#include <R.h> 
#include <Rdefines.h>
#include <Rmath.h> 
#include <stdio.h>
#include <math.h>
#include <stdlib.h>

void useC(double *i, int *size_i, double *d)                   

{
  int x;                                                  
  
  for (x=0; x<size_i[0]; x++){                            
      d[x] = d[x] * i[x]; 
      printf( "%2d is %4f \n",x, (double) d[x]);      
  }
}