1 static char help[] = "Demonstrates the DMLocalToLocal bug in PETSc 3.6.\n\n";
2
3 /*
4 Use the options
5 -da_grid_x <nx> - number of grid points in x direction, if M < 0
6 -da_grid_y <ny> - number of grid points in y direction, if N < 0
7 -da_processors_x <MX> number of processors in x directio
8 -da_processors_y <MY> number of processors in x direction
9
10 Contributed by Constantine Khroulev
11 */
12
13 #include <petscdm.h>
14 #include <petscdmda.h>
15
PrintVecWithGhosts(DM da,Vec v)16 PetscErrorCode PrintVecWithGhosts(DM da, Vec v)
17 {
18 PetscScalar **p;
19 PetscInt i, j;
20 MPI_Comm com;
21 PetscMPIInt rank;
22 DMDALocalInfo info;
23
24 com = PetscObjectComm((PetscObject)da);
25 PetscCallMPI(MPI_Comm_rank(com, &rank));
26 PetscCall(DMDAGetLocalInfo(da, &info));
27 PetscCall(PetscSynchronizedPrintf(com, "begin rank %d portion (with ghosts, %" PetscInt_FMT " x %" PetscInt_FMT ")\n", rank, info.gxm, info.gym));
28 PetscCall(DMDAVecGetArray(da, v, &p));
29 for (i = info.gxs; i < info.gxs + info.gxm; i++) {
30 for (j = info.gys; j < info.gys + info.gym; j++) PetscCall(PetscSynchronizedPrintf(com, "%g, ", (double)PetscRealPart(p[j][i])));
31 PetscCall(PetscSynchronizedPrintf(com, "\n"));
32 }
33 PetscCall(DMDAVecRestoreArray(da, v, &p));
34 PetscCall(PetscSynchronizedPrintf(com, "end rank %d portion\n", rank));
35 PetscCall(PetscSynchronizedFlush(com, PETSC_STDOUT));
36 return PETSC_SUCCESS;
37 }
38
39 /* Set a Vec v to value, but do not touch ghosts. */
VecSetOwned(DM da,Vec v,PetscScalar value)40 PetscErrorCode VecSetOwned(DM da, Vec v, PetscScalar value)
41 {
42 PetscScalar **p;
43 PetscInt i, j, xs, xm, ys, ym;
44
45 PetscCall(DMDAGetCorners(da, &xs, &ys, 0, &xm, &ym, 0));
46 PetscCall(DMDAVecGetArray(da, v, &p));
47 for (i = xs; i < xs + xm; i++) {
48 for (j = ys; j < ys + ym; j++) p[j][i] = value;
49 }
50 PetscCall(DMDAVecRestoreArray(da, v, &p));
51 return PETSC_SUCCESS;
52 }
53
main(int argc,char ** argv)54 int main(int argc, char **argv)
55 {
56 PetscInt M = 4, N = 3;
57 DM da;
58 Vec local;
59 PetscScalar value = 0.0;
60 DMBoundaryType bx = DM_BOUNDARY_PERIODIC, by = DM_BOUNDARY_PERIODIC;
61 DMDAStencilType stype = DMDA_STENCIL_BOX;
62
63 PetscFunctionBeginUser;
64 PetscCall(PetscInitialize(&argc, &argv, NULL, help));
65 PetscCall(DMDACreate2d(PETSC_COMM_WORLD, bx, by, stype, M, N, PETSC_DECIDE, PETSC_DECIDE, 1, 1, NULL, NULL, &da));
66 PetscCall(DMSetFromOptions(da));
67 PetscCall(DMSetUp(da));
68 PetscCall(DMCreateLocalVector(da, &local));
69
70 PetscCall(VecSet(local, value));
71 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "\nAfter setting all values to %d:\n", (int)PetscRealPart(value)));
72 PetscCall(PrintVecWithGhosts(da, local));
73 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "done\n"));
74
75 value += 1.0;
76 /* set values owned by a process, leaving ghosts alone */
77 PetscCall(VecSetOwned(da, local, value));
78
79 /* print after re-setting interior values again */
80 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "\nAfter setting interior values to %d:\n", (int)PetscRealPart(value)));
81 PetscCall(PrintVecWithGhosts(da, local));
82 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "done\n"));
83
84 /* communicate ghosts */
85 PetscCall(DMLocalToLocalBegin(da, local, INSERT_VALUES, local));
86 PetscCall(DMLocalToLocalEnd(da, local, INSERT_VALUES, local));
87
88 /* print again */
89 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "\nAfter local-to-local communication:\n"));
90 PetscCall(PrintVecWithGhosts(da, local));
91 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "done\n"));
92
93 /* Free memory */
94 PetscCall(VecDestroy(&local));
95 PetscCall(DMDestroy(&da));
96 PetscCall(PetscFinalize());
97 return 0;
98 }
99
100 /*TEST
101
102 test:
103 nsize: 2
104
105 TEST*/
106