Ginkgo: ginkgo/core/solver/gcr.hpp Source File

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gcr.hpp
1// SPDX-FileCopyrightText: 2017 - 2025 The Ginkgo authors
2//
3// SPDX-License-Identifier: BSD-3-Clause
4
5#ifndef GKO_PUBLIC_CORE_SOLVER_GCR_HPP_
6#define GKO_PUBLIC_CORE_SOLVER_GCR_HPP_
7
8
9#include <vector>
10
11#include <ginkgo/core/base/array.hpp>
12#include <ginkgo/core/base/exception_helpers.hpp>
13#include <ginkgo/core/base/lin_op.hpp>
14#include <ginkgo/core/base/math.hpp>
15#include <ginkgo/core/base/types.hpp>
16#include <ginkgo/core/config/config.hpp>
17#include <ginkgo/core/config/registry.hpp>
18#include <ginkgo/core/log/logger.hpp>
19#include <ginkgo/core/matrix/dense.hpp>
20#include <ginkgo/core/matrix/identity.hpp>
21#include <ginkgo/core/solver/solver_base.hpp>
22#include <ginkgo/core/stop/combined.hpp>
23#include <ginkgo/core/stop/criterion.hpp>
24
25
26namespace gko {
27namespace solver {
28
29
30constexpr size_type gcr_default_krylov_dim = 100u;
31
32
47template <typename ValueType = default_precision>
48 class Gcr
49 : public EnableLinOp<Gcr<ValueType>>,
50 public EnablePreconditionedIterativeSolver<ValueType, Gcr<ValueType>>,
51 public Transposable {
52 friend class EnableLinOp<Gcr>;
53 friend class EnablePolymorphicObject<Gcr, LinOp>;
54 GKO_ASSERT_SUPPORTED_VALUE_TYPE;
55
56public:
57 using value_type = ValueType;
58 using transposed_type = Gcr<ValueType>;
59
60 std::unique_ptr<LinOp> transpose() const override;
61
62 std::unique_ptr<LinOp> conj_transpose() const override;
63
69 bool apply_uses_initial_guess() const override { return true; }
70
76 size_type get_krylov_dim() const { return parameters_.krylov_dim; }
77
83 void set_krylov_dim(size_type other) { parameters_.krylov_dim = other; }
84
85 class Factory;
86
87 struct parameters_type
88 : enable_preconditioned_iterative_solver_factory_parameters<
89 parameters_type, Factory> {
91 size_type GKO_FACTORY_PARAMETER_SCALAR(krylov_dim, 0u);
92 };
93 GKO_ENABLE_LIN_OP_FACTORY(Gcr, parameters, Factory);
94 GKO_ENABLE_BUILD_METHOD(Factory);
95
109 static parameters_type parse(const config::pnode& config,
110 const config::registry& context,
111 const config::type_descriptor& td_for_child =
112 config::make_type_descriptor<ValueType>());
113
114protected:
115 void apply_impl(const LinOp* b, LinOp* x) const override;
116
117 template <typename VectorType>
118 void apply_dense_impl(const VectorType* b, VectorType* x) const;
119
120 void apply_impl(const LinOp* alpha, const LinOp* b, const LinOp* beta,
121 LinOp* x) const override;
122
123 explicit Gcr(std::shared_ptr<const Executor> exec)
124 : EnableLinOp<Gcr>(std::move(exec))
125 {}
126
127 explicit Gcr(const Factory* factory,
128 std::shared_ptr<const LinOp> system_matrix)
129 : EnableLinOp<Gcr>(factory->get_executor(),
130 gko::transpose(system_matrix->get_size())),
131 EnablePreconditionedIterativeSolver<ValueType, Gcr<ValueType>>{
132 std::move(system_matrix), factory->get_parameters()},
133 parameters_{factory->get_parameters()}
134 {
135 if (!parameters_.krylov_dim) {
136 parameters_.krylov_dim = gcr_default_krylov_dim;
137 }
138 }
139};
140
141
142template <typename ValueType>
143 struct workspace_traits<Gcr<ValueType>> {
144 using Solver = Gcr<ValueType>;
145 // number of vectors used by this workspace
146 static int num_vectors(const Solver&);
147 // number of arrays used by this workspace
148 static int num_arrays(const Solver&);
149 // array containing the num_vectors names for the workspace vectors
150 static std::vector<std::string> op_names(const Solver&);
151 // array containing the num_arrays names for the workspace vectors
152 static std::vector<std::string> array_names(const Solver&);
153 // array containing all varying scalar vectors (independent of problem size)
154 static std::vector<int> scalars(const Solver&);
155 // array containing all varying vectors (dependent on problem size)
156 static std::vector<int> vectors(const Solver&);
157
158 // residual vector
159 constexpr static int residual = 0;
160 // preconditioned vector
161 constexpr static int precon_residual = 1;
162 // A* preconditioned vector
163 constexpr static int A_precon_residual = 2;
164 // krylov bases (p in the algorithm)
165 constexpr static int krylov_bases_p = 3;
166 // mapped krylov bases (Ap in the algorithm)
167 constexpr static int mapped_krylov_bases_Ap = 4;
168 // tmp rAp parameter (r dot Ap in the algorithm)
169 constexpr static int tmp_rAp = 5;
170 // tmp minus beta parameter (-beta in the algorithm)
171 constexpr static int tmp_minus_beta = 6;
172 // array of norms of Ap
173 constexpr static int Ap_norms = 7;
174 // residual norm scalar
175 constexpr static int residual_norm = 8;
176 // constant 1.0 scalar
177 constexpr static int one = 9;
178 // constant -1.0 scalar
179 constexpr static int minus_one = 10;
180
181 // stopping status array
182 constexpr static int stop = 0;
183 // reduction tmp array
184 constexpr static int tmp = 1;
185 // final iteration number array
186 constexpr static int final_iter_nums = 2;
187};
188
189
190} // namespace solver
191} // namespace gko
192
193
194#endif // GKO_PUBLIC_CORE_SOLVER_GCR_HPP_
gko::EnableLinOp
The EnableLinOp mixin can be used to provide sensible default implementations of the majority of the ...
Definition lin_op.hpp:879
gko::EnablePolymorphicObject
This mixin inherits from (a subclass of) PolymorphicObject and provides a base implementation of a ne...
Definition polymorphic_object.hpp:668
gko::LinOp
Definition lin_op.hpp:117
gko::Transposable
Linear operators which support transposition should implement the Transposable interface.
Definition lin_op.hpp:433
gko::config::pnode
pnode describes a tree of properties.
Definition property_tree.hpp:28
gko::config::registry
This class stores additional context for creating Ginkgo objects from configuration files.
Definition registry.hpp:167
gko::config::type_descriptor
This class describes the value and index types to be used when building a Ginkgo type from a configur...
Definition type_descriptor.hpp:39
gko::solver::EnablePreconditionedIterativeSolver
A LinOp implementing this interface stores a system matrix and stopping criterion factory.
Definition solver_base.hpp:802
gko::solver::Factory
Definition ir.hpp:184
gko::solver::Gcr
GCR or the generalized conjugate residual method is an iterative type Krylov subspace method similar ...
Definition gcr.hpp:51
gko::solver::Gcr::parse
static parameters_type parse(const config::pnode &config, const config::registry &context, const config::type_descriptor &td_for_child=config::make_type_descriptor< ValueType >())
Create the parameters from the property_tree.
gko::solver::Gcr::get_krylov_dim
size_type get_krylov_dim() const
Gets the Krylov dimension of the solver.
Definition gcr.hpp:76
gko::solver::Gcr::conj_transpose
std::unique_ptr< LinOp > conj_transpose() const override
Returns a LinOp representing the conjugate transpose of the Transposable object.
gko::solver::Gcr::set_krylov_dim
void set_krylov_dim(size_type other)
Sets the Krylov dimension.
Definition gcr.hpp:83
gko::solver::Gcr::transpose
std::unique_ptr< LinOp > transpose() const override
Returns a LinOp representing the transpose of the Transposable object.
gko::solver::Gcr::apply_uses_initial_guess
bool apply_uses_initial_guess() const override
Return true as iterative solvers use the data in x as an initial guess.
Definition gcr.hpp:69
GKO_FACTORY_PARAMETER_SCALAR
#define GKO_FACTORY_PARAMETER_SCALAR(_name, _default)
Creates a scalar factory parameter in the factory parameters structure.
Definition abstract_factory.hpp:445
GKO_ENABLE_BUILD_METHOD
#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
GKO_ENABLE_LIN_OP_FACTORY
#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:1017
gko::solver
The ginkgo Solve namespace.
Definition bicg.hpp:28
gko
The Ginkgo namespace.
Definition abstract_factory.hpp:20
gko::size_type
std::size_t size_type
Integral type used for allocation quantities.
Definition types.hpp:90
gko::transpose
batch_dim< 2, DimensionType > transpose(const batch_dim< 2, DimensionType > &input)
Returns a batch_dim object with its dimensions swapped for batched operators.
Definition batch_dim.hpp:119
std
STL namespace.
gko::solver::Gcr::parameters_type
Definition gcr.hpp:89
gko::solver::Gcr::parameters_type::krylov_dim
size_type krylov_dim
Krylov subspace dimension/restart value.
Definition gcr.hpp:91
gko::solver::enable_preconditioned_iterative_solver_factory_parameters
Definition solver_base.hpp:855
gko::solver::workspace_traits
Traits class providing information on the type and location of workspace vectors inside a solver.
Definition solver_base.hpp:238