Actual source code: ex10.c


  2: static char help[] = "Tests ISFilter().\n\n";

  4: #include <petscis.h>
  5: #include <petscviewer.h>

  7: static PetscErrorCode CreateIS(MPI_Comm comm, PetscInt n, PetscInt first, PetscInt step, IS *is)
  8: {
  9:   PetscInt   *idx, i, j;
 10:   PetscMPIInt rank;

 12:   PetscFunctionBegin;
 13:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
 14:   *is = NULL;
 15:   first += rank;
 16:   PetscCall(PetscMalloc1(n, &idx));
 17:   for (i = 0, j = first; i < n; i++, j += step) idx[i] = j;
 18:   PetscCall(ISCreateGeneral(comm, n, idx, PETSC_OWN_POINTER, is));
 19:   PetscFunctionReturn(PETSC_SUCCESS);
 20: }

 22: int main(int argc, char **argv)
 23: {
 24:   IS          is;
 25:   PetscInt    n = 10, N, first = 0, step = 0, start, end;
 26:   PetscMPIInt rank;
 27:   MPI_Comm    comm;

 29:   PetscFunctionBeginUser;
 30:   PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
 31:   comm = PETSC_COMM_WORLD;
 32:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
 33:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));
 34:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-first", &first, NULL));
 35:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-step", &step, NULL));
 36:   start = 0;
 37:   end   = n;
 38:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-start", &start, NULL));
 39:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-end", &end, NULL));

 41:   PetscCall(CreateIS(comm, n, first, step, &is));
 42:   PetscCall(ISGeneralFilter(is, start, end));
 43:   PetscCall(ISView(is, PETSC_VIEWER_STDOUT_(comm)));
 44:   PetscCall(ISGetSize(is, &N));
 45:   PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_(comm), "global size: %" PetscInt_FMT "\n", N));

 47:   PetscCall(ISDestroy(&is));
 48:   PetscCall(PetscFinalize());
 49:   return 0;
 50: }

 52: /*TEST

 54:     test:
 55:       suffix: 1
 56:       nsize: 4
 57:       args: -n 6
 58:       args: -first -2
 59:       args: -step 1
 60:       args: -start {{-2 4}separate output} -end {{2 6}separate output}

 62: TEST*/