Actual source code: ex4.c
petsc-3.10.5 2019-03-28
2: static char help[] = "Demonstrates various vector routines for DMDA.\n\n";
4: /*T
5: Concepts: mathematical functions
6: Processors: n
7: T*/
9: /*
10: Include "petscpf.h" so that we can use pf functions and "petscdmda.h" so
11: we can use the PETSc distributed arrays
12: */
14: #include <petscpf.h>
15: #include <petscdm.h>
16: #include <petscdmda.h>
18: PetscErrorCode myfunction(void *ctx,PetscInt n,const PetscScalar *xy,PetscScalar *u)
19: {
20: PetscInt i;
23: for (i=0; i<n; i++) {
24: u[2*i] = xy[2*i];
25: u[2*i+1] = xy[2*i+1];
26: }
27: return(0);
28: }
30: int main(int argc,char **argv)
31: {
32: Vec u,xy;
33: DM da;
35: PetscInt m = 10, n = 10, dof = 2;
36: PF pf;
38: PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
39: 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: DMSetFromOptions(da);
41: DMSetUp(da);
42: DMDASetUniformCoordinates(da,0.0,1.0,0.0,1.0,0.0,1.0);
43: DMCreateGlobalVector(da,&u);
44: DMGetCoordinates(da,&xy);
46: DMDACreatePF(da,&pf);
47: PFSet(pf,myfunction,0,0,0,0);
48: PFSetFromOptions(pf);
50: PFApplyVec(pf,xy,u);
52: VecView(u,PETSC_VIEWER_DRAW_WORLD);
54: /*
55: Free work space. All PETSc objects should be destroyed when they
56: are no longer needed.
57: */
58: VecDestroy(&u);
59: PFDestroy(&pf);
60: DMDestroy(&da);
61: PetscFinalize();
62: return ierr;
63: }
67: /*TEST
69: test:
72: TEST*/