
is_square=True)
@linear_operator_algebra.RegisterMatmul(
linear_operator_lower_triangular.LinearOperatorLowerTriangular,
linear_operator_diag.LinearOperatorDiag)
def _matmul_linear_operator_tril_diag(linop_triangular, linop_diag):
return linear_operator_lower_triangular.LinearOperatorLowerTriangular(
tril=linop_triangular.to_dense() * linop_diag.diag,
is_non_singular=registrations_util.combined_non_singular_hint(
linop_diag, linop_triangular),
# This is safe to do since the Triangular matrix is only self-adjoint
# when it is a diagonal matrix, and hence commutes.
is_self_adjoint=registrations_util.combined_commuting_self_adjoint_hint(
linop_diag, linop_triangular),
is_positive_definite=None,
is_square=True)
# Circulant.
@linear_operator_algebra.RegisterMatmul(
linear_operator_circulant.LinearOperatorCirculant,
linear_operator_circulant.LinearOperatorCirculant)
def _matmul_linear_operator_circulant_circulant(linop_a, linop_b):
return linear_operator_circulant.LinearOperatorCirculant(
spectrum=linop_a.spectrum * linop_b.spectrum,
is_non_singular=registrations_util.combined_non_singular_hint(
linop_a, linop_b),
is_self_adjoint=registrations_util.combined_commuting_self_adjoint_hint(
linop_a, linop_b),
is_positive_definite=(
registrations_util.combined_commuting_positive_definite_hint(
linop_a, linop_b)),
is_square=True)