PreconditionSelector< Matrix, Vector > Class Template Reference
[Preconditioners]

Inheritance diagram for PreconditionSelector< Matrix, Vector >:

Inheritance graph
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List of all members.

Classes

class  ExcNoMatrixGivenToUse

Public Member Functions

 PreconditionSelector (const std::string &preconditioning, const typename Vector::value_type &omega=1.)
virtual ~PreconditionSelector ()
void use_matrix (const Matrix &M)
virtual void vmult (Vector &dst, const Vector &src) const

Static Public Member Functions

static std::string get_precondition_names ()

Protected Attributes

std::string preconditioning

Private Attributes

SmartPointer< const Matrix > A
const Vector::value_type omega


Detailed Description

template<class Matrix = SparseMatrix<double>, class Vector = ::Vector<double>>
class PreconditionSelector< Matrix, Vector >

Selects the preconditioner. The constructor of this class takes the name of the preconditioning and the damping parameter omega of the preconditioning and the use_matrix function takes the matrix that is used by the matrix-builtin precondition functions. Each time, the operator() function is called, this preselected preconditioner, this matrix and this omega is used for the preconditioning. This class is designed for being used as argument of the solve function of a Solver and it covers the selection of all matrix-builtin precondition functions. The selection of other preconditioners, like BlockSOR or ILU should be handled in derived classes by the user.

Usage

The simplest use of this class is the following:

 *                                  // generate a @p SolverControl and
 *                                  // a @p VectorMemory
 * SolverControl control;
 * VectorMemory<Vector<double> > memory;
 *                                  // generate a solver
 * SolverCG<SparseMatrix<double>, Vector<double> > solver(control, memory);
 *                                  // generate a @p PreconditionSelector
 * PreconditionSelector<SparseMatrix<double>, Vector<double> >
 *   preconditioning("jacobi", 1.);
 *                                  // give a matrix whose diagonal entries
 *                                  // are to be used for the preconditioning.
 *                                  // Generally the matrix of the linear
 *                                  // equation system Ax=b.
 * preconditioning.use_matrix(A);
 *                                  // call the @p solve function with this
 *                                  // preconditioning as last argument
 * solver.solve(A,x,b,preconditioning);
 * 
The same example where also the SolverSelector class is used reads
 *                                  // generate a @p SolverControl and
 *                                  // a @p VectorMemory
 * SolverControl control;
 * VectorMemory<Vector<double> > memory;
 *                                  // generate a @p SolverSelector that
 *                                  // calls the @p SolverCG
 * SolverSelector<SparseMatrix<double>, Vector<double> > 
 *   solver_selector("cg", control, memory);
 *                                  // generate a @p PreconditionSelector
 * PreconditionSelector<SparseMatrix<double>, Vector<double> >
 *   preconditioning("jacobi", 1.);
 *
 * preconditioning.use_matrix(A);
 *
 * solver_selector.solve(A,x,b,preconditioning);
 * 
Now the use of the SolverSelector in combination with the PreconditionSelector allows the user to select both, the solver and the preconditioner, at the beginning of his program and each time the solver is started (that is several times e.g. in a nonlinear iteration) this preselected solver and preconditioner is called.

Author:
Ralf Hartmann, 1999

Constructor & Destructor Documentation

template<class Matrix , class Vector >
PreconditionSelector< Matrix, Vector >::PreconditionSelector ( const std::string &  preconditioning,
const typename Vector::value_type omega = 1. 
) [inline]

Constructor. omega denotes the damping parameter of the preconditioning.

template<class Matrix , class Vector >
PreconditionSelector< Matrix, Vector >::~PreconditionSelector (  )  [inline, virtual]


Member Function Documentation

template<class Matrix , class Vector >
void PreconditionSelector< Matrix, Vector >::use_matrix ( const Matrix &  M  )  [inline]

Takes the matrix that is needed for preconditionings that involves a matrix. e.g. for precondition_jacobi, ~_sor, ~_ssor.

References PreconditionSelector< Matrix, Vector >::A.

template<class Matrix , class Vector >
void PreconditionSelector< Matrix, Vector >::vmult ( Vector dst,
const Vector src 
) const [inline, virtual]

Precondition procedure. Calls the preconditioning that was specified in the constructor.

References PreconditionSelector< Matrix, Vector >::A, Assert, PreconditionSelector< Matrix, Vector >::omega, and PreconditionSelector< Matrix, Vector >::preconditioning.

template<class Matrix , class Vector >
std::string PreconditionSelector< Matrix, Vector >::get_precondition_names (  )  [inline, static]

Get the names of all implemented preconditionings.


Member Data Documentation

template<class Matrix = SparseMatrix<double>, class Vector = ::Vector<double>>
std::string PreconditionSelector< Matrix, Vector >::preconditioning [protected]

Stores the name of the preconditioning.

Referenced by PreconditionSelector< Matrix, Vector >::vmult().

template<class Matrix = SparseMatrix<double>, class Vector = ::Vector<double>>
SmartPointer<const Matrix> PreconditionSelector< Matrix, Vector >::A [private]

template<class Matrix = SparseMatrix<double>, class Vector = ::Vector<double>>
const Vector::value_type PreconditionSelector< Matrix, Vector >::omega [private]

Stores the damping parameter of the preconditioner.

Referenced by PreconditionSelector< Matrix, Vector >::vmult().


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

deal.II documentation generated on Sat Aug 15 16:52:14 2009 by doxygen 1.5.9