NOX::Abstract::Group::ReturnType
LOCA::EigenvalueSort::LargestMagnitude::sort(int n, double* r_evals,
                         double* i_evals,
                         std::vector<int>* perm) const
{
  int i, j;
  int tempord = 0;
  double temp, tempr, tempi;
  Teuchos::LAPACK<int,double> lapack;

  //
  // Reset the index
  if (perm) {
    for (i=0; i < n; i++) {
      (*perm)[i] = i;
    }
  }

  //---------------------------------------------------------------
  // Sort eigenvalues in decreasing order of magnitude
  //---------------------------------------------------------------
  for (j=1; j < n; ++j) {
    tempr = r_evals[j]; tempi = i_evals[j];
    if (perm)
      tempord = (*perm)[j];
    temp=lapack.LAPY2(r_evals[j],i_evals[j]);
    for (i=j-1; i>=0 && lapack.LAPY2(r_evals[i],i_evals[i])<temp; --i) {
      r_evals[i+1]=r_evals[i]; i_evals[i+1]=i_evals[i];
      if (perm)
    (*perm)[i+1]=(*perm)[i];
    }
    r_evals[i+1] = tempr; i_evals[i+1] = tempi;
    if (perm)
      (*perm)[i+1] = tempord;
  }
  return NOX::Abstract::Group::Ok;
}
Пример #2
0
// ***********************************************************
int DG_Prob::Eigenvectors(const double Dt,
                          const Epetra_Map & Map)
{
  printf("Entrou em Eigenvectors\n");
 
#ifdef HAVE_MPI
  Epetra_MpiComm Comm(MPI_COMM_WORLD);
#else
  Epetra_SerialComm Comm;
#endif

  //MPI::COMM_WORLD.Barrier();
  Comm.Barrier();
  Teuchos::RCP<Epetra_FECrsMatrix> M = Teuchos::rcp(new Epetra_FECrsMatrix(Copy, Map,0));//&NNz[0]);
  Teuchos::RCP<Epetra_FEVector> RHS = Teuchos::rcp(new Epetra_FEVector(Map,1));
  
  DG_MatrizVetor_Epetra(Dt,M,RHS);

  Teuchos::RCP<Epetra_CrsMatrix> A = Teuchos::rcp(new Epetra_CrsMatrix(Copy, Map,0
                                                                       /* &NNz[0]*/) );
  Epetra_Export Exporter(Map,Map);
  A->PutScalar(0.0);
  A->Export(*(M.ptr()),Exporter,Add);
  A->FillComplete();

  using std::cout;
 // int nx = 5;
  bool boolret;
  int MyPID = Comm.MyPID();
  
  bool verbose = true;
  bool debug = false;
  std::string which("LR");
  
  Teuchos::CommandLineProcessor cmdp(false,true);
  cmdp.setOption("verbose","quiet",&verbose,"Print messages and results.");
  cmdp.setOption("debug","nodebug",&debug,"Print debugging information.");
  cmdp.setOption("sort",&which,"Targetted eigenvalues (SM,LM,SR,LR,SI,or LI).");
  
  typedef double ScalarType;
  typedef Teuchos::ScalarTraits<ScalarType>          SCT;
  typedef SCT::magnitudeType               MagnitudeType;
  typedef Epetra_MultiVector                          MV;
  typedef Epetra_Operator                             OP;
  typedef Anasazi::MultiVecTraits<ScalarType,MV>     MVT;
  typedef Anasazi::OperatorTraits<ScalarType,MV,OP>  OPT;
  
 
 // double rho = 2*nx+1;
  
  // Compute coefficients for discrete convection-diffution operator
 // const double one = 1.0;
  
 // int NumEntries, info;
  
  //************************************
  // Start the block Arnoldi iteration
  //***********************************
  //
  //  Variables used for the Block Krylov Schur Method
  //    
  int nev = 10;
  int blockSize = 1;
  int numBlocks = 20;
  int maxRestarts = 500;
  //int stepSize = 5;
  double tol = 1e-8;
  
  // Create a sort manager to pass into the block Krylov-Schur solver manager
  // -->  Make sure the reference-counted pointer is of type Anasazi::SortManager<>
  // -->  The block Krylov-Schur solver manager uses Anasazi::BasicSort<> by default,
  //      so you can also pass in the parameter "Which", instead of a sort manager.
  Teuchos::RCP<Anasazi::SortManager<MagnitudeType> > MySort =     
    Teuchos::rcp( new Anasazi::BasicSort<MagnitudeType>( which ) );
  
  // Set verbosity level
  int verbosity = Anasazi::Errors + Anasazi::Warnings;
  if (verbose) {
    verbosity += Anasazi::FinalSummary + Anasazi::TimingDetails;
  }
  if (debug) {
    verbosity += Anasazi::Debug;
  }
  //
  // Create parameter list to pass into solver manager
  //
  Teuchos::ParameterList MyPL;
  MyPL.set( "Verbosity", verbosity );
  MyPL.set( "Sort Manager", MySort );
  //MyPL.set( "Which", which );  
  MyPL.set( "Block Size", blockSize );
  MyPL.set( "Num Blocks", numBlocks );
  MyPL.set( "Maximum Restarts", maxRestarts );
  //MyPL.set( "Step Size", stepSize );
  MyPL.set( "Convergence Tolerance", tol );
  
  // Create an Epetra_MultiVector for an initial vector to start the solver.
  // Note:  This needs to have the same number of columns as the blocksize.
  Teuchos::RCP<Epetra_MultiVector> ivec = Teuchos::rcp( new Epetra_MultiVector(Map, blockSize) );
  ivec->Random();
  
  // Create the eigenproblem.
  Teuchos::RCP<Anasazi::BasicEigenproblem<double, MV, OP> > MyProblem =
    Teuchos::rcp( new Anasazi::BasicEigenproblem<double, MV, OP>(A, ivec) );
  
  // Inform the eigenproblem that the operator A is symmetric
  //MyProblem->setHermitian(rho==0.0); 
  
  // Set the number of eigenvalues requested
  MyProblem->setNEV( nev );
  
  // Inform the eigenproblem that you are finishing passing it information
  boolret = MyProblem->setProblem();
  if (boolret != true) {
    if (verbose && MyPID == 0) {
      cout << "Anasazi::BasicEigenproblem::setProblem() returned with error." << endl;
    }
#ifdef HAVE_MPI
    MPI_Finalize() ;
#endif
    return -1;
  }
  
  // Initialize the Block Arnoldi solver
  Anasazi::BlockKrylovSchurSolMgr<double, MV, OP> MySolverMgr(MyProblem, MyPL);
  
  // Solve the problem to the specified tolerances or length
  Anasazi::ReturnType returnCode = MySolverMgr.solve();
  if (returnCode != Anasazi::Converged && MyPID==0 && verbose) {
    cout << "Anasazi::EigensolverMgr::solve() returned unconverged." << endl;
  }
  
  // Get the Ritz values from the eigensolver
  std::vector<Anasazi::Value<double> > ritzValues = MySolverMgr.getRitzValues();
  
  // Output computed eigenvalues and their direct residuals
  if (verbose && MyPID==0) {
    int numritz = (int)ritzValues.size();
    cout.setf(std::ios_base::right, std::ios_base::adjustfield);
    cout<<endl<< "Computed Ritz Values"<< endl;
    if (MyProblem->isHermitian()) {
      cout<< std::setw(16) << "Real Part"
	  << endl;
      cout<<"-----------------------------------------------------------"<<endl;
      for (int i=0; i<numritz; i++) {
        cout<< std::setw(16) << ritzValues[i].realpart 
	    << endl;
      }  
      cout<<"-----------------------------------------------------------"<<endl;
    } 
    else {
      cout<< std::setw(16) << "Real Part"
	  << std::setw(16) << "Imag Part"
	  << endl;
      cout<<"-----------------------------------------------------------"<<endl;
      for (int i=0; i<numritz; i++) {
        cout<< std::setw(16) << ritzValues[i].realpart 
	    << std::setw(16) << ritzValues[i].imagpart 
	    << endl;
      }  
      cout<<"-----------------------------------------------------------"<<endl;
    }  
  }
  
  // Get the eigenvalues and eigenvectors from the eigenproblem
  Anasazi::Eigensolution<ScalarType,MV> sol = MyProblem->getSolution();
  std::vector<Anasazi::Value<ScalarType> > evals = sol.Evals;
  Teuchos::RCP<MV> evecs = sol.Evecs;
  std::vector<int> index = sol.index;
  int numev = sol.numVecs;
  
  if (numev > 0) {
    // Compute residuals.
    Teuchos::LAPACK<int,double> lapack;
    std::vector<double> normA(numev);
    
    if (MyProblem->isHermitian()) {
      // Get storage
      Epetra_MultiVector Aevecs(Map,numev);
      Teuchos::SerialDenseMatrix<int,double> B(numev,numev);
      B.putScalar(0.0); 
      for (int i=0; i<numev; i++) {B(i,i) = evals[i].realpart;}
      
      // Compute A*evecs
      OPT::Apply( *A, *evecs, Aevecs );
      
      // Compute A*evecs - lambda*evecs and its norm
      MVT::MvTimesMatAddMv( -1.0, *evecs, B, 1.0, Aevecs );
      MVT::MvNorm( Aevecs, normA );
      
      // Scale the norms by the eigenvalue
      for (int i=0; i<numev; i++) {
        normA[i] /= Teuchos::ScalarTraits<double>::magnitude( evals[i].realpart );
      }
    } else {
      // The problem is non-Hermitian.
      int i=0;
      std::vector<int> curind(1);
      std::vector<double> resnorm(1), tempnrm(1);
      Teuchos::RCP<MV> tempAevec;
      Teuchos::RCP<const MV> evecr, eveci;
      Epetra_MultiVector Aevec(Map,numev);
      
      // Compute A*evecs
      OPT::Apply( *A, *evecs, Aevec );
      
      Teuchos::SerialDenseMatrix<int,double> Breal(1,1), Bimag(1,1);
      while (i<numev) {
        if (index[i]==0) {
          // Get a view of the current eigenvector (evecr)
          curind[0] = i;
          evecr = MVT::CloneView( *evecs, curind );
	  
          // Get a copy of A*evecr
          tempAevec = MVT::CloneCopy( Aevec, curind );
	  
          // Compute A*evecr - lambda*evecr
          Breal(0,0) = evals[i].realpart;
          MVT::MvTimesMatAddMv( -1.0, *evecr, Breal, 1.0, *tempAevec );
	  
          // Compute the norm of the residual and increment counter
          MVT::MvNorm( *tempAevec, resnorm );
          normA[i] = resnorm[0]/Teuchos::ScalarTraits<MagnitudeType>::magnitude( evals[i].realpart );
          i++;
        } else {
          // Get a view of the real part of the eigenvector (evecr)
          curind[0] = i;
          evecr = MVT::CloneView( *evecs, curind );
	  
          // Get a copy of A*evecr
          tempAevec = MVT::CloneCopy( Aevec, curind );
	  
          // Get a view of the imaginary part of the eigenvector (eveci)
          curind[0] = i+1;
          eveci = MVT::CloneView( *evecs, curind );
	  
          // Set the eigenvalue into Breal and Bimag
          Breal(0,0) = evals[i].realpart;
          Bimag(0,0) = evals[i].imagpart;
	  
          // Compute A*evecr - evecr*lambdar + eveci*lambdai
          MVT::MvTimesMatAddMv( -1.0, *evecr, Breal, 1.0, *tempAevec );
          MVT::MvTimesMatAddMv( 1.0, *eveci, Bimag, 1.0, *tempAevec );
          MVT::MvNorm( *tempAevec, tempnrm );
	  
          // Get a copy of A*eveci
          tempAevec = MVT::CloneCopy( Aevec, curind );
	  
          // Compute A*eveci - eveci*lambdar - evecr*lambdai
          MVT::MvTimesMatAddMv( -1.0, *evecr, Bimag, 1.0, *tempAevec );
          MVT::MvTimesMatAddMv( -1.0, *eveci, Breal, 1.0, *tempAevec );
          MVT::MvNorm( *tempAevec, resnorm );
	  
          // Compute the norms and scale by magnitude of eigenvalue
          normA[i] = lapack.LAPY2( tempnrm[i], resnorm[i] ) /
            lapack.LAPY2( evals[i].realpart, evals[i].imagpart );
          normA[i+1] = normA[i];
	  
          i=i+2;
        }
      }
    }
    
    // Output computed eigenvalues and their direct residuals
    if (verbose && MyPID==0) {
      cout.setf(std::ios_base::right, std::ios_base::adjustfield);
      cout<<endl<< "Actual Residuals"<<endl;
      if (MyProblem->isHermitian()) {
        cout<< std::setw(16) << "Real Part"
	    << std::setw(20) << "Direct Residual"<< endl;
        cout<<"-----------------------------------------------------------"<<endl;
        for (int i=0; i<numev; i++) {
          cout<< std::setw(16) << evals[i].realpart 
	      << std::setw(20) << normA[i] << endl;
        }  
        cout<<"-----------------------------------------------------------"<<endl;
      } 
      else {
        cout<< std::setw(16) << "Real Part"
	    << std::setw(16) << "Imag Part"
	    << std::setw(20) << "Direct Residual"<< endl;
        cout<<"-----------------------------------------------------------"<<endl;
        for (int i=0; i<numev; i++) {
          cout<< std::setw(16) << evals[i].realpart 
	      << std::setw(16) << evals[i].imagpart 
	      << std::setw(20) << normA[i] << endl;
        }  
        cout<<"-----------------------------------------------------------"<<endl;
      }  
    }
  }
  
#ifdef EPETRA_MPI
  MPI_Finalize();
#endif  
  return 0;
}
Пример #3
0
int main(int argc, char *argv[]) {

#ifdef EPETRA_MPI
  // Initialize MPI
  MPI_Init(&argc,&argv);
  Epetra_MpiComm Comm(MPI_COMM_WORLD);
#else
  Epetra_SerialComm Comm;
#endif

  bool testFailed;
  bool boolret;
  int MyPID = Comm.MyPID();

  bool verbose = true;
  bool debug = false;
  std::string which("SM");

  Teuchos::CommandLineProcessor cmdp(false,true);
  cmdp.setOption("verbose","quiet",&verbose,"Print messages and results.");
  cmdp.setOption("debug","nodebug",&debug,"Print debugging information.");
  cmdp.setOption("sort",&which,"Targetted eigenvalues (SM,LM,SR,LR,SI,or LI).");
  if (cmdp.parse(argc,argv) != Teuchos::CommandLineProcessor::PARSE_SUCCESSFUL) {
#ifdef HAVE_MPI
    MPI_Finalize();
#endif
    return -1;
  }

  typedef double ScalarType;
  typedef Teuchos::ScalarTraits<ScalarType>          ScalarTypeTraits;
  typedef ScalarTypeTraits::magnitudeType            MagnitudeType;
  typedef Epetra_MultiVector                         MV;
  typedef Epetra_Operator                            OP;
  typedef Anasazi::MultiVecTraits<ScalarType,MV>     MVTraits;
  typedef Anasazi::OperatorTraits<ScalarType,MV,OP>  OpTraits;

  //  Dimension of the matrix
  int nx = 10;        // Discretization points in any one direction.
  int NumGlobalElements = nx*nx;  // Size of matrix nx*nx

  // Construct a Map that puts approximately the same number of
  // equations on each processor.

  Epetra_Map Map(NumGlobalElements, 0, Comm);

  // Get update list and number of local equations from newly created Map.

  int NumMyElements = Map.NumMyElements();

  std::vector<int> MyGlobalElements(NumMyElements);
  Map.MyGlobalElements(&MyGlobalElements[0]);

  // Create an integer vector NumNz that is used to build the Petra Matrix.
  // NumNz[i] is the Number of OFF-DIAGONAL term for the ith global equation
  // on this processor
  std::vector<int> NumNz(NumMyElements);

  /* We are building a matrix of block structure:

      | T -I          |
      |-I  T -I       |
      |   -I  T       |
      |        ...  -I|
      |           -I T|

   where each block is dimension nx by nx and the matrix is on the order of
   nx*nx.  The block T is a tridiagonal matrix.
  */

  for (int i=0; i<NumMyElements; i++) {
    if (MyGlobalElements[i] == 0 || MyGlobalElements[i] == NumGlobalElements-1 ||
        MyGlobalElements[i] == nx-1 || MyGlobalElements[i] == nx*(nx-1) ) {
      NumNz[i] = 3;
    }
    else if (MyGlobalElements[i] < nx || MyGlobalElements[i] > nx*(nx-1) ||
             MyGlobalElements[i]%nx == 0 || (MyGlobalElements[i]+1)%nx == 0) {
      NumNz[i] = 4;
    }
    else {
      NumNz[i] = 5;
    }
  }

  // Create an Epetra_Matrix

  Teuchos::RCP<Epetra_CrsMatrix> A = Teuchos::rcp( new Epetra_CrsMatrix(Copy, Map, &NumNz[0]) );

  // Diffusion coefficient, can be set by user.
  // When rho*h/2 <= 1, the discrete convection-diffusion operator has real eigenvalues.
  // When rho*h/2 > 1, the operator has complex eigenvalues.
  double rho = 2*(nx+1);

  // Compute coefficients for discrete convection-diffution operator
  const double one = 1.0;
  std::vector<double> Values(4);
  std::vector<int> Indices(4);
  double h = one /(nx+1);
  double h2 = h*h;
  double c = 5.0e-01*rho/ h;
  Values[0] = -one/h2 - c; Values[1] = -one/h2 + c; Values[2] = -one/h2; Values[3]= -one/h2;
  double diag = 4.0 / h2;
  int NumEntries, info;

  for (int i=0; i<NumMyElements; i++)
  {
    if (MyGlobalElements[i]==0)
    {
      Indices[0] = 1;
      Indices[1] = nx;
      NumEntries = 2;
      info = A->InsertGlobalValues(MyGlobalElements[i], NumEntries, &Values[1], &Indices[0]);
      assert( info==0 );
    }
    else if (MyGlobalElements[i] == nx*(nx-1))
    {
      Indices[0] = nx*(nx-1)+1;
      Indices[1] = nx*(nx-2);
      NumEntries = 2;
      info = A->InsertGlobalValues(MyGlobalElements[i], NumEntries, &Values[1], &Indices[0]);
      assert( info==0 );
    }
    else if (MyGlobalElements[i] == nx-1)
    {
      Indices[0] = nx-2;
      NumEntries = 1;
      info = A->InsertGlobalValues(MyGlobalElements[i], NumEntries, &Values[0], &Indices[0]);
      assert( info==0 );
      Indices[0] = 2*nx-1;
      info = A->InsertGlobalValues(MyGlobalElements[i], NumEntries, &Values[2], &Indices[0]);
      assert( info==0 );
    }
    else if (MyGlobalElements[i] == NumGlobalElements-1)
    {
      Indices[0] = NumGlobalElements-2;
      NumEntries = 1;
      info = A->InsertGlobalValues(MyGlobalElements[i], NumEntries, &Values[0], &Indices[0]);
      assert( info==0 );
      Indices[0] = nx*(nx-1)-1;
      info = A->InsertGlobalValues(MyGlobalElements[i], NumEntries, &Values[2], &Indices[0]);
      assert( info==0 );
    }
    else if (MyGlobalElements[i] < nx)
    {
      Indices[0] = MyGlobalElements[i]-1;
      Indices[1] = MyGlobalElements[i]+1;
      Indices[2] = MyGlobalElements[i]+nx;
      NumEntries = 3;
      info = A->InsertGlobalValues(MyGlobalElements[i], NumEntries, &Values[0], &Indices[0]);
      assert( info==0 );
    }
    else if (MyGlobalElements[i] > nx*(nx-1))
    {
      Indices[0] = MyGlobalElements[i]-1;
      Indices[1] = MyGlobalElements[i]+1;
      Indices[2] = MyGlobalElements[i]-nx;
      NumEntries = 3;
      info = A->InsertGlobalValues(MyGlobalElements[i], NumEntries, &Values[0], &Indices[0]);
      assert( info==0 );
    }
    else if (MyGlobalElements[i]%nx == 0)
    {
      Indices[0] = MyGlobalElements[i]+1;
      Indices[1] = MyGlobalElements[i]-nx;
      Indices[2] = MyGlobalElements[i]+nx;
      NumEntries = 3;
      info = A->InsertGlobalValues(MyGlobalElements[i], NumEntries, &Values[1], &Indices[0]);
      assert( info==0 );
    }
    else if ((MyGlobalElements[i]+1)%nx == 0)
    {
      Indices[0] = MyGlobalElements[i]-nx;
      Indices[1] = MyGlobalElements[i]+nx;
      NumEntries = 2;
      info = A->InsertGlobalValues(MyGlobalElements[i], NumEntries, &Values[2], &Indices[0]);
      assert( info==0 );
      Indices[0] = MyGlobalElements[i]-1;
      NumEntries = 1;
      info = A->InsertGlobalValues(MyGlobalElements[i], NumEntries, &Values[0], &Indices[0]);
      assert( info==0 );
    }
    else
    {
      Indices[0] = MyGlobalElements[i]-1;
      Indices[1] = MyGlobalElements[i]+1;
      Indices[2] = MyGlobalElements[i]-nx;
      Indices[3] = MyGlobalElements[i]+nx;
      NumEntries = 4;
      info = A->InsertGlobalValues(MyGlobalElements[i], NumEntries, &Values[0], &Indices[0]);
      assert( info==0 );
    }
    // Put in the diagonal entry
    info = A->InsertGlobalValues(MyGlobalElements[i], 1, &diag, &MyGlobalElements[i]);
    assert( info==0 );
  }

  // Finish up
  info = A->FillComplete();
  assert( info==0 );
  A->SetTracebackMode(1); // Shutdown Epetra Warning tracebacks

  //************************************
  // Start the block Davidson iteration
  //***********************************
  //
  //  Variables used for the Generalized Davidson Method
  //
  int nev = 4;
  int blockSize = 1;
  int maxDim = 50;
  int restartDim = 10;
  int maxRestarts = 500;
  double tol = 1e-10;

  // Set verbosity level
  int verbosity = Anasazi::Errors + Anasazi::Warnings;
  if (verbose) {
    verbosity += Anasazi::FinalSummary + Anasazi::TimingDetails;
  }
  if (debug) {
    verbosity += Anasazi::Debug;
  }
  //
  // Create parameter list to pass into solver manager
  //
  Teuchos::ParameterList MyPL;
  MyPL.set( "Verbosity", verbosity );
  MyPL.set( "Which", which );
  MyPL.set( "Block Size", blockSize );
  MyPL.set( "Maximum Subspace Dimension", maxDim);
  MyPL.set( "Restart Dimension", restartDim);
  MyPL.set( "Maximum Restarts", maxRestarts );
  MyPL.set( "Convergence Tolerance", tol );
  MyPL.set( "Relative Convergence Tolerance", true );
  MyPL.set( "Initial Guess", "User" );

  // Create an Epetra_MultiVector for an initial vector to start the solver.
  // Note:  This needs to have the same number of columns as the blocksize.
  Teuchos::RCP<Epetra_MultiVector> ivec = Teuchos::rcp( new Epetra_MultiVector(Map, blockSize) );
  ivec->Random();

  // Create the eigenproblem.
  Teuchos::RCP<Anasazi::BasicEigenproblem<double, MV, OP> > MyProblem = Teuchos::rcp(
    new Anasazi::BasicEigenproblem<double,MV,OP>() );
  MyProblem->setA(A);
  MyProblem->setInitVec(ivec);

  // Inform the eigenproblem that the operator A is non-Hermitian
  MyProblem->setHermitian(false);

  // Set the number of eigenvalues requested
  MyProblem->setNEV( nev );

  // Inform the eigenproblem that you are finishing passing it information
  boolret = MyProblem->setProblem();
  if (boolret != true) {
    if (verbose && MyPID == 0) {
      std::cout << "Anasazi::BasicEigenproblem::setProblem() returned with error." << std::endl;
    }
#ifdef HAVE_MPI
    MPI_Finalize() ;
#endif
    return -1;
  }

  // Initialize the Block Arnoldi solver
  Anasazi::GeneralizedDavidsonSolMgr<double, MV, OP> MySolverMgr(MyProblem, MyPL);

  // Solve the problem to the specified tolerances or length
  Anasazi::ReturnType returnCode = MySolverMgr.solve();
  testFailed = false;
  if (returnCode != Anasazi::Converged && MyPID==0 && verbose) {
    testFailed = true;
  }

  // Get the eigenvalues and eigenvectors from the eigenproblem
  Anasazi::Eigensolution<ScalarType,MV> sol = MyProblem->getSolution();
  std::vector<Anasazi::Value<ScalarType> > evals = sol.Evals;
  Teuchos::RCP<MV> evecs = sol.Evecs;
  std::vector<int> index = sol.index;
  int numev = sol.numVecs;

  // Output computed eigenvalues and their direct residuals
  if (verbose && MyPID==0) {
    int numritz = (int)evals.size();
    std::cout.setf(std::ios_base::right, std::ios_base::adjustfield);
    std::cout<<std::endl<< "Computed Ritz Values"<< std::endl;
    std::cout<< std::setw(16) << "Real Part"
        << std::setw(16) << "Imag Part"
        << std::endl;
    std::cout<<"-----------------------------------------------------------"<<std::endl;
    for (int i=0; i<numritz; i++) {
      std::cout<< std::setw(16) << evals[i].realpart
          << std::setw(16) << evals[i].imagpart
          << std::endl;
    }
    std::cout<<"-----------------------------------------------------------"<<std::endl;
  }

  if (numev > 0) {
    // Compute residuals.
    Teuchos::LAPACK<int,double> lapack;
    std::vector<double> normA(numev);

    // The problem is non-Hermitian.
    int i=0;
    std::vector<int> curind(1);
    std::vector<double> resnorm(1), tempnrm(1);
    Teuchos::RCP<MV> tempAevec;
    Teuchos::RCP<const MV> evecr, eveci;
    Epetra_MultiVector Aevec(Map,numev);

    // Compute A*evecs
    OpTraits::Apply( *A, *evecs, Aevec );

    Teuchos::SerialDenseMatrix<int,double> Breal(1,1), Bimag(1,1);
    while (i<numev) {
      if (index[i]==0) {
        // Get a view of the current eigenvector (evecr)
        curind[0] = i;
        evecr = MVTraits::CloneView( *evecs, curind );

        // Get a copy of A*evecr
        tempAevec = MVTraits::CloneCopy( Aevec, curind );

        // Compute A*evecr - lambda*evecr
        Breal(0,0) = evals[i].realpart;
        MVTraits::MvTimesMatAddMv( -1.0, *evecr, Breal, 1.0, *tempAevec );

        // Compute the norm of the residual and increment counter
        MVTraits::MvNorm( *tempAevec, resnorm );
        normA[i] = resnorm[0] / Teuchos::ScalarTraits<MagnitudeType>::magnitude( evals[i].realpart );
        i++;
      } else {
        // Get a view of the real part of the eigenvector (evecr)
        curind[0] = i;
        evecr = MVTraits::CloneView( *evecs, curind );

        // Get a copy of A*evecr
        tempAevec = MVTraits::CloneCopy( Aevec, curind );

        // Get a view of the imaginary part of the eigenvector (eveci)
        curind[0] = i+1;
        eveci = MVTraits::CloneView( *evecs, curind );

        // Set the eigenvalue into Breal and Bimag
        Breal(0,0) = evals[i].realpart;
        Bimag(0,0) = evals[i].imagpart;

        // Compute A*evecr - evecr*lambdar + eveci*lambdai
        MVTraits::MvTimesMatAddMv( -1.0, *evecr, Breal, 1.0, *tempAevec );
        MVTraits::MvTimesMatAddMv( 1.0, *eveci, Bimag, 1.0, *tempAevec );
        MVTraits::MvNorm( *tempAevec, tempnrm );

        // Get a copy of A*eveci
        tempAevec = MVTraits::CloneCopy( Aevec, curind );

        // Compute A*eveci - eveci*lambdar - evecr*lambdai
        MVTraits::MvTimesMatAddMv( -1.0, *evecr, Bimag, 1.0, *tempAevec );
        MVTraits::MvTimesMatAddMv( -1.0, *eveci, Breal, 1.0, *tempAevec );
        MVTraits::MvNorm( *tempAevec, resnorm );

        // Compute the norms and scale by magnitude of eigenvalue
        normA[i] = lapack.LAPY2( tempnrm[0], resnorm[0] ) /
          lapack.LAPY2( evals[i].realpart, evals[i].imagpart );
        normA[i+1] = normA[i];

        i=i+2;
      }
    }

    // Output computed eigenvalues and their direct residuals
    if (verbose && MyPID==0) {
      std::cout.setf(std::ios_base::right, std::ios_base::adjustfield);
      std::cout<<std::endl<< "Actual Residuals"<<std::endl;
      std::cout<< std::setw(16) << "Real Part"
          << std::setw(16) << "Imag Part"
          << std::setw(20) << "Direct Residual"<< std::endl;
      std::cout<<"-----------------------------------------------------------"<<std::endl;
      for (int j=0; j<numev; j++) {
        std::cout<< std::setw(16) << evals[j].realpart
            << std::setw(16) << evals[j].imagpart
            << std::setw(20) << normA[j] << std::endl;
        if ( normA[j] > tol ) {
          testFailed = true;
        }
      }
      std::cout<<"-----------------------------------------------------------"<<std::endl;
    }
  }

#ifdef EPETRA_MPI
  MPI_Finalize();
#endif

  if (testFailed) {
    if (verbose && MyPID==0) {
      std::cout << "End Result: TEST FAILED" << std::endl;
    }
    return -1;
  }
  //
  // Default return value
  //
  if (verbose && MyPID==0) {
    std::cout << "End Result: TEST PASSED" << std::endl;
  }

  return 0;
}
Пример #4
0
int main(int argc, char *argv[]) {

  Teuchos::GlobalMPISession mpisess(&argc,&argv,&cout);

  bool run_me = (mpisess.getRank() == 0);
  bool testFailed = false;

  if (run_me) {
    try {
      // useful typedefs
      typedef double                              ST;
      typedef Teuchos::ScalarTraits<ST>          STT;
      typedef STT::magnitudeType                  MT;
      typedef Teuchos::ScalarTraits<MT>          MTT;
      typedef Epetra_MultiVector                  MV;
      typedef Epetra_Operator                     OP;
      typedef Anasazi::MultiVecTraits<ST,MV>     MVT;
      typedef Anasazi::OperatorTraits<ST,MV,OP>  OPT;

      // parse here, so everyone knows about failure
      bool verbose    = false;
      bool debug      = false;
      std::string k_filename = "linearized_qevp_A.hb";
      std::string m_filename = "linearized_qevp_B.hb";
      int blockSize   = 1;
      int numBlocks   = 30;
      int nev         = 20;
      int maxRestarts = 0;
      int extraBlocks = 0;
      int stepSize    = 1;
      int numPrint    = 536;
      MT  tol = 1e-8;
      Teuchos::CommandLineProcessor cmdp(true,true);
      cmdp.setOption("verbose","quiet",&verbose,"Print messages and results.");
      cmdp.setOption("debug","normal",&debug,"Print debugging information.");
      cmdp.setOption("A-filename",&k_filename,"Filename and path of the stiffness matrix.");
      cmdp.setOption("B-filename",&m_filename,"Filename and path of the mass matrix.");
      cmdp.setOption("extra-blocks",&extraBlocks,"Extra blocks to keep on a restart.");
      cmdp.setOption("block-size",&blockSize,"Block size.");
      cmdp.setOption("num-blocks",&numBlocks,"Number of blocks in Krylov basis.");
      cmdp.setOption("step-size",&stepSize,"Step size.");
      cmdp.setOption("nev",&nev,"Number of eigenvalues to compute.");
      cmdp.setOption("num-restarts",&maxRestarts,"Maximum number of restarts.");
      cmdp.setOption("tol",&tol,"Convergence tolerance.");
      cmdp.setOption("num-print",&numPrint,"Number of Ritz values to print.");
      // parse() will throw an exception on error
      cmdp.parse(argc,argv);

      // Get the stiffness and mass matrices
      Epetra_SerialComm Comm;
      RCP<Epetra_Map> Map;
      RCP<Epetra_CrsMatrix> A, B;
      EpetraExt::readEpetraLinearSystem( k_filename, Comm, &A, &Map );
      EpetraExt::readEpetraLinearSystem( m_filename, Comm, &B, &Map );

      //
      // *******************************************************
      // Set up Amesos direct solver for inner iteration
      // *******************************************************
      //
      // Create Epetra linear problem class to solve "Kx = b"
      Epetra_LinearProblem AmesosProblem;
      AmesosProblem.SetOperator(A.get());
      // Create Amesos factory and solver for solving "Kx = b" using a direct factorization
      Amesos amesosFactory;
      RCP<Amesos_BaseSolver> AmesosSolver = rcp( amesosFactory.Create( "Klu", AmesosProblem ) );
      // The AmesosGenOp class assumes that the symbolic/numeric factorizations have already
      // been performed on the linear problem.
      AmesosSolver->SymbolicFactorization();
      AmesosSolver->NumericFactorization();

      //
      // ************************************
      // Start the block Arnoldi iteration
      // ************************************
      //
      //  Variables used for the Block Arnoldi Method
      //
      int verbosity = Anasazi::Errors + Anasazi::Warnings + Anasazi::FinalSummary;
      if (verbose) {
        verbosity += Anasazi::IterationDetails;
      }
      if (debug) {
        verbosity += Anasazi::Debug;
      }
      //
      // Create parameter list to pass into solver
      //
      Teuchos::ParameterList MyPL;
      MyPL.set( "Verbosity", verbosity );
      MyPL.set( "Which", "LM" );
      MyPL.set( "Block Size", blockSize );
      MyPL.set( "Num Blocks", numBlocks );
      MyPL.set( "Maximum Restarts", maxRestarts );
      MyPL.set( "Convergence Tolerance", tol );
      MyPL.set( "Step Size", stepSize );
      MyPL.set( "Extra NEV Blocks", extraBlocks );
      MyPL.set( "Print Number of Ritz Values", numPrint );

      // Create an Epetra_MultiVector for an initial vector to start the solver.
      // Note:  This needs to have the same number of columns as the blocksize.
      RCP<Epetra_MultiVector> ivec = rcp( new Epetra_MultiVector(A->Map(), blockSize) );
      // MVT::MvRandom( *ivec ); // FINISH: put this back in
      MVT::MvInit(*ivec,1.0);

      // Create the Epetra_Operator for the spectral transformation using the Amesos direct solver.
      RCP<AmesosGenOp> Aop = rcp( new AmesosGenOp(AmesosProblem, AmesosSolver, B) );

      // standard inner product; B is not symmetric positive definite, and Op has no symmetry.
      RCP<Anasazi::BasicEigenproblem<ST,MV,OP> > MyProblem = 
        rcp( new Anasazi::BasicEigenproblem<ST,MV,OP>(Aop, ivec) );
      MyProblem->setHermitian(false);
      MyProblem->setNEV( nev );
      // Inform the eigenproblem that you are finished passing it information
      TEUCHOS_TEST_FOR_EXCEPTION( MyProblem->setProblem() != true, 
                          std::runtime_error, "Anasazi::BasicEigenproblem::setProblem() returned with error.");

      // Initialize the Block Arnoldi solver
      Anasazi::BlockKrylovSchurSolMgr<ST,MV,OP> MySolverMgr(MyProblem, MyPL);

      // Solve the problem to the specified tolerances or length
      Anasazi::ReturnType returnCode = MySolverMgr.solve();

      // Get the eigenvalues and eigenvectors from the eigenproblem
      Anasazi::Eigensolution<ST,MV> sol = MyProblem->getSolution();
      vector<Anasazi::Value<ST> > evals = sol.Evals;
      RCP<MV> evecs = sol.Evecs;
      vector<int> index = sol.index;
      int numev = sol.numVecs;

      if (returnCode != Anasazi::Converged) {
        cout << "Anasazi::EigensolverMgr::solve() returned unconverged, computing " << numev << " of " << nev << endl;
      }
      else {
        cout << "Anasazi::EigensolverMgr::solve() returned converged, computing " << numev << " of " << nev << endl;
      }

      if (numev > 0) {
        // Compute residuals.
        Teuchos::LAPACK<int,MT> lapack;
        vector<MT> normA(numev);

        // Back-transform the eigenvalues
        for (int i=0; i<numev; ++i) {
          MT mag2 = lapack.LAPY2(evals[i].realpart,evals[i].imagpart);
          mag2 = mag2*mag2;
          evals[i].realpart /=   mag2;
          evals[i].imagpart /= (-mag2);
        }

        // The problem is non-Hermitian.
        vector<int> curind(1);
        vector<MT> resnorm(1), tempnrm(1);
        Teuchos::RCP<const MV> Av_r, Av_i, Bv_r, Bv_i;
        Epetra_MultiVector Aevec(*Map,numev), Bevec(*Map,numev), res(*Map,1);

        // Compute A*evecs, B*evecs
        OPT::Apply( *A, *evecs, Aevec );
        OPT::Apply( *B, *evecs, Bevec );

        for (int i=0; i<numev;) {
          if (index[i]==0) {
            // Get views of the real part of A*evec,B*evec
            curind[0] = i;
            Av_r = MVT::CloneView( Aevec, curind );
            Bv_r = MVT::CloneView( Bevec, curind );

            // Compute set res = lambda*B*evec - A*evec
            // eigenvalue and eigenvector are both real
            MVT::MvAddMv(evals[i].realpart,*Bv_r,-1.0,*Av_r,res);

            // Compute the norm of the residual and increment counter
            MVT::MvNorm( res, resnorm );
            // Scale the residual
            normA[i] = resnorm[0];
            MT mag = MTT::magnitude(evals[i].realpart);
            if ( mag > MTT::one() ) {
              normA[i] /= mag;
            }
            // done with this eigenvector
            i++;
          } else {
            // Get a copy of A*evec, B*evec
            curind[0] = i;
            Av_r = MVT::CloneCopy( Aevec, curind );
            Bv_r = MVT::CloneView( Bevec, curind );
            // Get the imaginary part of A*evec,B*evec
            curind[0] = i+1;
            Av_i = MVT::CloneCopy( Aevec, curind );
            Bv_i = MVT::CloneView( Bevec, curind );
            // grab temp copies of the eigenvalue
            MT l_r = evals[i].realpart,
               l_i = evals[i].imagpart;

            // Compute real part of B*evec*lambda - A*evec
            // B is real
            //   evec =   evec_r +   evec_i*i
            // lambda = lambda_r + lambda_i*i
            // 
            // evec*lambda = evec_r*lambda_r - evec_i*lambda_i + evec_r*lambda_i*i + evec_i*lambda_r*i
            //
            // res = B*evec*lambda - A*evec
            //     = B*(evec_r*lambda_r - evec_i*lambda_i + evec_r*lambda_i*i + evec_i*lambda_r*i) - A*evec_r - A*evec_i*i
            //     = (B*evec_r*lambda_r - B*evec_i*lambda_i - A*evec_r) + (B*evec_r*lambda_i + B*evec_i*lambda_r - A*evec_i)*i
            // real(res) = B*evec_r*lambda_r - B*evec_i*lambda_i - A*evec_r
            // imag(res) = B*evec_r*lambda_i + B*evec_i*lambda_r - A*evec_i

            // compute real part of residual and its norm
            MVT::MvAddMv(l_r,*Bv_r, -l_i,*Bv_i, res);
            MVT::MvAddMv(MTT::one(),res, -MTT::one(),*Av_r, res);
            MVT::MvNorm(res,tempnrm);
            // compute imag part of residual and its norm
            MVT::MvAddMv(l_i,*Bv_r, l_r,*Bv_i, res);
            MVT::MvAddMv(MTT::one(),res, -MTT::one(),*Av_i, res);
            MVT::MvNorm(res,resnorm);

            // Compute the norms and scale by magnitude of eigenvalue
            normA[i] = lapack.LAPY2( tempnrm[0], resnorm[0] );
            MT mag = lapack.LAPY2(evals[i].realpart, evals[i].imagpart);
            if (mag > MTT::one()) {
              normA[i] /= mag;
            }
            normA[i+1] = normA[i];
            // done with this conjugate pair
            i=i+2;
          }
        }

        // Output computed eigenvalues and their direct residuals
        cout.setf(std::ios_base::right, std::ios_base::adjustfield);        
        cout<<endl<< "Actual Residuals"<<endl;
        cout<< std::setw(16) << "Real Part"
          << std::setw(16) << "Imag Part"
          << std::setw(20) << "Direct Residual"<< endl;
        cout<<"-----------------------------------------------------------"<<endl;
        for (int j=0; j<numev; j++) {
          cout<< std::setw(16) << evals[j].realpart 
            << std::setw(16) << evals[j].imagpart 
            << std::setw(20) << normA[j] << endl;
          if (normA[j] > tol) {
            testFailed = true;
          }
        }  
        cout<<"-----------------------------------------------------------"<<endl;
      }
    }
    catch (std::exception &e) {
      cout << "Caught exception: " << endl << e.what() << endl;
      testFailed = true;
    }
  }
  else { // run_me == false 
    cout << "\nNot running on processor " << mpisess.getRank() << ". Serial problem only." << endl;
  }
  if (mpisess.getRank() == 0) {
    if (testFailed) {
      cout << "End Result: TEST FAILED" << endl;
    }
    else {
      cout << "End Result: TEST PASSED" << endl;
    }
  }
  return 0;
}
int main(int argc, char *argv[]) {
  using std::cout;

  //
  bool haveM = false;

#ifdef EPETRA_MPI  
  // Initialize MPI  
  MPI_Init(&argc,&argv);   
  Epetra_MpiComm Comm( MPI_COMM_WORLD );  
#else  
  Epetra_SerialComm Comm;  
#endif
  
  int MyPID = Comm.MyPID();

  bool verbose=false;
  bool isHermitian=false;
  std::string k_filename = "";
  std::string m_filename = "";
  std::string which = "SM";
  Teuchos::CommandLineProcessor cmdp(false,true);
  cmdp.setOption("verbose","quiet",&verbose,"Print messages and results.");
  cmdp.setOption("hermitian","non-hermitian",&isHermitian,"The eigenproblem being read in is Hermitian.");
  cmdp.setOption("sort",&which,"Targetted eigenvalues (SM,LM,SR,or LR).");
  cmdp.setOption("K-filename",&k_filename,"Filename and path of the stiffness matrix.");
  cmdp.setOption("M-filename",&m_filename,"Filename and path of the mass matrix.");
  if (cmdp.parse(argc,argv) != Teuchos::CommandLineProcessor::PARSE_SUCCESSFUL) {
#ifdef HAVE_MPI
    MPI_Finalize();
#endif
    return -1;
  }
  //
  //**********************************************************************
  //******************Set up the problem to be solved*********************
  //**********************************************************************
  //
  // *****Read in matrix from file******
  //
  Teuchos::RCP<Epetra_Map> Map;
  Teuchos::RCP<Epetra_CrsMatrix> K, M;
  EpetraExt::readEpetraLinearSystem( k_filename, Comm, &K, &Map );

  {
    string testFile = "/tmp/test.mtx";
    EpetraExt::RowMatrixToMatrixMarketFile(testFile.c_str(),*K);
  }
  if (haveM) {
    EpetraExt::readEpetraLinearSystem( m_filename, Comm, &M, &Map );
  }
  //
  //************************************
  // Start the block Arnoldi iteration
  //***********************************         
  //
  //  Variables used for the Block Arnoldi Method
  // 
  int nev = 1;
  int blockSize = 10;
//  int nevBlocks;
//  if (nev%blockSize) {
//    nevBlocks = nev/blockSize + 1;
//  } else {
//    nevBlocks = nev/blockSize;
//  }
  
  int numBlocks = 4;
  int maxRestarts = 10000;
  int step = 10;
  double tol = 1.0e-12;
  
  // Set verbosity level
  int verbosity = Anasazi::Errors + Anasazi::Warnings;
  if (verbose) {
    verbosity += Anasazi::FinalSummary + Anasazi::TimingDetails;
  }
  //
  // Create parameter list to pass into solver
  //
  Teuchos::ParameterList MyPL;
  MyPL.set( "Verbosity", verbosity );
  MyPL.set( "Which", which );
  MyPL.set( "Block Size", blockSize );
  MyPL.set( "Num Blocks", numBlocks );
  MyPL.set( "Maximum Restarts", maxRestarts );
  MyPL.set( "Convergence Tolerance", tol );
  MyPL.set( "Step Size", step );

  typedef Epetra_MultiVector MV;
  typedef Epetra_Operator OP;
  typedef Anasazi::MultiVecTraits<double, MV> MVT;
  typedef Anasazi::OperatorTraits<double, MV, OP> OPT;
  //
  // Create the eigenproblem to be solved.
  //
  Teuchos::RCP<Epetra_MultiVector> ivec = Teuchos::rcp( new Epetra_MultiVector(*Map, blockSize) );
  ivec->Random();
  
  Teuchos::RCP<Anasazi::BasicEigenproblem<double, MV, OP> > MyProblem;
  if (haveM) {
    MyProblem = Teuchos::rcp( new Anasazi::BasicEigenproblem<double, MV, OP>(K, M, ivec) );
  }
  else { 
    MyProblem = Teuchos::rcp( new Anasazi::BasicEigenproblem<double, MV, OP>(K, ivec) );
  }

  // Inform the eigenproblem that the (K,M) is Hermitian
  MyProblem->setHermitian( isHermitian );

  // Set the number of eigenvalues requested 
  MyProblem->setNEV( nev );

  // Inform the eigenproblem that you are finished passing it information
  bool boolret = MyProblem->setProblem();
  if (boolret != true) {
    if (verbose && MyPID == 0) {
      cout << "Anasazi::BasicEigenproblem::setProblem() returned with error." << endl;
    }
#ifdef HAVE_MPI
    MPI_Finalize() ;
#endif
    return -1;
  }

  // Initialize the Block Arnoldi solver
  Anasazi::BlockKrylovSchurSolMgr<double, MV, OP> MySolverMgr(MyProblem, MyPL);
    
  // Solve the problem to the specified tolerances or length
  Anasazi::ReturnType returnCode = MySolverMgr.solve();
  if (returnCode != Anasazi::Converged && MyPID==0 && verbose) {
    cout << "Anasazi::EigensolverMgr::solve() returned unconverged." << endl;
  }
  
  // Get the eigenvalues and eigenvectors from the eigenproblem
  Anasazi::Eigensolution<double,MV> sol = MyProblem->getSolution();
  std::vector<Anasazi::Value<double> > evals = sol.Evals;
  Teuchos::RCP<MV> evecs = sol.Evecs;
  std::vector<int> index = sol.index;
  int numev = sol.numVecs;

  if (numev > 0) {
    // Compute residuals.
    Teuchos::LAPACK<int,double> lapack;
    std::vector<double> normR(numev);
    
    if (MyProblem->isHermitian()) {
      // Get storage
      Epetra_MultiVector Kevecs(*Map,numev);
      Teuchos::RCP<Epetra_MultiVector> Mevecs;
      Teuchos::SerialDenseMatrix<int,double> B(numev,numev);
      B.putScalar(0.0); 
      for (int i=0; i<numev; i++) {B(i,i) = evals[i].realpart;}
      
      // Compute A*evecs
      OPT::Apply( *K, *evecs, Kevecs );
      if (haveM) {
        Mevecs = Teuchos::rcp( new Epetra_MultiVector(*Map,numev) );
        OPT::Apply( *M, *evecs, *Mevecs );
      } 
      else {
        Mevecs = evecs;
      }
      
      // Compute A*evecs - lambda*evecs and its norm
      MVT::MvTimesMatAddMv( -1.0, *Mevecs, B, 1.0, Kevecs );
      MVT::MvNorm( Kevecs, normR );
      
      // Scale the norms by the eigenvalue
      for (int i=0; i<numev; i++) {
        normR[i] /= Teuchos::ScalarTraits<double>::magnitude( evals[i].realpart );
      }
    } else {
      // The problem is non-Hermitian.
      int i=0;
      std::vector<int> curind(1);
      std::vector<double> resnorm(1), tempnrm(1);
      Teuchos::RCP<MV> tempKevec, Mevecs;
      Teuchos::RCP<const MV> tempeveci, tempMevec;
      Epetra_MultiVector Kevecs(*Map,numev);
      
      // Compute K*evecs
      OPT::Apply( *K, *evecs, Kevecs );
      if (haveM) {
        Mevecs = Teuchos::rcp( new Epetra_MultiVector(*Map,numev) );
        OPT::Apply( *M, *evecs, *Mevecs );
      }
      else {
        Mevecs = evecs;
      }
      
      Teuchos::SerialDenseMatrix<int,double> Breal(1,1), Bimag(1,1);
      while (i<numev) {
        if (index[i]==0) {
          // Get a view of the M*evecr
          curind[0] = i;
          tempMevec = MVT::CloneView( *Mevecs, curind );

          // Get a copy of A*evecr
          tempKevec = MVT::CloneCopy( Kevecs, curind );

          // Compute K*evecr - lambda*M*evecr
          Breal(0,0) = evals[i].realpart;
          MVT::MvTimesMatAddMv( -1.0, *tempMevec, Breal, 1.0, *tempKevec );

          // Compute the norm of the residual and increment counter
          MVT::MvNorm( *tempKevec, resnorm );
          normR[i] = resnorm[0]/Teuchos::ScalarTraits<double>::magnitude( evals[i].realpart );
          i++;
        } else {
          // Get a view of the real part of M*evecr
          curind[0] = i;
          tempMevec = MVT::CloneView( *Mevecs, curind );

          // Get a copy of K*evecr
          tempKevec = MVT::CloneCopy( Kevecs, curind );

          // Get a view of the imaginary part of the eigenvector (eveci)
          curind[0] = i+1;
          tempeveci = MVT::CloneView( *Mevecs, curind );

          // Set the eigenvalue into Breal and Bimag
          Breal(0,0) = evals[i].realpart;
          Bimag(0,0) = evals[i].imagpart;

          // Compute K*evecr - M*evecr*lambdar + M*eveci*lambdai
          MVT::MvTimesMatAddMv( -1.0, *tempMevec, Breal, 1.0, *tempKevec );
          MVT::MvTimesMatAddMv( 1.0, *tempeveci, Bimag, 1.0, *tempKevec );
          MVT::MvNorm( *tempKevec, tempnrm );

          // Get a copy of K*eveci
          tempKevec = MVT::CloneCopy( Kevecs, curind );

          // Compute K*eveci - M*eveci*lambdar - M*evecr*lambdai
          MVT::MvTimesMatAddMv( -1.0, *tempMevec, Bimag, 1.0, *tempKevec );
          MVT::MvTimesMatAddMv( -1.0, *tempeveci, Breal, 1.0, *tempKevec );
          MVT::MvNorm( *tempKevec, resnorm );

          // Compute the norms and scale by magnitude of eigenvalue
          normR[i] = lapack.LAPY2( tempnrm[i], resnorm[i] ) /
            lapack.LAPY2( evals[i].realpart, evals[i].imagpart );
          normR[i+1] = normR[i];

          i=i+2;
        }
      }
    }

    // Output computed eigenvalues and their direct residuals
    
    if (verbose && MyPID==0) {      
      cout.setf(std::ios_base::right, std::ios_base::adjustfield);	
      cout<<endl<< "Actual Residuals"<<endl;
      if (MyProblem->isHermitian()) {
        cout<< std::setw(16) << "Real Part"
          << std::setw(20) << "Direct Residual"<< endl;
        cout<<"-----------------------------------------------------------"<<endl;
        for (int i=0; i<numev; i++) {
          cout<< std::setw(16) << evals[i].realpart 
            << std::setw(20) << normR[i] << endl;
        }  
        cout<<"-----------------------------------------------------------"<<endl;
      } 
      else {
        cout<< std::setw(16) << "Real Part"
          << std::setw(16) << "Imag Part"
          << std::setw(20) << "Direct Residual"<< endl;
        cout<<"-----------------------------------------------------------"<<endl;
        for (int i=0; i<numev; i++) {
          cout<< std::setw(16) << evals[i].realpart 
            << std::setw(16) << evals[i].imagpart 
            << std::setw(20) << normR[i] << endl;
        }  
        cout<<"-----------------------------------------------------------"<<endl;
      }  
    }
  }

#ifdef EPETRA_MPI
    MPI_Finalize() ;
#endif
    return 0;

} // end BlockKrylovSchurEpetraExFile.cpp
int main(int argc, char *argv[]) {
  using std::cout;
  using std::endl;
  //
  bool haveM = true;

#ifdef EPETRA_MPI
  // Initialize MPI
  MPI_Init(&argc,&argv);
  Epetra_MpiComm Comm( MPI_COMM_WORLD );
#else
  Epetra_SerialComm Comm;
#endif

  int MyPID = Comm.MyPID();

  bool verbose=false;
  bool isHermitian=false;
  std::string k_filename = "bfw782a.mtx";
  std::string m_filename = "bfw782b.mtx";
  std::string which = "LR";
  Teuchos::CommandLineProcessor cmdp(false,true);
  cmdp.setOption("verbose","quiet",&verbose,"Print messages and results.");
  cmdp.setOption("sort",&which,"Targetted eigenvalues (SM,LM,SR,or LR).");
  cmdp.setOption("K-filename",&k_filename,"Filename and path of the stiffness matrix.");
  cmdp.setOption("M-filename",&m_filename,"Filename and path of the mass matrix.");
  if (cmdp.parse(argc,argv) != Teuchos::CommandLineProcessor::PARSE_SUCCESSFUL) {
#ifdef HAVE_MPI
    MPI_Finalize();
#endif
    return -1;
  }
  //
  //**********************************************************************
  //******************Set up the problem to be solved*********************
  //**********************************************************************
  //
  // *****Read in matrix from file******
  //
  Teuchos::RCP<Epetra_Map> Map;
  Teuchos::RCP<Epetra_CrsMatrix> K, M;
  EpetraExt::readEpetraLinearSystem( k_filename, Comm, &K, &Map );

  if (haveM) {
    EpetraExt::readEpetraLinearSystem( m_filename, Comm, &M, &Map );
  }
  //
  // Build Preconditioner
  //
  Ifpack factory;
  std::string ifpack_type = "ILUT";
  int overlap = 0;
  Teuchos::RCP<Ifpack_Preconditioner> ifpack_prec = Teuchos::rcp(
          factory.Create( ifpack_type, K.get(), overlap ) );

  //
  // Set parameters and compute preconditioner
  //
  Teuchos::ParameterList ifpack_params;
  double droptol = 1e-2;
  double fill = 2.0;
  ifpack_params.set("fact: drop tolerance",droptol);
  ifpack_params.set("fact: ilut level-of-fill",fill);
  ifpack_prec->SetParameters(ifpack_params);
  ifpack_prec->Initialize();
  ifpack_prec->Compute();

  //
  // GeneralizedDavidson expects preconditioner to be applied with
  //  "Apply" rather than "Apply_Inverse"
  //
  Teuchos::RCP<Epetra_Operator> prec = Teuchos::rcp(
          new Epetra_InvOperator(ifpack_prec.get()) );

  //
  //************************************
  // Start the block Davidson iteration
  //***********************************
  //
  //  Variables used for the Block Arnoldi Method
  //
  int nev = 5;
  int blockSize = 5;
  int maxDim = 40;
  int maxRestarts = 10;
  double tol = 1.0e-8;

  // Set verbosity level
  int verbosity = Anasazi::Errors + Anasazi::Warnings;
  if (verbose) {
    verbosity += Anasazi::FinalSummary + Anasazi::TimingDetails;
  }
  //
  // Create parameter list to pass into solver
  //
  Teuchos::ParameterList MyPL;
  MyPL.set( "Verbosity", verbosity );
  MyPL.set( "Which", which );
  MyPL.set( "Block Size", blockSize );
  MyPL.set( "Maximum Subspace Dimension", maxDim );
  MyPL.set( "Maximum Restarts", maxRestarts );
  MyPL.set( "Convergence Tolerance", tol );
  MyPL.set( "Initial Guess", "User" );

  typedef Epetra_MultiVector MV;
  typedef Epetra_Operator OP;
  typedef Anasazi::MultiVecTraits<double, MV> MVT;
  typedef Anasazi::OperatorTraits<double, MV, OP> OPT;
  //
  // Create the eigenproblem to be solved.
  //
  Teuchos::RCP<Epetra_MultiVector> ivec = Teuchos::rcp( new Epetra_MultiVector(*Map, blockSize) );
  ivec->Random();

  Teuchos::RCP<Anasazi::BasicEigenproblem<double, MV, OP> > MyProblem;
  if (haveM) {
    MyProblem = Teuchos::rcp( new Anasazi::BasicEigenproblem<double, MV, OP>() );
    MyProblem->setA(K);
    MyProblem->setM(M);
    MyProblem->setPrec(prec);
    MyProblem->setInitVec(ivec);
  }
  else {
    MyProblem = Teuchos::rcp( new Anasazi::BasicEigenproblem<double, MV, OP>() );
    MyProblem->setA(K);
    MyProblem->setPrec(prec);
    MyProblem->setInitVec(ivec);
  }

  // Inform the eigenproblem that the (K,M) is Hermitian
  MyProblem->setHermitian( isHermitian );

  // Set the number of eigenvalues requested
  MyProblem->setNEV( nev );

  // Inform the eigenproblem that you are finished passing it information
  bool boolret = MyProblem->setProblem();
  if (boolret != true) {
    if (verbose && MyPID == 0) {
      cout << "Anasazi::BasicEigenproblem::setProblem() returned with error." << endl;
    }
#ifdef HAVE_MPI
    MPI_Finalize() ;
#endif
    return -1;
  }

  // Initialize the Block Arnoldi solver
  Anasazi::GeneralizedDavidsonSolMgr<double, MV, OP> MySolverMgr(MyProblem, MyPL);

  // Solve the problem to the specified tolerances or length
  Anasazi::ReturnType returnCode = MySolverMgr.solve();
  if (returnCode != Anasazi::Converged && MyPID==0 && verbose) {
    cout << "Anasazi::EigensolverMgr::solve() returned unconverged." << endl;
  }

  // Get the eigenvalues and eigenvectors from the eigenproblem
  Anasazi::Eigensolution<double,MV> sol = MyProblem->getSolution();
  std::vector<Anasazi::Value<double> > evals = sol.Evals;
  Teuchos::RCP<MV> evecs = sol.Evecs;
  std::vector<int> index = sol.index;
  int numev = sol.numVecs;

  if (numev > 0) {
    // Compute residuals.
    Teuchos::LAPACK<int,double> lapack;
    std::vector<double> normR(numev);

    // The problem is non-Hermitian.
    int i=0;
    std::vector<int> curind(1);
    std::vector<double> resnorm(1), tempnrm(1);
    Teuchos::RCP<MV> tempKevec, Mevecs;
    Teuchos::RCP<const MV> tempeveci, tempMevec;
    Epetra_MultiVector Kevecs(*Map,numev);

    // Compute K*evecs
    OPT::Apply( *K, *evecs, Kevecs );
    if (haveM) {
      Mevecs = Teuchos::rcp( new Epetra_MultiVector(*Map,numev) );
      OPT::Apply( *M, *evecs, *Mevecs );
    }
    else {
      Mevecs = evecs;
    }

    Teuchos::SerialDenseMatrix<int,double> Breal(1,1), Bimag(1,1);
    while (i<numev) {
      if (index[i]==0) {
        // Get a view of the M*evecr
        curind[0] = i;
        tempMevec = MVT::CloneView( *Mevecs, curind );

        // Get a copy of A*evecr
        tempKevec = MVT::CloneCopy( Kevecs, curind );

        // Compute K*evecr - lambda*M*evecr
        Breal(0,0) = evals[i].realpart;
        MVT::MvTimesMatAddMv( -1.0, *tempMevec, Breal, 1.0, *tempKevec );

        // Compute the norm of the residual and increment counter
        MVT::MvNorm( *tempKevec, resnorm );
        normR[i] = resnorm[0];
        i++;
      } else {
        // Get a view of the real part of M*evecr
        curind[0] = i;
        tempMevec = MVT::CloneView( *Mevecs, curind );

        // Get a copy of K*evecr
        tempKevec = MVT::CloneCopy( Kevecs, curind );

        // Get a view of the imaginary part of the eigenvector (eveci)
        curind[0] = i+1;
        tempeveci = MVT::CloneView( *Mevecs, curind );

        // Set the eigenvalue into Breal and Bimag
        Breal(0,0) = evals[i].realpart;
        Bimag(0,0) = evals[i].imagpart;

        // Compute K*evecr - M*evecr*lambdar + M*eveci*lambdai
        MVT::MvTimesMatAddMv( -1.0, *tempMevec, Breal, 1.0, *tempKevec );
        MVT::MvTimesMatAddMv( 1.0, *tempeveci, Bimag, 1.0, *tempKevec );
        MVT::MvNorm( *tempKevec, tempnrm );

        // Get a copy of K*eveci
        tempKevec = MVT::CloneCopy( Kevecs, curind );

        // Compute K*eveci - M*eveci*lambdar - M*evecr*lambdai
        MVT::MvTimesMatAddMv( -1.0, *tempMevec, Bimag, 1.0, *tempKevec );
        MVT::MvTimesMatAddMv( -1.0, *tempeveci, Breal, 1.0, *tempKevec );
        MVT::MvNorm( *tempKevec, resnorm );

        // Compute the norms and scale by magnitude of eigenvalue
        normR[i] = lapack.LAPY2( tempnrm[0], resnorm[0] );
        normR[i+1] = normR[i];

        i=i+2;
      }
    }

    // Output computed eigenvalues and their direct residuals
    if (verbose && MyPID==0) {
      cout.setf(std::ios_base::right, std::ios_base::adjustfield);
      cout<<endl<< "Actual Residuals"<<endl;
      cout<< std::setw(16) << "Real Part"
        << std::setw(16) << "Imag Part"
        << std::setw(20) << "Direct Residual"<< endl;
      cout<<"-----------------------------------------------------------"<<endl;
      for (int j=0; j<numev; j++) {
        cout<< std::setw(16) << evals[j].realpart
          << std::setw(16) << evals[j].imagpart
          << std::setw(20) << normR[j] << endl;
      }
      cout<<"-----------------------------------------------------------"<<endl;
    }
  }

#ifdef EPETRA_MPI
    MPI_Finalize() ;
#endif
    return 0;

} // end BlockKrylovSchurEpetraExFile.cpp