xref: /petsc/src/dm/tutorials/ex4.c (revision 327415f76d85372a4417cf1aaa14db707d4d6c04)
1c4762a1bSJed Brown 
2c4762a1bSJed Brown static char help[] = "Demonstrates various vector routines for DMDA.\n\n";
3c4762a1bSJed Brown 
4c4762a1bSJed Brown /*
5c4762a1bSJed Brown   Include "petscpf.h" so that we can use pf functions and "petscdmda.h" so
6c4762a1bSJed Brown  we can use the PETSc distributed arrays
7c4762a1bSJed Brown */
8c4762a1bSJed Brown 
9c4762a1bSJed Brown #include <petscpf.h>
10c4762a1bSJed Brown #include <petscdm.h>
11c4762a1bSJed Brown #include <petscdmda.h>
12c4762a1bSJed Brown 
13c4762a1bSJed Brown PetscErrorCode myfunction(void *ctx,PetscInt n,const PetscScalar *xy,PetscScalar *u)
14c4762a1bSJed Brown {
15c4762a1bSJed Brown   PetscInt i;
16c4762a1bSJed Brown 
17c4762a1bSJed Brown   PetscFunctionBeginUser;
18c4762a1bSJed Brown   for (i=0; i<n; i++) {
19c4762a1bSJed Brown     u[2*i]   = xy[2*i];
20c4762a1bSJed Brown     u[2*i+1] = xy[2*i+1];
21c4762a1bSJed Brown   }
22c4762a1bSJed Brown   PetscFunctionReturn(0);
23c4762a1bSJed Brown }
24c4762a1bSJed Brown 
25c4762a1bSJed Brown int main(int argc,char **argv)
26c4762a1bSJed Brown {
27c4762a1bSJed Brown   Vec            u,xy;
28c4762a1bSJed Brown   DM             da;
29c4762a1bSJed Brown   PetscInt       m = 10, n = 10, dof = 2;
30c4762a1bSJed Brown   PF             pf;
31c4762a1bSJed Brown 
32*327415f7SBarry Smith   PetscFunctionBeginUser;
339566063dSJacob Faibussowitsch   PetscCall(PetscInitialize(&argc,&argv,(char*)0,help));
349566063dSJacob Faibussowitsch   PetscCall(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,m,n,PETSC_DECIDE,PETSC_DECIDE,dof,1,0,0,&da));
359566063dSJacob Faibussowitsch   PetscCall(DMSetFromOptions(da));
369566063dSJacob Faibussowitsch   PetscCall(DMSetUp(da));
379566063dSJacob Faibussowitsch   PetscCall(DMDASetUniformCoordinates(da,0.0,1.0,0.0,1.0,0.0,1.0));
389566063dSJacob Faibussowitsch   PetscCall(DMCreateGlobalVector(da,&u));
399566063dSJacob Faibussowitsch   PetscCall(DMGetCoordinates(da,&xy));
40c4762a1bSJed Brown 
419566063dSJacob Faibussowitsch   PetscCall(DMDACreatePF(da,&pf));
429566063dSJacob Faibussowitsch   PetscCall(PFSet(pf,myfunction,0,0,0,0));
439566063dSJacob Faibussowitsch   PetscCall(PFSetFromOptions(pf));
44c4762a1bSJed Brown 
459566063dSJacob Faibussowitsch   PetscCall(PFApplyVec(pf,xy,u));
46c4762a1bSJed Brown 
479566063dSJacob Faibussowitsch   PetscCall(VecView(u,PETSC_VIEWER_DRAW_WORLD));
48c4762a1bSJed Brown 
49c4762a1bSJed Brown   /*
50c4762a1bSJed Brown      Free work space.  All PETSc objects should be destroyed when they
51c4762a1bSJed Brown      are no longer needed.
52c4762a1bSJed Brown   */
539566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&u));
549566063dSJacob Faibussowitsch   PetscCall(PFDestroy(&pf));
559566063dSJacob Faibussowitsch   PetscCall(DMDestroy(&da));
569566063dSJacob Faibussowitsch   PetscCall(PetscFinalize());
57b122ec5aSJacob Faibussowitsch   return 0;
58c4762a1bSJed Brown }
59c4762a1bSJed Brown 
60c4762a1bSJed Brown /*TEST
61c4762a1bSJed Brown 
62c4762a1bSJed Brown    test:
63c4762a1bSJed Brown 
64c4762a1bSJed Brown TEST*/
65