xref: /petsc/src/dm/tests/ex43.c (revision 48a46eb9bd028bec07ec0f396b1a3abb43f14558)
1c4762a1bSJed Brown static char help[] = "Demonstrates the DMLocalToLocal bug in PETSc 3.6.\n\n";
2c4762a1bSJed Brown 
3c4762a1bSJed Brown /*
4c4762a1bSJed Brown Use the options
5c4762a1bSJed Brown      -da_grid_x <nx> - number of grid points in x direction, if M < 0
6c4762a1bSJed Brown      -da_grid_y <ny> - number of grid points in y direction, if N < 0
7c4762a1bSJed Brown      -da_processors_x <MX> number of processors in x directio
8c4762a1bSJed Brown      -da_processors_y <MY> number of processors in x direction
9c4762a1bSJed Brown 
10c4762a1bSJed Brown   Contributed by Constantine Khroulev
11c4762a1bSJed Brown */
12c4762a1bSJed Brown 
13c4762a1bSJed Brown #include <petscdm.h>
14c4762a1bSJed Brown #include <petscdmda.h>
15c4762a1bSJed Brown 
169371c9d4SSatish Balay PetscErrorCode PrintVecWithGhosts(DM da, Vec v) {
17c4762a1bSJed Brown   PetscScalar **p;
18c4762a1bSJed Brown   PetscInt      i, j;
19c4762a1bSJed Brown   MPI_Comm      com;
20c4762a1bSJed Brown   PetscMPIInt   rank;
21c4762a1bSJed Brown   DMDALocalInfo info;
22c4762a1bSJed Brown 
23c4762a1bSJed Brown   com = PetscObjectComm((PetscObject)da);
249566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_rank(com, &rank));
259566063dSJacob Faibussowitsch   PetscCall(DMDAGetLocalInfo(da, &info));
2663a3b9bcSJacob Faibussowitsch   PetscCall(PetscSynchronizedPrintf(com, "begin rank %d portion (with ghosts, %" PetscInt_FMT " x %" PetscInt_FMT ")\n", rank, info.gxm, info.gym));
279566063dSJacob Faibussowitsch   PetscCall(DMDAVecGetArray(da, v, &p));
28c4762a1bSJed Brown   for (i = info.gxs; i < info.gxs + info.gxm; i++) {
29*48a46eb9SPierre Jolivet     for (j = info.gys; j < info.gys + info.gym; j++) PetscCall(PetscSynchronizedPrintf(com, "%g, ", (double)PetscRealPart(p[j][i])));
309566063dSJacob Faibussowitsch     PetscCall(PetscSynchronizedPrintf(com, "\n"));
31c4762a1bSJed Brown   }
329566063dSJacob Faibussowitsch   PetscCall(DMDAVecRestoreArray(da, v, &p));
339566063dSJacob Faibussowitsch   PetscCall(PetscSynchronizedPrintf(com, "end rank %d portion\n", rank));
349566063dSJacob Faibussowitsch   PetscCall(PetscSynchronizedFlush(com, PETSC_STDOUT));
35c4762a1bSJed Brown   return 0;
36c4762a1bSJed Brown }
37c4762a1bSJed Brown 
38c4762a1bSJed Brown /* Set a Vec v to value, but do not touch ghosts. */
399371c9d4SSatish Balay PetscErrorCode VecSetOwned(DM da, Vec v, PetscScalar value) {
40c4762a1bSJed Brown   PetscScalar **p;
41c4762a1bSJed Brown   PetscInt      i, j, xs, xm, ys, ym;
42c4762a1bSJed Brown 
439566063dSJacob Faibussowitsch   PetscCall(DMDAGetCorners(da, &xs, &ys, 0, &xm, &ym, 0));
449566063dSJacob Faibussowitsch   PetscCall(DMDAVecGetArray(da, v, &p));
45c4762a1bSJed Brown   for (i = xs; i < xs + xm; i++) {
469371c9d4SSatish Balay     for (j = ys; j < ys + ym; j++) { p[j][i] = value; }
47c4762a1bSJed Brown   }
489566063dSJacob Faibussowitsch   PetscCall(DMDAVecRestoreArray(da, v, &p));
49c4762a1bSJed Brown   return 0;
50c4762a1bSJed Brown }
51c4762a1bSJed Brown 
529371c9d4SSatish Balay int main(int argc, char **argv) {
53c4762a1bSJed Brown   PetscInt        M = 4, N = 3;
54c4762a1bSJed Brown   DM              da;
55c4762a1bSJed Brown   Vec             local;
56c4762a1bSJed Brown   PetscScalar     value = 0.0;
57c4762a1bSJed Brown   DMBoundaryType  bx = DM_BOUNDARY_PERIODIC, by = DM_BOUNDARY_PERIODIC;
58c4762a1bSJed Brown   DMDAStencilType stype = DMDA_STENCIL_BOX;
59c4762a1bSJed Brown 
60327415f7SBarry Smith   PetscFunctionBeginUser;
619566063dSJacob Faibussowitsch   PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
629566063dSJacob Faibussowitsch   PetscCall(DMDACreate2d(PETSC_COMM_WORLD, bx, by, stype, M, N, PETSC_DECIDE, PETSC_DECIDE, 1, 1, NULL, NULL, &da));
639566063dSJacob Faibussowitsch   PetscCall(DMSetFromOptions(da));
649566063dSJacob Faibussowitsch   PetscCall(DMSetUp(da));
659566063dSJacob Faibussowitsch   PetscCall(DMCreateLocalVector(da, &local));
66c4762a1bSJed Brown 
679566063dSJacob Faibussowitsch   PetscCall(VecSet(local, value));
689566063dSJacob Faibussowitsch   PetscCall(PetscPrintf(PETSC_COMM_WORLD, "\nAfter setting all values to %d:\n", (int)PetscRealPart(value)));
699566063dSJacob Faibussowitsch   PetscCall(PrintVecWithGhosts(da, local));
709566063dSJacob Faibussowitsch   PetscCall(PetscPrintf(PETSC_COMM_WORLD, "done\n"));
71c4762a1bSJed Brown 
72c4762a1bSJed Brown   value += 1.0;
73c4762a1bSJed Brown   /* set values owned by a process, leaving ghosts alone */
749566063dSJacob Faibussowitsch   PetscCall(VecSetOwned(da, local, value));
75c4762a1bSJed Brown 
76c4762a1bSJed Brown   /* print after re-setting interior values again */
779566063dSJacob Faibussowitsch   PetscCall(PetscPrintf(PETSC_COMM_WORLD, "\nAfter setting interior values to %d:\n", (int)PetscRealPart(value)));
789566063dSJacob Faibussowitsch   PetscCall(PrintVecWithGhosts(da, local));
799566063dSJacob Faibussowitsch   PetscCall(PetscPrintf(PETSC_COMM_WORLD, "done\n"));
80c4762a1bSJed Brown 
81c4762a1bSJed Brown   /* communicate ghosts */
829566063dSJacob Faibussowitsch   PetscCall(DMLocalToLocalBegin(da, local, INSERT_VALUES, local));
839566063dSJacob Faibussowitsch   PetscCall(DMLocalToLocalEnd(da, local, INSERT_VALUES, local));
84c4762a1bSJed Brown 
85c4762a1bSJed Brown   /* print again */
869566063dSJacob Faibussowitsch   PetscCall(PetscPrintf(PETSC_COMM_WORLD, "\nAfter local-to-local communication:\n"));
879566063dSJacob Faibussowitsch   PetscCall(PrintVecWithGhosts(da, local));
889566063dSJacob Faibussowitsch   PetscCall(PetscPrintf(PETSC_COMM_WORLD, "done\n"));
89c4762a1bSJed Brown 
90c4762a1bSJed Brown   /* Free memory */
919566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&local));
929566063dSJacob Faibussowitsch   PetscCall(DMDestroy(&da));
939566063dSJacob Faibussowitsch   PetscCall(PetscFinalize());
94b122ec5aSJacob Faibussowitsch   return 0;
95c4762a1bSJed Brown }
96c4762a1bSJed Brown 
97c4762a1bSJed Brown /*TEST
98c4762a1bSJed Brown 
99c4762a1bSJed Brown    test:
100c4762a1bSJed Brown       nsize: 2
101c4762a1bSJed Brown 
102c4762a1bSJed Brown TEST*/
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