gko::batch::solver::Cg< ValueType > Class Template Reference

Cg or the Conjugate Gradient is a Krylov subspace solver. More...

#include <ginkgo/core/solver/batch_cg.hpp>

Inheritance diagram for gko::batch::solver::Cg< ValueType >:

Collaboration diagram for gko::batch::solver::Cg< ValueType >:

Classes
class	Factory
struct	parameters_type

Public Types
using	value_type = ValueType
using	real_type = gko::remove_complex< ValueType >
Public Types inherited from gko::batch::solver::EnableBatchSolver< Cg< ValueType >, ValueType >
using	real_type = remove_complex< ValueType >
Public Types inherited from gko::EnablePolymorphicAssignment< Cg< ValueType > >
using	result_type = Cg< ValueType >
Public Types inherited from gko::ConvertibleTo< Cg< ValueType > >
using	result_type = Cg< ValueType >

Public Member Functions
const parameters_type &	get_parameters () const
Public Member Functions inherited from gko::batch::solver::EnableBatchSolver< Cg< ValueType >, ValueType >
const Cg< ValueType > *	apply (ptr_param< const MultiVector< ValueType >> b, ptr_param< MultiVector< ValueType >> x) const
const Cg< ValueType > *	apply (ptr_param< const MultiVector< ValueType >> alpha, ptr_param< const MultiVector< ValueType >> b, ptr_param< const MultiVector< ValueType >> beta, ptr_param< MultiVector< ValueType >> x) const
Cg< ValueType > *	apply (ptr_param< const MultiVector< ValueType >> b, ptr_param< MultiVector< ValueType >> x)
Cg< ValueType > *	apply (ptr_param< const MultiVector< ValueType >> alpha, ptr_param< const MultiVector< ValueType >> b, ptr_param< const MultiVector< ValueType >> beta, ptr_param< MultiVector< ValueType >> x)
Public Member Functions inherited from gko::batch::solver::BatchSolver
std::shared_ptr< const BatchLinOp >	get_system_matrix () const
	Returns the system operator (matrix) of the linear system. More...
std::shared_ptr< const BatchLinOp >	get_preconditioner () const
	Returns the generated preconditioner. More...
double	get_tolerance () const
	Get the residual tolerance used by the solver. More...
void	reset_tolerance (double res_tol)
	Update the residual tolerance to be used by the solver. More...
int	get_max_iterations () const
	Get the maximum number of iterations set on the solver. More...
void	reset_max_iterations (int max_iterations)
	Set the maximum number of iterations for the solver to use, independent of the factory that created it. More...
::gko::batch::stop::tolerance_type	get_tolerance_type () const
	Get the tolerance type. More...
void	reset_tolerance_type (::gko::batch::stop::tolerance_type tol_type)
	Set the type of tolerance check to use inside the solver. More...
Public Member Functions inherited from gko::EnableAbstractPolymorphicObject< Cg< ValueType >, BatchLinOp >
std::unique_ptr< Cg< ValueType > >	create_default (std::shared_ptr< const Executor > exec) const
std::unique_ptr< Cg< ValueType > >	create_default () const
std::unique_ptr< Cg< ValueType > >	clone (std::shared_ptr< const Executor > exec) const
std::unique_ptr< Cg< ValueType > >	clone () const
Cg< ValueType > *	copy_from (const PolymorphicObject *other)
std::enable_if_t< std::is_base_of< PolymorphicObject, std::decay_t< Derived > >::value, Cg< ValueType > > *	copy_from (std::unique_ptr< Derived > &&other)
std::enable_if_t< std::is_base_of< PolymorphicObject, std::decay_t< Derived > >::value, Cg< ValueType > > *	copy_from (const std::unique_ptr< Derived > &other)
Cg< ValueType > *	copy_from (const std::shared_ptr< const PolymorphicObject > &other)
Cg< ValueType > *	move_from (ptr_param< PolymorphicObject > other)
Cg< ValueType > *	clear ()
Public Member Functions inherited from gko::EnablePolymorphicAssignment< Cg< ValueType > >
void	convert_to (result_type *result) const override
	Converts the implementer to an object of type result_type. More...
void	move_to (result_type *result) override
	Converts the implementer to an object of type result_type by moving data from this object. More...
Public Member Functions inherited from gko::ConvertibleTo< Cg< ValueType > >
void	convert_to (ptr_param< result_type > result) const
void	move_to (ptr_param< result_type > result)

Static Public Member Functions
static auto	build () -> decltype(Factory ::create())

Friends
class	EnableBatchLinOp< Cg >
class	EnablePolymorphicObject< Cg, BatchLinOp >

Detailed Description

template<typename ValueType = default_precision>
class gko::batch::solver::Cg< ValueType >

Cg or the Conjugate Gradient is a Krylov subspace solver.

It is a short recurrence solver that is generally used to solve linear systems with SPD matrices.

This solver solves a batch of linear systems using the Cg algorithm. Each linear system in the batch can converge independently.

Unless otherwise specified via the preconditioner factory parameter, this implementation does not use any preconditioner by default. The type of tolerance (absolute or relative) and the maximum number of iterations to be used in the stopping criterion can be set via the factory parameters.

Note

The tolerance check is against the internal residual computed within the solver process. This implicit (internal) residual can diverge from the true residual (||b - Ax||). A posterori checks (by computing the true residual, ||b - Ax||) are recommended to ensure that the solution has converged to the desired tolerance.

Template Parameters

ValueType

precision of matrix elements

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The documentation for this class was generated from the following file:

• ginkgo/core/solver/batch_cg.hpp