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 ;
}
