Actual source code: ex4.c
2: static char help[] = "Demonstrates using ISLocalToGlobalMappings.\n\n";
4: #include <petscis.h>
5: #include <petscviewer.h>
7: int main(int argc, char **argv)
8: {
9: PetscInt i, n = 4, indices[] = {0, 3, 9, 12}, m = 2, input[] = {0, 2};
10: PetscInt output[2], inglobals[13], outlocals[13];
11: ISLocalToGlobalMapping mapping;
14: PetscInitialize(&argc, &argv, (char *)0, help);
16: /*
17: Create a local to global mapping. Each processor independently
18: creates a mapping
19: */
20: ISLocalToGlobalMappingCreate(PETSC_COMM_WORLD, 1, n, indices, PETSC_COPY_VALUES, &mapping);
21: ISLocalToGlobalMappingSetFromOptions(mapping);
23: /*
24: Map a set of local indices to their global values
25: */
26: ISLocalToGlobalMappingApply(mapping, m, input, output);
27: PetscIntView(m, output, PETSC_VIEWER_STDOUT_WORLD);
29: /*
30: Map some global indices to local, retaining the ones without a local index by -1
31: */
32: for (i = 0; i < 13; i++) inglobals[i] = i;
33: ISGlobalToLocalMappingApply(mapping, IS_GTOLM_MASK, 13, inglobals, NULL, outlocals);
34: PetscIntView(13, outlocals, PETSC_VIEWER_STDOUT_WORLD);
36: /*
37: Map some global indices to local, dropping the ones without a local index.
38: */
39: ISGlobalToLocalMappingApply(mapping, IS_GTOLM_DROP, 13, inglobals, &m, outlocals);
40: PetscIntView(m, outlocals, PETSC_VIEWER_STDOUT_WORLD);
42: ISLocalToGlobalMappingView(mapping, PETSC_VIEWER_STDOUT_WORLD);
43: /*
44: Free the space used by the local to global mapping
45: */
46: ISLocalToGlobalMappingDestroy(&mapping);
48: PetscFinalize();
49: return 0;
50: }
52: /*TEST
54: test:
56: test:
57: suffix: 2
58: args: -islocaltoglobalmapping_type hash
60: TEST*/