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

Inheritance diagram for gko::solver::Multigrid:

Classes
class	Factory

struct	parameters_type

Public Member Functions
bool	apply_uses_initial_guess () const override

std::vector< std::shared_ptr< const gko::multigrid::MultigridLevel > >	get_mg_level_list () const

std::vector< std::shared_ptr< const LinOp > >	get_pre_smoother_list () const

std::vector< std::shared_ptr< const LinOp > >	get_mid_smoother_list () const

std::vector< std::shared_ptr< const LinOp > >	get_post_smoother_list () const

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

multigrid::cycle	get_cycle () const

void	set_cycle (multigrid::cycle cycle)

const parameters_type &	get_parameters () const

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

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

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

Multigrid *	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< ConcreteType, ResultType >
void	convert_to (result_type *result) const override

void	move_to (result_type *result) override

Public Member Functions inherited from gko::ConvertibleTo< ResultType >
void	convert_to (ptr_param< result_type > result) const

void	move_to (ptr_param< result_type > result)

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

EnableSolverBase &	operator= (EnableSolverBase &&other)

	EnableSolverBase (std::shared_ptr< const LinOp > 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< Multigrid >
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<>())

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

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

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

void	generate ()

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

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

void	validate ()

void	verify_legal_length (bool checked, size_type len, size_type ref_len)

void	create_state () const

Protected Member Functions inherited from gko::EnableLinOp< Multigrid >
Multigrid *	self () noexcept

const Multigrid *	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< Multigrid >
void	set_system_matrix (std::shared_ptr< const LinOp > 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< Multigrid >
	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

Multigrid *	self () noexcept

const Multigrid *	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< Multigrid >

class	EnablePolymorphicObject< Multigrid, LinOp >

class	EnableApplyWithInitialGuess< Multigrid >

Additional Inherited Members
Public Types inherited from gko::EnablePolymorphicAssignment< ConcreteType, ResultType >
using	result_type = ResultType

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

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

Detailed Description

Multigrid methods have a hierarchy of many levels, whose corase level is a subset of the fine level, of the problem. The coarse level solves the system on the residual of fine level and fine level will use the coarse solution to correct its own result. Multigrid solves the problem by relatively cheap step in each level and refining the result when prolongating back.

The main step of each level

Presmooth (solve on the fine level)
Calculate residual
Restrict (reduce the problem dimension)
Solve residual in next level
Prolongate (return to the fine level size)
Postsmooth (correct the answer in fine level)

Ginkgo uses the index from 0 for finest level (original problem size) ~ N for the coarsest level (the coarsest solver), and its level counts is N (N multigrid level generation).

Member Function Documentation

◆ apply_uses_initial_guess()

bool gko::solver::Multigrid::apply_uses_initial_guess ( ) const

inlineoverride

Return true as iterative solvers use the data in x as an initial guess or false if multigrid always set the input as zero

Returns: bool it is related to parameters variable zero_guess

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

◆ apply_with_initial_guess_impl() [1/2]

void gko::solver::Multigrid::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< Multigrid >.

◆ apply_with_initial_guess_impl() [2/2]

void gko::solver::Multigrid::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< Multigrid >.

◆ generate()

void gko::solver::Multigrid::generate ( )

protected

Generates the analysis structure from the system matrix and the right hand side needed for the level solver.

◆ get_coarsest_solver()

std::shared_ptr< const LinOp > gko::solver::Multigrid::get_coarsest_solver ( ) const

inline

Gets the operator at the coarsest level.

Returns: the coarsest operator

◆ get_cycle()

multigrid::cycle gko::solver::Multigrid::get_cycle ( ) const

inline

Get the cycle of multigrid

Returns: the multigrid::cycle

References gko::solver::Multigrid::parameters_type::cycle.

◆ get_mg_level_list()

std::vector< std::shared_ptr< const gko::multigrid::MultigridLevel > > gko::solver::Multigrid::get_mg_level_list ( ) const

inline

Gets the list of MultigridLevel operators.

Returns: the list of MultigridLevel operators

◆ get_mid_smoother_list()

std::vector< std::shared_ptr< const LinOp > > gko::solver::Multigrid::get_mid_smoother_list ( ) const

inline

Gets the list of mid-smoother operators.

Returns: the list of mid-smoother operators

◆ get_post_smoother_list()

std::vector< std::shared_ptr< const LinOp > > gko::solver::Multigrid::get_post_smoother_list ( ) const

inline

Gets the list of post-smoother operators.

Returns: the list of post-smoother operators

◆ get_pre_smoother_list()

std::vector< std::shared_ptr< const LinOp > > gko::solver::Multigrid::get_pre_smoother_list ( ) const

inline

Gets the list of pre-smoother operators.

Returns: the list of pre-smoother operators

◆ parse()

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

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

Returns: parameters

Note: Multigrid does not support the selector option in file config

◆ set_cycle()

void gko::solver::Multigrid::set_cycle ( multigrid::cycle cycle )

inline

Set the cycle of multigrid

Parameters

multigrid::cycle the new cycle

References gko::solver::Multigrid::parameters_type::cycle.

◆ validate()

void gko::solver::Multigrid::validate ( )

protected

validate checks the given parameters are valid or not.

◆ verify_legal_length()

void gko::solver::Multigrid::verify_legal_length	(	bool	checked,
		size_type	len,
		size_type	ref_len
	)

protected

verify_legal_length is to check whether the given len is legal for ref_len if checked is activated. Throw GKO_NOT_SUPPORTED if the length is illegal.

Parameters

checked	whether check the length
len	the length of input
ref_len	the length of reference

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

ginkgo/core/solver/multigrid.hpp

Multigrid Class Reference

Multigrid Class Reference#

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions

Friends

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ apply_uses_initial_guess()

◆ apply_with_initial_guess_impl() [1/2]

◆ apply_with_initial_guess_impl() [2/2]

◆ generate()

◆ get_coarsest_solver()

◆ get_cycle()

◆ get_mg_level_list()

◆ get_mid_smoother_list()

◆ get_post_smoother_list()

◆ get_pre_smoother_list()

◆ parse()

◆ set_cycle()

◆ validate()

◆ verify_legal_length()