Ginkgo Generated from branch based on master. 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/config/config.hpp>
18#include <ginkgo/core/config/registry.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
52template <typename ValueType = default_precision>
53class Fcg
54 : public EnableLinOp<Fcg<ValueType>>,
55 public EnablePreconditionedIterativeSolver<ValueType, Fcg<ValueType>>,
56 public Transposable {
57 friend class EnableLinOp<Fcg>;
58 friend class EnablePolymorphicObject<Fcg, LinOp>;
59
60public:
61 using value_type = ValueType;
63
64 std::unique_ptr<LinOp> transpose() const override;
65
66 std::unique_ptr<LinOp> conj_transpose() const override;
67
73 bool apply_uses_initial_guess() const override { return true; }
74
75 class Factory;
76
80
83
97 static parameters_type parse(const config::pnode& config,
98 const config::registry& context,
99 const config::type_descriptor& td_for_child =
100 config::make_type_descriptor<ValueType>());
101
102protected:
103 void apply_impl(const LinOp* b, LinOp* x) const override;
104
105 template <typename VectorType>
106 void apply_dense_impl(const VectorType* b, VectorType* x) const;
107
108 void apply_impl(const LinOp* alpha, const LinOp* b, const LinOp* beta,
109 LinOp* x) const override;
110
111 explicit Fcg(std::shared_ptr<const Executor> exec)
112 : EnableLinOp<Fcg>(std::move(exec))
113 {}
114
115 explicit Fcg(const Factory* factory,
116 std::shared_ptr<const LinOp> system_matrix)
117 : EnableLinOp<Fcg>(factory->get_executor(),
118 gko::transpose(system_matrix->get_size())),
119 EnablePreconditionedIterativeSolver<ValueType, Fcg<ValueType>>{
120 std::move(system_matrix), factory->get_parameters()},
121 parameters_{factory->get_parameters()}
122 {}
123};
124
125
126template <typename ValueType>
127struct workspace_traits<Fcg<ValueType>> {
128 using Solver = Fcg<ValueType>;
129 // number of vectors used by this workspace
130 static int num_vectors(const Solver&);
131 // number of arrays used by this workspace
132 static int num_arrays(const Solver&);
133 // array containing the num_vectors names for the workspace vectors
134 static std::vector<std::string> op_names(const Solver&);
135 // array containing the num_arrays names for the workspace vectors
136 static std::vector<std::string> array_names(const Solver&);
137 // array containing all varying scalar vectors (independent of problem size)
138 static std::vector<int> scalars(const Solver&);
139 // array containing all varying vectors (dependent on problem size)
140 static std::vector<int> vectors(const Solver&);
141
142 // residual vector
143 constexpr static int r = 0;
144 // preconditioned residual vector
145 constexpr static int z = 1;
146 // p vector
147 constexpr static int p = 2;
148 // q vector
149 constexpr static int q = 3;
150 // t vector
151 constexpr static int t = 4;
152 // alpha scalar
153 constexpr static int alpha = 5;
154 // beta scalar
155 constexpr static int beta = 6;
156 // previous rho scalar
157 constexpr static int prev_rho = 7;
158 // current rho scalar
159 constexpr static int rho = 8;
160 // current rho_t scalar
161 constexpr static int rho_t = 9;
162 // constant 1.0 scalar
163 constexpr static int one = 10;
164 // constant -1.0 scalar
165 constexpr static int minus_one = 11;
166
167 // stopping status array
168 constexpr static int stop = 0;
169 // reduction tmp array
170 constexpr static int tmp = 1;
171};
172
173
174} // namespace solver
175} // namespace gko
176
177
178#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
const dim< 2 > & get_size() const noexcept
Returns the size of the operator.
Definition lin_op.hpp:211
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
pnode describes a tree of properties.
Definition property_tree.hpp:28
This class stores additional context for creating Ginkgo objects from configuration files.
Definition registry.hpp:168
This class describes the value and index types to be used when building a Ginkgo type from a configur...
Definition type_descriptor.hpp:37
A LinOp implementing this interface stores a system matrix and stopping criterion factory.
Definition solver_base.hpp:788
Definition fcg.hpp:81
FCG or the flexible conjugate gradient method is an iterative type Krylov subspace method which is su...
Definition fcg.hpp:56
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.
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.
bool apply_uses_initial_guess() const override
Return true as iterative solvers use the data in x as an initial guess.
Definition fcg.hpp:73
#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