Ifpack_ILUT Class Reference

Ifpack_ILUT: A class for constructing and using an incomplete Cholesky factorization of a given Epetra_RowMatrix. More...

#include <Ifpack_ILUT.h>

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List of all members.

Public Member Functions

 Ifpack_ILUT (const Epetra_RowMatrix *A)
 Ifpack_ILUT constuctor with variable number of indices per row.
virtual ~Ifpack_ILUT ()
 Ifpack_ILUT Destructor.
int SetParameters (Teuchos::ParameterList &parameterlis)
 Set parameters using a Teuchos::ParameterList object.
int Initialize ()
 Initialize L and U with values from user matrix A.
bool IsInitialized () const
 Returns true if the preconditioner has been successfully initialized.
int Compute ()
 Compute IC factor U using the specified graph, diagonal perturbation thresholds and relaxation parameters.
bool IsComputed () const
 If factor is completed, this query returns true, otherwise it returns false.
int ApplyInverse (const Epetra_MultiVector &X, Epetra_MultiVector &Y) const
 Returns the result of a Ifpack_ILUT forward/back solve on a Epetra_MultiVector X in Y.
int Apply (const Epetra_MultiVector &X, Epetra_MultiVector &Y) const
double Condest (const Ifpack_CondestType CT=Ifpack_Cheap, const int MaxIters=1550, const double Tol=1e-9, Epetra_RowMatrix *Matrix_in=0)
 Computed the estimated condition number and returns the value.
double Condest () const
 Returns the computed estimated condition number, or -1.0 if no computed.
int SetUseTranspose (bool UseTranspose_in)
 If set true, transpose of this operator will be applied.
double NormInf () const
 Returns 0.0 because this class cannot compute Inf-norm.
bool HasNormInf () const
 Returns false because this class cannot compute an Inf-norm.
bool UseTranspose () const
 Returns the current UseTranspose setting.
const Epetra_Map & OperatorDomainMap () const
 Returns the Epetra_Map object associated with the domain of this operator.
const Epetra_Map & OperatorRangeMap () const
 Returns the Epetra_Map object associated with the range of this operator.
const Epetra_Comm & Comm () const
 Returns the Epetra_BlockMap object associated with the range of this matrix operator.
const Epetra_RowMatrix & Matrix () const
 Returns a reference to the matrix to be preconditioned.
const Epetra_CrsMatrix & L () const
 Returns a reference to the L factor.
const Epetra_CrsMatrix & U () const
 Returns a reference to the U factor.
const char * Label () const
 Returns the label of this object.
int SetLabel (const char *Label_in)
 Sets the label for this object.
virtual ostream & Print (std::ostream &os) const
 Prints basic information on iostream. This function is used by operator<<.
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 in the application of the preconditioner.
double LevelOfFill () const
double RelaxValue () const
 Set relative threshold value.
double AbsoluteThreshold () const
 Get absolute threshold value.
double RelativeThreshold () const
 Get relative threshold value.
double DropTolerance () const
 Gets the dropping tolerance.
int NumGlobalNonzeros () const
 Returns the number of nonzero entries in the global graph.
int NumMyNonzeros () const
 Returns the number of nonzero entries in the local graph.


Detailed Description

Ifpack_ILUT: A class for constructing and using an incomplete Cholesky factorization of a given Epetra_RowMatrix.

The Ifpack_ILUT class computes a "Relaxed" ILUT factorization with level k fill of a given Epetra_RowMatrix.

Please refer to General description of incomplete factorizations for a general description of the ILU algorithm.

The complete list of supported parameters is reported in page List of Supported Parameters.

Author:
Marzio Sala, SNL 9214.
Date:
Last modified on 22-Jan-05.

Constructor & Destructor Documentation

Ifpack_ILUT::Ifpack_ILUT ( const Epetra_RowMatrix *  A  ) 

Ifpack_ILUT constuctor with variable number of indices per row.

virtual Ifpack_ILUT::~Ifpack_ILUT (  )  [virtual]

Ifpack_ILUT Destructor.


Member Function Documentation

double Ifpack_ILUT::AbsoluteThreshold (  )  const [inline]

Get absolute threshold value.

int Ifpack_ILUT::Apply ( const Epetra_MultiVector &  X,
Epetra_MultiVector &  Y 
) const

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

Returns the result of a Ifpack_ILUT forward/back solve on a Epetra_MultiVector X in Y.

Parameters:
X - (In) A Epetra_MultiVector of dimension NumVectors to solve for.
Y - (Out) A Epetra_MultiVector of dimension NumVectorscontaining result.
Returns:
Integer error code, set to 0 if successful.

Implements Ifpack_Preconditioner.

virtual double Ifpack_ILUT::ApplyInverseFlops (  )  const [inline, virtual]

Returns the number of flops in the application of the preconditioner.

Implements Ifpack_Preconditioner.

virtual double Ifpack_ILUT::ApplyInverseTime (  )  const [inline, virtual]

Returns the time spent in ApplyInverse().

Implements Ifpack_Preconditioner.

const Epetra_Comm& Ifpack_ILUT::Comm (  )  const [inline]

Returns the Epetra_BlockMap object associated with the range of this matrix operator.

int Ifpack_ILUT::Compute (  )  [virtual]

Compute IC factor U using the specified graph, diagonal perturbation thresholds and relaxation parameters.

This function computes the RILU(k) factors L and U using the current:

  1. Ifpack_IlukGraph specifying the structure of L and U.
  2. Value for the RILU(k) relaxation parameter.
  3. Value for the a priori diagonal threshold values.
InitValues() must be called before the factorization can proceed.

Implements Ifpack_Preconditioner.

virtual double Ifpack_ILUT::ComputeFlops (  )  const [inline, virtual]

Returns the number of flops in the computation phase.

Implements Ifpack_Preconditioner.

virtual double Ifpack_ILUT::ComputeTime (  )  const [inline, virtual]

Returns the time spent in Compute().

Implements Ifpack_Preconditioner.

double Ifpack_ILUT::Condest (  )  const [inline, virtual]

Returns the computed estimated condition number, or -1.0 if no computed.

Implements Ifpack_Preconditioner.

double Ifpack_ILUT::Condest ( const Ifpack_CondestType  CT = Ifpack_Cheap,
const int  MaxIters = 1550,
const double  Tol = 1e-9,
Epetra_RowMatrix *  Matrix_in = 0 
) [virtual]

Computed the estimated condition number and returns the value.

Implements Ifpack_Preconditioner.

double Ifpack_ILUT::DropTolerance (  )  const [inline]

Gets the dropping tolerance.

bool Ifpack_ILUT::HasNormInf (  )  const [inline]

Returns false because this class cannot compute an Inf-norm.

int Ifpack_ILUT::Initialize (  )  [virtual]

Initialize L and U with values from user matrix A.

Copies values from the user's matrix into the nonzero pattern of L and U.

Parameters:
In A - User matrix to be factored.
Warning:
The graph of A must be identical to the graph passed in to Ifpack_IlukGraph constructor.

Implements Ifpack_Preconditioner.

virtual double Ifpack_ILUT::InitializeFlops (  )  const [inline, virtual]

Returns the number of flops in the initialization phase.

Implements Ifpack_Preconditioner.

virtual double Ifpack_ILUT::InitializeTime (  )  const [inline, virtual]

Returns the time spent in Initialize().

Implements Ifpack_Preconditioner.

bool Ifpack_ILUT::IsComputed (  )  const [inline, virtual]

If factor is completed, this query returns true, otherwise it returns false.

Implements Ifpack_Preconditioner.

bool Ifpack_ILUT::IsInitialized (  )  const [inline, virtual]

Returns true if the preconditioner has been successfully initialized.

Implements Ifpack_Preconditioner.

const Epetra_CrsMatrix& Ifpack_ILUT::L (  )  const [inline]

Returns a reference to the L factor.

const char* Ifpack_ILUT::Label (  )  const [inline]

Returns the label of this object.

double Ifpack_ILUT::LevelOfFill (  )  const [inline]

const Epetra_RowMatrix& Ifpack_ILUT::Matrix (  )  const [inline, virtual]

Returns a reference to the matrix to be preconditioned.

Implements Ifpack_Preconditioner.

double Ifpack_ILUT::NormInf (  )  const [inline]

Returns 0.0 because this class cannot compute Inf-norm.

virtual int Ifpack_ILUT::NumApplyInverse (  )  const [inline, virtual]

Returns the number of calls to ApplyInverse().

Implements Ifpack_Preconditioner.

virtual int Ifpack_ILUT::NumCompute (  )  const [inline, virtual]

Returns the number of calls to Compute().

Implements Ifpack_Preconditioner.

int Ifpack_ILUT::NumGlobalNonzeros (  )  const [inline]

Returns the number of nonzero entries in the global graph.

virtual int Ifpack_ILUT::NumInitialize (  )  const [inline, virtual]

Returns the number of calls to Initialize().

Implements Ifpack_Preconditioner.

int Ifpack_ILUT::NumMyNonzeros (  )  const [inline]

Returns the number of nonzero entries in the local graph.

const Epetra_Map& Ifpack_ILUT::OperatorDomainMap (  )  const [inline]

Returns the Epetra_Map object associated with the domain of this operator.

const Epetra_Map& Ifpack_ILUT::OperatorRangeMap (  )  const [inline]

Returns the Epetra_Map object associated with the range of this operator.

virtual ostream& Ifpack_ILUT::Print ( std::ostream &  os  )  const [virtual]

Prints basic information on iostream. This function is used by operator<<.

Implements Ifpack_Preconditioner.

double Ifpack_ILUT::RelativeThreshold (  )  const [inline]

Get relative threshold value.

double Ifpack_ILUT::RelaxValue (  )  const [inline]

Set relative threshold value.

int Ifpack_ILUT::SetLabel ( const char *  Label_in  )  [inline]

Sets the label for this object.

int Ifpack_ILUT::SetParameters ( Teuchos::ParameterList &  parameterlis  )  [virtual]

Set parameters using a Teuchos::ParameterList object.

Implements Ifpack_Preconditioner.

int Ifpack_ILUT::SetUseTranspose ( bool  UseTranspose_in  )  [inline]

If set true, transpose of this operator will be applied.

This flag allows the transpose of the given operator to be used implicitly. Setting this flag affects only the Apply() and ApplyInverse() methods. If the implementation of this interface does not support transpose use, this method should return a value of -1.

Parameters:
UseTranspose_in - (In) If true, multiply by the transpose of operator, otherwise just use operator.
Returns:
Always returns 0.

const Epetra_CrsMatrix& Ifpack_ILUT::U (  )  const [inline]

Returns a reference to the U factor.

bool Ifpack_ILUT::UseTranspose (  )  const [inline]

Returns the current UseTranspose setting.


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

Generated on Thu Dec 17 11:06:44 2009 for IFPACK Robust Algebraic Preconditioner Package by  doxygen 1.5.9