1 
2 static char help[] = "Compares BLAS dots on different machines. Input\n\
3 arguments are\n\
4   -n <length> : local vector length\n\n";
5 
6 
7 #include <petscvec.h>
8 
main(int argc,char ** argv)9 int main(int argc,char **argv)
10 {
11   PetscErrorCode ierr;
12   PetscInt       n = 15,i;
13   PetscScalar    v;
14   Vec            x,y;
15 
16   ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
17   ierr = PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);CHKERRQ(ierr);
18   if (n < 5) n = 5;
19 
20 
21   /* create two vectors */
22   ierr = VecCreateSeq(PETSC_COMM_SELF,n,&x);CHKERRQ(ierr);
23   ierr = VecCreateSeq(PETSC_COMM_SELF,n,&y);CHKERRQ(ierr);
24 
25   for (i=0; i<n; i++) {
26     v    = ((PetscReal)i) + 1.0/(((PetscReal)i) + .35);
27     ierr = VecSetValues(x,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr);
28     v   += 1.375547826473644376;
29     ierr = VecSetValues(y,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr);
30   }
31   ierr = VecAssemblyBegin(y);CHKERRQ(ierr);
32   ierr = VecAssemblyEnd(y);CHKERRQ(ierr);
33 
34   ierr = VecDot(x,y,&v);CHKERRQ(ierr);
35   ierr = PetscFPrintf(PETSC_COMM_WORLD,stdout,"Vector inner product %16.12e\n",(double)PetscRealPart(v));CHKERRQ(ierr);
36 
37   ierr = VecDestroy(&x);CHKERRQ(ierr);
38   ierr = VecDestroy(&y);CHKERRQ(ierr);
39 
40   ierr = PetscFinalize();
41   return ierr;
42 }
43 
44 
45 
46 /*TEST
47 
48    test:
49 
50 TEST*/
51