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 PetscErrorCode ierr; 35 PetscInt m = 10, n = 10, dof = 2; 36 PF pf; 37 38 ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr; 39 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 CHKERRQ(DMSetFromOptions(da)); 41 CHKERRQ(DMSetUp(da)); 42 CHKERRQ(DMDASetUniformCoordinates(da,0.0,1.0,0.0,1.0,0.0,1.0)); 43 CHKERRQ(DMCreateGlobalVector(da,&u)); 44 CHKERRQ(DMGetCoordinates(da,&xy)); 45 46 CHKERRQ(DMDACreatePF(da,&pf)); 47 CHKERRQ(PFSet(pf,myfunction,0,0,0,0)); 48 CHKERRQ(PFSetFromOptions(pf)); 49 50 CHKERRQ(PFApplyVec(pf,xy,u)); 51 52 CHKERRQ(VecView(u,PETSC_VIEWER_DRAW_WORLD)); 53 54 /* 55 Free work space. All PETSc objects should be destroyed when they 56 are no longer needed. 57 */ 58 CHKERRQ(VecDestroy(&u)); 59 CHKERRQ(PFDestroy(&pf)); 60 CHKERRQ(DMDestroy(&da)); 61 ierr = PetscFinalize(); 62 return ierr; 63 } 64 65 /*TEST 66 67 test: 68 69 TEST*/ 70