1 2 static char help[] = "Demonstrates various vector routines for DMDA.\n\n"; 3 4 /*T 5 Concepts: mathematical functions 6 Processors: n 7 T*/ 8 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 */ 13 14 #include <petscpf.h> 15 #include <petscdm.h> 16 #include <petscdmda.h> 17 18 PetscErrorCode myfunction(void *ctx,PetscInt n,const PetscScalar *xy,PetscScalar *u) 19 { 20 PetscInt i; 21 22 PetscFunctionBeginUser; 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 PetscFunctionReturn(0); 28 } 29 30 int main(int argc,char **argv) 31 { 32 Vec u,xy; 33 DM da; 34 PetscInt m = 10, n = 10, dof = 2; 35 PF pf; 36 37 PetscCall(PetscInitialize(&argc,&argv,(char*)0,help)); 38 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)); 39 PetscCall(DMSetFromOptions(da)); 40 PetscCall(DMSetUp(da)); 41 PetscCall(DMDASetUniformCoordinates(da,0.0,1.0,0.0,1.0,0.0,1.0)); 42 PetscCall(DMCreateGlobalVector(da,&u)); 43 PetscCall(DMGetCoordinates(da,&xy)); 44 45 PetscCall(DMDACreatePF(da,&pf)); 46 PetscCall(PFSet(pf,myfunction,0,0,0,0)); 47 PetscCall(PFSetFromOptions(pf)); 48 49 PetscCall(PFApplyVec(pf,xy,u)); 50 51 PetscCall(VecView(u,PETSC_VIEWER_DRAW_WORLD)); 52 53 /* 54 Free work space. All PETSc objects should be destroyed when they 55 are no longer needed. 56 */ 57 PetscCall(VecDestroy(&u)); 58 PetscCall(PFDestroy(&pf)); 59 PetscCall(DMDestroy(&da)); 60 PetscCall(PetscFinalize()); 61 return 0; 62 } 63 64 /*TEST 65 66 test: 67 68 TEST*/ 69