xref: /petsc/src/dm/tutorials/ex5.c (revision b122ec5aa1bd4469eb4e0673542fb7de3f411254)
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*b122ec5aSJacob Faibussowitsch   CHKERRQ(PetscInitialize(&argc,&argv,(char*)0,help));
225f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscViewerDrawOpen(PETSC_COMM_WORLD,0,"",300,0,300,300,&viewer));
23c4762a1bSJed Brown 
24c4762a1bSJed Brown   /* Read options */
255f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-M",&M,NULL));
265f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-N",&N,NULL));
275f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscOptionsGetBool(NULL,NULL,"-star_stencil",&flg,NULL));
28c4762a1bSJed Brown   if (flg) stype = DMDA_STENCIL_STAR;
29c4762a1bSJed Brown 
30c4762a1bSJed Brown   /* Create distributed array and get vectors */
315f80ce2aSJacob Faibussowitsch   CHKERRQ(DMDACreate2d(PETSC_COMM_WORLD,bx,by,stype,M,N,PETSC_DECIDE,PETSC_DECIDE,1,1,NULL,NULL,&da));
325f80ce2aSJacob Faibussowitsch   CHKERRQ(DMSetFromOptions(da));
335f80ce2aSJacob Faibussowitsch   CHKERRQ(DMSetUp(da));
345f80ce2aSJacob Faibussowitsch   CHKERRQ(DMCreateGlobalVector(da,&global));
355f80ce2aSJacob Faibussowitsch   CHKERRQ(DMCreateLocalVector(da,&local));
36c4762a1bSJed Brown 
37c4762a1bSJed Brown   value = -3.0;
385f80ce2aSJacob Faibussowitsch   CHKERRQ(VecSet(global,value));
395f80ce2aSJacob Faibussowitsch   CHKERRQ(DMGlobalToLocalBegin(da,global,INSERT_VALUES,local));
405f80ce2aSJacob Faibussowitsch   CHKERRQ(DMGlobalToLocalEnd(da,global,INSERT_VALUES,local));
41c4762a1bSJed Brown 
425f80ce2aSJacob Faibussowitsch   CHKERRQ(DMDASetElementType(da,DMDA_ELEMENT_P1));
435f80ce2aSJacob Faibussowitsch   CHKERRQ(DMDAGetElements(da,&ne,&nc,&e));
445f80ce2aSJacob Faibussowitsch   CHKERRQ(VecGetArray(local,&lv));
45c4762a1bSJed Brown   for (i=0; i<ne; i++) {
465f80ce2aSJacob Faibussowitsch     CHKERRQ(PetscSynchronizedPrintf(PETSC_COMM_WORLD,"i %D e[3*i] %D %D %D\n",i,e[3*i],e[3*i+1],e[3*i+2]));
47c4762a1bSJed Brown     lv[e[3*i]] = i;
48c4762a1bSJed Brown   }
495f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscSynchronizedFlush(PETSC_COMM_WORLD,stdout));
505f80ce2aSJacob Faibussowitsch   CHKERRQ(VecRestoreArray(local,&lv));
515f80ce2aSJacob Faibussowitsch   CHKERRQ(DMDARestoreElements(da,&ne,&nc,&e));
52c4762a1bSJed Brown 
535f80ce2aSJacob Faibussowitsch   CHKERRQ(DMLocalToGlobalBegin(da,local,ADD_VALUES,global));
545f80ce2aSJacob Faibussowitsch   CHKERRQ(DMLocalToGlobalEnd(da,local,ADD_VALUES,global));
55c4762a1bSJed Brown 
565f80ce2aSJacob Faibussowitsch   CHKERRQ(DMView(da,viewer));
575f80ce2aSJacob Faibussowitsch   CHKERRQ(VecView(global,viewer));
58c4762a1bSJed Brown 
59c4762a1bSJed Brown   /* Free memory */
605f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscViewerDestroy(&viewer));
615f80ce2aSJacob Faibussowitsch   CHKERRQ(VecDestroy(&local));
625f80ce2aSJacob Faibussowitsch   CHKERRQ(VecDestroy(&global));
635f80ce2aSJacob Faibussowitsch   CHKERRQ(DMDestroy(&da));
64*b122ec5aSJacob Faibussowitsch   CHKERRQ(PetscFinalize());
65*b122ec5aSJacob Faibussowitsch   return 0;
66c4762a1bSJed Brown }
67c4762a1bSJed Brown 
68c4762a1bSJed Brown /*TEST
69c4762a1bSJed Brown 
70c4762a1bSJed Brown    test:
71c4762a1bSJed Brown      requires: x
72c4762a1bSJed Brown 
73c4762a1bSJed Brown    test:
74c4762a1bSJed Brown      suffix: 2
75c4762a1bSJed Brown      nsize: 2
76c4762a1bSJed Brown      requires: x
77c4762a1bSJed Brown 
78c4762a1bSJed Brown TEST*/
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