Ginkgo Generated from branch based on main. Ginkgo version 1.10.0
A numerical linear algebra library targeting many-core architectures
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gcr.hpp
1// SPDX-FileCopyrightText: 2017 - 2024 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>
48class 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
55public:
56 using value_type = ValueType;
57 using transposed_type = Gcr<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
82 void set_krylov_dim(size_type other) { parameters_.krylov_dim = other; }
83
84 class Factory;
85
92 GKO_ENABLE_LIN_OP_FACTORY(Gcr, parameters, Factory);
94
108 static parameters_type parse(const config::pnode& config,
109 const config::registry& context,
110 const config::type_descriptor& td_for_child =
111 config::make_type_descriptor<ValueType>());
112
113protected:
114 void apply_impl(const LinOp* b, LinOp* x) const override;
115
116 template <typename VectorType>
117 void apply_dense_impl(const VectorType* b, VectorType* x) const;
118
119 void apply_impl(const LinOp* alpha, const LinOp* b, const LinOp* beta,
120 LinOp* x) const override;
121
122 explicit Gcr(std::shared_ptr<const Executor> exec)
123 : EnableLinOp<Gcr>(std::move(exec))
124 {}
125
126 explicit Gcr(const Factory* factory,
127 std::shared_ptr<const LinOp> system_matrix)
128 : EnableLinOp<Gcr>(factory->get_executor(),
129 gko::transpose(system_matrix->get_size())),
130 EnablePreconditionedIterativeSolver<ValueType, Gcr<ValueType>>{
131 std::move(system_matrix), factory->get_parameters()},
132 parameters_{factory->get_parameters()}
133 {
134 if (!parameters_.krylov_dim) {
135 parameters_.krylov_dim = gcr_default_krylov_dim;
136 }
137 }
138};
139
140
141template <typename ValueType>
142struct workspace_traits<Gcr<ValueType>> {
143 using Solver = Gcr<ValueType>;
144 // number of vectors used by this workspace
145 static int num_vectors(const Solver&);
146 // number of arrays used by this workspace
147 static int num_arrays(const Solver&);
148 // array containing the num_vectors names for the workspace vectors
149 static std::vector<std::string> op_names(const Solver&);
150 // array containing the num_arrays names for the workspace vectors
151 static std::vector<std::string> array_names(const Solver&);
152 // array containing all varying scalar vectors (independent of problem size)
153 static std::vector<int> scalars(const Solver&);
154 // array containing all varying vectors (dependent on problem size)
155 static std::vector<int> vectors(const Solver&);
156
157 // residual vector
158 constexpr static int residual = 0;
159 // preconditioned vector
160 constexpr static int precon_residual = 1;
161 // A* preconditioned vector
162 constexpr static int A_precon_residual = 2;
163 // krylov bases (p in the algorithm)
164 constexpr static int krylov_bases_p = 3;
165 // mapped krylov bases (Ap in the algorithm)
166 constexpr static int mapped_krylov_bases_Ap = 4;
167 // tmp rAp parameter (r dot Ap in the algorithm)
168 constexpr static int tmp_rAp = 5;
169 // tmp minus beta parameter (-beta in the algorithm)
170 constexpr static int tmp_minus_beta = 6;
171 // array of norms of Ap
172 constexpr static int Ap_norms = 7;
173 // residual norm scalar
174 constexpr static int residual_norm = 8;
175 // constant 1.0 scalar
176 constexpr static int one = 9;
177 // constant -1.0 scalar
178 constexpr static int minus_one = 10;
179
180 // stopping status array
181 constexpr static int stop = 0;
182 // reduction tmp array
183 constexpr static int tmp = 1;
184 // final iteration number array
185 constexpr static int final_iter_nums = 2;
186};
187
188
189} // namespace solver
190} // namespace gko
191
192
193#endif // GKO_PUBLIC_CORE_SOLVER_GCR_HPP_
The EnableLinOp mixin can be used to provide sensible default implementations of the majority of the ...
Definition lin_op.hpp:879
This mixin inherits from (a subclass of) PolymorphicObject and provides a base implementation of a ne...
Definition polymorphic_object.hpp:668
Definition lin_op.hpp:117
const dim< 2 > & get_size() const noexcept
Returns the size of the operator.
Definition lin_op.hpp:210
std::shared_ptr< const Executor > get_executor() const noexcept
Returns the Executor of the object.
Definition polymorphic_object.hpp:243
Linear operators which support transposition should implement the Transposable interface.
Definition lin_op.hpp:433
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:167
This class describes the value and index types to be used when building a Ginkgo type from a configur...
Definition type_descriptor.hpp:39
A LinOp implementing this interface stores a system matrix and stopping criterion factory.
Definition solver_base.hpp:802
GCR or the generalized conjugate residual method is an iterative type Krylov subspace method similar ...
Definition gcr.hpp:51
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.
size_type get_krylov_dim() const
Gets the Krylov dimension of the solver.
Definition gcr.hpp:75
std::unique_ptr< LinOp > conj_transpose() const override
Returns a LinOp representing the conjugate transpose of the Transposable object.
void set_krylov_dim(size_type other)
Sets the Krylov dimension.
Definition gcr.hpp:82
std::unique_ptr< LinOp > transpose() const override
Returns a LinOp representing the 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 gcr.hpp:68
#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:1017
The ginkgo Solve namespace.
Definition bicg.hpp:28
The Ginkgo namespace.
Definition abstract_factory.hpp:20
std::size_t size_type
Integral type used for allocation quantities.
Definition types.hpp:90
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
STL namespace.
size_type krylov_dim
Krylov subspace dimension/restart value.
Definition gcr.hpp:90
Traits class providing information on the type and location of workspace vectors inside a solver.
Definition solver_base.hpp:238