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Ifpack_ILUT Class Reference

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

#include <Ifpack_ILUT.h>

Inheritance diagram for Ifpack_ILUT:
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List of all members.

 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_MapOperatorDomainMap () const
 Returns the Epetra_Map object associated with the domain of this operator.
const Epetra_MapOperatorRangeMap () const
 Returns the Epetra_Map object associated with the range of this operator.
const Epetra_CommComm () const
 Returns the Epetra_BlockMap object associated with the range of this matrix operator.
const Epetra_RowMatrixMatrix () const
 Returns a reference to the matrix to be preconditioned.
const Epetra_CrsMatrixL () const
 Returns a reference to the L factor.
const Epetra_CrsMatrixU () 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.
 Ifpack_ILUT (const Ifpack_ILUT &RHS)
 Copy constructor (should never be used)
Ifpack_ILUToperator= (const Ifpack_ILUT &RHS)
 operator= (should never be used)
void Destroy ()
 Releases all allocated memory.
const Epetra_RowMatrixA_
 reference to the matrix to be preconditioned.
const Epetra_CommComm_
 Reference to the communicator object.
Teuchos::RefCountPtr
< Epetra_CrsMatrix
L_
 L factor.
Teuchos::RefCountPtr
< Epetra_CrsMatrix
U_
 U factor.
double Condest_
 Condition number estimate.
double Relax_
 relaxation value
double Athresh_
 Absolute threshold.
double Rthresh_
 Relative threshold.
double LevelOfFill_
 Level-of-fill.
double DropTolerance_
 Discards all elements below this tolerance.
string Label_
 Label for this object.
bool IsInitialized_
 true if this object has been initialized
bool IsComputed_
 true if this object has been computed
bool UseTranspose_
 true if transpose has to be used.
int NumMyRows_
 Number of local rows.
int NumInitialize_
 Contains the number of successful calls to Initialize().
int NumCompute_
 Contains the number of successful call to Compute().
int NumApplyInverse_
 Contains the number of successful call to ApplyInverse().
double InitializeTime_
 Contains the time for all successful calls to Initialize().
double ComputeTime_
 Contains the time for all successful calls to Compute().
double ApplyInverseTime_
 Contains the time for all successful calls to ApplyInverse().
double ComputeFlops_
 Contains the number of flops for Compute().
double ApplyInverseFlops_
 Contain sthe number of flops for ApplyInverse().
Epetra_Time Time_
 Used for timing purposed.
int GlobalNonzeros_
 Global number of nonzeros in L and U factors.
Teuchos::RefCountPtr
< Epetra_SerialComm
SerialComm_
Teuchos::RefCountPtr< Epetra_MapSerialMap_

Detailed Description

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

The Ifpack_ILUT class computes a "Relaxed" ILUT factorization with dual threshold dropping of small elements of a given Epetra_RowMatrix.

This implementation does not use the algorithm that is described in ifp_ilu. The algorithm drops entries in a row (i) of matrix A that are smaller than drop_tolerance even before the factorization of row i then computes the factorization for that row. This is different than the usual algorithm where the drop tolerance is applied to the factored rows.

The complete list of supported parameters is reported in page ifp_params.

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

Definition at line 68 of file Ifpack_ILUT.h.


Constructor & Destructor Documentation

Ifpack_ILUT::Ifpack_ILUT ( const Epetra_RowMatrix A)

Ifpack_ILUT constuctor with variable number of indices per row.

Definition at line 52 of file Ifpack_ILUT.cpp.

Ifpack_ILUT::~Ifpack_ILUT ( ) [virtual]

Ifpack_ILUT Destructor.

Definition at line 80 of file Ifpack_ILUT.cpp.

Ifpack_ILUT::Ifpack_ILUT ( const Ifpack_ILUT RHS) [inline, private]

Copy constructor (should never be used)

Definition at line 300 of file Ifpack_ILUT.h.


Member Function Documentation

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

Set parameters using a Teuchos::ParameterList object.

Implements Ifpack_Preconditioner.

Definition at line 93 of file Ifpack_ILUT.cpp.

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:
InA - 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.

Definition at line 127 of file Ifpack_ILUT.cpp.

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

Returns true if the preconditioner has been successfully initialized.

Implements Ifpack_Preconditioner.

Definition at line 100 of file Ifpack_ILUT.h.

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.

Definition at line 162 of file Ifpack_ILUT.cpp.

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

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

Implements Ifpack_Preconditioner.

Definition at line 117 of file Ifpack_ILUT.h.

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.

Definition at line 488 of file Ifpack_ILUT.cpp.

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

Implements Epetra_Operator.

Definition at line 535 of file Ifpack_ILUT.cpp.

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.

Definition at line 542 of file Ifpack_ILUT.cpp.

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

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

Implements Ifpack_Preconditioner.

Definition at line 141 of file Ifpack_ILUT.h.

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

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.

Implements Epetra_Operator.

Definition at line 156 of file Ifpack_ILUT.h.

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

Returns 0.0 because this class cannot compute Inf-norm.

Implements Epetra_Operator.

Definition at line 159 of file Ifpack_ILUT.h.

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

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

Implements Epetra_Operator.

Definition at line 162 of file Ifpack_ILUT.h.

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

Returns the current UseTranspose setting.

Implements Epetra_Operator.

Definition at line 165 of file Ifpack_ILUT.h.

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

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

Implements Epetra_Operator.

Definition at line 168 of file Ifpack_ILUT.h.

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

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

Implements Epetra_Operator.

Definition at line 171 of file Ifpack_ILUT.h.

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

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

Implements Epetra_Operator.

Definition at line 174 of file Ifpack_ILUT.h.

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

Returns a reference to the matrix to be preconditioned.

Implements Ifpack_Preconditioner.

Definition at line 177 of file Ifpack_ILUT.h.

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

Returns a reference to the L factor.

Definition at line 183 of file Ifpack_ILUT.h.

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

Returns a reference to the U factor.

Definition at line 186 of file Ifpack_ILUT.h.

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

Returns the label of this object.

Implements Epetra_Operator.

Definition at line 189 of file Ifpack_ILUT.h.

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

Sets the label for this object.

Definition at line 195 of file Ifpack_ILUT.h.

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

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

Implements Ifpack_Preconditioner.

Definition at line 558 of file Ifpack_ILUT.cpp.

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

Returns the number of calls to Initialize().

Implements Ifpack_Preconditioner.

Definition at line 205 of file Ifpack_ILUT.h.

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

Returns the number of calls to Compute().

Implements Ifpack_Preconditioner.

Definition at line 211 of file Ifpack_ILUT.h.

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

Returns the number of calls to ApplyInverse().

Implements Ifpack_Preconditioner.

Definition at line 217 of file Ifpack_ILUT.h.

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

Returns the time spent in Initialize().

Implements Ifpack_Preconditioner.

Definition at line 223 of file Ifpack_ILUT.h.

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

Returns the time spent in Compute().

Implements Ifpack_Preconditioner.

Definition at line 229 of file Ifpack_ILUT.h.

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

Returns the time spent in ApplyInverse().

Implements Ifpack_Preconditioner.

Definition at line 235 of file Ifpack_ILUT.h.

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

Returns the number of flops in the initialization phase.

Implements Ifpack_Preconditioner.

Definition at line 241 of file Ifpack_ILUT.h.

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

Returns the number of flops in the computation phase.

Implements Ifpack_Preconditioner.

Definition at line 246 of file Ifpack_ILUT.h.

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

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

Implements Ifpack_Preconditioner.

Definition at line 251 of file Ifpack_ILUT.h.

double Ifpack_ILUT::LevelOfFill ( ) const [inline]

Definition at line 256 of file Ifpack_ILUT.h.

double Ifpack_ILUT::RelaxValue ( ) const [inline]

Set relative threshold value.

Definition at line 261 of file Ifpack_ILUT.h.

double Ifpack_ILUT::AbsoluteThreshold ( ) const [inline]

Get absolute threshold value.

Definition at line 266 of file Ifpack_ILUT.h.

double Ifpack_ILUT::RelativeThreshold ( ) const [inline]

Get relative threshold value.

Definition at line 272 of file Ifpack_ILUT.h.

double Ifpack_ILUT::DropTolerance ( ) const [inline]

Gets the dropping tolerance.

Definition at line 278 of file Ifpack_ILUT.h.

int Ifpack_ILUT::NumGlobalNonzeros ( ) const [inline]

Returns the number of nonzero entries in the global graph.

Definition at line 284 of file Ifpack_ILUT.h.

int Ifpack_ILUT::NumMyNonzeros ( ) const [inline]

Returns the number of nonzero entries in the local graph.

Definition at line 290 of file Ifpack_ILUT.h.

Ifpack_ILUT& Ifpack_ILUT::operator= ( const Ifpack_ILUT RHS) [inline, private]

operator= (should never be used)

Definition at line 307 of file Ifpack_ILUT.h.

void Ifpack_ILUT::Destroy ( ) [private]

Releases all allocated memory.

Definition at line 86 of file Ifpack_ILUT.cpp.


Member Data Documentation

reference to the matrix to be preconditioned.

Definition at line 319 of file Ifpack_ILUT.h.

const Epetra_Comm& Ifpack_ILUT::Comm_ [private]

Reference to the communicator object.

Definition at line 321 of file Ifpack_ILUT.h.

L factor.

Definition at line 323 of file Ifpack_ILUT.h.

U factor.

Definition at line 325 of file Ifpack_ILUT.h.

double Ifpack_ILUT::Condest_ [private]

Condition number estimate.

Definition at line 327 of file Ifpack_ILUT.h.

double Ifpack_ILUT::Relax_ [private]

relaxation value

Definition at line 329 of file Ifpack_ILUT.h.

double Ifpack_ILUT::Athresh_ [private]

Absolute threshold.

Definition at line 331 of file Ifpack_ILUT.h.

double Ifpack_ILUT::Rthresh_ [private]

Relative threshold.

Definition at line 333 of file Ifpack_ILUT.h.

double Ifpack_ILUT::LevelOfFill_ [private]

Level-of-fill.

Definition at line 335 of file Ifpack_ILUT.h.

double Ifpack_ILUT::DropTolerance_ [private]

Discards all elements below this tolerance.

Definition at line 337 of file Ifpack_ILUT.h.

string Ifpack_ILUT::Label_ [private]

Label for this object.

Definition at line 339 of file Ifpack_ILUT.h.

true if this object has been initialized

Definition at line 341 of file Ifpack_ILUT.h.

true if this object has been computed

Definition at line 343 of file Ifpack_ILUT.h.

true if transpose has to be used.

Definition at line 345 of file Ifpack_ILUT.h.

int Ifpack_ILUT::NumMyRows_ [private]

Number of local rows.

Definition at line 347 of file Ifpack_ILUT.h.

Contains the number of successful calls to Initialize().

Definition at line 349 of file Ifpack_ILUT.h.

int Ifpack_ILUT::NumCompute_ [private]

Contains the number of successful call to Compute().

Definition at line 351 of file Ifpack_ILUT.h.

int Ifpack_ILUT::NumApplyInverse_ [mutable, private]

Contains the number of successful call to ApplyInverse().

Definition at line 353 of file Ifpack_ILUT.h.

double Ifpack_ILUT::InitializeTime_ [private]

Contains the time for all successful calls to Initialize().

Definition at line 355 of file Ifpack_ILUT.h.

double Ifpack_ILUT::ComputeTime_ [private]

Contains the time for all successful calls to Compute().

Definition at line 357 of file Ifpack_ILUT.h.

double Ifpack_ILUT::ApplyInverseTime_ [mutable, private]

Contains the time for all successful calls to ApplyInverse().

Definition at line 359 of file Ifpack_ILUT.h.

double Ifpack_ILUT::ComputeFlops_ [private]

Contains the number of flops for Compute().

Definition at line 361 of file Ifpack_ILUT.h.

double Ifpack_ILUT::ApplyInverseFlops_ [mutable, private]

Contain sthe number of flops for ApplyInverse().

Definition at line 363 of file Ifpack_ILUT.h.

Epetra_Time Ifpack_ILUT::Time_ [mutable, private]

Used for timing purposed.

Definition at line 365 of file Ifpack_ILUT.h.

Global number of nonzeros in L and U factors.

Definition at line 367 of file Ifpack_ILUT.h.

Definition at line 368 of file Ifpack_ILUT.h.

Definition at line 369 of file Ifpack_ILUT.h.


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