// ====================================================================== 
bool BasicTest(string PrecType, const Teuchos::RefCountPtr<Epetra_RowMatrix>& A,bool backward, bool reorder=false)
{
  Epetra_MultiVector LHS(A->RowMatrixRowMap(), NumVectors);
  Epetra_MultiVector RHS(A->RowMatrixRowMap(), NumVectors);
  LHS.PutScalar(0.0); RHS.Random();

  double starting_residual = Galeri::ComputeNorm(&*A, &LHS, &RHS);
  Epetra_LinearProblem Problem(&*A, &LHS, &RHS);

  // Set up the list
  Teuchos::ParameterList List;
  List.set("relaxation: damping factor", 1.0);
  List.set("relaxation: sweeps",2550);
  List.set("relaxation: type", PrecType);
  if(backward) List.set("relaxation: backward mode",backward);

  // Reordering if needed
  int NumRows=A->NumMyRows();
  std::vector<int> RowList(NumRows);
  if(reorder) {
    for(int i=0; i<NumRows; i++)
      RowList[i]=i;
    List.set("relaxation: number of local smoothing indices",NumRows);
    List.set("relaxation: local smoothing indices",RowList.size()>0? &RowList[0] : (int*)0);
  }

  Ifpack_PointRelaxation Point(&*A);

  Point.SetParameters(List);
  Point.Compute();
  // use the preconditioner as solver, with 1550 iterations
  Point.ApplyInverse(RHS,LHS);

  // compute the real residual

  double residual = Galeri::ComputeNorm(&*A, &LHS, &RHS);
  
  if (A->Comm().MyPID() == 0 && verbose)
    cout << "||A * x - b||_2 (scaled) = " << residual / starting_residual << endl;
  
  // Jacobi is very slow to converge here
  if (residual / starting_residual < 1e-2) {
    if (verbose)
      cout << "BasicTest Test passed" << endl;
    return(true);
  }
  else {
    if (verbose)
      cout << "BasicTest Test failed!" << endl;
    return(false);
  }
}
Esempio n. 2
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void W32Table::setElement(W32WidgetPtr element, int row, int fromColumn, int toColumn) {
	if (!element.isNull()) {
		if (row >= (int)myRows.size()) {
			myRows.insert(myRows.end(), row - myRows.size() + 1, RowList());
		}
		RowList &rowList = myRows[row];

		RowList::iterator it = rowList.begin();
		bool canInsertAfter = true;
		for (; it != rowList.end(); ++it) {
			if (it->XFrom > toColumn) {
				break;
			}
			canInsertAfter = it->XTo < fromColumn;
		}
		if (canInsertAfter) {
			rowList.insert(it, CellInfo(fromColumn, toColumn, element));
		}
	}
}
// ====================================================================== 
bool KrylovTest(string PrecType, const Teuchos::RefCountPtr<Epetra_RowMatrix>& A, bool backward, bool reorder=false)
{
  Epetra_MultiVector LHS(A->RowMatrixRowMap(), NumVectors);
  Epetra_MultiVector RHS(A->RowMatrixRowMap(), NumVectors);
  LHS.PutScalar(0.0); RHS.Random();

  Epetra_LinearProblem Problem(&*A, &LHS, &RHS);

  // Set up the list
  Teuchos::ParameterList List;
  List.set("relaxation: damping factor", 1.0);
  List.set("relaxation: type", PrecType);
  if(backward) List.set("relaxation: backward mode",backward);  

  // Reordering if needed
  int NumRows=A->NumMyRows();
  std::vector<int> RowList(NumRows);
  if(reorder) {
    for(int i=0; i<NumRows; i++)
      RowList[i]=i;
    List.set("relaxation: number of local smoothing indices",NumRows);
    List.set("relaxation: local smoothing indices",RowList.size()>0? &RowList[0] : (int*)0);
  }


  int Iters1, Iters10;

  if (verbose) {
    cout << "Krylov test: Using " << PrecType 
         << " with AztecOO" << endl;
  }

  // ============================================== //
  // get the number of iterations with 1 sweep only //
  // ============================================== //
  {

    List.set("relaxation: sweeps",1);
    Ifpack_PointRelaxation Point(&*A);
    Point.SetParameters(List);
    Point.Compute();

    // set AztecOO solver object
    AztecOO AztecOOSolver(Problem);
    AztecOOSolver.SetAztecOption(AZ_solver,Solver);
    AztecOOSolver.SetAztecOption(AZ_output,AZ_none);
    AztecOOSolver.SetPrecOperator(&Point);

    AztecOOSolver.Iterate(2550,1e-5);

    double TrueResidual = AztecOOSolver.TrueResidual();
    // some output
    if (verbose && Problem.GetMatrix()->Comm().MyPID() == 0) {
      cout << "Norm of the true residual = " << TrueResidual << endl;
    }
    Iters1 = AztecOOSolver.NumIters();
  }
 
  // ======================================================== //
  // now re-run with 10 sweeps, solver should converge faster
  // ======================================================== //
  {
    List.set("relaxation: sweeps",10);
    Ifpack_PointRelaxation Point(&*A);
    Point.SetParameters(List);
    Point.Compute();
    LHS.PutScalar(0.0);

    // set AztecOO solver object
    AztecOO AztecOOSolver(Problem);
    AztecOOSolver.SetAztecOption(AZ_solver,Solver);
    AztecOOSolver.SetAztecOption(AZ_output,AZ_none);
    AztecOOSolver.SetPrecOperator(&Point);
    AztecOOSolver.Iterate(2550,1e-5);

    double TrueResidual = AztecOOSolver.TrueResidual();
    // some output
    if (verbose && Problem.GetMatrix()->Comm().MyPID() == 0) {
      cout << "Norm of the true residual = " << TrueResidual << endl;
    }
    Iters10 = AztecOOSolver.NumIters();
  }

  if (verbose) {
    cout << "Iters_1 = " << Iters1 << ", Iters_10 = " << Iters10 << endl;
    cout << "(second number should be smaller than first one)" << endl;
  }

  if (Iters10 > Iters1) {
    if (verbose)
      cout << "KrylovTest TEST FAILED!" << endl;
    return(false);
  }
  else {
    if (verbose)
      cout << "KrylovTest TEST PASSED" << endl;
    return(true);
  }
}