xref: /petsc/src/vec/is/ao/tests/ex2.c (revision df4cd43f92eaa320656440c40edb1046daee8f75)
1 
2 static char help[] = "Tests application ordering.\n\n";
3 
4 #include <petscsys.h>
5 #include <petscao.h>
6 #include <petscviewer.h>
7 
8 int main(int argc, char **argv)
9 {
10   PetscMPIInt rank, size;
11   PetscInt    n, *ispetsc, *isapp, start, N, i;
12   AO          ao;
13 
14   PetscFunctionBeginUser;
15   PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
16   PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));
17   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
18   n = rank + 2;
19   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
20 
21   /* create the orderings */
22   PetscCall(PetscMalloc2(n, &ispetsc, n, &isapp));
23 
24   PetscCallMPI(MPI_Scan(&n, &start, 1, MPIU_INT, MPI_SUM, PETSC_COMM_WORLD));
25   PetscCallMPI(MPI_Allreduce(&n, &N, 1, MPIU_INT, MPI_SUM, PETSC_COMM_WORLD));
26   start -= n;
27 
28   for (i = 0; i < n; i++) {
29     ispetsc[i] = start + i;
30     isapp[i]   = N - start - i - 1;
31   }
32 
33   /* create the application ordering */
34   PetscCall(AOCreateBasic(PETSC_COMM_WORLD, n, isapp, ispetsc, &ao));
35   PetscCall(AOView(ao, PETSC_VIEWER_STDOUT_WORLD));
36 
37   /* check the mapping */
38   PetscCall(AOPetscToApplication(ao, n, ispetsc));
39   for (i = 0; i < n; i++) {
40     if (ispetsc[i] != isapp[i]) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "[%d] Problem with mapping %" PetscInt_FMT " to %" PetscInt_FMT "\n", rank, i, ispetsc[i]));
41   }
42   PetscCall(PetscFree2(ispetsc, isapp));
43 
44   PetscCall(AODestroy(&ao));
45   PetscCall(PetscFinalize());
46   return 0;
47 }
48 
49 /*TEST
50 
51    test:
52 
53    test:
54       suffix: 2
55       nsize: 2
56 
57    test:
58       suffix: 3
59       nsize: 3
60 
61 TEST*/
62