Actual source code: ex11.c
1: static char help[] = "Scatters between parallel vectors. \n\
2: uses block index sets\n\n";
4: #include <petscvec.h>
6: int main(int argc, char **argv)
7: {
8: PetscInt bs = 1, n = 5, N, i, low;
9: PetscInt ix0[3] = {5, 7, 9}, iy0[3] = {1, 2, 4}, ix1[3] = {2, 3, 1}, iy1[3] = {0, 3, 9};
10: PetscMPIInt size, rank;
11: PetscScalar *array;
12: Vec x, x1, y;
13: IS isx, isy;
14: VecScatter ctx;
15: VecScatterType type;
16: PetscBool flg;
18: PetscFunctionBeginUser;
19: PetscCall(PetscInitialize(&argc, &argv, NULL, help));
20: PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
21: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
23: PetscCheck(size >= 2, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, "Must run more than one processor");
25: PetscCall(PetscOptionsGetInt(NULL, NULL, "-bs", &bs, NULL));
26: n = bs * n;
28: /* Create vector x over shared memory */
29: PetscCall(VecCreate(PETSC_COMM_WORLD, &x));
30: PetscCall(VecSetSizes(x, n, PETSC_DECIDE));
31: PetscCall(VecSetFromOptions(x));
33: PetscCall(VecGetOwnershipRange(x, &low, NULL));
34: PetscCall(VecGetArray(x, &array));
35: for (i = 0; i < n; i++) array[i] = (PetscScalar)(i + low);
36: PetscCall(VecRestoreArray(x, &array));
37: /* PetscCall(VecView(x,PETSC_VIEWER_STDOUT_WORLD)); */
39: /* Test some vector functions */
40: PetscCall(VecAssemblyBegin(x));
41: PetscCall(VecAssemblyEnd(x));
43: PetscCall(VecGetSize(x, &N));
44: PetscCall(VecGetLocalSize(x, &n));
46: PetscCall(VecDuplicate(x, &x1));
47: PetscCall(VecCopy(x, x1));
48: PetscCall(VecEqual(x, x1, &flg));
49: PetscCheck(flg, PetscObjectComm((PetscObject)x), PETSC_ERR_ARG_WRONG, "x1 != x");
51: PetscCall(VecScale(x1, 2.0));
52: PetscCall(VecSet(x1, 10.0));
53: /* PetscCall(VecView(x1,PETSC_VIEWER_STDOUT_WORLD)); */
55: /* Create vector y over shared memory */
56: PetscCall(VecCreate(PETSC_COMM_WORLD, &y));
57: PetscCall(VecSetSizes(y, n, PETSC_DECIDE));
58: PetscCall(VecSetFromOptions(y));
59: PetscCall(VecGetArray(y, &array));
60: for (i = 0; i < n; i++) array[i] = -(PetscScalar)(i + 100 * rank);
61: PetscCall(VecRestoreArray(y, &array));
62: PetscCall(VecAssemblyBegin(y));
63: PetscCall(VecAssemblyEnd(y));
64: /* PetscCall(VecView(y,PETSC_VIEWER_STDOUT_WORLD)); */
66: /* Create two index sets */
67: if (rank == 0) {
68: PetscCall(ISCreateBlock(PETSC_COMM_SELF, bs, 3, ix0, PETSC_COPY_VALUES, &isx));
69: PetscCall(ISCreateBlock(PETSC_COMM_SELF, bs, 3, iy0, PETSC_COPY_VALUES, &isy));
70: } else {
71: PetscCall(ISCreateBlock(PETSC_COMM_SELF, bs, 3, ix1, PETSC_COPY_VALUES, &isx));
72: PetscCall(ISCreateBlock(PETSC_COMM_SELF, bs, 3, iy1, PETSC_COPY_VALUES, &isy));
73: }
75: if (rank == 10) {
76: PetscCall(PetscPrintf(PETSC_COMM_SELF, "\n[%d] isx:\n", rank));
77: PetscCall(ISView(isx, PETSC_VIEWER_STDOUT_SELF));
78: PetscCall(PetscPrintf(PETSC_COMM_SELF, "\n[%d] isy:\n", rank));
79: PetscCall(ISView(isy, PETSC_VIEWER_STDOUT_SELF));
80: }
82: /* Create Vector scatter */
83: PetscCall(VecScatterCreate(x, isx, y, isy, &ctx));
84: PetscCall(VecScatterSetFromOptions(ctx));
85: PetscCall(VecScatterGetType(ctx, &type));
86: PetscCall(PetscPrintf(PETSC_COMM_WORLD, "scatter type %s\n", type));
88: /* Test forward vecscatter */
89: PetscCall(VecSet(y, 0.0));
90: PetscCall(VecScatterBegin(ctx, x, y, ADD_VALUES, SCATTER_FORWARD));
91: PetscCall(VecScatterEnd(ctx, x, y, ADD_VALUES, SCATTER_FORWARD));
92: PetscCall(PetscPrintf(PETSC_COMM_WORLD, "\nSCATTER_FORWARD y:\n"));
93: PetscCall(VecView(y, PETSC_VIEWER_STDOUT_WORLD));
95: /* Test reverse vecscatter */
96: PetscCall(VecSet(x, 0.0));
97: PetscCall(VecSet(y, 0.0));
98: PetscCall(VecGetOwnershipRange(y, &low, NULL));
99: PetscCall(VecGetArray(y, &array));
100: for (i = 0; i < n; i++) array[i] = (PetscScalar)(i + low);
101: PetscCall(VecRestoreArray(y, &array));
102: PetscCall(VecScatterBegin(ctx, y, x, ADD_VALUES, SCATTER_REVERSE));
103: PetscCall(VecScatterEnd(ctx, y, x, ADD_VALUES, SCATTER_REVERSE));
104: PetscCall(PetscPrintf(PETSC_COMM_WORLD, "\nSCATTER_REVERSE x:\n"));
105: PetscCall(VecView(x, PETSC_VIEWER_STDOUT_WORLD));
107: /* Free objects */
108: PetscCall(VecScatterDestroy(&ctx));
109: PetscCall(ISDestroy(&isx));
110: PetscCall(ISDestroy(&isy));
111: PetscCall(VecDestroy(&x));
112: PetscCall(VecDestroy(&x1));
113: PetscCall(VecDestroy(&y));
114: PetscCall(PetscFinalize());
115: return 0;
116: }
118: /*TEST
120: test:
121: nsize: 2
123: TEST*/