Generalized preconditioned conjugate gradient solver. More...

#include <dune/istl/solvers.hh>

Public Types
typedef X	domain_type
	Type of the domain of the operator to be inverted.

typedef X	range_type
	Type of the range of the operator to be inverted.

typedef X::field_type	field_type
	The field type of the operator.

typedef FieldTraits< field_type >::real_type	real_type
	The real type of the field type (is the same if using real numbers, but differs for std::complex)

typedef Simd::Scalar< real_type >	scalar_real_type
	scalar type underlying the field_type

Public Member Functions
	GeneralizedPCGSolver (const LinearOperator< X, X > &op, Preconditioner< X, X > &prec, scalar_real_type reduction, int maxit, int verbose, int restart=10)
	Set up nonlinear preconditioned conjugate gradient solver. More...

	GeneralizedPCGSolver (const LinearOperator< X, X > &op, const ScalarProduct< X > &sp, Preconditioner< X, X > &prec, scalar_real_type reduction, int maxit, int verbose, int restart=10)
	Set up nonlinear preconditioned conjugate gradient solver. More...

	GeneralizedPCGSolver (std::shared_ptr< const LinearOperator< X, X > > op, std::shared_ptr< Preconditioner< X, X > > prec, const ParameterTree &configuration)
	Constructor. More...

	GeneralizedPCGSolver (std::shared_ptr< const LinearOperator< X, X > > op, std::shared_ptr< const ScalarProduct< X > > sp, std::shared_ptr< Preconditioner< X, X > > prec, scalar_real_type reduction, int maxit, int verbose, int restart=10)
	Set up nonlinear preconditioned conjugate gradient solver. More...

void	apply (X &x, X &b, InverseOperatorResult &res) override
	Apply inverse operator. More...

void	apply (X &x, X &b, double reduction, InverseOperatorResult &res) override
	Apply inverse operator with given reduction factor. More...

SolverCategory::Category	category () const override
	Category of the solver (see SolverCategory::Category)

Protected Member Functions
void	printHeader (std::ostream &s) const
	helper function for printing header of solver output

void	printOutput (std::ostream &s, const CountType &iter, const DataType &norm, const DataType &norm_old) const
	helper function for printing solver output

void	printOutput (std::ostream &s, const CountType &iter, const DataType &norm) const
	helper function for printing solver output

Detailed Description

template<class X>
class Dune::GeneralizedPCGSolver< X >

Generalized preconditioned conjugate gradient solver.

A preconditioned conjugate gradient that allows the preconditioner to change between iterations.

One example for such preconditioner is AMG when used without a direct coarse solver. In this case the number of iterations performed on the coarsest level might change between applications.

In contrast to CGSolver the search directions are stored and the orthogonalization is done explicitly.

Constructor & Destructor Documentation

◆ GeneralizedPCGSolver() [1/4]

template<class X >

Dune::GeneralizedPCGSolver< X >::GeneralizedPCGSolver	(	const LinearOperator< X, X > &	op,
		Preconditioner< X, X > &	prec,
		scalar_real_type	reduction,
		int	maxit,
		int	verbose,
		int	restart = `10`
	)

inline

Set up nonlinear preconditioned conjugate gradient solver.

Parameters

restart number of GMRes cycles before restart

◆ GeneralizedPCGSolver() [2/4]

template<class X >

Dune::GeneralizedPCGSolver< X >::GeneralizedPCGSolver	(	const LinearOperator< X, X > &	op,
		const ScalarProduct< X > &	sp,
		Preconditioner< X, X > &	prec,
		scalar_real_type	reduction,
		int	maxit,
		int	verbose,
		int	restart = `10`
	)

inline

Set up nonlinear preconditioned conjugate gradient solver.

Parameters

restart When to restart the construction of the Krylov search space.

◆ GeneralizedPCGSolver() [3/4]

template<class X >

Dune::GeneralizedPCGSolver< X >::GeneralizedPCGSolver	(	std::shared_ptr< const LinearOperator< X, X > >	op,
		std::shared_ptr< Preconditioner< X, X > >	prec,
		const ParameterTree &	configuration
	)

inline

Constructor.

Additional parameter:

ParameterTree Key	Meaning
restart	number of PCG cycles before restart

See ISTL_Factory for the ParameterTree layout and examples.

◆ GeneralizedPCGSolver() [4/4]

template<class X >

Dune::GeneralizedPCGSolver< X >::GeneralizedPCGSolver	(	std::shared_ptr< const LinearOperator< X, X > >	op,
		std::shared_ptr< const ScalarProduct< X > >	sp,
		std::shared_ptr< Preconditioner< X, X > >	prec,
		scalar_real_type	reduction,
		int	maxit,
		int	verbose,
		int	restart = `10`
	)

inline

Set up nonlinear preconditioned conjugate gradient solver.

Parameters

restart When to restart the construction of the Krylov search space.

Member Function Documentation

◆ apply() [1/2]

void Dune::IterativeSolver< X, X >::apply	(	X &	x,
		X &	b,
		double	reduction,
		InverseOperatorResult &	res
	)

inlineoverridevirtualinherited

Apply inverse operator with given reduction factor.

apply inverse operator, with given convergence criteria.

Warning: Right hand side b may be overwritten!

Parameters

x	The left hand side to store the result in.
b	The right hand side
reduction	The minimum defect reduction to achieve.
res	Object to store the statistics about applying the operator.

Exceptions

SolverAbort When the solver detects a problem and cannot continue

Implements Dune::InverseOperator< X, X >.

Reimplemented in Dune::RestartedGMResSolver< X, X >.