Actual source code: ex4.c
petsc-3.12.0 2019-09-29
2: static char help[] = "Scatters from a parallel vector into seqential vectors.\n\n";
4: #include <petscvec.h>
6: int main(int argc,char **argv)
7: {
9: PetscMPIInt rank;
10: PetscInt n = 5,idx1[2] = {0,3},idx2[2] = {1,4};
11: PetscScalar one = 1.0,two = 2.0;
12: Vec x,y;
13: IS is1,is2;
14: VecScatter ctx = 0;
16: PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
17: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
18: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
20: /* create two vectors */
21: VecCreate(PETSC_COMM_WORLD,&x);
22: VecSetSizes(x,n,PETSC_DECIDE);
23: VecSetFromOptions(x);
24: VecCreate(PETSC_COMM_SELF,&y);
25: VecSetSizes(y,n,PETSC_DECIDE);
26: VecSetFromOptions(y);
28: /* create two index sets */
29: ISCreateGeneral(PETSC_COMM_SELF,2,idx1,PETSC_COPY_VALUES,&is1);
30: ISCreateGeneral(PETSC_COMM_SELF,2,idx2,PETSC_COPY_VALUES,&is2);
32: VecSet(x,one);
33: VecSet(y,two);
34: VecScatterCreate(x,is1,y,is2,&ctx);
35: VecScatterBegin(ctx,x,y,INSERT_VALUES,SCATTER_FORWARD);
36: VecScatterEnd(ctx,x,y,INSERT_VALUES,SCATTER_FORWARD);
37: VecScatterDestroy(&ctx);
39: if (!rank) {VecView(y,PETSC_VIEWER_STDOUT_SELF);}
41: ISDestroy(&is1);
42: ISDestroy(&is2);
44: VecDestroy(&x);
45: VecDestroy(&y);
46: PetscFinalize();
47: return ierr;
48: }
51: /*TEST
53: test:
54: nsize: 2
55: filter: grep -v type
57: test:
58: suffix: cuda
59: args: -vec_type cuda
60: output_file: output/ex4_1.out
61: filter: grep -v type
62: requires: cuda
64: test:
65: suffix: cuda2
66: nsize: 2
67: args: -vec_type cuda
68: output_file: output/ex4_1.out
69: filter: grep -v type
70: requires: cuda
72: TEST*/