Actual source code: ex8.c
1: /*$Id: ex8.c,v 1.46 2001/08/07 03:02:26 balay Exp $*/
3: static char help[] = "Demonstrates scattering with strided index sets.nn";
5: #include petscvec.h
6: #include petscsys.h
8: int main(int argc,char **argv)
9: {
10: int n = 6,ierr,loc[6] = {0,1,2,3,4,5};
11: PetscScalar two = 2.0,vals[6] = {10,11,12,13,14,15};
12: Vec x,y;
13: IS is1,is2;
14: VecScatter ctx = 0;
16: PetscInitialize(&argc,&argv,(char*)0,help);
18: /* create two vectors */
19: VecCreateSeq(PETSC_COMM_SELF,n,&x);
20: VecDuplicate(x,&y);
22: /* create two index sets */
23: ISCreateStride(PETSC_COMM_SELF,3,0,2,&is1);
24: ISCreateStride(PETSC_COMM_SELF,3,1,2,&is2);
26: VecSetValues(x,6,loc,vals,INSERT_VALUES);
27: VecView(x,PETSC_VIEWER_STDOUT_SELF);
28: PetscPrintf(PETSC_COMM_SELF,"----n");
29: VecSet(&two,y);
30: VecScatterCreate(x,is1,y,is2,&ctx);
31: VecScatterBegin(x,y,INSERT_VALUES,SCATTER_FORWARD,ctx);
32: VecScatterEnd(x,y,INSERT_VALUES,SCATTER_FORWARD,ctx);
33: VecScatterDestroy(ctx);
34:
35: VecView(y,PETSC_VIEWER_STDOUT_SELF);
37: ISDestroy(is1);
38: ISDestroy(is2);
39: VecDestroy(x);
40: VecDestroy(y);
42: PetscFinalize();
43: return 0;
44: }
45: