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Ifpack Class Reference

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

#include <Ifpack.h>

List of all members.

Public Types

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, IHSS, SORA
}
 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.

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

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 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 
IHSS 
SORA 

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 195 of file Ifpack.h.

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.

Definition at line 189 of file Ifpack.cpp.

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!

Definition at line 266 of file Ifpack.cpp.

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().

Definition at line 285 of file Ifpack.cpp.


Member Data Documentation

const int Ifpack::numPrecTypes [static]
Initial value:
    +5



    +8





    






    +3

Definition at line 162 of file Ifpack.h.

List of the preconditioner types as enum values .

Definition at line 184 of file Ifpack.h.

const char * Ifpack::precTypeNames [static]

List of preconditioner types as string values.

Definition at line 187 of file Ifpack.h.

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

Definition at line 191 of file Ifpack.h.


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