IFPACK Development
Public Member Functions
Ifpack_Chebyshev Class Reference

Ifpack_Chebyshev: class for preconditioning with Chebyshev polynomials in Ifpack. More...

#include <Ifpack_Chebyshev.h>

Inheritance diagram for Ifpack_Chebyshev:
Inheritance graph
[legend]
Collaboration diagram for Ifpack_Chebyshev:
Collaboration graph
[legend]

List of all members.

Public Member Functions

virtual int SetUseTranspose (bool UseTranspose_in)
 Ifpack_Chebyshev (const Epetra_Operator *Matrix)
 Ifpack_Chebyshev constructor with given Epetra_Operator/Epetra_RowMatrix.
 Ifpack_Chebyshev (const Epetra_RowMatrix *Matrix)
 Ifpack_Chebyshev constructor with given Epetra_Operator/Epetra_RowMatrix.
virtual ~Ifpack_Chebyshev ()
 Destructor.
virtual int Apply (const Epetra_MultiVector &X, Epetra_MultiVector &Y) const
 Applies the matrix to an Epetra_MultiVector.
virtual int ApplyInverse (const Epetra_MultiVector &X, Epetra_MultiVector &Y) const
 Applies the preconditioner to X, returns the result in Y.
virtual double NormInf () const
 Returns the infinity norm of the global matrix (not implemented)
virtual const char * Label () const
virtual bool UseTranspose () const
 Returns the current UseTranspose setting.
virtual bool HasNormInf () const
 Returns true if the this object can provide an approximate Inf-norm, false otherwise.
virtual const Epetra_CommComm () const
 Returns a pointer to the Epetra_Comm communicator associated with this operator.
virtual const Epetra_MapOperatorDomainMap () const
 Returns the Epetra_Map object associated with the domain of this operator.
virtual const Epetra_MapOperatorRangeMap () const
 Returns the Epetra_Map object associated with the range of this operator.
virtual int Initialize ()
 Computes all it is necessary to initialize the preconditioner.
virtual bool IsInitialized () const
 Returns true if the preconditioner has been successfully initialized, false otherwise.
virtual bool IsComputed () const
 Returns true if the preconditioner has been successfully computed.
virtual int Compute ()
 Computes the preconditioners.
virtual double GetLambdaMax ()
 Returns an approximation to the largest eigenvalue.
virtual double GetLambdaMin ()
 Contains an approximation to the smallest eigenvalue.
virtual const Epetra_RowMatrixMatrix () const
 Returns a pointer to the matrix to be preconditioned.
virtual double Condest (const Ifpack_CondestType CT=Ifpack_Cheap, const int MaxIters=1550, const double Tol=1e-9, Epetra_RowMatrix *Matrix_in=0)
 Computes the condition number estimates and returns the value.
virtual double Condest () const
 Returns the condition number estimate, or -1.0 if not computed.
virtual int SetParameters (Teuchos::ParameterList &List)
 Sets all the parameters for the preconditioner.
virtual ostream & Print (ostream &os) const
 Prints object to an output stream.
virtual int NumInitialize () const
 Returns the number of calls to Initialize().
virtual int NumCompute () const
 Returns the number of calls to Compute().
virtual int NumApplyInverse () const
 Returns the number of calls to ApplyInverse().
virtual double InitializeTime () const
 Returns the time spent in Initialize().
virtual double ComputeTime () const
 Returns the time spent in Compute().
virtual double ApplyInverseTime () const
 Returns the time spent in ApplyInverse().
virtual double InitializeFlops () const
 Returns the number of flops in the initialization phase.
virtual double ComputeFlops () const
 Returns the number of flops in the computation phase.
virtual double ApplyInverseFlops () const
 Returns the number of flops for the application of the preconditioner.

Static Public Member Functions

static int PowerMethod (const Epetra_Operator &Operator, const Epetra_Vector &InvPointDiagonal, const int MaximumIterations, double &LambdaMax)
 Simple power method to compute lambda_max.
static int CG (const Epetra_Operator &Operator, const Epetra_Vector &InvPointDiagonal, const int MaximumIterations, double &lambda_min, double &lambda_max)
 Uses AztecOO's CG to estimate lambda_min and lambda_max.

Detailed Description

Ifpack_Chebyshev: class for preconditioning with Chebyshev polynomials in Ifpack.

The Ifpack_Chebyshev class enables the construction of preconditioners based on Chebyshev polynomials for an Epetra_RowMatrix. Ifpack_Chebyshev is derived from the Ifpack_Preconditioner class, which is itself derived from Epetra_Operator. Therefore this object can be used as preconditioner everywhere an ApplyInverse() method is required in the preconditioning step.

The class is an adaptation of the routine ML_Cheby in Smoother/ml_smoother.h

(04/04/06) Flops are not counted in the routine ApplyInverse()

(04/04/06) The switch to use the transpose matrix is not used in ApplyInverse()

The list of parameters is

Author:
Ulrich Hetmaniuk. SNL 1414.
Date:
Last modified on 04-Apr-06.

Definition at line 91 of file Ifpack_Chebyshev.h.


Constructor & Destructor Documentation

Ifpack_Chebyshev::Ifpack_Chebyshev ( const Epetra_Operator Matrix)

Ifpack_Chebyshev constructor with given Epetra_Operator/Epetra_RowMatrix.

Creates an instance of Ifpack_Chebyshev class.

Parameters:
Matrix- (In) Pointer to the operator to precondition.

Definition at line 70 of file Ifpack_Chebyshev.cpp.

Ifpack_Chebyshev::Ifpack_Chebyshev ( const Epetra_RowMatrix Matrix)

Ifpack_Chebyshev constructor with given Epetra_Operator/Epetra_RowMatrix.

Creates an instance of Ifpack_Chebyshev class.

Parameters:
Matrix- (In) Pointer to the matrix to precondition.

Definition at line 112 of file Ifpack_Chebyshev.cpp.


Member Function Documentation

int Ifpack_Chebyshev::Apply ( const Epetra_MultiVector X,
Epetra_MultiVector Y 
) const [inline, virtual]

Applies the matrix to an Epetra_MultiVector.

Parameters:
X- (In) A Epetra_MultiVector of dimension NumVectors to multiply with matrix.
Y- (Out) A Epetra_MultiVector of dimension NumVectors containing the result.
Returns:
Integer error code, set to 0 if successful.

Implements Epetra_Operator.

Definition at line 215 of file Ifpack_Chebyshev.cpp.

References IsComputed(), Epetra_MultiVector::NumVectors(), and UseTranspose().

int Ifpack_Chebyshev::ApplyInverse ( const Epetra_MultiVector X,
Epetra_MultiVector Y 
) const [virtual]

Applies the preconditioner to X, returns the result in Y.

Parameters:
X- (In) A Epetra_MultiVector of dimension NumVectors to be preconditioned.
Y- (InOut) A Epetra_MultiVector of dimension NumVectors containing result.
Returns:
Integer error code, set to 0 if successful.
Warning:
This routine is NOT AztecOO complaint.

Implements Ifpack_Preconditioner.

Definition at line 424 of file Ifpack_Chebyshev.cpp.

References Epetra_MultiVector::ExtractView(), IsComputed(), Epetra_MultiVector::MyLength(), Epetra_MultiVector::NumVectors(), Epetra_MultiVector::Pointers(), Epetra_MultiVector::Scale(), Epetra_MultiVector::Update(), and Epetra_MultiVector::Values().

virtual int Ifpack_Chebyshev::SetUseTranspose ( bool  UseTranspose_in) [inline, virtual]

This flag can be used to apply the preconditioner to the transpose of the input operator.

Returns:
Integer error code, set to 0 if successful. Set to -1 if this implementation does not support transpose.

Implements Epetra_Operator.

Definition at line 123 of file Ifpack_Chebyshev.h.


The documentation for this class was generated from the following files:
 All Classes Files Functions Variables Typedefs Enumerations Friends