1 2 static char help[] = "Tests DMDA with variable multiple degrees of freedom per node.\n\n"; 3 4 /* 5 This code only compiles with gcc, since it is not ANSI C 6 */ 7 8 #include <petscdm.h> 9 #include <petscdmda.h> 10 11 PetscErrorCode doit(DM da,Vec global) 12 { 13 PetscInt i,j,k,M,N,dof; 14 15 PetscCall(DMDAGetInfo(da,0,&M,&N,0,0,0,0,&dof,0,0,0,0,0)); 16 { 17 struct {PetscScalar inside[dof];} **mystruct; 18 PetscCall(DMDAVecGetArrayRead(da,global,(void*) &mystruct)); 19 for (i=0; i<N; i++) { 20 for (j=0; j<M; j++) { 21 for (k=0; k<dof; k++) { 22 PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D %D %g\n",i,j,(double)mystruct[i][j].inside[0])); 23 24 mystruct[i][j].inside[1] = 2.1; 25 } 26 } 27 } 28 PetscCall(DMDAVecRestoreArrayRead(da,global,(void*) &mystruct)); 29 } 30 PetscFunctionReturn(0); 31 } 32 33 int main(int argc,char **argv) 34 { 35 PetscInt dof = 2,M = 3,N = 3,m = PETSC_DECIDE,n = PETSC_DECIDE; 36 DM da; 37 Vec global,local; 38 39 PetscCall(PetscInitialize(&argc,&argv,(char*)0,help)); 40 PetscCall(PetscOptionsGetInt(NULL,0,"-dof",&dof,0)); 41 /* Create distributed array and get vectors */ 42 PetscCall(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,M,N,m,n,dof,1,NULL,NULL,&da)); 43 PetscCall(DMSetFromOptions(da)); 44 PetscCall(DMSetUp(da)); 45 PetscCall(DMCreateGlobalVector(da,&global)); 46 PetscCall(DMCreateLocalVector(da,&local)); 47 48 PetscCall(doit(da,global)); 49 50 PetscCall(VecView(global,0)); 51 52 /* Free memory */ 53 PetscCall(VecDestroy(&local)); 54 PetscCall(VecDestroy(&global)); 55 PetscCall(DMDestroy(&da)); 56 PetscCall(PetscFinalize()); 57 return 0; 58 } 59