xref: /petsc/src/dm/tutorials/ex5.c (revision 327415f76d85372a4417cf1aaa14db707d4d6c04)
1c4762a1bSJed Brown 
2c4762a1bSJed Brown static char help[] = "Tests DMDAGetElements() and VecView() contour plotting for 2d DMDAs.\n\n";
3c4762a1bSJed Brown 
4c4762a1bSJed Brown #include <petscdm.h>
5c4762a1bSJed Brown #include <petscdmda.h>
6c4762a1bSJed Brown #include <petscdraw.h>
7c4762a1bSJed Brown 
8c4762a1bSJed Brown int main(int argc,char **argv)
9c4762a1bSJed Brown {
10c4762a1bSJed Brown   PetscInt         M = 10,N = 8,ne,nc,i;
11c4762a1bSJed Brown   const PetscInt   *e;
12c4762a1bSJed Brown   PetscBool        flg = PETSC_FALSE;
13c4762a1bSJed Brown   DM               da;
14c4762a1bSJed Brown   PetscViewer      viewer;
15c4762a1bSJed Brown   Vec              local,global;
16c4762a1bSJed Brown   PetscScalar      value;
17c4762a1bSJed Brown   DMBoundaryType   bx    = DM_BOUNDARY_NONE,by = DM_BOUNDARY_NONE;
18c4762a1bSJed Brown   DMDAStencilType  stype = DMDA_STENCIL_BOX;
19c4762a1bSJed Brown   PetscScalar      *lv;
20c4762a1bSJed Brown 
21*327415f7SBarry Smith   PetscFunctionBeginUser;
229566063dSJacob Faibussowitsch   PetscCall(PetscInitialize(&argc,&argv,(char*)0,help));
239566063dSJacob Faibussowitsch   PetscCall(PetscViewerDrawOpen(PETSC_COMM_WORLD,0,"",300,0,300,300,&viewer));
24c4762a1bSJed Brown 
25c4762a1bSJed Brown   /* Read options */
269566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL,NULL,"-M",&M,NULL));
279566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL,NULL,"-N",&N,NULL));
289566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetBool(NULL,NULL,"-star_stencil",&flg,NULL));
29c4762a1bSJed Brown   if (flg) stype = DMDA_STENCIL_STAR;
30c4762a1bSJed Brown 
31c4762a1bSJed Brown   /* Create distributed array and get vectors */
329566063dSJacob Faibussowitsch   PetscCall(DMDACreate2d(PETSC_COMM_WORLD,bx,by,stype,M,N,PETSC_DECIDE,PETSC_DECIDE,1,1,NULL,NULL,&da));
339566063dSJacob Faibussowitsch   PetscCall(DMSetFromOptions(da));
349566063dSJacob Faibussowitsch   PetscCall(DMSetUp(da));
359566063dSJacob Faibussowitsch   PetscCall(DMCreateGlobalVector(da,&global));
369566063dSJacob Faibussowitsch   PetscCall(DMCreateLocalVector(da,&local));
37c4762a1bSJed Brown 
38c4762a1bSJed Brown   value = -3.0;
399566063dSJacob Faibussowitsch   PetscCall(VecSet(global,value));
409566063dSJacob Faibussowitsch   PetscCall(DMGlobalToLocalBegin(da,global,INSERT_VALUES,local));
419566063dSJacob Faibussowitsch   PetscCall(DMGlobalToLocalEnd(da,global,INSERT_VALUES,local));
42c4762a1bSJed Brown 
439566063dSJacob Faibussowitsch   PetscCall(DMDASetElementType(da,DMDA_ELEMENT_P1));
449566063dSJacob Faibussowitsch   PetscCall(DMDAGetElements(da,&ne,&nc,&e));
459566063dSJacob Faibussowitsch   PetscCall(VecGetArray(local,&lv));
46c4762a1bSJed Brown   for (i=0; i<ne; i++) {
4763a3b9bcSJacob Faibussowitsch     PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD,"i %" PetscInt_FMT " e[3*i] %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n",i,e[3*i],e[3*i+1],e[3*i+2]));
48c4762a1bSJed Brown     lv[e[3*i]] = i;
49c4762a1bSJed Brown   }
509566063dSJacob Faibussowitsch   PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD,stdout));
519566063dSJacob Faibussowitsch   PetscCall(VecRestoreArray(local,&lv));
529566063dSJacob Faibussowitsch   PetscCall(DMDARestoreElements(da,&ne,&nc,&e));
53c4762a1bSJed Brown 
549566063dSJacob Faibussowitsch   PetscCall(DMLocalToGlobalBegin(da,local,ADD_VALUES,global));
559566063dSJacob Faibussowitsch   PetscCall(DMLocalToGlobalEnd(da,local,ADD_VALUES,global));
56c4762a1bSJed Brown 
579566063dSJacob Faibussowitsch   PetscCall(DMView(da,viewer));
589566063dSJacob Faibussowitsch   PetscCall(VecView(global,viewer));
59c4762a1bSJed Brown 
60c4762a1bSJed Brown   /* Free memory */
619566063dSJacob Faibussowitsch   PetscCall(PetscViewerDestroy(&viewer));
629566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&local));
639566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&global));
649566063dSJacob Faibussowitsch   PetscCall(DMDestroy(&da));
659566063dSJacob Faibussowitsch   PetscCall(PetscFinalize());
66b122ec5aSJacob Faibussowitsch   return 0;
67c4762a1bSJed Brown }
68c4762a1bSJed Brown 
69c4762a1bSJed Brown /*TEST
70c4762a1bSJed Brown 
71c4762a1bSJed Brown    test:
72c4762a1bSJed Brown      requires: x
73c4762a1bSJed Brown 
74c4762a1bSJed Brown    test:
75c4762a1bSJed Brown      suffix: 2
76c4762a1bSJed Brown      nsize: 2
77c4762a1bSJed Brown      requires: x
78c4762a1bSJed Brown 
79c4762a1bSJed Brown TEST*/
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