Actual source code: ex18.c


  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>

  8: int main(int argc,char **argv)
  9: {
 10:   PetscInt       n = 15,i;
 11:   PetscScalar    v;
 12:   Vec            x,y;

 14:   PetscInitialize(&argc,&argv,(char*)0,help);
 15:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 16:   if (n < 5) n = 5;

 18:   /* create two vectors */
 19:   VecCreateSeq(PETSC_COMM_SELF,n,&x);
 20:   VecCreateSeq(PETSC_COMM_SELF,n,&y);

 22:   for (i=0; i<n; i++) {
 23:     v    = ((PetscReal)i) + 1.0/(((PetscReal)i) + .35);
 24:     VecSetValues(x,1,&i,&v,INSERT_VALUES);
 25:     v   += 1.375547826473644376;
 26:     VecSetValues(y,1,&i,&v,INSERT_VALUES);
 27:   }
 28:   VecAssemblyBegin(y);
 29:   VecAssemblyEnd(y);

 31:   VecDot(x,y,&v);
 32:   PetscFPrintf(PETSC_COMM_WORLD,stdout,"Vector inner product %16.12e\n",(double)PetscRealPart(v));

 34:   VecDestroy(&x);
 35:   VecDestroy(&y);

 37:   PetscFinalize();
 38:   return 0;
 39: }

 41: /*TEST

 43:    test:

 45: TEST*/