xref: /petsc/src/dm/tests/ex32.c (revision ffa8c5705e8ab2cf85ee1d14dbe507a6e2eb5283)
1 static char help[] = "Tests DMDA ghost coordinates\n\n";
2 
3 #include <petscdm.h>
4 #include <petscdmda.h>
5 
6 static PetscErrorCode CompareGhostedCoords(Vec gc1,Vec gc2)
7 {
8   PetscReal      nrm,gnrm;
9   Vec            tmp;
10 
11   PetscFunctionBeginUser;
12   PetscCall(VecDuplicate(gc1,&tmp));
13   PetscCall(VecWAXPY(tmp,-1.0,gc1,gc2));
14   PetscCall(VecNorm(tmp,NORM_INFINITY,&nrm));
15   PetscCallMPI(MPI_Allreduce(&nrm,&gnrm,1,MPIU_REAL,MPIU_MAX,PETSC_COMM_WORLD));
16   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"norm of difference of ghosted coordinates %8.2e\n",gnrm));
17   PetscCall(VecDestroy(&tmp));
18   PetscFunctionReturn(0);
19 }
20 
21 static PetscErrorCode TestQ2Q1DA(void)
22 {
23   DM             Q2_da,Q1_da,cda;
24   PetscInt       mx,my,mz;
25   Vec            coords,gcoords,gcoords2;
26 
27   PetscFunctionBeginUser;
28   mx   = 7;
29   my   = 11;
30   mz   = 13;
31   PetscCall(DMDACreate3d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,mx,my,mz,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,3,2,0,0,0,&Q2_da));
32   PetscCall(DMSetFromOptions(Q2_da));
33   PetscCall(DMSetUp(Q2_da));
34   PetscCall(DMDASetUniformCoordinates(Q2_da,-1.0,1.0,-2.0,2.0,-3.0,3.0));
35   PetscCall(DMGetCoordinates(Q2_da,&coords));
36   PetscCall(DMDACreate3d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,mx,my,mz,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,3,1,0,0,0,&Q1_da));
37   PetscCall(DMSetFromOptions(Q1_da));
38   PetscCall(DMSetUp(Q1_da));
39   PetscCall(DMSetCoordinates(Q1_da,coords));
40 
41   /* Get ghost coordinates one way */
42   PetscCall(DMGetCoordinatesLocal(Q1_da,&gcoords));
43 
44   /* And another */
45   PetscCall(DMGetCoordinates(Q1_da,&coords));
46   PetscCall(DMGetCoordinateDM(Q1_da,&cda));
47   PetscCall(DMGetLocalVector(cda,&gcoords2));
48   PetscCall(DMGlobalToLocalBegin(cda,coords,INSERT_VALUES,gcoords2));
49   PetscCall(DMGlobalToLocalEnd(cda,coords,INSERT_VALUES,gcoords2));
50 
51   PetscCall(CompareGhostedCoords(gcoords,gcoords2));
52   PetscCall(DMRestoreLocalVector(cda,&gcoords2));
53 
54   PetscCall(VecScale(coords,10.0));
55   PetscCall(VecScale(gcoords,10.0));
56   PetscCall(DMGetCoordinatesLocal(Q1_da,&gcoords2));
57   PetscCall(CompareGhostedCoords(gcoords,gcoords2));
58 
59   PetscCall(DMDestroy(&Q2_da));
60   PetscCall(DMDestroy(&Q1_da));
61   PetscFunctionReturn(0);
62 }
63 
64 int main(int argc,char **argv)
65 {
66 
67   PetscCall(PetscInitialize(&argc,&argv,0,help));
68   PetscCall(TestQ2Q1DA());
69   PetscCall(PetscFinalize());
70   return 0;
71 }
72 
73 /*TEST
74 
75    test:
76       nsize: 2
77 
78 TEST*/
79