Beispiel #1
0
 int main(int argc, char *argv[])
{
  using std::cout;
  using std::endl;

  int ierr = 0, i, j;
  int nx, ny;

#ifdef EPETRA_MPI

  // Initialize MPI

  MPI_Init(&argc,&argv);
  //int size, rank; // Number of MPI processes, My process ID

  //MPI_Comm_size(MPI_COMM_WORLD, &size);
  //MPI_Comm_rank(MPI_COMM_WORLD, &rank);
  Epetra_MpiComm Comm( MPI_COMM_WORLD );

#else

  //int size = 1; // Serial case (not using MPI)
  //int rank = 0;

  Epetra_SerialComm Comm;
#endif

  bool verbose = false;

  int nextarg = 1;
  // Check if we should print results to standard out
  if (argc>1) if (argv[1][0]=='-' && argv[1][1]=='v') {
    verbose = true;
    nextarg++;
  }

  // char tmp;
  // if (rank==0) cout << "Press any key to continue..."<< endl;
  // if (rank==0) cin >> tmp;
  // Comm.Barrier();

  int MyPID = Comm.MyPID();
  int NumProc = Comm.NumProc();

  if (verbose && MyPID==0)
    cout << Ifpack_Version() << endl << endl;

  if (verbose) cout << Comm <<endl;

  //int sqrtNumProc = (int) ceil(sqrt((double) NumProc));

  bool verbose1 = verbose;
  verbose = verbose && (MyPID==0);

  if (verbose1 && argc != 4) {
    nx = 10;
    ny = 12*NumProc;
    cout << "Setting nx = " << nx << ", ny = " << ny << endl;
  }
    else if (!verbose1 && argc != 3) {
    nx = 10;
    ny = 12*NumProc;
    }
  else {
    nx = atoi(argv[nextarg++]);
    if (nx<3) {cout << "nx = " << nx << ": Must be greater than 2 for meaningful graph." << endl; exit(1);}
    ny = atoi(argv[nextarg++]);
    if (ny<3) {cout << "ny = " << ny << ": Must be greater than 2 for meaningful graph." << endl; exit(1);}
  }

  int NumGlobalPoints = nx*ny;
  int IndexBase = 0;

  if (verbose)
    cout << "\n\n*****Building 5 point matrix, Level 1 and 2 filled matrices for" << endl
         << "  nx = " << nx << ",  ny = " << ny << endl<< endl;


  // Create a 5 point stencil graph, level 1 fill of it and level 2 fill of it

  Epetra_Map Map(NumGlobalPoints, IndexBase, Comm);

  int NumMyPoints = Map.NumMyPoints();

  Epetra_CrsGraph A(Copy, Map, 5);
  Epetra_CrsGraph L0(Copy, Map, Map, 2);
  Epetra_CrsGraph U0(Copy, Map, Map, 2);
  Epetra_CrsGraph L1(Copy, Map, Map, 3);
  Epetra_CrsGraph U1(Copy, Map, Map, 3);
  Epetra_CrsGraph L2(Copy, Map, Map, 4);
  Epetra_CrsGraph U2(Copy, Map, Map, 4);

  // Add  rows one-at-a-time

  std::vector<int> Indices(4); // Work space

  for (j=0; j<ny; j++) {
    for (i=0; i<nx; i++) {
      int Row = i+j*nx;
      if (Map.MyGID(Row)) { // Only work on rows I own

        //**** Work on lower triangle of all three matrices ****

        // Define entries (i-1,j), (i,j-1)

        int k = 0;
        if (i>0)    Indices[k++] = i-1 + j   *nx;
        if (j>0)    Indices[k++] = i   +(j-1)*nx;

        // Define lower triangular terms of original matrix and L(0)
        assert(A.InsertGlobalIndices(Row, k, &Indices[0])>=0);
        assert(L0.InsertGlobalIndices(Row, k, &Indices[0])>=0);

        // Define entry (i+1,j-1)
        if ((i<nx-1) && (j>0   )) Indices[k++] = i+1 +(j-1)*nx;


        // Define lower triangle of level(1) fill matrix
        assert(L1.InsertGlobalIndices(Row, k, &Indices[0])>=0);

        // Define entry (i+2, j-1)

        if ((i<nx-2) && (j>0   )) Indices[k++] = i+2 +(j-1)*nx;

        // Define lower triangle of level(2) fill matrix
        assert(L2.InsertGlobalIndices(Row, k, &Indices[0])>=0);

        // Define main diagonal of original matrix
        assert(A.InsertGlobalIndices(Row, 1, &Row)>=0);

        k = 0; // Reset index counter

        //**** Work on upper triangle of all three matrices ****

        // Define entries (i+1,j), ( i,j+1)

        if (i<nx-1) Indices[k++] = i+1 + j   *nx;
        if (j<ny-1) Indices[k++] = i   +(j+1)*nx;

        // Define upper  triangular terms of original matrix and L(0)
        assert(A.InsertGlobalIndices(Row, k, &Indices[0])>=0);
        assert(U0.InsertGlobalIndices(Row, k, &Indices[0])>=0);

        // Define entry (i-1,j+1)

        if ((i>0   ) && (j<ny-1)) Indices[k++] = i-1 +(j+1)*nx;

        // Define upper triangle of level(1) fill matrix
        assert(U1.InsertGlobalIndices(Row, k, &Indices[0])>=0);

        // Define entry (i-2, j+1)

        if ((i>1   ) && (j<ny-1)) Indices[k++] = i-2 +(j+1)*nx;

        // Define upper triangle of level(2) fill matrix
        assert(U2.InsertGlobalIndices(Row, k, &Indices[0])>=0);
      }
    }
  }

  // Finish up
  if (verbose) cout << "\n\nCompleting A" << endl<< endl;
  assert(A.FillComplete()==0);
  if (verbose) cout << "\n\nCompleting L0" << endl<< endl;
  assert(L0.FillComplete()==0);
  if (verbose) cout << "\n\nCompleting U0" << endl<< endl;
  assert(U0.FillComplete()==0);
  if (verbose) cout << "\n\nCompleting L1" << endl<< endl;
  assert(L1.FillComplete()==0);
  if (verbose) cout << "\n\nCompleting U1" << endl<< endl;
  assert(U1.FillComplete()==0);
  if (verbose) cout << "\n\nCompleting L2" << endl<< endl;
  assert(L2.FillComplete()==0);
  if (verbose) cout << "\n\nCompleting U2" << endl<< endl;
  assert(U2.FillComplete()==0);

  if (verbose) cout << "\n\n*****Testing ILU(0) constructor on A" << endl<< endl;

  Ifpack_IlukGraph ILU0(A, 0, 0);
  assert(ILU0.ConstructFilledGraph()==0);

  assert(check(L0, U0, ILU0, NumGlobalPoints, NumMyPoints, 0, verbose)==0);

  if (verbose) cout << "\n\n*****Testing ILU(1) constructor on A" << endl<< endl;

  Ifpack_IlukGraph ILU1(A, 1, 0);
  assert(ILU1.ConstructFilledGraph()==0);

  assert(check(L1, U1, ILU1, NumGlobalPoints, NumMyPoints, 1, verbose)==0);

  if (verbose) cout << "\n\n*****Testing ILU(2) constructor on A" << endl<< endl;

  Ifpack_IlukGraph ILU2(A, 2, 0);
  assert(ILU2.ConstructFilledGraph()==0);

  assert(check(L2, U2, ILU2, NumGlobalPoints, NumMyPoints, 2, verbose)==0);

  if (verbose) cout << "\n\n*****Testing copy constructor" << endl<< endl;

  Ifpack_IlukGraph ILUC(ILU2);

  assert(check(L2, U2, ILUC, NumGlobalPoints, NumMyPoints, 2, verbose)==0);

  if (verbose) cout << "\n\n*****Testing copy constructor" << endl<< endl;

  Teuchos::RefCountPtr<Ifpack_IlukGraph> OverlapGraph;
  for (int overlap = 1; overlap < 4; overlap++) {
    if (verbose) cout << "\n\n*********************************************" << endl;
    if (verbose) cout << "\n\nConstruct Level 1 fill with Overlap = " << overlap << ".\n\n" << endl;

    OverlapGraph = Teuchos::rcp( new Ifpack_IlukGraph(A, 1, overlap) );
    assert(OverlapGraph->ConstructFilledGraph()==0);

    if (verbose) {
      cout << "Number of Global Rows     = " << OverlapGraph->NumGlobalRows() << endl;
      cout << "Number of Global Nonzeros = " << OverlapGraph->NumGlobalNonzeros() << endl;
      cout << "Number of Local Rows     = " << OverlapGraph->NumMyRows() << endl;
      cout << "Number of Local Nonzeros = " << OverlapGraph->NumMyNonzeros() << endl;
    }
  }

  if (verbose1) {
    // Test ostream << operator (if verbose1)
    // Construct a Map that puts 6 equations on each PE

    int NumElements1 = 6;
    int NumPoints1 = NumElements1;

    // Create an integer vector NumNz that is used to build the Petra Matrix.
    // NumNz[i] is the Number of terms for the ith global equation on this processor

    std::vector<int> NumNz1(NumPoints1);

    // We are building a tridiagonal matrix where each row has (-1 2 -1)
    // So we need 2 off-diagonal terms (except for the first and last equation)

    for (i=0; i<NumPoints1; i++)
      if (i==0 || i == NumPoints1-1)
        NumNz1[i] = 2;
      else
        NumNz1[i] = 3;

    // Create a Epetra_Matrix

    Epetra_Map Map1(NumPoints1, NumPoints1, 1, Comm);
    Epetra_CrsGraph A1(Copy, Map1, &NumNz1[0]);

    // Add  rows one-at-a-time
    // Need some vectors to help
    // Off diagonal Values will always be -1


    std::vector<int> Indices1(2);
    int NumEntries1;

    for (i=0; i<NumPoints1; i++)
      {
        if (i==0)
          {
            Indices1[0] = 2;
            NumEntries1 = 1;
          }
        else if (i == NumPoints1-1)
          {
            Indices1[0] = NumPoints1-1;
            NumEntries1 = 1;
          }
        else
          {
            Indices1[0] = i;
            Indices1[1] = i+2;
            NumEntries1 = 2;
          }
        assert(A1.InsertGlobalIndices(i+1, NumEntries1, &Indices1[0])==0);
        int ip1 = i+1;
        assert(A1.InsertGlobalIndices(ip1, 1, &ip1)==0); // Put in the diagonal entry
      }

    // Finish up
    assert(A1.FillComplete()==0);

    if (verbose) cout << "\n\nPrint out tridiagonal matrix with IndexBase = 1.\n\n" << endl;
    cout << A1 << endl;

    if (verbose) cout << "\n\nConstruct Level 1 fill with IndexBase = 1.\n\n" << endl;

    Ifpack_IlukGraph ILU11(A1, 1, 0);
    assert(ILU11.ConstructFilledGraph()==0);

    if (verbose) cout << "\n\nPrint out Level 1 ILU graph of tridiagonal matrix with IndexBase = 1.\n\n" << endl;
    if (verbose1) cout << ILU11 << endl;

  }

#ifdef EPETRA_MPI
  MPI_Finalize() ;
#endif


/* end main
*/
return ierr ;
}
Beispiel #2
0
int main(int argc, char *argv[]) {

#ifdef HAVE_MPI
  MPI_Init(&argc,&argv);
  Epetra_MpiComm Comm (MPI_COMM_WORLD);
#else
  Epetra_SerialComm Comm;
#endif

  int MyPID = Comm.MyPID();
  bool verbose = false; 
  if (MyPID==0) verbose = true;

  Teuchos::ParameterList GaleriList;
  int nx = 30; 

  GaleriList.set("nx", nx);
  GaleriList.set("ny", nx * Comm.NumProc());
  GaleriList.set("mx", 1);
  GaleriList.set("my", Comm.NumProc());
  Teuchos::RefCountPtr<Epetra_Map> Map = Teuchos::rcp( Galeri::CreateMap("Cartesian2D", Comm, GaleriList) );
  Teuchos::RefCountPtr<Epetra_CrsMatrix> A = Teuchos::rcp( Galeri::CreateCrsMatrix("Laplace2D", &*Map, GaleriList) );
  Teuchos::RefCountPtr<Epetra_MultiVector> LHS = Teuchos::rcp( new Epetra_MultiVector(*Map, 1) );
  Teuchos::RefCountPtr<Epetra_MultiVector> RHS = Teuchos::rcp( new Epetra_MultiVector(*Map, 1) );
  LHS->PutScalar(0.0); RHS->Random();

  // ============================ //
  // Construct ILU preconditioner //
  // ---------------------------- //

  // I wanna test funky values to be sure that they have the same
  // influence on the algorithms, both old and new
  int    LevelFill = 2;
  double DropTol = 0.3333;
  double Athresh = 0.0123;
  double Rthresh = 0.9876;
  double Relax   = 0.1;
  int    Overlap = 2;
  
  Teuchos::RefCountPtr<Ifpack_IlukGraph> Graph;
  Teuchos::RefCountPtr<Ifpack_CrsRiluk> RILU;

  Graph = Teuchos::rcp( new Ifpack_IlukGraph(A->Graph(), LevelFill, Overlap) );
  int ierr;
  ierr = Graph->ConstructFilledGraph();
  IFPACK_CHK_ERR(ierr);

  RILU = Teuchos::rcp( new Ifpack_CrsRiluk(*Graph) );
  RILU->SetAbsoluteThreshold(Athresh);
  RILU->SetRelativeThreshold(Rthresh);
  RILU->SetRelaxValue(Relax);
  int initerr = RILU->InitValues(*A);
  if (initerr!=0) cout << Comm << "*ERR* InitValues = " << initerr;

  RILU->Factor();

  // Define label for printing out during the solve phase
  string label = "Ifpack_CrsRiluk Preconditioner: LevelFill = " + toString(LevelFill) +
                                                 " Overlap = " + toString(Overlap) +
                                                 " Athresh = " + toString(Athresh) +
                                                 " Rthresh = " + toString(Rthresh);
  // Here we create an AztecOO object
  LHS->PutScalar(0.0);

  int Niters = 1200;

  AztecOO solver;
  solver.SetUserMatrix(&*A);
  solver.SetLHS(&*LHS);
  solver.SetRHS(&*RHS);
  solver.SetAztecOption(AZ_solver,AZ_gmres);
  solver.SetPrecOperator(&*RILU);
  solver.SetAztecOption(AZ_output, 16); 
  solver.Iterate(Niters, 5.0e-5);

  int OldIters = solver.NumIters();

  // now rebuild the same preconditioner using RILU, we expect the same
  // number of iterations

  Ifpack Factory;
  Teuchos::RefCountPtr<Ifpack_Preconditioner> Prec = Teuchos::rcp( Factory.Create("ILU", &*A, Overlap) );

  Teuchos::ParameterList List;
  List.get("fact: level-of-fill", LevelFill);
  List.get("fact: drop tolerance", DropTol);
  List.get("fact: absolute threshold", Athresh);
  List.get("fact: relative threshold", Rthresh);
  List.get("fact: relax value", Relax);

  IFPACK_CHK_ERR(Prec->SetParameters(List));
  IFPACK_CHK_ERR(Prec->Compute());

  // Here we create an AztecOO object
  LHS->PutScalar(0.0);

  solver.SetUserMatrix(&*A);
  solver.SetLHS(&*LHS);
  solver.SetRHS(&*RHS);
  solver.SetAztecOption(AZ_solver,AZ_gmres);
  solver.SetPrecOperator(&*Prec);
  solver.SetAztecOption(AZ_output, 16); 
  solver.Iterate(Niters, 5.0e-5);

  int NewIters = solver.NumIters();

  if (OldIters != NewIters)
    IFPACK_CHK_ERR(-1);


#ifdef HAVE_IFPACK_SUPERLU
  // Now test w/ SuperLU's ILU, if we've got it
  Teuchos::RefCountPtr<Ifpack_Preconditioner> Prec2 = Teuchos::rcp( Factory.Create("SILU", &*A,0) ); 
  Teuchos::ParameterList SList;
  SList.set("fact: drop tolerance",1e-4);
  SList.set("fact: zero pivot threshold",.1);
  SList.set("fact: maximum fill factor",10.0);
  // NOTE: There is a bug in SuperLU 4.0 which will crash the code if the maximum fill factor is set too low.
  // This bug was reported to Sherry Li on 4/8/10.
  SList.set("fact: silu drop rule",9);

  IFPACK_CHK_ERR(Prec2->SetParameters(SList));
  IFPACK_CHK_ERR(Prec2->Compute());

  LHS->PutScalar(0.0);
  solver.SetPrecOperator(&*Prec2);
  solver.Iterate(Niters, 5.0e-5);
  Prec2->Print(cout);

#endif


#ifdef HAVE_MPI
  MPI_Finalize() ;
#endif

  return(EXIT_SUCCESS);
}