xref: /petsc/src/dm/tests/ex7.c (revision ebead697dbf761eb322f829370bbe90b3bd93fa3)
1 
2 static char help[] = "Tests DMLocalToLocalxxx() for DMDA.\n\n";
3 
4 #include <petscdmda.h>
5 
6 int main(int argc,char **argv)
7 {
8   PetscMPIInt      rank;
9   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;
10   PetscBool        flg = PETSC_FALSE,flg2,flg3;
11   DMBoundaryType   periodic;
12   DMDAStencilType  stencil_type;
13   DM               da;
14   Vec              local,global,local_copy;
15   PetscScalar      value;
16   PetscReal        norm,work;
17   PetscViewer      viewer;
18   char             filename[64];
19   FILE             *file;
20 
21   PetscFunctionBeginUser;
22   PetscCall(PetscInitialize(&argc,&argv,(char*)0,help));
23   PetscCall(PetscOptionsGetInt(NULL,NULL,"-M",&M,NULL));
24   PetscCall(PetscOptionsGetInt(NULL,NULL,"-N",&N,NULL));
25   PetscCall(PetscOptionsGetInt(NULL,NULL,"-dof",&dof,NULL));
26   PetscCall(PetscOptionsGetInt(NULL,NULL,"-stencil_width",&stencil_width,NULL));
27   PetscCall(PetscOptionsGetInt(NULL,NULL,"-periodic",&pt,NULL));
28 
29   periodic = (DMBoundaryType) pt;
30 
31   PetscCall(PetscOptionsGetInt(NULL,NULL,"-stencil_type",&st,NULL));
32 
33   stencil_type = (DMDAStencilType) st;
34 
35   PetscCall(PetscOptionsHasName(NULL,NULL,"-grid2d",&flg2));
36   PetscCall(PetscOptionsHasName(NULL,NULL,"-grid3d",&flg3));
37   if (flg2) {
38     PetscCall(DMDACreate2d(PETSC_COMM_WORLD,periodic,periodic,stencil_type,M,N,m,n,dof,stencil_width,NULL,NULL,&da));
39   } else if (flg3) {
40     PetscCall(DMDACreate3d(PETSC_COMM_WORLD,periodic,periodic,periodic,stencil_type,M,N,P,m,n,p,dof,stencil_width,NULL,NULL,NULL,&da));
41   } else {
42     PetscCall(DMDACreate1d(PETSC_COMM_WORLD,periodic,M,dof,stencil_width,NULL,&da));
43   }
44   PetscCall(DMSetFromOptions(da));
45   PetscCall(DMSetUp(da));
46 
47   PetscCall(DMCreateGlobalVector(da,&global));
48   PetscCall(DMCreateLocalVector(da,&local));
49   PetscCall(VecDuplicate(local,&local_copy));
50 
51   /* zero out vectors so that ghostpoints are zero */
52   value = 0;
53   PetscCall(VecSet(local,value));
54   PetscCall(VecSet(local_copy,value));
55 
56   PetscCall(VecGetOwnershipRange(global,&start,&end));
57   for (i=start; i<end; i++) {
58     value = i + 1;
59     PetscCall(VecSetValues(global,1,&i,&value,INSERT_VALUES));
60   }
61   PetscCall(VecAssemblyBegin(global));
62   PetscCall(VecAssemblyEnd(global));
63 
64   PetscCall(DMGlobalToLocalBegin(da,global,INSERT_VALUES,local));
65   PetscCall(DMGlobalToLocalEnd(da,global,INSERT_VALUES,local));
66 
67   PetscCall(DMLocalToLocalBegin(da,local,INSERT_VALUES,local_copy));
68   PetscCall(DMLocalToLocalEnd(da,local,INSERT_VALUES,local_copy));
69 
70   PetscCall(PetscOptionsGetBool(NULL,NULL,"-save",&flg,NULL));
71   if (flg) {
72     PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank));
73     sprintf(filename,"local.%d",rank);
74     PetscCall(PetscViewerASCIIOpen(PETSC_COMM_SELF,filename,&viewer));
75     PetscCall(PetscViewerASCIIGetPointer(viewer,&file));
76     PetscCall(VecView(local,viewer));
77     fprintf(file,"Vector with correct ghost points\n");
78     PetscCall(VecView(local_copy,viewer));
79     PetscCall(PetscViewerDestroy(&viewer));
80   }
81 
82   PetscCall(VecAXPY(local_copy,-1.0,local));
83   PetscCall(VecNorm(local_copy,NORM_MAX,&work));
84   PetscCallMPI(MPI_Allreduce(&work,&norm,1,MPIU_REAL,MPIU_MAX,PETSC_COMM_WORLD));
85   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Norm of difference %g should be zero\n",(double)norm));
86 
87   PetscCall(VecDestroy(&local_copy));
88   PetscCall(VecDestroy(&local));
89   PetscCall(VecDestroy(&global));
90   PetscCall(DMDestroy(&da));
91   PetscCall(PetscFinalize());
92   return 0;
93 }
94 
95 /*TEST
96 
97    test:
98       nsize: 8
99       args: -dof 3 -stencil_width 2 -M 50 -N 50 -periodic
100 
101    test:
102       suffix: 2
103       nsize: 8
104       args: -dof 3 -stencil_width 2 -M 50 -N 50 -periodic -grid2d
105       output_file: output/ex7_1.out
106 
107    test:
108       suffix: 3
109       nsize: 8
110       args: -dof 3 -stencil_width 2 -M 50 -N 50 -periodic -grid3d
111       output_file: output/ex7_1.out
112 
113 TEST*/
114