Actual source code: ex32.c
petsc-3.4.2 2013-07-02
1: static char help[] = "Tests DMDA ghost coordinates\n\n";
3: #include <petscdmda.h>
7: static PetscErrorCode CompareGhostedCoords(Vec gc1,Vec gc2)
8: {
10: PetscReal nrm,gnrm;
11: Vec tmp;
14: VecDuplicate(gc1,&tmp);
15: VecWAXPY(tmp,-1.0,gc1,gc2);
16: VecNorm(tmp,NORM_INFINITY,&nrm);
17: MPI_Allreduce(&nrm,&gnrm,1,MPIU_REAL,MPIU_MAX,PETSC_COMM_WORLD);
18: PetscPrintf(PETSC_COMM_WORLD,"norm of difference of ghosted coordinates %8.2e\n",gnrm);
19: VecDestroy(&tmp);
20: return(0);
21: }
25: static PetscErrorCode TestQ2Q1DA(void)
26: {
27: DM Q2_da,Q1_da,cda;
28: PetscInt mx,my,mz;
29: Vec coords,gcoords,gcoords2;
32: mx = 7;
33: my = 11;
34: mz = 13;
35: DMDACreate3d(PETSC_COMM_WORLD,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,DMDA_STENCIL_BOX,mx,my,mz,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,3,2,0,0,0,&Q2_da);
36: DMDASetUniformCoordinates(Q2_da,-1.0,1.0,-2.0,2.0,-3.0,3.0);
37: DMGetCoordinates(Q2_da,&coords);
38: DMDACreate3d(PETSC_COMM_WORLD,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,DMDA_STENCIL_BOX,mx,my,mz,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,3,1,0,0,0,&Q1_da);
39: DMSetCoordinates(Q1_da,coords);
41: /* Get ghost coordinates one way */
42: DMGetCoordinatesLocal(Q1_da,&gcoords);
44: /* And another */
45: DMGetCoordinates(Q1_da,&coords);
46: DMGetCoordinateDM(Q1_da,&cda);
47: DMGetLocalVector(cda,&gcoords2);
48: DMGlobalToLocalBegin(cda,coords,INSERT_VALUES,gcoords2);
49: DMGlobalToLocalEnd(cda,coords,INSERT_VALUES,gcoords2);
51: CompareGhostedCoords(gcoords,gcoords2);
52: DMRestoreLocalVector(cda,&gcoords2);
54: VecScale(coords,10.0);
55: VecScale(gcoords,10.0);
56: DMGetCoordinatesLocal(Q1_da,&gcoords2);
57: CompareGhostedCoords(gcoords,gcoords2);
59: DMDestroy(&Q2_da);
60: DMDestroy(&Q1_da);
61: return(0);
62: }
66: int main(int argc,char **argv)
67: {
70: PetscInitialize(&argc,&argv,0,help);
71: TestQ2Q1DA();
72: PetscFinalize();
73: return 0;
74: }