Ifpack Class Reference

Ifpack: a function class to define Ifpack preconditioners. More...

#include <Ifpack.h>

List of all members.

Public Types

 absolute_threshold
 relative_threshold
 drop_tolerance
 fill_tolerance
 relax_value
 level_fill
 level_overlap
 num_steps
 use_reciprocal
 overlap_mode
 POINT_RELAXATION
 POINT_RELAXATION_STAND_ALONE
 BLOCK_RELAXATION
 BLOCK_RELAXATION_STAND_ALONE
 BLOCK_RELAXATION_STAND_ALONE_ILU
 IC
 IC_STAND_ALONE
 ICT
 ICT_STAND_ALONE
 ILU
 ILU_STAND_ALONE
 ILUT
 ILUT_STAND_ALONE
 CHEBYSHEV
enum  parameter {
  absolute_threshold, relative_threshold, drop_tolerance, fill_tolerance,
  relax_value, level_fill, level_overlap, num_steps,
  use_reciprocal, overlap_mode
}
enum  EPrecType {
  POINT_RELAXATION, POINT_RELAXATION_STAND_ALONE, BLOCK_RELAXATION, BLOCK_RELAXATION_STAND_ALONE,
  BLOCK_RELAXATION_STAND_ALONE_ILU, IC, IC_STAND_ALONE, ICT,
  ICT_STAND_ALONE, ILU, ILU_STAND_ALONE, ILUT,
  ILUT_STAND_ALONE, CHEBYSHEV
}
 Enum for the type of preconditioner. More...

Public Member Functions

Ifpack_PreconditionerCreate (const string PrecType, Epetra_RowMatrix *Matrix, const int overlap=0)
 Creates an instance of Ifpack_Preconditioner given the string name of the preconditioner type (can fail with bad input).
int SetParameters (int argc, char *argv[], Teuchos::ParameterList &List, string &PrecType, int &Overlap)
 Sets the options in List from the command line.

Static Public Member Functions

static const char * toString (const EPrecType precType)
 Function that gives the string name for preconditioner given its enumerication value.
static Ifpack_PreconditionerCreate (EPrecType PrecType, Epetra_RowMatrix *Matrix, const int overlap=0)
 Creates an instance of Ifpack_Preconditioner given the enum value of the preconditioner type (can not fail, no bad input possible).

Static Public Attributes

static const int numPrecTypes
 
static const EPrecType precTypeValues [numPrecTypes]
 List of the preconditioner types as enum values .
static const char * precTypeNames [numPrecTypes]
 List of preconditioner types as string values.
static const bool supportsUnsymmetric [numPrecTypes]
 List of bools that determines if the precondtioner type supports unsymmetric matrices.

Classes

struct  param_struct


Detailed Description

Ifpack: a function class to define Ifpack preconditioners.

Class Ifpack is a function class, that contains just one method: Create(). Using Create(), users can easily define a variety of IFPACK preconditioners.

Create requires 3 arguments:

The first argument can assume the following values:

Note:
Objects in stand-alone mode cannot use reordering, variable overlap, and singleton filters. However, their construction can be slightly faster than the non stand-alone counterpart.

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

#include "Ifpack.h"

...

Ifpack Factory;

Epetra_RowMatrix* A; // A is FillComplete()'d.
string PrecType = "ILU"; // use incomplete LU on each process
int OverlapLevel = 1; // one row of overlap among the processes
Ifpack_Preconditioner* Prec = Factory.Create(PrecType, A, OverlapLevel);
assert (Prec != 0);

Teuchos::ParameterList List;
List.set("fact: level-of-fill", 5); // use ILU(5)

IFPACK_CHK_ERR(Prec->SetParameters(List));
IFPACK_CHK_ERR(Prec->Initialize());
IFPACK_CHK_ERR(Prec->Compute());

// now Prec can be used as AztecOO preconditioner
// like for instance
AztecOO AztecOOSolver(*Problem);

// specify solver
AztecOOSolver.SetAztecOption(AZ_solver,AZ_gmres);
AztecOOSolver.SetAztecOption(AZ_output,32);

// Set Prec as preconditioning operator
AztecOOSolver.SetPrecOperator(Prec);

// Call the solver
AztecOOSolver.Iterate(1550,1e-8);

// print information on stdout
cout << *Prec;

// delete the preconditioner
delete Prec;

Author:
Marzio Sala, (formally) SNL org. 1414
Date:
Last updated on 25-Jan-05.

Definition at line 120 of file Ifpack.h.


Member Enumeration Documentation

enum Ifpack::parameter

Enumerator:
absolute_threshold 
relative_threshold 
drop_tolerance 
fill_tolerance 
relax_value 
level_fill 
level_overlap 
num_steps 
use_reciprocal 
overlap_mode 

Definition at line 42 of file ifp_parameters.h.

enum Ifpack::EPrecType

Enum for the type of preconditioner.

Enumerator:
POINT_RELAXATION 
POINT_RELAXATION_STAND_ALONE 
BLOCK_RELAXATION 
BLOCK_RELAXATION_STAND_ALONE 
BLOCK_RELAXATION_STAND_ALONE_ILU 
IC 
IC_STAND_ALONE 
ICT 
ICT_STAND_ALONE 
ILU 
ILU_STAND_ALONE 
ILUT 
ILUT_STAND_ALONE 
CHEBYSHEV 

Definition at line 124 of file Ifpack.h.


Member Function Documentation

static const char* Ifpack::toString ( const EPrecType  precType  )  [inline, static]

Function that gives the string name for preconditioner given its enumerication value.

Definition at line 187 of file Ifpack.h.

static Ifpack_Preconditioner* Ifpack::Create ( EPrecType  PrecType,
Epetra_RowMatrix Matrix,
const int  overlap = 0 
) [static]

Creates an instance of Ifpack_Preconditioner given the enum value of the preconditioner type (can not fail, no bad input possible).

Parameters:
PrecType (In) - Enum value of preconditioner type to be created.
Matrix (In) - Matrix used to define the preconditioner
overlap (In) - specified overlap, defaulted to 0.

Ifpack_Preconditioner* Ifpack::Create ( const string  PrecType,
Epetra_RowMatrix Matrix,
const int  overlap = 0 
)

Creates an instance of Ifpack_Preconditioner given the string name of the preconditioner type (can fail with bad input).

Parameters:
PrecType (In) - String name of preconditioner type to be created.
Matrix (In) - Matrix used to define the preconditioner
overlap (In) - specified overlap, defaulted to 0.
Returns 0 if the preconditioner with that input name does not exist. Otherwise, return a newly created preconditioner object. Note that the client is responsible for calling delete on the returned object once it is finished using it!

int Ifpack::SetParameters ( int  argc,
char *  argv[],
Teuchos::ParameterList &  List,
string &  PrecType,
int &  Overlap 
)

Sets the options in List from the command line.

Note: If you want full support for all parameters, consider reading in a parameter list from an XML file as supported by the Teuchos helper function Teuchos::updateParametersFromXmlFile() or Teuchos::updateParametersFromXmlStream().


Member Data Documentation

const int Ifpack::numPrecTypes [static]

Initial value:

    +5



    +8





    



    +1

Definition at line 157 of file Ifpack.h.

const Ifpack::EPrecType Ifpack::precTypeValues [static]

List of the preconditioner types as enum values .

Definition at line 176 of file Ifpack.h.

const char * Ifpack::precTypeNames [static]

List of preconditioner types as string values.

Definition at line 179 of file Ifpack.h.

const bool Ifpack::supportsUnsymmetric [static]

List of bools that determines if the precondtioner type supports unsymmetric matrices.

Definition at line 183 of file Ifpack.h.


The documentation for this class was generated from the following files:
Generated on Tue Jul 13 09:27:25 2010 for Ifpack Package Browser (Single Doxygen Collection) by  doxygen 1.4.7