/* This is a handy utility to calculate cumulative errors in the 
 * series generated by the numerical solutions programs for Homework 7
 * ecalc.c V 0.9 written in C by Stefan Joe-Yen November 1995
 */

#include<stdio.h>
#include<stdlib.h>
#include<math.h>

/* Set Up the size of the standard and experimental series */
#define N 10
#define N2 5

main()
{
   float t[N+1], w[N+1], t2[N2+1], w2[N2+1], error[N2+1], cerror;
   int i, j, stride;

   /* Initialize variables */
   stride = N/N2;
   cerror = 0;

   /* Input the data */

   for (i=0; i<=N; i++) {
   scanf("%f %f", &t[i], &w[i]);
   }
   for (i=0; i<=N2; i++) {
   scanf("%f %f", &t2[i], &w2[i]);
   }
   
   /* calculate the cumulative error */ 
   for (i=0; i<=N2; i++) {
   error[i] = fabs(w[stride * i] - w2[i]);
/* printf("%f %f %f\r\n", w[stride * i], w2[i], error[i]); /* diagnostic */ 
   cerror += error[i];
   }

   /* Print cumulative and average error */
   printf("Cumulative error for the series is %f\r\n", cerror);
   printf("Average error for the series is %f\r\n", cerror/(N2+1));   
}