conjugate gradient method More...

#include <dune/istl/solvers.hh>

Inheritance diagram for Dune::CGSolver< X >:

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
	CGSolver (const LinearOperator< X, X > &op, Preconditioner< X, X > &prec, scalar_real_type reduction, int maxit, int verbose, bool condition_estimate)
	Constructor to initialize a CG solver.
	CGSolver (const LinearOperator< X, X > &op, const ScalarProduct< X > &sp, Preconditioner< X, X > &prec, scalar_real_type reduction, int maxit, int verbose, bool condition_estimate)
	Constructor to initialize a CG solver.
	CGSolver (std::shared_ptr< const LinearOperator< X, X > > op, std::shared_ptr< ScalarProduct< X > > sp, std::shared_ptr< Preconditioner< X, X > > prec, scalar_real_type reduction, int maxit, int verbose, bool condition_estimate)
	Constructor to initialize a CG solver.
virtual void	apply (X &x, X &b, InverseOperatorResult &res)
	Apply inverse operator.
virtual void	apply (X &x, X &b, double reduction, InverseOperatorResult &res)
	Apply inverse operator with given reduction factor.
virtual SolverCategory::Category	category () const
	Category of the solver (see SolverCategory::Category).
std::string	name () const

Protected Types
using	Iteration = typename IterativeSolver<X,X>::template Iteration<unsigned int>
enum

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

Protected Attributes
std::shared_ptr< const LinearOperator< X, X > >	_op
std::shared_ptr< Preconditioner< X, X > >	_prec
std::shared_ptr< const ScalarProduct< X > >	_sp
scalar_real_type	_reduction
int	_maxit
int	_verbose
SolverCategory::Category	_category

Static Protected Attributes
static constexpr bool	enableConditionEstimate = (std::is_same_v<field_type,float> \|\| std::is_same_v<field_type,double>)

Detailed Description

template<class X>
class Dune::CGSolver< X >

conjugate gradient method

Member Typedef Documentation

◆ domain_type

typedef X Dune::InverseOperator< X, X >::domain_type

inherited

Type of the domain of the operator to be inverted.

◆ field_type

typedef X::field_type Dune::InverseOperator< X, X >::field_type

inherited

The field type of the operator.

◆ Iteration

template<class X>

using Dune::CGSolver< X >::Iteration = typename IterativeSolver<X,X>::template Iteration<unsigned int>

protected

◆ range_type

typedef X Dune::InverseOperator< X, X >::range_type

inherited

Type of the range of the operator to be inverted.

◆ real_type

typedef FieldTraits<field_type>::real_type Dune::InverseOperator< X, X >::real_type

inherited

The real type of the field type (is the same if using real numbers, but differs for std::complex).

◆ scalar_real_type

typedef Simd::Scalar<real_type> Dune::InverseOperator< X, X >::scalar_real_type

inherited

scalar type underlying the field_type

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

protectedinherited

Constructor & Destructor Documentation

◆ CGSolver() [1/3]

template<class X>

Dune::CGSolver< X >::CGSolver	(	const LinearOperator< X, X > &	op,
		Preconditioner< X, X > &	prec,
		scalar_real_type	reduction,
		int	maxit,
		int	verbose,
		bool	condition_estimate )

inline

Constructor to initialize a CG solver.

Parameters

condition_estimate Whether to calculate an estimate of the condition number. The estimate is given in the InverseOperatorResult returned by apply(). This is only supported for float and double field types.

◆ CGSolver() [2/3]

template<class X>

Dune::CGSolver< X >::CGSolver	(	const LinearOperator< X, X > &	op,
		const ScalarProduct< X > &	sp,
		Preconditioner< X, X > &	prec,
		scalar_real_type	reduction,
		int	maxit,
		int	verbose,
		bool	condition_estimate )

inline

Constructor to initialize a CG solver.

Parameters

condition_estimate Whether to calculate an estimate of the condition number. The estimate is given in the InverseOperatorResult returned by apply(). This is only supported for float and double field types.

◆ CGSolver() [3/3]

template<class X>

Dune::CGSolver< X >::CGSolver	(	std::shared_ptr< const LinearOperator< X, X > >	op,
		std::shared_ptr< ScalarProduct< X > >	sp,
		std::shared_ptr< Preconditioner< X, X > >	prec,
		scalar_real_type	reduction,
		int	maxit,
		int	verbose,
		bool	condition_estimate )

inline

Constructor to initialize a CG solver.

Parameters

condition_estimate Whether to calculate an estimate of the condition number. The estimate is given in the InverseOperatorResult returned by apply(). This is only supported for float and double field types.

Member Function Documentation

◆ apply() [1/2]

template<class X>

virtual void Dune::CGSolver< X >::apply	(	X &	x,
		X &	b,
		InverseOperatorResult &	res )

inlinevirtual

Apply inverse operator.

Apply inverse operator,.

Warning: Note: right hand side b may be overwritten!

Parameters

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

Exceptions

SolverAbort When the solver detects a problem and cannot continue

Note: Currently, the CGSolver aborts when a NaN or infinite defect is detected. However, -ffinite-math-only (implied by -ffast-math) can inhibit a result from becoming NaN that really should be NaN. E.g. numeric_limits<double>::quiet_NaN()*0.0==0.0 with gcc-5.3 -ffast-math.

Implements Dune::InverseOperator< X, X >.

◆ apply() [2/2]

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

inlinevirtualinherited

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 >.

◆ category()

virtual SolverCategory::Category Dune::IterativeSolver< X, X >::category ( ) const

inlinevirtualinherited

Category of the solver (see SolverCategory::Category).

Implements Dune::InverseOperator< X, X >.

◆ name()

std::string Dune::IterativeSolver< X, X >::name ( ) const

inlineinherited

◆ printHeader()

void Dune::InverseOperator< X, X >::printHeader ( std::ostream & s ) const

inlineprotectedinherited

helper function for printing header of solver output

◆ printOutput() [1/2]

void Dune::InverseOperator< X, X >::printOutput	(	std::ostream &	s,
		const CountType &	iter,
		const DataType &	norm ) const

inlineprotectedinherited

helper function for printing solver output

◆ printOutput() [2/2]

void Dune::InverseOperator< X, X >::printOutput	(	std::ostream &	s,
		const CountType &	iter,
		const DataType &	norm,
		const DataType &	norm_old ) const

inlineprotectedinherited

helper function for printing solver output

Member Data Documentation

◆ _category

SolverCategory::Category Dune::IterativeSolver< X, X >::_category

protectedinherited

◆ _maxit

int Dune::IterativeSolver< X, X >::_maxit

protectedinherited

◆ _op

std::shared_ptr<const LinearOperator<X,X> > Dune::IterativeSolver< X, X >::_op

protectedinherited

◆ _prec

std::shared_ptr<Preconditioner<X,X> > Dune::IterativeSolver< X, X >::_prec

protectedinherited

◆ _reduction

scalar_real_type Dune::IterativeSolver< X, X >::_reduction

protectedinherited

◆ _sp

std::shared_ptr<const ScalarProduct<X> > Dune::IterativeSolver< X, X >::_sp

protectedinherited

◆ _verbose

int Dune::IterativeSolver< X, X >::_verbose

protectedinherited

◆ enableConditionEstimate

template<class X>

bool Dune::CGSolver< X >::enableConditionEstimate = (std::is_same_v<field_type,float> || std::is_same_v<field_type,double>)

staticconstexprprotected

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

solvers.hh

Public Types

Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

Member Typedef Documentation

◆ domain_type

◆ field_type

◆ Iteration

◆ range_type

◆ real_type

◆ scalar_real_type

Member Enumeration Documentation

◆ anonymous enum

Constructor & Destructor Documentation

◆ CGSolver() [1/3]

◆ CGSolver() [2/3]

◆ CGSolver() [3/3]

Member Function Documentation

◆ apply() [1/2]

◆ apply() [2/2]

◆ category()

◆ name()

◆ printHeader()

◆ printOutput() [1/2]

◆ printOutput() [2/2]

Member Data Documentation

◆ _category

◆ _maxit

◆ _op

◆ _prec

◆ _reduction

◆ _sp

◆ _verbose

◆ enableConditionEstimate