1 static char help[] = "Scatters between parallel vectors. \n\
2 uses block index sets\n\n";
3
4 #include <petscvec.h>
5
main(int argc,char ** argv)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;
17
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));
22
23 PetscCheck(size >= 2, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, "Must run more than one processor");
24
25 PetscCall(PetscOptionsGetInt(NULL, NULL, "-bs", &bs, NULL));
26 n = bs * n;
27
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));
32
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)); */
38
39 /* Test some vector functions */
40 PetscCall(VecAssemblyBegin(x));
41 PetscCall(VecAssemblyEnd(x));
42
43 PetscCall(VecGetSize(x, &N));
44 PetscCall(VecGetLocalSize(x, &n));
45
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");
50
51 PetscCall(VecScale(x1, 2.0));
52 PetscCall(VecSet(x1, 10.0));
53 /* PetscCall(VecView(x1,PETSC_VIEWER_STDOUT_WORLD)); */
54
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)); */
65
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 }
74
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 }
81
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));
87
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));
94
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));
106
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 }
117
118 /*TEST
119
120 test:
121 nsize: 2
122
123 TEST*/
124