xref: /petsc/src/dm/tests/ex43.c (revision c4762a1b19cd2af06abeed90e8f9d34fb975dd94)
1*c4762a1bSJed Brown static char help[] = "Demonstrates the DMLocalToLocal bug in PETSc 3.6.\n\n";
2*c4762a1bSJed Brown 
3*c4762a1bSJed Brown /*
4*c4762a1bSJed Brown Use the options
5*c4762a1bSJed Brown      -da_grid_x <nx> - number of grid points in x direction, if M < 0
6*c4762a1bSJed Brown      -da_grid_y <ny> - number of grid points in y direction, if N < 0
7*c4762a1bSJed Brown      -da_processors_x <MX> number of processors in x directio
8*c4762a1bSJed Brown      -da_processors_y <MY> number of processors in x direction
9*c4762a1bSJed Brown 
10*c4762a1bSJed Brown   Contributed by Constantine Khroulev
11*c4762a1bSJed Brown */
12*c4762a1bSJed Brown 
13*c4762a1bSJed Brown #include <petscdm.h>
14*c4762a1bSJed Brown #include <petscdmda.h>
15*c4762a1bSJed Brown 
16*c4762a1bSJed Brown PetscErrorCode PrintVecWithGhosts(DM da, Vec v)
17*c4762a1bSJed Brown {
18*c4762a1bSJed Brown   PetscScalar    **p;
19*c4762a1bSJed Brown   PetscInt       i, j;
20*c4762a1bSJed Brown   PetscErrorCode ierr;
21*c4762a1bSJed Brown   MPI_Comm       com;
22*c4762a1bSJed Brown   PetscMPIInt    rank;
23*c4762a1bSJed Brown   DMDALocalInfo  info;
24*c4762a1bSJed Brown 
25*c4762a1bSJed Brown   com = PetscObjectComm((PetscObject)da);
26*c4762a1bSJed Brown   ierr = MPI_Comm_rank(com, &rank);CHKERRQ(ierr);
27*c4762a1bSJed Brown   ierr = DMDAGetLocalInfo(da, &info);CHKERRQ(ierr);
28*c4762a1bSJed Brown   ierr = PetscSynchronizedPrintf(com, "begin rank %d portion (with ghosts, %D x %D)\n",rank, info.gxm, info.gym);CHKERRQ(ierr);
29*c4762a1bSJed Brown   ierr = DMDAVecGetArray(da, v, &p);CHKERRQ(ierr);
30*c4762a1bSJed Brown   for (i = info.gxs; i < info.gxs + info.gxm; i++) {
31*c4762a1bSJed Brown     for (j = info.gys; j < info.gys + info.gym; j++) {
32*c4762a1bSJed Brown       ierr = PetscSynchronizedPrintf(com, "%g, ", (double) PetscRealPart(p[j][i]));CHKERRQ(ierr);
33*c4762a1bSJed Brown     }
34*c4762a1bSJed Brown     ierr = PetscSynchronizedPrintf(com, "\n");CHKERRQ(ierr);
35*c4762a1bSJed Brown   }
36*c4762a1bSJed Brown   ierr = DMDAVecRestoreArray(da, v, &p);CHKERRQ(ierr);
37*c4762a1bSJed Brown   ierr = PetscSynchronizedPrintf(com, "end rank %d portion\n", rank);CHKERRQ(ierr);
38*c4762a1bSJed Brown   ierr = PetscSynchronizedFlush(com, PETSC_STDOUT);CHKERRQ(ierr);
39*c4762a1bSJed Brown   return 0;
40*c4762a1bSJed Brown }
41*c4762a1bSJed Brown 
42*c4762a1bSJed Brown /* Set a Vec v to value, but do not touch ghosts. */
43*c4762a1bSJed Brown PetscErrorCode VecSetOwned(DM da, Vec v, PetscScalar value)
44*c4762a1bSJed Brown {
45*c4762a1bSJed Brown   PetscScalar    **p;
46*c4762a1bSJed Brown   PetscInt         i, j, xs, xm, ys, ym;
47*c4762a1bSJed Brown   PetscErrorCode   ierr;
48*c4762a1bSJed Brown 
49*c4762a1bSJed Brown   ierr = DMDAGetCorners(da, &xs, &ys, 0, &xm, &ym, 0);CHKERRQ(ierr);
50*c4762a1bSJed Brown   ierr = DMDAVecGetArray(da, v, &p);CHKERRQ(ierr);
51*c4762a1bSJed Brown   for (i = xs; i < xs + xm; i++) {
52*c4762a1bSJed Brown     for (j = ys; j < ys + ym; j++) {
53*c4762a1bSJed Brown       p[j][i] = value;
54*c4762a1bSJed Brown     }
55*c4762a1bSJed Brown   }
56*c4762a1bSJed Brown   ierr = DMDAVecRestoreArray(da, v, &p);CHKERRQ(ierr);
57*c4762a1bSJed Brown   return 0;
58*c4762a1bSJed Brown }
59*c4762a1bSJed Brown 
60*c4762a1bSJed Brown int main(int argc, char **argv)
61*c4762a1bSJed Brown {
62*c4762a1bSJed Brown   PetscInt         M = 4, N = 3;
63*c4762a1bSJed Brown   PetscErrorCode   ierr;
64*c4762a1bSJed Brown   DM               da;
65*c4762a1bSJed Brown   Vec              local;
66*c4762a1bSJed Brown   PetscScalar      value = 0.0;
67*c4762a1bSJed Brown   DMBoundaryType   bx    = DM_BOUNDARY_PERIODIC, by = DM_BOUNDARY_PERIODIC;
68*c4762a1bSJed Brown   DMDAStencilType  stype = DMDA_STENCIL_BOX;
69*c4762a1bSJed Brown 
70*c4762a1bSJed Brown   ierr = PetscInitialize(&argc, &argv, (char*)0, help);if (ierr) return ierr;
71*c4762a1bSJed Brown   ierr = DMDACreate2d(PETSC_COMM_WORLD,bx,by,stype,M,N,PETSC_DECIDE,PETSC_DECIDE,1,1,NULL,NULL,&da);CHKERRQ(ierr);
72*c4762a1bSJed Brown   ierr = DMSetFromOptions(da);CHKERRQ(ierr);
73*c4762a1bSJed Brown   ierr = DMSetUp(da);CHKERRQ(ierr);
74*c4762a1bSJed Brown   ierr = DMCreateLocalVector(da, &local);CHKERRQ(ierr);
75*c4762a1bSJed Brown 
76*c4762a1bSJed Brown   ierr  = VecSet(local, value);CHKERRQ(ierr);
77*c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_WORLD, "\nAfter setting all values to %d:\n", (int)PetscRealPart(value));CHKERRQ(ierr);
78*c4762a1bSJed Brown   ierr = PrintVecWithGhosts(da, local);CHKERRQ(ierr);
79*c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_WORLD, "done\n");CHKERRQ(ierr);
80*c4762a1bSJed Brown 
81*c4762a1bSJed Brown   value += 1.0;
82*c4762a1bSJed Brown   /* set values owned by a process, leaving ghosts alone */
83*c4762a1bSJed Brown   ierr = VecSetOwned(da, local, value);CHKERRQ(ierr);
84*c4762a1bSJed Brown 
85*c4762a1bSJed Brown   /* print after re-setting interior values again */
86*c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_WORLD, "\nAfter setting interior values to %d:\n", (int)PetscRealPart(value));CHKERRQ(ierr);
87*c4762a1bSJed Brown   ierr = PrintVecWithGhosts(da, local);CHKERRQ(ierr);
88*c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_WORLD, "done\n");CHKERRQ(ierr);
89*c4762a1bSJed Brown 
90*c4762a1bSJed Brown   /* communicate ghosts */
91*c4762a1bSJed Brown   ierr  = DMLocalToLocalBegin(da, local, INSERT_VALUES, local);CHKERRQ(ierr);
92*c4762a1bSJed Brown   ierr  = DMLocalToLocalEnd(da, local, INSERT_VALUES, local);CHKERRQ(ierr);
93*c4762a1bSJed Brown 
94*c4762a1bSJed Brown   /* print again */
95*c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_WORLD, "\nAfter local-to-local communication:\n");CHKERRQ(ierr);
96*c4762a1bSJed Brown   ierr = PrintVecWithGhosts(da, local);CHKERRQ(ierr);
97*c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_WORLD, "done\n");CHKERRQ(ierr);
98*c4762a1bSJed Brown 
99*c4762a1bSJed Brown   /* Free memory */
100*c4762a1bSJed Brown   ierr = VecDestroy(&local);CHKERRQ(ierr);
101*c4762a1bSJed Brown   ierr = DMDestroy(&da);CHKERRQ(ierr);
102*c4762a1bSJed Brown   ierr = PetscFinalize();
103*c4762a1bSJed Brown   return ierr;
104*c4762a1bSJed Brown }
105*c4762a1bSJed Brown 
106*c4762a1bSJed Brown 
107*c4762a1bSJed Brown /*TEST
108*c4762a1bSJed Brown 
109*c4762a1bSJed Brown    test:
110*c4762a1bSJed Brown       nsize: 2
111*c4762a1bSJed Brown 
112*c4762a1bSJed Brown TEST*/
113