PreconditionUseMatrix< MatrixType, VectorType > Class Template Reference

#include <deal.II/lac/precondition.h>

Inheritance diagram for PreconditionUseMatrix< MatrixType, VectorType >:

Public Types
using	function_ptr = void(MatrixType::*)(VectorType &, const VectorType &) const

Public Member Functions
	PreconditionUseMatrix (const MatrixType &M, const function_ptr method)
void	vmult (VectorType &dst, const VectorType &src) const
Public Member Functions inherited from Subscriptor
	Subscriptor ()
	Subscriptor (const Subscriptor &)
	Subscriptor (Subscriptor &&) noexcept
virtual	~Subscriptor ()
Subscriptor &	operator= (const Subscriptor &)
Subscriptor &	operator= (Subscriptor &&) noexcept
void	subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const
void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const
unsigned int	n_subscriptions () const
template<typename StreamType >
void	list_subscribers (StreamType &stream) const
void	list_subscribers () const
template<class Archive >
void	serialize (Archive &ar, const unsigned int version)

Private Attributes
const MatrixType &	matrix
const function_ptr	precondition

Additional Inherited Members
Static Public Member Functions inherited from Subscriptor
static ::ExceptionBase &	ExcInUse (int arg1, std::string arg2, std::string arg3)
static ::ExceptionBase &	ExcNoSubscriber (std::string arg1, std::string arg2)

Detailed Description

template<typename MatrixType = SparseMatrix<double>, class VectorType = Vector<double>>
class PreconditionUseMatrix< MatrixType, VectorType >

Preconditioner using a matrix-builtin function. This class forms a preconditioner suitable for the LAC solver classes. Since many preconditioning methods are based on matrix entries, these have to be implemented as member functions of the underlying matrix implementation. This class now is intended to allow easy access to these member functions from LAC solver classes.

It seems that all builtin preconditioners have a relaxation parameter, so please use PreconditionRelaxation for these.

You will usually not want to create a named object of this type, although possible. The most common use is like this:

SolverGMRES<SparseMatrix<double> Vector<double>> gmres(control,memory,500);
 
gmres.solve(
  matrix, solution, right_hand_side,
  PreconditionUseMatrix<SparseMatrix<double>,Vector<double> >(
    matrix, &SparseMatrix<double>::template precondition_Jacobi<double>));

This creates an unnamed object to be passed as the fourth parameter to the solver function of the SolverGMRES class. It assumes that the SparseMatrix class has a function precondition_Jacobi taking two vectors (source and destination) as parameters (Actually, there is no function like that, the existing function takes a third parameter, denoting the relaxation parameter; this example is therefore only meant to illustrate the general idea).

Note that due to the default template parameters, the above example could be written shorter as follows:

...
gmres.solve(
  matrix, solution, right_hand_side,
  PreconditionUseMatrix<>(
    matrix,&SparseMatrix<double>::template precondition_Jacobi<double>));

Author

Guido Kanschat, Wolfgang Bangerth, 1999

Definition at line 365 of file precondition.h.

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

• include/deal.II/lac/precondition.h