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 ierr = DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,m,n,PETSC_DECIDE,PETSC_DECIDE,dof,1,0,0,&da);CHKERRQ(ierr); 40 ierr = DMSetFromOptions(da);CHKERRQ(ierr); 41 ierr = DMSetUp(da);CHKERRQ(ierr); 42 ierr = DMDASetUniformCoordinates(da,0.0,1.0,0.0,1.0,0.0,1.0);CHKERRQ(ierr); 43 ierr = DMCreateGlobalVector(da,&u);CHKERRQ(ierr); 44 ierr = DMGetCoordinates(da,&xy);CHKERRQ(ierr); 45 46 ierr = DMDACreatePF(da,&pf);CHKERRQ(ierr); 47 ierr = PFSet(pf,myfunction,0,0,0,0);CHKERRQ(ierr); 48 ierr = PFSetFromOptions(pf);CHKERRQ(ierr); 49 50 ierr = PFApplyVec(pf,xy,u);CHKERRQ(ierr); 51 52 ierr = VecView(u,PETSC_VIEWER_DRAW_WORLD);CHKERRQ(ierr); 53 54 /* 55 Free work space. All PETSc objects should be destroyed when they 56 are no longer needed. 57 */ 58 ierr = VecDestroy(&u);CHKERRQ(ierr); 59 ierr = PFDestroy(&pf);CHKERRQ(ierr); 60 ierr = DMDestroy(&da);CHKERRQ(ierr); 61 ierr = PetscFinalize(); 62 return ierr; 63 } 64 65 66 67 /*TEST 68 69 test: 70 71 72 TEST*/ 73