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A numerical linear algebra library targeting many-core architectures
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cgs.hpp
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32
33#ifndef GKO_PUBLIC_CORE_SOLVER_CGS_HPP_
34#define GKO_PUBLIC_CORE_SOLVER_CGS_HPP_
35
36
37#include <vector>
38
39
40#include <ginkgo/core/base/array.hpp>
41#include <ginkgo/core/base/exception_helpers.hpp>
42#include <ginkgo/core/base/lin_op.hpp>
43#include <ginkgo/core/base/math.hpp>
44#include <ginkgo/core/base/types.hpp>
45#include <ginkgo/core/log/logger.hpp>
46#include <ginkgo/core/matrix/dense.hpp>
47#include <ginkgo/core/matrix/identity.hpp>
48#include <ginkgo/core/solver/solver_base.hpp>
49#include <ginkgo/core/stop/combined.hpp>
50#include <ginkgo/core/stop/criterion.hpp>
51
52
53namespace gko {
54namespace solver {
55
56
70template <typename ValueType = default_precision>
71class Cgs
72 : public EnableLinOp<Cgs<ValueType>>,
73 public EnablePreconditionedIterativeSolver<ValueType, Cgs<ValueType>>,
74 public Transposable {
75 friend class EnableLinOp<Cgs>;
76 friend class EnablePolymorphicObject<Cgs, LinOp>;
77
78public:
79 using value_type = ValueType;
81
82 std::unique_ptr<LinOp> transpose() const override;
83
84 std::unique_ptr<LinOp> conj_transpose() const override;
85
91 bool apply_uses_initial_guess() const override { return true; }
92
93 class Factory;
94
98
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 Cgs(std::shared_ptr<const Executor> exec)
112 : EnableLinOp<Cgs>(std::move(exec))
113 {}
114
115 explicit Cgs(const Factory* factory,
116 std::shared_ptr<const LinOp> system_matrix)
117 : EnableLinOp<Cgs>(factory->get_executor(),
118 gko::transpose(system_matrix->get_size())),
119 EnablePreconditionedIterativeSolver<ValueType, Cgs<ValueType>>{
120 std::move(system_matrix), factory->get_parameters()},
121 parameters_{factory->get_parameters()}
122 {}
123};
124
125
126template <typename ValueType>
127struct workspace_traits<Cgs<ValueType>> {
128 using Solver = Cgs<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 // r tilde vector
145 constexpr static int r_tld = 1;
146 // p vector
147 constexpr static int p = 2;
148 // q vector
149 constexpr static int q = 3;
150 // u vector
151 constexpr static int u = 4;
152 // u hat vector
153 constexpr static int u_hat = 5;
154 // v hat vector
155 constexpr static int v_hat = 6;
156 // t vector
157 constexpr static int t = 7;
158 // alpha scalar
159 constexpr static int alpha = 8;
160 // beta scalar
161 constexpr static int beta = 9;
162 // beta scalar
163 constexpr static int gamma = 10;
164 // previous rho scalar
165 constexpr static int prev_rho = 11;
166 // current rho scalar
167 constexpr static int rho = 12;
168 // constant 1.0 scalar
169 constexpr static int one = 13;
170 // constant -1.0 scalar
171 constexpr static int minus_one = 14;
172
173 // stopping status array
174 constexpr static int stop = 0;
175 // reduction tmp array
176 constexpr static int tmp = 1;
177};
178
179
180} // namespace solver
181} // namespace gko
182
183
184#endif // GKO_PUBLIC_CORE_SOLVER_CGS_HPP_
The EnableLinOp mixin can be used to provide sensible default implementations of the majority of the ...
Definition lin_op.hpp:908
This mixin inherits from (a subclass of) PolymorphicObject and provides a base implementation of a ne...
Definition polymorphic_object.hpp:691
Definition lin_op.hpp:146
std::shared_ptr< const Executor > get_executor() const noexcept
Returns the Executor of the object.
Definition polymorphic_object.hpp:263
Linear operators which support transposition should implement the Transposable interface.
Definition lin_op.hpp:462
Definition cgs.hpp:99
CGS or the conjugate gradient square method is an iterative type Krylov subspace method which is suit...
Definition cgs.hpp:74
bool apply_uses_initial_guess() const override
Return true as iterative solvers use the data in x as an initial guess.
Definition cgs.hpp:91
std::unique_ptr< LinOp > conj_transpose() const override
Returns a LinOp representing the conjugate transpose of the Transposable object.
std::unique_ptr< LinOp > transpose() const override
Returns a LinOp representing the transpose of the Transposable object.
A LinOp implementing this interface stores a system matrix and stopping criterion factory.
Definition solver_base.hpp:816
#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:422
#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:1046
The Ginkgo namespace.
Definition abstract_factory.hpp:48
constexpr T one()
Returns the multiplicative identity for T.
Definition math.hpp:803
Traits class providing information on the type and location of workspace vectors inside a solver.
Definition solver_base.hpp:267