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

| Ginkgo Generated from branch based on main. Ginkgo version 1.11.0 A numerical linear algebra library targeting many-core architectures

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cg.hpp
1// SPDX-FileCopyrightText: 2017 - 2025 The Ginkgo authors
2//
3// SPDX-License-Identifier: BSD-3-Clause
4
5#ifndef GKO_PUBLIC_CORE_SOLVER_CG_HPP_
6#define GKO_PUBLIC_CORE_SOLVER_CG_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/config/type_descriptor.hpp>
19#include <ginkgo/core/log/logger.hpp>
20#include <ginkgo/core/matrix/dense.hpp>
21#include <ginkgo/core/matrix/identity.hpp>
22#include <ginkgo/core/solver/solver_base.hpp>
23#include <ginkgo/core/stop/combined.hpp>
24#include <ginkgo/core/stop/criterion.hpp>
25
26
27namespace gko {
28namespace solver {
29
30
47template <typename ValueType = default_precision>
48 class Cg : public EnableLinOp<Cg<ValueType>>,
49 public EnablePreconditionedIterativeSolver<ValueType, Cg<ValueType>>,
50 public Transposable {
51 friend class EnableLinOp<Cg>;
52 friend class EnablePolymorphicObject<Cg, LinOp>;
53 GKO_ASSERT_SUPPORTED_VALUE_TYPE;
54
55public:
56 using value_type = ValueType;
57 using transposed_type = Cg<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
70 class Factory;
71
72 struct parameters_type
73 : enable_preconditioned_iterative_solver_factory_parameters<
74 parameters_type, Factory> {};
75
76 GKO_ENABLE_LIN_OP_FACTORY(Cg, parameters, Factory);
77 GKO_ENABLE_BUILD_METHOD(Factory);
78
92 static parameters_type parse(const config::pnode& config,
93 const config::registry& context,
94 const config::type_descriptor& td_for_child =
95 config::make_type_descriptor<ValueType>());
96
97protected:
98 void apply_impl(const LinOp* b, LinOp* x) const override;
99
100 template <typename VectorType>
101 void apply_dense_impl(const VectorType* b, VectorType* x) const;
102
103 void apply_impl(const LinOp* alpha, const LinOp* b, const LinOp* beta,
104 LinOp* x) const override;
105
106 explicit Cg(std::shared_ptr<const Executor> exec)
107 : EnableLinOp<Cg>(std::move(exec))
108 {}
109
110 explicit Cg(const Factory* factory,
111 std::shared_ptr<const LinOp> system_matrix)
112 : EnableLinOp<Cg>(factory->get_executor(),
113 gko::transpose(system_matrix->get_size())),
114 EnablePreconditionedIterativeSolver<ValueType, Cg<ValueType>>{
115 std::move(system_matrix), factory->get_parameters()},
116 parameters_{factory->get_parameters()}
117 {}
118};
119
120
121template <typename ValueType>
122 struct workspace_traits<Cg<ValueType>> {
123 using Solver = Cg<ValueType>;
124 // number of vectors used by this workspace
125 static int num_vectors(const Solver&);
126 // number of arrays used by this workspace
127 static int num_arrays(const Solver&);
128 // array containing the num_vectors names for the workspace vectors
129 static std::vector<std::string> op_names(const Solver&);
130 // array containing the num_arrays names for the workspace vectors
131 static std::vector<std::string> array_names(const Solver&);
132 // array containing all varying scalar vectors (independent of problem size)
133 static std::vector<int> scalars(const Solver&);
134 // array containing all varying vectors (dependent on problem size)
135 static std::vector<int> vectors(const Solver&);
136
137 // residual vector
138 constexpr static int r = 0;
139 // preconditioned residual vector
140 constexpr static int z = 1;
141 // p vector
142 constexpr static int p = 2;
143 // q vector
144 constexpr static int q = 3;
145 // beta scalar
146 constexpr static int beta = 4;
147 // previous rho scalar
148 constexpr static int prev_rho = 5;
149 // current rho scalar
150 constexpr static int rho = 6;
151 // constant 1.0 scalar
152 constexpr static int one = 7;
153 // constant -1.0 scalar
154 constexpr static int minus_one = 8;
155
156 // stopping status array
157 constexpr static int stop = 0;
158 // reduction tmp array
159 constexpr static int tmp = 1;
160};
161
162
163} // namespace solver
164} // namespace gko
165
166
167#endif // GKO_PUBLIC_CORE_SOLVER_CG_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::Cg
CG or the conjugate gradient method is an iterative type Krylov subspace method which is suitable for...
Definition cg.hpp:50
gko::solver::Cg::conj_transpose
std::unique_ptr< LinOp > conj_transpose() const override
Returns a LinOp representing the conjugate transpose of the Transposable object.
gko::solver::Cg::transpose
std::unique_ptr< LinOp > transpose() const override
Returns a LinOp representing the transpose of the Transposable object.
gko::solver::Cg::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::Cg::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 cg.hpp:68
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_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::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::Cg::parameters_type
Definition cg.hpp:74
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