#include <Amesos_Scalapack.h>
Inheritance diagram for Amesos_Scalapack:
Public Member Functions  
Constructor methods  
Amesos_Scalapack (const Epetra_LinearProblem &LinearProblem)  
Amesos_Scalapack Constructor.  
~Amesos_Scalapack (void)  
Amesos_Scalapack 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 A^{T} X = B).  
Additional methods required to support the Epetra_Operator interface.  
const Epetra_LinearProblem *  GetProblem () const 
Get a pointer to the Problem.  
bool  MatrixShapeOK () const 
Returns true if SCALAPACK can handle this matrix shape.  
int  SetUseTranspose (bool UseTranspose) 
SetUseTranpose(true) is more efficient in Amesos_Scalapack.  
bool  UseTranspose () const 
Returns the current UseTranspose setting.  
const Epetra_Comm &  Comm () const 
Returns a pointer to the Epetra_Comm communicator associated with this matrix.  
int  SetParameters (Teuchos::ParameterList &ParameterList) 
Updates internal variables.  
void  PrintTiming () 
Print timing information.  
void  PrintStatus () 
Print information about the factorization and solution phases.  
Protected Attributes  
int  iam_ 
int  NumGlobalElements_ 
int  NumGlobalNonzeros_ 
int  nprow_ 
int  npcol_ 
int  ictxt_ 
int  m_per_p_ 
int  DescA_ [10] 
Epetra_Map *  ScaLAPACK1DMap_ 
Epetra_CrsMatrix *  ScaLAPACK1DMatrix_ 
Epetra_Map *  VectorMap_ 
vector< double >  DenseA_ 
vector< int >  Ipiv_ 
int  NumOurRows_ 
int  NumOurColumns_ 
bool  UseTranspose_ 
const Epetra_LinearProblem *  Problem_ 
double  ConTime_ 
double  SymTime_ 
double  NumTime_ 
double  SolTime_ 
double  VecTime_ 
double  MatTime_ 
int  NumSymbolicFact_ 
Number of symbolic factorization phases.  
int  NumNumericFact_ 
Number of numeric factorization phases.  
int  NumSolve_ 
Number of solves.  
bool  TwoD_distribution_ 
int  grid_nb_ 
int  mypcol_ 
int  myprow_ 
Epetra_CrsMatrix *  FatOut_ 
int  nb_ 
int  lda_ 
Epetra_Time *  Time_ 
Time object. 
Amesos_Scalapack, an objectoriented wrapper for LAPACK and ScaLAPACK, will solve a linear systems of equations: A X = B
using Epetra objects and the ScaLAPACK library, where A
is an Epetra_RowMatrix and X
and B
are Epetra_MultiVector objects.
<br /><br />
Amesos_Scalapack can be competitive for matrices that are not particularly sparse. ScaLAPACK solves matrices for which the fillin is roughly 10% to 20% of the matrix size in time comparable to that achieve by other Amesos classes. Amesos_Scalapack scales well and hence its performance advantage will be largest when large number of processes are involved.
<br /><br />
Amesos_Scalapack uses the ScaLAPACK functions PDGETRF and PDGETRS if more than one process is used. If only one process is used, Amesos_ScaLAPACK uses the LAPACK function PDGETRF and PDGETRS.
<br /><br />
AmesosScaLAPACK uses full partial pivoting and will therefore provide answers that are at least as accurate as any direct sparse solver.
<br /><br />
AmesosScalapack makes sense under the following circumstances:
Amesos_Scalapack supports the following parameters which are common to accross multiple Amesos solvers:
None of the following limitations would be particularly difficult to remove.
<br /><br />
The present implementation limits the number of right hand sides to the number of rows assigned to each process. i.e. nrhs < n/p.
<br /><br />
The present implementation does not take advantage of symmetric or symmetric positive definite matrices, although ScaLAPACK has separate routines to take advantages of such matrices.

Amesos_Scalapack Constructor. Creates an Amesos_Scalapack instance, using an Epetra_LinearProblem, passing in an alreadydefined Epetra_LinearProblem object. Note: The operator in LinearProblem must be an Epetra_RowMatrix. 

Amesos_Scalapack Destructor. Completely deletes an Amesos_Scalapack object. 

Returns true if SCALAPACK can handle this matrix shape. Returns true if the matrix shape is one that SCALAPACK can handle. SCALAPACK only works with square matrices. Implements Amesos_BaseSolver. 

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(). preconditions:
postconditions:
Implements Amesos_BaseSolver. 

Updates internal variables. <br >Preconditions:
<br >Postconditions:
Implements Amesos_BaseSolver. 

SetUseTranpose(true) is more efficient in Amesos_Scalapack.
Implements Amesos_BaseSolver. 

Solves A X = B (or A^{T} X = B). preconditions:
postconditions:
Implements Amesos_BaseSolver. 

Performs SymbolicFactorization on the matrix A. There is no symbolic factorization phase in ScaLAPACK, as it operates only on dense matrices. Hence, Amesos_Scalapack::SymbolicFactorization() takes no action.
Implements Amesos_BaseSolver. 