xref: /petsc/src/dm/tutorials/ex4.c (revision 3ba1676111f5c958fe6c2729b46ca4d523958bb3)
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 
13d71ae5a4SJacob Faibussowitsch PetscErrorCode myfunction(void *ctx, PetscInt n, const PetscScalar *xy, PetscScalar *u)
14d71ae5a4SJacob Faibussowitsch {
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   }
22*3ba16761SJacob Faibussowitsch   PetscFunctionReturn(PETSC_SUCCESS);
23c4762a1bSJed Brown }
24c4762a1bSJed Brown 
25d71ae5a4SJacob Faibussowitsch int main(int argc, char **argv)
26d71ae5a4SJacob Faibussowitsch {
27c4762a1bSJed Brown   Vec      u, xy;
28c4762a1bSJed Brown   DM       da;
29c4762a1bSJed Brown   PetscInt m = 10, n = 10, dof = 2;
30c4762a1bSJed Brown   PF       pf;
31c4762a1bSJed Brown 
32327415f7SBarry 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