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

Inheritance diagram for gko::solver::Ir< ValueType >:

Classes
class	Factory

struct	parameters_type

Public Types
using	value_type = ValueType

using	transposed_type = Ir< ValueType >

Public Types inherited from gko::EnablePolymorphicAssignment< ConcreteLinOp >
using	result_type = ConcreteLinOp

Public Types inherited from gko::ConvertibleTo< ResultType >
using	result_type = ResultType

Public Member Functions
std::unique_ptr< LinOp >	transpose () const override

std::unique_ptr< LinOp >	conj_transpose () const override

bool	apply_uses_initial_guess () const override

std::shared_ptr< const LinOp >	get_solver () const

void	set_solver (std::shared_ptr< const LinOp > new_solver)

Ir &	operator= (const Ir &)

Ir &	operator= (Ir &&)

	Ir (const Ir &)

	Ir (Ir &&)

const parameters_type &	get_parameters () const

Public Member Functions inherited from gko::EnableLinOp< ConcreteLinOp, PolymorphicBase >
const ConcreteLinOp *	apply (ptr_param< const LinOp > b, ptr_param< LinOp > x) const

ConcreteLinOp *	apply (ptr_param< const LinOp > b, ptr_param< LinOp > x)

const ConcreteLinOp *	apply (ptr_param< const LinOp > alpha, ptr_param< const LinOp > b, ptr_param< const LinOp > beta, ptr_param< LinOp > x) const

ConcreteLinOp *	apply (ptr_param< const LinOp > alpha, ptr_param< const LinOp > b, ptr_param< const LinOp > beta, ptr_param< LinOp > x)

Public Member Functions inherited from gko::EnableAbstractPolymorphicObject< AbstractObject, PolymorphicBase >
std::unique_ptr< AbstractObject >	create_default (std::shared_ptr< const Executor > exec) const

std::unique_ptr< AbstractObject >	create_default () const

std::unique_ptr< AbstractObject >	clone (std::shared_ptr< const Executor > exec) const

std::unique_ptr< AbstractObject >	clone () const

AbstractObject *	copy_from (const PolymorphicObject *other)

template<typename Derived >
std::enable_if_t< std::is_base_of< PolymorphicObject, std::decay_t< Derived > >::value, AbstractObject > *	copy_from (std::unique_ptr< Derived > &&other)

template<typename Derived >
std::enable_if_t< std::is_base_of< PolymorphicObject, std::decay_t< Derived > >::value, AbstractObject > *	copy_from (const std::unique_ptr< Derived > &other)

AbstractObject *	copy_from (const std::shared_ptr< const PolymorphicObject > &other)

AbstractObject *	move_from (ptr_param< PolymorphicObject > other)

AbstractObject *	clear ()

Public Member Functions inherited from gko::PolymorphicObject
PolymorphicObject &	operator= (const PolymorphicObject &)

std::unique_ptr< PolymorphicObject >	create_default (std::shared_ptr< const Executor > exec) const

std::unique_ptr< PolymorphicObject >	create_default () const

std::unique_ptr< PolymorphicObject >	clone (std::shared_ptr< const Executor > exec) const

std::unique_ptr< PolymorphicObject >	clone () const

PolymorphicObject *	copy_from (const PolymorphicObject *other)

template<typename Derived , typename Deleter >
std::enable_if_t< std::is_base_of< PolymorphicObject, std::decay_t< Derived > >::value, PolymorphicObject > *	copy_from (std::unique_ptr< Derived, Deleter > &&other)

template<typename Derived , typename Deleter >
std::enable_if_t< std::is_base_of< PolymorphicObject, std::decay_t< Derived > >::value, PolymorphicObject > *	copy_from (const std::unique_ptr< Derived, Deleter > &other)

PolymorphicObject *	copy_from (const std::shared_ptr< const PolymorphicObject > &other)

PolymorphicObject *	move_from (ptr_param< PolymorphicObject > other)

PolymorphicObject *	clear ()

std::shared_ptr< const Executor >	get_executor () const noexcept

Public Member Functions inherited from gko::log::EnableLogging< PolymorphicObject >
void	add_logger (std::shared_ptr< const Logger > logger) override

void	remove_logger (const Logger *logger) override

void	remove_logger (ptr_param< const Logger > logger)

const std::vector< std::shared_ptr< const Logger > > &	get_loggers () const override

void	clear_loggers () override

Public Member Functions inherited from gko::log::Loggable
void	remove_logger (ptr_param< const Logger > logger)

Public Member Functions inherited from gko::EnablePolymorphicAssignment< ConcreteLinOp >
void	convert_to (result_type *result) const override

void	move_to (result_type *result) override

Public Member Functions inherited from gko::ConvertibleTo< ResultType >
virtual void	convert_to (result_type *result) const =0

void	convert_to (ptr_param< result_type > result) const

virtual void	move_to (result_type *result)=0

void	move_to (ptr_param< result_type > result)

Public Member Functions inherited from gko::solver::EnableSolverBase< DerivedType, MatrixType >
EnableSolverBase &	operator= (const EnableSolverBase &other)

EnableSolverBase &	operator= (EnableSolverBase &&other)

	EnableSolverBase (std::shared_ptr< const MatrixType > system_matrix)

	EnableSolverBase (const EnableSolverBase &other)

	EnableSolverBase (EnableSolverBase &&other)

int	get_num_workspace_ops () const override

std::vector< std::string >	get_workspace_op_names () const override

std::vector< int >	get_workspace_scalars () const override

std::vector< int >	get_workspace_vectors () const override

Public Member Functions inherited from gko::solver::SolverBase< MatrixType >
std::shared_ptr< const MatrixType >	get_system_matrix () const

Public Member Functions inherited from gko::solver::EnableIterativeBase< DerivedType >
EnableIterativeBase &	operator= (const EnableIterativeBase &other)

EnableIterativeBase &	operator= (EnableIterativeBase &&other)

	EnableIterativeBase (std::shared_ptr< const stop::CriterionFactory > stop_factory)

	EnableIterativeBase (const EnableIterativeBase &other)

	EnableIterativeBase (EnableIterativeBase &&other)

void	set_stop_criterion_factory (std::shared_ptr< const stop::CriterionFactory > new_stop_factory) override

Public Member Functions inherited from gko::solver::IterativeBase
std::shared_ptr< const stop::CriterionFactory >	get_stop_criterion_factory () const

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

static parameters_type	parse (const config::pnode &config, const config::registry &context, const config::type_descriptor &td_for_child=config::make_type_descriptor< ValueType >())

Protected Member Functions
void	apply_impl (const LinOp b, LinOp x) const override

template<typename VectorType >
void	apply_dense_impl (const VectorType b, VectorType x, initial_guess_mode guess) const

void	apply_impl (const LinOp alpha, const LinOp b, const LinOp beta, LinOp x) const override

void	apply_with_initial_guess_impl (const LinOp b, LinOp x, initial_guess_mode guess) const override

void	apply_with_initial_guess_impl (const LinOp alpha, const LinOp b, const LinOp beta, LinOp x, initial_guess_mode guess) const override

void	set_relaxation_factor (std::shared_ptr< const matrix::Dense< ValueType > > new_factor)

	Ir (std::shared_ptr< const Executor > exec)

	Ir (const Factory *factory, std::shared_ptr< const LinOp > system_matrix)

Protected Member Functions inherited from gko::EnableLinOp< ConcreteLinOp, PolymorphicBase >
ConcreteLinOp *	self () noexcept

const ConcreteLinOp *	self () const noexcept

Protected Member Functions inherited from gko::EnablePolymorphicObject< ConcreteObject, PolymorphicBase >
std::unique_ptr< PolymorphicObject >	create_default_impl (std::shared_ptr< const Executor > exec) const override

PolymorphicObject *	copy_from_impl (const PolymorphicObject *other) override

PolymorphicObject *	copy_from_impl (std::unique_ptr< PolymorphicObject > other) override

PolymorphicObject *	move_from_impl (PolymorphicObject *other) override

PolymorphicObject *	move_from_impl (std::unique_ptr< PolymorphicObject > other) override

PolymorphicObject *	clear_impl () override

Protected Member Functions inherited from gko::PolymorphicObject
	PolymorphicObject (std::shared_ptr< const Executor > exec)

	PolymorphicObject (const PolymorphicObject &other)

Protected Member Functions inherited from gko::log::EnableLogging< PolymorphicObject >
void	log (Params &&... params) const

Protected Member Functions inherited from gko::solver::EnableSolverBase< DerivedType, MatrixType >
void	set_system_matrix (std::shared_ptr< const MatrixType > new_system_matrix)

void	setup_workspace () const

Protected Member Functions inherited from gko::solver::SolverBase< MatrixType >
void	set_system_matrix_base (std::shared_ptr< const MatrixType > system_matrix)

Protected Member Functions inherited from gko::solver::EnableApplyWithInitialGuess< DerivedType >
	EnableApplyWithInitialGuess (initial_guess_mode guess=initial_guess_mode::provided)

void	apply_with_initial_guess (const LinOp b, LinOp x, initial_guess_mode guess) const override

void	apply_with_initial_guess (const LinOp alpha, const LinOp b, const LinOp beta, LinOp x, initial_guess_mode guess) const override

DerivedType *	self () noexcept

const DerivedType *	self () const noexcept

Protected Member Functions inherited from gko::solver::ApplyWithInitialGuess
void	apply_with_initial_guess (ptr_param< const LinOp > b, ptr_param< LinOp > x, initial_guess_mode guess) const

void	apply_with_initial_guess (ptr_param< const LinOp > alpha, ptr_param< const LinOp > b, ptr_param< const LinOp > beta, ptr_param< LinOp > x, initial_guess_mode guess) const

initial_guess_mode	get_default_initial_guess () const

	ApplyWithInitialGuess (initial_guess_mode guess=initial_guess_mode::provided)

void	set_default_initial_guess (initial_guess_mode guess)

Friends
class	EnableLinOp< Ir >

class	EnablePolymorphicObject< Ir, LinOp >

class	EnableApplyWithInitialGuess< Ir >

Additional Inherited Members
Protected Attributes inherited from gko::log::EnableLogging< PolymorphicObject >
std::vector< std::shared_ptr< const Logger > >	loggers_

Detailed Description

template<typename ValueType = default_precision>
class gko::solver::Ir< ValueType >

Iterative refinement (IR) is an iterative method that uses another coarse method to approximate the error of the current solution via the current residual. Moreover, it can be also considered as preconditioned Richardson iteration with relaxation factor = 1.

For any approximation of the solution solution to the system Ax = b, the residual is defined as: residual = b - A solution. The error in solution, e = x - solution (with x being the exact solution) can be obtained as the solution to the residual equation Ae = residual, since A e = Ax - A solution = b - A solution = residual. Then, the real solution is computed as x = relaxation_factor * solution + e. Instead of accurately solving the residual equation Ae = residual, the solution of the system e can be approximated to obtain the approximation error using a coarse method solver, which is used to update solution, and the entire process is repeated with the updated solution. This yields the iterative refinement method:

solution = initial_guess
while not converged:
    residual = b - A solution
    error = solver(A, residual)
    solution = solution + relaxation_factor * error

With relaxation_factor equal to 1 (default), the solver is Iterative Refinement, with relaxation_factor equal to a value other than 1, the solver is a Richardson iteration, with possibility for additional preconditioning.

Assuming that solver has accuracy c, i.e., | e - error | <= c | e |, iterative refinement will converge with a convergence rate of c. Indeed, from e - error = x - solution - error = x - solution* (where solution* denotes the value stored in solution after the update) and e = inv(A) residual = inv(A)b - inv(A) A solution = x - solution it follows that | x - solution* | <= c | x - solution |.

Unless otherwise specified via the solver factory parameter, this implementation uses the identity operator (i.e. the solver that approximates the solution of a system Ax = b by setting x := b) as the default inner solver. Such a setting results in a relaxation method known as the Richardson iteration with parameter 1, which is guaranteed to converge for matrices whose spectrum is strictly contained within the unit disc around 1 (i.e., all its eigenvalues lambda have to satisfy the equation `|relaxation_factor * lambda - 1| < 1).

Template Parameters

ValueType precision of matrix elements

Constructor & Destructor Documentation

◆ Ir() [1/2]

template<typename ValueType = default_precision>

gko::solver::Ir< ValueType >::Ir ( const Ir< ValueType > & )

Copy-constructs an IR solver. Inherits the executor, shallow-copies inner solver, stopping criterion and system matrix.

◆ Ir() [2/2]

template<typename ValueType = default_precision>

gko::solver::Ir< ValueType >::Ir ( Ir< ValueType > && )

Move-constructs an IR solver. Preserves the executor, moves inner solver, stopping criterion and system matrix. The moved-from object is empty (0x0 and nullptr inner solver, stopping criterion and system matrix)

Member Function Documentation

◆ apply_uses_initial_guess()

template<typename ValueType = default_precision>

bool gko::solver::Ir< ValueType >::apply_uses_initial_guess ( ) const

inlineoverride

Return true as iterative solvers use the data in x as an initial guess.

Returns: true as iterative solvers use the data in x as an initial guess.

References gko::solver::ApplyWithInitialGuess::get_default_initial_guess(), and gko::solver::provided.

◆ apply_with_initial_guess_impl() [1/2]

template<typename ValueType = default_precision>

void gko::solver::Ir< ValueType >::apply_with_initial_guess_impl	(	const LinOp *	alpha,
		const LinOp *	b,
		const LinOp *	beta,
		LinOp *	x,
		initial_guess_mode	guess
	)		const

overrideprotectedvirtual

The class should override this method and must modify the input vectors according to the initial_guess_mode

Implements gko::solver::EnableApplyWithInitialGuess< DerivedType >.

◆ apply_with_initial_guess_impl() [2/2]

template<typename ValueType = default_precision>

void gko::solver::Ir< ValueType >::apply_with_initial_guess_impl	(	const LinOp *	b,
		LinOp *	x,
		initial_guess_mode	guess
	)		const

overrideprotectedvirtual

The class should override this method and must modify the input vectors according to the initial_guess_mode

Implements gko::solver::EnableApplyWithInitialGuess< DerivedType >.

◆ conj_transpose()

template<typename ValueType = default_precision>

std::unique_ptr< LinOp > gko::solver::Ir< ValueType >::conj_transpose ( ) const

overridevirtual

Returns a LinOp representing the conjugate transpose of the Transposable object.

Returns: a pointer to the new conjugate transposed object

Implements gko::Transposable.

◆ get_solver()

template<typename ValueType = default_precision>

std::shared_ptr< const LinOp > gko::solver::Ir< ValueType >::get_solver ( ) const

inline

Returns the solver operator used as the inner solver.

Returns: the solver operator used as the inner solver

◆ operator=() [1/2]

template<typename ValueType = default_precision>

Ir & gko::solver::Ir< ValueType >::operator= ( const Ir< ValueType > & )

Copy-assigns an IR solver. Preserves the executor, shallow-copies inner solver, stopping criterion and system matrix. If the executors mismatch, clones inner solver, stopping criterion and system matrix onto this executor.

◆ operator=() [2/2]

template<typename ValueType = default_precision>

Ir & gko::solver::Ir< ValueType >::operator= ( Ir< ValueType > && )

Move-assigns an IR solver. Preserves the executor, moves inner solver, stopping criterion and system matrix. If the executors mismatch, clones inner solver, stopping criterion and system matrix onto this executor. The moved-from object is empty (0x0 and nullptr inner solver, stopping criterion and system matrix)

◆ parse()

template<typename ValueType = default_precision>

static parameters_type gko::solver::Ir< ValueType >::parse	(	const config::pnode &	config,
		const config::registry &	context,
		const config::type_descriptor &	td_for_child = `config::make_type_descriptor< ValueType >()`
	)

static

Create the parameters from the property_tree. Because this is directly tied to the specific type, the value/index type settings within config are ignored and type_descriptor is only used for children configs.

Parameters

config	the property tree for setting
context	the registry
td_for_child	the type descriptor for children configs. The default uses the value type of this class.

Returns: parameters

◆ set_solver()

template<typename ValueType = default_precision>

void gko::solver::Ir< ValueType >::set_solver ( std::shared_ptr< const LinOp > new_solver )

Sets the solver operator used as the inner solver.

Parameters

new_solver the new inner solver

◆ transpose()

template<typename ValueType = default_precision>

std::unique_ptr< LinOp > gko::solver::Ir< ValueType >::transpose ( ) const

overridevirtual

Returns a LinOp representing the transpose of the Transposable object.

Returns: a pointer to the new transposed object

Implements gko::Transposable.

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

ginkgo/core/solver/ir.hpp

Ir< ValueType > Class Template Reference

Ir< ValueType > Class Template Reference#

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Ir() [1/2]

◆ Ir() [2/2]

Member Function Documentation

◆ apply_uses_initial_guess()

◆ apply_with_initial_guess_impl() [1/2]

◆ apply_with_initial_guess_impl() [2/2]

◆ conj_transpose()

◆ get_solver()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ parse()

◆ set_solver()

◆ transpose()

Ir< ValueType > Class Template Reference

Ir&lt; ValueType &gt; Class Template Reference#

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Ir() [1/2]

◆ Ir() [2/2]

Member Function Documentation

◆ apply_uses_initial_guess()

◆ apply_with_initial_guess_impl() [1/2]

◆ apply_with_initial_guess_impl() [2/2]

◆ conj_transpose()

◆ get_solver()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ parse()

◆ set_solver()

◆ transpose()

Ir< ValueType > Class Template Reference#