Actual source code: ex3.c
1: static char help[] = "Tests parallel vector assembly. Input arguments are\n\
2: -n <length> : local vector length\n\n";
4: #include <petscvec.h>
6: int main(int argc, char **argv)
7: {
8: PetscMPIInt size, rank;
9: PetscInt n = 5, idx;
10: PetscScalar one = 1.0, two = 2.0, three = 3.0;
11: Vec x, y;
13: PetscFunctionBeginUser;
14: PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
15: PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));
16: if (n < 5) n = 5;
17: PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
18: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
20: PetscCheck(size >= 2, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, "Must be run with at least two processors");
22: /* create two vector */
23: PetscCall(VecCreateSeq(PETSC_COMM_SELF, n, &x));
24: PetscCall(VecCreate(PETSC_COMM_WORLD, &y));
25: PetscCall(VecSetSizes(y, n, PETSC_DECIDE));
26: PetscCall(VecSetFromOptions(y));
27: PetscCall(VecSet(x, one));
28: PetscCall(VecSet(y, two));
30: if (rank == 1) {
31: idx = 2;
32: PetscCall(VecSetValues(y, 1, &idx, &three, INSERT_VALUES));
33: idx = 0;
34: PetscCall(VecSetValues(y, 1, &idx, &two, INSERT_VALUES));
35: idx = 0;
36: PetscCall(VecSetValues(y, 1, &idx, &one, INSERT_VALUES));
37: } else {
38: idx = 7;
39: PetscCall(VecSetValues(y, 1, &idx, &three, INSERT_VALUES));
40: }
41: PetscCall(VecAssemblyBegin(y));
42: PetscCall(VecAssemblyEnd(y));
44: PetscCall(VecView(y, PETSC_VIEWER_STDOUT_WORLD));
46: PetscCall(VecDestroy(&x));
47: PetscCall(VecDestroy(&y));
49: PetscCall(PetscFinalize());
50: return 0;
51: }
53: /*TEST
55: test:
56: nsize: 2
58: test:
59: suffix: 2
60: nsize: 2
61: args: -vec_view ascii::ascii_info
63: TEST*/