Ginkgo Generated from develop branch based on develop. Ginkgo version 1.8.0
A numerical linear algebra library targeting many-core architectures
Loading...
Searching...
No Matches
fcg.hpp
1// SPDX-FileCopyrightText: 2017 - 2024 The Ginkgo authors
2//
3// SPDX-License-Identifier: BSD-3-Clause
4
5#ifndef GKO_PUBLIC_CORE_SOLVER_FCG_HPP_
6#define GKO_PUBLIC_CORE_SOLVER_FCG_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
50template <typename ValueType = default_precision>
51class Fcg
52 : public EnableLinOp<Fcg<ValueType>>,
53 public EnablePreconditionedIterativeSolver<ValueType, Fcg<ValueType>>,
54 public Transposable {
55 friend class EnableLinOp<Fcg>;
56 friend class EnablePolymorphicObject<Fcg, LinOp>;
57
58public:
59 using value_type = ValueType;
61
62 std::unique_ptr<LinOp> transpose() const override;
63
64 std::unique_ptr<LinOp> conj_transpose() const override;
65
71 bool apply_uses_initial_guess() const override { return true; }
72
73 class Factory;
74
78
81
82protected:
83 void apply_impl(const LinOp* b, LinOp* x) const override;
84
85 template <typename VectorType>
86 void apply_dense_impl(const VectorType* b, VectorType* x) const;
87
88 void apply_impl(const LinOp* alpha, const LinOp* b, const LinOp* beta,
89 LinOp* x) const override;
90
91 explicit Fcg(std::shared_ptr<const Executor> exec)
92 : EnableLinOp<Fcg>(std::move(exec))
93 {}
94
95 explicit Fcg(const Factory* factory,
96 std::shared_ptr<const LinOp> system_matrix)
97 : EnableLinOp<Fcg>(factory->get_executor(),
98 gko::transpose(system_matrix->get_size())),
99 EnablePreconditionedIterativeSolver<ValueType, Fcg<ValueType>>{
100 std::move(system_matrix), factory->get_parameters()},
101 parameters_{factory->get_parameters()}
102 {}
103};
104
105
106template <typename ValueType>
107struct workspace_traits<Fcg<ValueType>> {
108 using Solver = Fcg<ValueType>;
109 // number of vectors used by this workspace
110 static int num_vectors(const Solver&);
111 // number of arrays used by this workspace
112 static int num_arrays(const Solver&);
113 // array containing the num_vectors names for the workspace vectors
114 static std::vector<std::string> op_names(const Solver&);
115 // array containing the num_arrays names for the workspace vectors
116 static std::vector<std::string> array_names(const Solver&);
117 // array containing all varying scalar vectors (independent of problem size)
118 static std::vector<int> scalars(const Solver&);
119 // array containing all varying vectors (dependent on problem size)
120 static std::vector<int> vectors(const Solver&);
121
122 // residual vector
123 constexpr static int r = 0;
124 // preconditioned residual vector
125 constexpr static int z = 1;
126 // p vector
127 constexpr static int p = 2;
128 // q vector
129 constexpr static int q = 3;
130 // t vector
131 constexpr static int t = 4;
132 // alpha scalar
133 constexpr static int alpha = 5;
134 // beta scalar
135 constexpr static int beta = 6;
136 // previous rho scalar
137 constexpr static int prev_rho = 7;
138 // current rho scalar
139 constexpr static int rho = 8;
140 // current rho_t scalar
141 constexpr static int rho_t = 9;
142 // constant 1.0 scalar
143 constexpr static int one = 10;
144 // constant -1.0 scalar
145 constexpr static int minus_one = 11;
146
147 // stopping status array
148 constexpr static int stop = 0;
149 // reduction tmp array
150 constexpr static int tmp = 1;
151};
152
153
154} // namespace solver
155} // namespace gko
156
157
158#endif // GKO_PUBLIC_CORE_SOLVER_FCG_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 fcg.hpp:79
FCG or the flexible conjugate gradient method is an iterative type Krylov subspace method which is su...
Definition fcg.hpp:54
std::unique_ptr< LinOp > transpose() const override
Returns a LinOp representing the transpose of the Transposable object.
std::unique_ptr< LinOp > conj_transpose() const override
Returns a LinOp representing the conjugate transpose of the Transposable object.
bool apply_uses_initial_guess() const override
Return true as iterative solvers use the data in x as an initial guess.
Definition fcg.hpp:71
#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
Traits class providing information on the type and location of workspace vectors inside a solver.
Definition solver_base.hpp:239