Amesos_Lapack Class Reference

Amesos_Lapack: an interface to LAPACK. More...

#include <Amesos_Lapack.h>

Inheritance diagram for Amesos_Lapack:

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Collaboration diagram for Amesos_Lapack:
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List of all members.

Public Member Functions

Constructor methods
 Amesos_Lapack (const Epetra_LinearProblem &LinearProblem)
 Amesos_Lapack Constructor.
 ~Amesos_Lapack (void)
 Amesos_Lapack Destructor.
Mathematical functions.
int SymbolicFactorization ()
 Performs SymbolicFactorization on the matrix A.
int NumericFactorization ()
 Performs NumericFactorization on the matrix A.
int Solve ()
 Solves A X = B (or AT x = B).
Additional methods required to support the Epetra_Operator interface.
const Epetra_LinearProblemGetProblem () const
 Returns the Epetra_LinearProblem.
bool MatrixShapeOK () const
 Returns true if the solver can handle this matrix shape.
int SetUseTranspose (bool UseTranspose)
 If set true, X will be set to the solution of AT X = B (not A X = B).
bool UseTranspose () const
 Returns the current UseTranspose setting.
const Epetra_CommComm () const
 Returns a pointer to the Epetra_Comm communicator associated with this operator.
int SetParameters (Teuchos::ParameterList &ParameterList)
 Updates internal variables.
int GEEV (Epetra_Vector &Er, Epetra_Vector &Ei)
 Computes the eigenvalues of the linear system matrix using DGEEV.
void PrintTiming ()
 Print timing information.
void PrintStatus ()
 Print information about the factorization and solution phases.

Protected Member Functions

const Epetra_RowMatrixMatrix () const
 Returns a pointer to the linear system matrix.
int NumGlobalRows () const
 Returns the number of global rows, or -1 if Matrix() returns 0.
int NumMyRows () const
 Returns the number of local rows, or -1 if Matrix() returns 0.
const Epetra_MapSerialMap ()
 Returns a reference to serial map (that with all elements on process 0). Builds SerialMap_ if necessary or required.
Epetra_RowMatrixSerialMatrix ()
 Returns a reference to serial matrix (that with all rows on process 0). Builds SerialMap_ if necessary or required.
Epetra_CrsMatrixSerialCrsMatrix ()
const Epetra_ImportImporter ()
 Returns a reference to the importer map. Builds SerialMap_ if necessary or required.
int SolveSerial (Epetra_MultiVector &X, const Epetra_MultiVector &B)
 Solves the linear system, when only one process is used.
int SolveDistributed (Epetra_MultiVector &X, const Epetra_MultiVector &B)
 Solves the linear system, when more than one process is used.
int DistributedToSerial ()
 Converts a distributed matrix to serial matrix.
int SerialToDense ()
 Converts a serial matrix to dense format.
int DenseToFactored ()
 Factors the matrix using LAPACK.

Protected Attributes

Teuchos::RefCountPtr< Epetra_RowMatrixSerialMatrix_
Teuchos::RefCountPtr< Epetra_CrsMatrixSerialCrsMatrix_
Teuchos::RefCountPtr< Epetra_MapSerialMap_
Teuchos::RefCountPtr< Epetra_ImportImporter_
Epetra_SerialDenseMatrix DenseMatrix_
 Dense matrix.
Epetra_SerialDenseMatrix DenseLHS_
 Dense LHS.
Epetra_SerialDenseMatrix DenseRHS_
 Dense RHS.
Epetra_SerialDenseSolver DenseSolver_
 Linear problem for dense matrix and vectors.
bool UseTranspose_
 If true, the linear system with the transpose will be solved.
const Epetra_LinearProblemProblem_
 Pointer to the linear problem.
int NumSymbolicFact_
 Number of calls to SymbolicFactorization().
int NumNumericFact_
 Number of calls to NumericFactorization().
int NumSolve_
 Number of calls to Solver().
int NumGlobalRows_
int NumGlobalNonzeros_

Detailed Description

Amesos_Lapack: an interface to LAPACK.

Class Amesos_Lapack enables the solution of the distributed linear system, defined by an Epetra_LinearProblem, using LAPACK.

Amesos_Lapack stores the lineaar system matrix as an Epetra_SerialDensMatrix. The linear problem is an Epetra_SerialDenseProblem. Amesos_Lapack factorizes the matrix using DGETRF().

Date:
Last updated on 16-Mar-05.
Author:
Marzio Sala, 9214.


Constructor & Destructor Documentation

Amesos_Lapack::Amesos_Lapack const Epetra_LinearProblem LinearProblem  ) 
 

Amesos_Lapack Constructor.

Creates an Amesos_Lapack instance, using an Epetra_LinearProblem, passing in an already-defined Epetra_LinearProblem object.

Note: The operator in LinearProblem must be an Epetra_RowMatrix.

Amesos_Lapack::~Amesos_Lapack void   ) 
 

Amesos_Lapack Destructor.

Completely deletes an Amesos_Lapack object.


Member Function Documentation

int Amesos_Lapack::GEEV Epetra_Vector Er,
Epetra_Vector Ei
 

Computes the eigenvalues of the linear system matrix using DGEEV.

Parameters:
Er - (Out) On processor zero only, it will contain the real component of the eigenvalues.
Ei - (Out) On processor zero only, it will contain the imaginary component of the eigenvalues.
Note:
Er and Ei must have been allocated so that the local length on processor 0 equals the global size of the matrix.

const Epetra_LinearProblem* Amesos_Lapack::GetProblem  )  const [inline, virtual]
 

Returns the Epetra_LinearProblem.

Warning! Do not call return->SetOperator(...) to attempt to change the Epetra_Operator object (even if the new matrix has the same structure). This new operator matrix will be ignored!

Implements Amesos_BaseSolver.

bool Amesos_Lapack::MatrixShapeOK  )  const [virtual]
 

Returns true if the solver can handle this matrix shape.

Returns true if the matrix shape is one that the underlying sparse direct solver can handle. Classes that work only on square matrices should return false for rectangular matrices. Classes that work only on symmetric matrices whould return false for non-symmetric matrices.

Implements Amesos_BaseSolver.

int Amesos_Lapack::NumericFactorization  )  [virtual]
 

Performs NumericFactorization on the matrix A.

In addition to performing numeric factorization on the matrix A, the call to NumericFactorization() implies that no change will be made to the underlying matrix without a subsequent call to NumericFactorization().

<br >Preconditions:

  • GetProblem().GetOperator() != 0 (return -1)
  • MatrixShapeOk(GetProblem().GetOperator()) == true (return -6)
  • The non-zero structure of the matrix should not have changed since the last call to SymbolicFactorization(). (return -2 if the number of non-zeros changes) Other changes can have arbitrary consequences.
  • The distribution of the matrix should not have changed since the last call to SymbolicFactorization()
  • The matrix should be indexed from 0 to n-1, unless the parameter "Reindex" was set to "true" prior to the call to SymbolicFactorization(). (return -3 - if caught)
  • The paremeter "Reindex" should not be set to "true" except on CrsMatrices. (return -4)
  • The paremeter "Reindex" should not be set to "true" unless Amesos was built with EpetraExt, i.e. with --enable-epetraext on the configure line. (return -4)
  • Internal errors retur -5.

<br >Postconditions:

  • Numeric Factorization will be performed (or marked to be performed) allowing Solve() to be performed correctly despite a potential change in in the matrix values (though not in the non-zero structure).

Returns:
Integer error code, set to 0 if successful.

Implements Amesos_BaseSolver.

int Amesos_Lapack::SetParameters Teuchos::ParameterList ParameterList  )  [virtual]
 

Updates internal variables.

<br >Preconditions:

  • None.

<br >Postconditions:

  • Internal variables controlling the factorization and solve will be updated and take effect on all subseuent calls to NumericFactorization() and Solve().
  • All parameters whose value are to differ from the default values must be included in ParameterList. Parameters not specified in ParameterList revert to their default values.

Returns:
Integer error code, set to 0 if successful.

Implements Amesos_BaseSolver.

int Amesos_Lapack::SetUseTranspose bool  UseTranspose  )  [inline, virtual]
 

If set true, X will be set to the solution of AT X = B (not A X = B).

If the implementation of this interface does not support transpose use, this method should return a value of -1.

<br >Preconditions:

<br >Postconditions:

  • The next factorization and solve will be performed with the new value of UseTranspose.

Parameters:
UseTranspose -- (In) If true, solve AT X = B, otherwise solve A X = B.
Returns:
Integer error code, set to 0 if successful. Set to -1 if this implementation does not support transpose.

Implements Amesos_BaseSolver.

int Amesos_Lapack::Solve  )  [virtual]
 

Solves A X = B (or AT x = B).

<br >Preconditions:

<br >Postconditions:

  • X will be set such that A X = B (or AT X = B), within the limits of the accuracy of the underlying solver.

Returns:
Integer error code, set to 0 if successful.

Implements Amesos_BaseSolver.

int Amesos_Lapack::SymbolicFactorization  )  [virtual]
 

Performs SymbolicFactorization on the matrix A.

In addition to performing symbolic factorization on the matrix A, the call to SymbolicFactorization() implies that no change will be made to the non-zero structure of the underlying matrix without a subsequent call to SymbolicFactorization().

<br >Preconditions:

<br >Postconditions:

Returns:
Integer error code, set to 0 if successful.

Implements Amesos_BaseSolver.


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