Actual source code: ex7.c
petsc-3.7.3 2016-08-01
2: static char help[] = "Tests DMLocalToLocalxxx() for DMDA.\n\n";
4: #include <petscdmda.h>
8: int main(int argc,char **argv)
9: {
10: PetscMPIInt rank;
11: PetscInt M=8,dof=1,stencil_width=1,i,start,end,P=5,N = 6,m=PETSC_DECIDE,n=PETSC_DECIDE,p=PETSC_DECIDE,pt = 0,st = 0;
12: PetscErrorCode ierr;
13: PetscBool flg = PETSC_FALSE,flg2,flg3;
14: DMBoundaryType periodic;
15: DMDAStencilType stencil_type;
16: DM da;
17: Vec local,global,local_copy;
18: PetscScalar value;
19: PetscReal norm,work;
20: PetscViewer viewer;
21: char filename[64];
22: FILE *file;
24: PetscInitialize(&argc,&argv,(char*)0,help);
26: PetscOptionsGetInt(NULL,NULL,"-M",&M,NULL);
27: PetscOptionsGetInt(NULL,NULL,"-N",&N,NULL);
28: PetscOptionsGetInt(NULL,NULL,"-dof",&dof,NULL);
29: PetscOptionsGetInt(NULL,NULL,"-stencil_width",&stencil_width,NULL);
30: PetscOptionsGetInt(NULL,NULL,"-periodic",&pt,NULL);
32: periodic = (DMBoundaryType) pt;
34: PetscOptionsGetInt(NULL,NULL,"-stencil_type",&st,NULL);
36: stencil_type = (DMDAStencilType) st;
38: PetscOptionsHasName(NULL,NULL,"-grid2d",&flg2);
39: PetscOptionsHasName(NULL,NULL,"-grid3d",&flg3);
40: if (flg2) {
41: DMDACreate2d(PETSC_COMM_WORLD,periodic,periodic,stencil_type,M,N,m,n,dof,stencil_width,
42: NULL,NULL,&da);
43: } else if (flg3) {
44: DMDACreate3d(PETSC_COMM_WORLD,periodic,periodic,periodic,stencil_type,M,N,P,m,n,p,dof,stencil_width,
45: NULL,NULL,NULL,&da);
46: } else {
47: DMDACreate1d(PETSC_COMM_WORLD,periodic,M,dof,stencil_width,NULL,&da);
48: }
50: DMCreateGlobalVector(da,&global);
51: DMCreateLocalVector(da,&local);
52: VecDuplicate(local,&local_copy);
55: /* zero out vectors so that ghostpoints are zero */
56: value = 0;
57: VecSet(local,value);
58: VecSet(local_copy,value);
60: VecGetOwnershipRange(global,&start,&end);
61: for (i=start; i<end; i++) {
62: value = i + 1;
63: VecSetValues(global,1,&i,&value,INSERT_VALUES);
64: }
65: VecAssemblyBegin(global);
66: VecAssemblyEnd(global);
68: DMGlobalToLocalBegin(da,global,INSERT_VALUES,local);
69: DMGlobalToLocalEnd(da,global,INSERT_VALUES,local);
72: DMLocalToLocalBegin(da,local,INSERT_VALUES,local_copy);
73: DMLocalToLocalEnd(da,local,INSERT_VALUES,local_copy);
76: PetscOptionsGetBool(NULL,NULL,"-save",&flg,NULL);
77: if (flg) {
78: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
79: sprintf(filename,"local.%d",rank);
80: PetscViewerASCIIOpen(PETSC_COMM_SELF,filename,&viewer);
81: PetscViewerASCIIGetPointer(viewer,&file);
82: VecView(local,viewer);
83: fprintf(file,"Vector with correct ghost points\n");
84: VecView(local_copy,viewer);
85: PetscViewerDestroy(&viewer);
86: }
88: VecAXPY(local_copy,-1.0,local);
89: VecNorm(local_copy,NORM_MAX,&work);
90: MPI_Allreduce(&work,&norm,1,MPIU_REAL,MPIU_MAX,PETSC_COMM_WORLD);
91: PetscPrintf(PETSC_COMM_WORLD,"Norm of difference %g should be zero\n",(double)norm);
93: VecDestroy(&local_copy);
94: VecDestroy(&local);
95: VecDestroy(&global);
96: DMDestroy(&da);
97: PetscFinalize();
98: return 0;
99: }