Actual source code: ex11.c
2: static char help[] = "Scatters between parallel vectors. \n\
3: uses block index sets\n\n";
5: #include <petscvec.h>
7: int main(int argc, char **argv)
8: {
9: PetscInt bs = 1, n = 5, N, i, low;
10: PetscInt ix0[3] = {5, 7, 9}, iy0[3] = {1, 2, 4}, ix1[3] = {2, 3, 1}, iy1[3] = {0, 3, 9};
11: PetscMPIInt size, rank;
12: PetscScalar *array;
13: Vec x, x1, y;
14: IS isx, isy;
15: VecScatter ctx;
16: VecScatterType type;
17: PetscBool flg;
20: PetscInitialize(&argc, &argv, (char *)0, help);
21: MPI_Comm_size(PETSC_COMM_WORLD, &size);
22: MPI_Comm_rank(PETSC_COMM_WORLD, &rank);
26: PetscOptionsGetInt(NULL, NULL, "-bs", &bs, NULL);
27: n = bs * n;
29: /* Create vector x over shared memory */
30: VecCreate(PETSC_COMM_WORLD, &x);
31: VecSetSizes(x, n, PETSC_DECIDE);
32: VecSetFromOptions(x);
34: VecGetOwnershipRange(x, &low, NULL);
35: VecGetArray(x, &array);
36: for (i = 0; i < n; i++) array[i] = (PetscScalar)(i + low);
37: VecRestoreArray(x, &array);
38: /* VecView(x,PETSC_VIEWER_STDOUT_WORLD); */
40: /* Test some vector functions */
41: VecAssemblyBegin(x);
42: VecAssemblyEnd(x);
44: VecGetSize(x, &N);
45: VecGetLocalSize(x, &n);
47: VecDuplicate(x, &x1);
48: VecCopy(x, x1);
49: VecEqual(x, x1, &flg);
52: VecScale(x1, 2.0);
53: VecSet(x1, 10.0);
54: /* VecView(x1,PETSC_VIEWER_STDOUT_WORLD); */
56: /* Create vector y over shared memory */
57: VecCreate(PETSC_COMM_WORLD, &y);
58: VecSetSizes(y, n, PETSC_DECIDE);
59: VecSetFromOptions(y);
60: VecGetArray(y, &array);
61: for (i = 0; i < n; i++) array[i] = -(PetscScalar)(i + 100 * rank);
62: VecRestoreArray(y, &array);
63: VecAssemblyBegin(y);
64: VecAssemblyEnd(y);
65: /* VecView(y,PETSC_VIEWER_STDOUT_WORLD); */
67: /* Create two index sets */
68: if (rank == 0) {
69: ISCreateBlock(PETSC_COMM_SELF, bs, 3, ix0, PETSC_COPY_VALUES, &isx);
70: ISCreateBlock(PETSC_COMM_SELF, bs, 3, iy0, PETSC_COPY_VALUES, &isy);
71: } else {
72: ISCreateBlock(PETSC_COMM_SELF, bs, 3, ix1, PETSC_COPY_VALUES, &isx);
73: ISCreateBlock(PETSC_COMM_SELF, bs, 3, iy1, PETSC_COPY_VALUES, &isy);
74: }
76: if (rank == 10) {
77: PetscPrintf(PETSC_COMM_SELF, "\n[%d] isx:\n", rank);
78: ISView(isx, PETSC_VIEWER_STDOUT_SELF);
79: PetscPrintf(PETSC_COMM_SELF, "\n[%d] isy:\n", rank);
80: ISView(isy, PETSC_VIEWER_STDOUT_SELF);
81: }
83: /* Create Vector scatter */
84: VecScatterCreate(x, isx, y, isy, &ctx);
85: VecScatterSetFromOptions(ctx);
86: VecScatterGetType(ctx, &type);
87: PetscPrintf(PETSC_COMM_WORLD, "scatter type %s\n", type);
89: /* Test forward vecscatter */
90: VecSet(y, 0.0);
91: VecScatterBegin(ctx, x, y, ADD_VALUES, SCATTER_FORWARD);
92: VecScatterEnd(ctx, x, y, ADD_VALUES, SCATTER_FORWARD);
93: PetscPrintf(PETSC_COMM_WORLD, "\nSCATTER_FORWARD y:\n");
94: VecView(y, PETSC_VIEWER_STDOUT_WORLD);
96: /* Test reverse vecscatter */
97: VecSet(x, 0.0);
98: VecSet(y, 0.0);
99: VecGetOwnershipRange(y, &low, NULL);
100: VecGetArray(y, &array);
101: for (i = 0; i < n; i++) array[i] = (PetscScalar)(i + low);
102: VecRestoreArray(y, &array);
103: VecScatterBegin(ctx, y, x, ADD_VALUES, SCATTER_REVERSE);
104: VecScatterEnd(ctx, y, x, ADD_VALUES, SCATTER_REVERSE);
105: PetscPrintf(PETSC_COMM_WORLD, "\nSCATTER_REVERSE x:\n");
106: VecView(x, PETSC_VIEWER_STDOUT_WORLD);
108: /* Free objects */
109: VecScatterDestroy(&ctx);
110: ISDestroy(&isx);
111: ISDestroy(&isy);
112: VecDestroy(&x);
113: VecDestroy(&x1);
114: VecDestroy(&y);
115: PetscFinalize();
116: return 0;
117: }
119: /*TEST
121: test:
122: nsize: 2
124: TEST*/