Ginkgo Generated from develop branch based on develop. Ginkgo version 1.8.0
A numerical linear algebra library targeting many-core architectures
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gmres.hpp
1// SPDX-FileCopyrightText: 2017 - 2024 The Ginkgo authors
2//
3// SPDX-License-Identifier: BSD-3-Clause
4
5#ifndef GKO_PUBLIC_CORE_SOLVER_GMRES_HPP_
6#define GKO_PUBLIC_CORE_SOLVER_GMRES_HPP_
7
8
9#include <vector>
10
11
12#include <ginkgo/core/base/array.hpp>
13#include <ginkgo/core/base/exception_helpers.hpp>
14#include <ginkgo/core/base/lin_op.hpp>
15#include <ginkgo/core/base/math.hpp>
16#include <ginkgo/core/base/types.hpp>
17#include <ginkgo/core/log/logger.hpp>
18#include <ginkgo/core/matrix/dense.hpp>
19#include <ginkgo/core/matrix/identity.hpp>
20#include <ginkgo/core/solver/solver_base.hpp>
21#include <ginkgo/core/stop/combined.hpp>
22#include <ginkgo/core/stop/criterion.hpp>
23
24
25namespace gko {
26namespace solver {
27
28
29[[deprecated]] constexpr size_type default_krylov_dim = 100u;
30
31constexpr size_type gmres_default_krylov_dim = 100u;
32
33
47template <typename ValueType = default_precision>
48class Gmres
49 : public EnableLinOp<Gmres<ValueType>>,
50 public EnablePreconditionedIterativeSolver<ValueType, Gmres<ValueType>>,
51 public Transposable {
52 friend class EnableLinOp<Gmres>;
53 friend class EnablePolymorphicObject<Gmres, LinOp>;
54
55public:
56 using value_type = ValueType;
58
59 std::unique_ptr<LinOp> transpose() const override;
60
61 std::unique_ptr<LinOp> conj_transpose() const override;
62
68 bool apply_uses_initial_guess() const override { return true; }
69
75 size_type get_krylov_dim() const { return parameters_.krylov_dim; }
76
83
84
85 class Factory;
86
98
99protected:
100 void apply_impl(const LinOp* b, LinOp* x) const override;
101
102 template <typename VectorType>
103 void apply_dense_impl(const VectorType* b, VectorType* x) const;
104
105 void apply_impl(const LinOp* alpha, const LinOp* b, const LinOp* beta,
106 LinOp* x) const override;
107
108 explicit Gmres(std::shared_ptr<const Executor> exec)
109 : EnableLinOp<Gmres>(std::move(exec))
110 {}
111
112 explicit Gmres(const Factory* factory,
113 std::shared_ptr<const LinOp> system_matrix)
114 : EnableLinOp<Gmres>(factory->get_executor(),
115 gko::transpose(system_matrix->get_size())),
116 EnablePreconditionedIterativeSolver<ValueType, Gmres<ValueType>>{
117 std::move(system_matrix), factory->get_parameters()},
118 parameters_{factory->get_parameters()}
119 {
120 if (!parameters_.krylov_dim) {
121 parameters_.krylov_dim = gmres_default_krylov_dim;
122 }
123 }
124};
125
126
127template <typename ValueType>
128struct workspace_traits<Gmres<ValueType>> {
129 using Solver = Gmres<ValueType>;
130 // number of vectors used by this workspace
131 static int num_vectors(const Solver&);
132 // number of arrays used by this workspace
133 static int num_arrays(const Solver&);
134 // array containing the num_vectors names for the workspace vectors
135 static std::vector<std::string> op_names(const Solver&);
136 // array containing the num_arrays names for the workspace vectors
137 static std::vector<std::string> array_names(const Solver&);
138 // array containing all varying scalar vectors (independent of problem size)
139 static std::vector<int> scalars(const Solver&);
140 // array containing all varying vectors (dependent on problem size)
141 static std::vector<int> vectors(const Solver&);
142
143 // residual vector
144 constexpr static int residual = 0;
145 // preconditioned vector
146 constexpr static int preconditioned_vector = 1;
147 // krylov basis multivector
148 constexpr static int krylov_bases = 2;
149 // hessenberg matrix
150 constexpr static int hessenberg = 3;
151 // givens sin parameters
152 constexpr static int givens_sin = 4;
153 // givens cos parameters
154 constexpr static int givens_cos = 5;
155 // coefficients of the residual in Krylov space
156 constexpr static int residual_norm_collection = 6;
157 // residual norm scalar
158 constexpr static int residual_norm = 7;
159 // solution of the least-squares problem in Krylov space
160 constexpr static int y = 8;
161 // solution of the least-squares problem mapped to the full space
162 constexpr static int before_preconditioner = 9;
163 // preconditioned solution of the least-squares problem
164 constexpr static int after_preconditioner = 10;
165 // constant 1.0 scalar
166 constexpr static int one = 11;
167 // constant -1.0 scalar
168 constexpr static int minus_one = 12;
169 // temporary norm vector of next_krylov to copy into hessenberg matrix
170 constexpr static int next_krylov_norm_tmp = 13;
171 // preconditioned krylov basis multivector
172 constexpr static int preconditioned_krylov_bases = 14;
173
174 // stopping status array
175 constexpr static int stop = 0;
176 // reduction tmp array
177 constexpr static int tmp = 1;
178 // final iteration number array
179 constexpr static int final_iter_nums = 2;
180};
181
182
183} // namespace solver
184} // namespace gko
185
186
187#endif // GKO_PUBLIC_CORE_SOLVER_GMRES_HPP_
The EnableLinOp mixin can be used to provide sensible default implementations of the majority of the ...
Definition lin_op.hpp:880
This mixin inherits from (a subclass of) PolymorphicObject and provides a base implementation of a ne...
Definition polymorphic_object.hpp:663
Definition lin_op.hpp:118
std::shared_ptr< const Executor > get_executor() const noexcept
Returns the Executor of the object.
Definition polymorphic_object.hpp:235
Linear operators which support transposition should implement the Transposable interface.
Definition lin_op.hpp:434
A LinOp implementing this interface stores a system matrix and stopping criterion factory.
Definition solver_base.hpp:788
Definition gmres.hpp:96
GMRES or the generalized minimal residual method is an iterative type Krylov subspace method which is...
Definition gmres.hpp:51
std::unique_ptr< LinOp > conj_transpose() const override
Returns a LinOp representing the conjugate transpose of the Transposable object.
std::unique_ptr< LinOp > transpose() const override
Returns a LinOp representing the transpose of the Transposable object.
size_type get_krylov_dim() const
Gets the Krylov dimension of the solver.
Definition gmres.hpp:75
bool apply_uses_initial_guess() const override
Return true as iterative solvers use the data in x as an initial guess.
Definition gmres.hpp:68
void set_krylov_dim(size_type other)
Sets the Krylov dimension.
Definition gmres.hpp:82
#define GKO_FACTORY_PARAMETER_SCALAR(_name, _default)
Creates a scalar factory parameter in the factory parameters structure.
Definition abstract_factory.hpp:445
#define GKO_ENABLE_BUILD_METHOD(_factory_name)
Defines a build method for the factory, simplifying its construction by removing the repetitive typin...
Definition abstract_factory.hpp:394
#define GKO_ENABLE_LIN_OP_FACTORY(_lin_op, _parameters_name, _factory_name)
This macro will generate a default implementation of a LinOpFactory for the LinOp subclass it is defi...
Definition lin_op.hpp:1018
The Ginkgo namespace.
Definition abstract_factory.hpp:20
constexpr T one()
Returns the multiplicative identity for T.
Definition math.hpp:775
std::size_t size_type
Integral type used for allocation quantities.
Definition types.hpp:92
size_type krylov_dim
Krylov subspace dimension/restart value.
Definition gmres.hpp:91
bool flexible
Flexible GMRES.
Definition gmres.hpp:94
Traits class providing information on the type and location of workspace vectors inside a solver.
Definition solver_base.hpp:239