xref: /petsc/src/dm/tutorials/ex4.c (revision 5f80ce2ab25dff0f4601e710601cbbcecf323266)
1c4762a1bSJed Brown 
2c4762a1bSJed Brown static char help[] = "Demonstrates various vector routines for DMDA.\n\n";
3c4762a1bSJed Brown 
4c4762a1bSJed Brown /*T
5c4762a1bSJed Brown    Concepts: mathematical functions
6c4762a1bSJed Brown    Processors: n
7c4762a1bSJed Brown T*/
8c4762a1bSJed Brown 
9c4762a1bSJed Brown /*
10c4762a1bSJed Brown   Include "petscpf.h" so that we can use pf functions and "petscdmda.h" so
11c4762a1bSJed Brown  we can use the PETSc distributed arrays
12c4762a1bSJed Brown */
13c4762a1bSJed Brown 
14c4762a1bSJed Brown #include <petscpf.h>
15c4762a1bSJed Brown #include <petscdm.h>
16c4762a1bSJed Brown #include <petscdmda.h>
17c4762a1bSJed Brown 
18c4762a1bSJed Brown PetscErrorCode myfunction(void *ctx,PetscInt n,const PetscScalar *xy,PetscScalar *u)
19c4762a1bSJed Brown {
20c4762a1bSJed Brown   PetscInt i;
21c4762a1bSJed Brown 
22c4762a1bSJed Brown   PetscFunctionBeginUser;
23c4762a1bSJed Brown   for (i=0; i<n; i++) {
24c4762a1bSJed Brown     u[2*i]   = xy[2*i];
25c4762a1bSJed Brown     u[2*i+1] = xy[2*i+1];
26c4762a1bSJed Brown   }
27c4762a1bSJed Brown   PetscFunctionReturn(0);
28c4762a1bSJed Brown }
29c4762a1bSJed Brown 
30c4762a1bSJed Brown int main(int argc,char **argv)
31c4762a1bSJed Brown {
32c4762a1bSJed Brown   Vec            u,xy;
33c4762a1bSJed Brown   DM             da;
34c4762a1bSJed Brown   PetscErrorCode ierr;
35c4762a1bSJed Brown   PetscInt       m = 10, n = 10, dof = 2;
36c4762a1bSJed Brown   PF             pf;
37c4762a1bSJed Brown 
38c4762a1bSJed Brown   ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
39*5f80ce2aSJacob Faibussowitsch   CHKERRQ(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,m,n,PETSC_DECIDE,PETSC_DECIDE,dof,1,0,0,&da));
40*5f80ce2aSJacob Faibussowitsch   CHKERRQ(DMSetFromOptions(da));
41*5f80ce2aSJacob Faibussowitsch   CHKERRQ(DMSetUp(da));
42*5f80ce2aSJacob Faibussowitsch   CHKERRQ(DMDASetUniformCoordinates(da,0.0,1.0,0.0,1.0,0.0,1.0));
43*5f80ce2aSJacob Faibussowitsch   CHKERRQ(DMCreateGlobalVector(da,&u));
44*5f80ce2aSJacob Faibussowitsch   CHKERRQ(DMGetCoordinates(da,&xy));
45c4762a1bSJed Brown 
46*5f80ce2aSJacob Faibussowitsch   CHKERRQ(DMDACreatePF(da,&pf));
47*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PFSet(pf,myfunction,0,0,0,0));
48*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PFSetFromOptions(pf));
49c4762a1bSJed Brown 
50*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PFApplyVec(pf,xy,u));
51c4762a1bSJed Brown 
52*5f80ce2aSJacob Faibussowitsch   CHKERRQ(VecView(u,PETSC_VIEWER_DRAW_WORLD));
53c4762a1bSJed Brown 
54c4762a1bSJed Brown   /*
55c4762a1bSJed Brown      Free work space.  All PETSc objects should be destroyed when they
56c4762a1bSJed Brown      are no longer needed.
57c4762a1bSJed Brown   */
58*5f80ce2aSJacob Faibussowitsch   CHKERRQ(VecDestroy(&u));
59*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PFDestroy(&pf));
60*5f80ce2aSJacob Faibussowitsch   CHKERRQ(DMDestroy(&da));
61c4762a1bSJed Brown   ierr = PetscFinalize();
62c4762a1bSJed Brown   return ierr;
63c4762a1bSJed Brown }
64c4762a1bSJed Brown 
65c4762a1bSJed Brown /*TEST
66c4762a1bSJed Brown 
67c4762a1bSJed Brown    test:
68c4762a1bSJed Brown 
69c4762a1bSJed Brown TEST*/
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