Actual source code: ex3.c
2: static char help[] = "Tests parallel vector assembly. Input arguments are\n\
3: -n <length> : local vector length\n\n";
5: #include petscvec.h
9: int main(int argc,char **argv)
10: {
11: PetscMPIInt size,rank;
13: PetscInt n = 5,idx;
14: PetscScalar one = 1.0,two = 2.0,three = 3.0;
15: Vec x,y;
17: PetscInitialize(&argc,&argv,(char*)0,help);
18: PetscOptionsGetInt(PETSC_NULL,"-n",&n,PETSC_NULL);
19: if (n < 5) n = 5;
20: MPI_Comm_size(PETSC_COMM_WORLD,&size);
21: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
23: if (size < 2) SETERRQ(1,"Must be run with at least two processors");
25: /* create two vector */
26: VecCreateSeq(PETSC_COMM_SELF,n,&x);
27: VecCreate(PETSC_COMM_WORLD,&y);
28: VecSetSizes(y,n,PETSC_DECIDE);
29: VecSetFromOptions(y);
30: VecSet(x,one);
31: VecSet(y,two);
33: if (rank == 1) {
34: idx = 2; VecSetValues(y,1,&idx,&three,INSERT_VALUES);
35: idx = 0; VecSetValues(y,1,&idx,&two,INSERT_VALUES);
36: idx = 0; VecSetValues(y,1,&idx,&one,INSERT_VALUES);
37: }
38: else {
39: idx = 7; VecSetValues(y,1,&idx,&three,INSERT_VALUES);
40: }
41: VecAssemblyBegin(y);
42: VecAssemblyEnd(y);
44: VecView(y,PETSC_VIEWER_STDOUT_WORLD);
46: VecDestroy(x);
47: VecDestroy(y);
49: PetscFinalize();
50: return 0;
51: }
52: