"Factory" for creating Ifpack2 preconditioners. More...

#include <Ifpack2_Factory_decl.hpp>

Static Public Member Functions
template<class MatrixType >
static Teuchos::RCP < Preconditioner< typename MatrixType::scalar_type, typename MatrixType::local_ordinal_type, typename MatrixType::global_ordinal_type, typename MatrixType::node_type > >	create (const std::string &precType, const Teuchos::RCP< const MatrixType > &matrix)
	Create an instance of Ifpack2_Preconditioner given the string name of the preconditioner type. More...

template<class MatrixType >
static Teuchos::RCP < Preconditioner< typename MatrixType::scalar_type, typename MatrixType::local_ordinal_type, typename MatrixType::global_ordinal_type, typename MatrixType::node_type > >	create (const std::string &precType, const Teuchos::RCP< const MatrixType > &matrix, const int overlap)
	Create an instance of Ifpack2_Preconditioner given the string name of the preconditioner type. More...

Detailed Description

"Factory" for creating Ifpack2 preconditioners.

This class' create() method lets users create an instance of any Ifpack2 preconditioner.

The create() method has three arguments:

a string, indicating the type of preconditioner to compute;
a pointer to a Tpetra::RowMatrix, representing the matrix to be used to define the preconditioner;
an optional integer (defaults to 0), that specifies the amount of overlap between processes (if the input matrix is distributed over multiple processes).

The first argument can assume the following values:

"DIAGONAL": returns an instance of Ifpack2::Diagonal.
"RELAXATION": returns an instance of Ifpack2::Relaxation.
"CHEBYSHEV": returns an instance of Ifpack2::Chebyshev (overlap is ignored).
"ILUT": returns an instance of Ifpack2::ILUT.
"RILUK": returns an instance of Ifpack2::RILUK.
"RBILUK": returns an instance of Ifpack2::Experimental::RBILUK.

The following fragment of code shows the basic usage of this class.

#include "Ifpack2_Factory.hpp"
// ...
using Teuchos::ParameterList;
using Teuchos::RCP;
typedef double Scalar;
typedef Tpetra::CrsMatrix<Scalar> crs_matrix_type;
typedef Ifpack2::Preconditioner<Scalar> prec_type;
// ...
Ifpack2::Factory factory;
RCP<crs_matrix_type> A;
// ... fill A and call fillComplete() ...
// Use ILUT (incomplete LU with thresholding) on each process.
const std::string precType = "ILUT";
RCP<prec_type> prec = factory.create (precType, A);
ParameterList params;
params.set ("fact: ilut level-of-fill", 5.0); // ILUT(fill=5, drop=0)
prec->setParameters (params);
prec->initialize ();
prec->compute ();
// now prec can be used as a preconditioner

Member Function Documentation

template<class MatrixType >

static Teuchos::RCP<Preconditioner<typename MatrixType::scalar_type, typename MatrixType::local_ordinal_type, typename MatrixType::global_ordinal_type, typename MatrixType::node_type> > Ifpack2::Factory::create	(	const std::string &	precType,
		const Teuchos::RCP< const MatrixType > &	matrix
	)

inlinestatic

Create an instance of Ifpack2_Preconditioner given the string name of the preconditioner type.

Parameters

precType	[in] Name of preconditioner type to be created.
matrix	[in] Matrix used to define the preconditioner

Throw an exception if the preconditioner with that input name does not exist. Otherwise, return a newly created preconditioner object.