// @HEADER
// ***********************************************************************
// 
//                      Didasko Tutorial Package
//                 Copyright (2005) Sandia Corporation
// 
// Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive
// license for use of this work by or on behalf of the U.S. Government.
// 
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 2.1 of the
// License, or (at your option) any later version.
//  
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//  
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA
// Questions? Contact Michael A. Heroux (maherou@sandia.gov) 
// 
// ***********************************************************************
// @HEADER

// Compute the lowest eigenvalue and the corresponding eigenvector

#include "Didasko_ConfigDefs.h"
#if defined(HAVE_DIDASKO_EPETRA) && defined(HAVE_DIDASKO_ANASAZI) && defined(HAVE_DIDASKO_TEUCHOS) && defined(HAVE_DIDASKO_TRIUTILS) && defined(FIXME)
//not compatible with the new anasazi interacae

#include "Epetra_ConfigDefs.h"
#ifdef HAVE_MPI
#include "mpi.h"
#include "Epetra_MpiComm.h"
#else
#include "Epetra_SerialComm.h"
#endif
#include "Epetra_RowMatrix.h"
#include "Epetra_CrsMatrix.h"

#include "AnasaziConfigDefs.hpp"
#include "AnasaziPetraInterface.hpp"
#include "AnasaziBlockArnoldi.hpp"

#include "Trilinos_Util_CrsMatrixGallery.h"

using namespace Trilinos_Util;

int main(int argc, char *argv[])
{
    
#ifdef HAVE_MPI
  MPI_Init(&argc,&argv);
  Epetra_MpiComm Comm(MPI_COMM_WORLD);
#else
  Epetra_SerialComm Comm;
#endif

  // initialize an Gallery object
  CrsMatrixGallery Gallery("laplace_2d", Comm);
  Gallery.Set("problem_size", 100);

  // Get pointer to the linear system matrix
  Epetra_CrsMatrix * RowA = Gallery.GetMatrix();

  // set Anasazi default values
  int block = 1;
  int length = 30;
  int nev = 1;
  double tol = 1.0e-14;
  // SM is the smallest eigenvalue, LM the largest one (in magnitude).
  // Please check the Anasazi documentation.
  string which="SM";
  int restarts = 100;
  //int step = 1;
  int step = restarts*length*block;

  // create an Anasazi vector, based on Epetra vector, and fill it with
  // defautl values
  const Epetra_Map * Map = &(RowA->DomainMap());
  Anasazi::PetraVec<double> ivec(*Map, block);
  ivec.MvRandom();

  // Call the ctor that calls the petra ctor for a matrix
  Anasazi::PetraMat<double> Amat(*RowA);    
  Anasazi::Eigenproblem<double> MyProblem(&Amat, &ivec);

  // Initialize the Block Arnoldi solver
  Anasazi::BlockArnoldi<double> MyBlockArnoldi(MyProblem, tol, nev, length, block, 
                           which, step, restarts);
    
  // Inform the solver that the problem is not symmetric (change if required)
  MyBlockArnoldi.setSymmetric(false);
  MyBlockArnoldi.setDebugLevel(0);

  // Solve the problem to the specified tolerances or length
  MyBlockArnoldi.solve();
  
  // Obtain results directly
  double * resids = MyBlockArnoldi.getResiduals();
  double * evalr = MyBlockArnoldi.getEvals(); 
  double * evali = MyBlockArnoldi.getiEvals();

  // Retrieve eigenvectors
  Anasazi::PetraVec<double> evecr(*Map, nev);
  MyBlockArnoldi.getEvecs( evecr );
  Anasazi::PetraVec<double> eveci(*Map, nev);
  MyBlockArnoldi.getiEvecs( eveci );

  // Output results to screen
  if( Comm.MyPID() == 0 ) {
    for( int i=0 ; i<nev ; ++i ) 
      cout << "eval[" << i << "] = " << evalr[i] << " + i " << evali[i] << endl;
    MyBlockArnoldi.currentStatus();
  }
  
  // free memory
  if( resids ) delete [] resids;
  if( evalr ) delete [] evalr;
  if( evali ) delete [] evali;
  
#ifdef HAVE_MPI
  MPI_Finalize();
#endif

  return(EXIT_SUCCESS);

}

#else

#include <stdlib.h>
#include <stdio.h>
#ifdef HAVE_MPI
#include "mpi.h"
#endif

int main(int argc, char *argv[])
{
#ifdef HAVE_MPI
  MPI_Init(&argc, &argv);
#endif

  puts("Please configure Didasko with:");
  puts("--enable-epetra");
  puts("--enable-teuchos");
  puts("--enable-triutils");
  puts("--enable-anasazi");

#ifdef HAVE_MPI
  MPI_Finalize();
#endif
  return 0;
}

#endif

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