Actual source code: ex18.c
petsc-3.7.3 2016-07-24
2: static char help[] = "Compares BLAS dots on different machines. Input\n\
3: arguments are\n\
4: -n <length> : local vector length\n\n";
6: #include <petscvec.h>
10: int main(int argc,char **argv)
11: {
13: PetscInt n = 15,i;
14: PetscScalar v;
15: Vec x,y;
17: PetscInitialize(&argc,&argv,(char*)0,help);
18: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
19: if (n < 5) n = 5;
22: /* create two vectors */
23: VecCreateSeq(PETSC_COMM_SELF,n,&x);
24: VecCreateSeq(PETSC_COMM_SELF,n,&y);
26: for (i=0; i<n; i++) {
27: v = ((PetscReal)i) + 1.0/(((PetscReal)i) + .35);
28: VecSetValues(x,1,&i,&v,INSERT_VALUES);
29: v += 1.375547826473644376;
30: VecSetValues(y,1,&i,&v,INSERT_VALUES);
31: }
32: VecAssemblyBegin(y);
33: VecAssemblyEnd(y);
35: VecDot(x,y,&v);
36: PetscFPrintf(PETSC_COMM_WORLD,stdout,"Vector inner product %16.12e\n",v);
38: VecDestroy(&x);
39: VecDestroy(&y);
41: PetscFinalize();
42: return 0;
43: }