/* ---------------------------------- */
/* save as c1a.c                      */
/* ---------------------------------- */
#include "x_hfile.h"
#include      "fa.h"
/* --------------------------------- */
int main(void)
{
double (*P_f)(double x, double y);

double                  n;
double                  a;
double                  b;
double                 y0;

 P_f = Y_p;
   n =       10.0;
   a =        1.0;
   b =        2.4;
  y0 =        1.59;

 clrscrn();
 
 printf(" Heun's method to approximate the solution\n" 
        " of the differential equation.\n\n" 
        "  y' = %s\n\n",Y_peq);

 p_Heun_s_Method(a,
                        b,
                        n,
                        y0,
                        (*P_f));

 printf("                    y_n = %.10f\n\n",
          Heun_s_Method(a,
                        b,
                        n,
                        y0,
                        (*P_f))
        );

 printf(" The exact value is y   = 5.790805\n\n");

 stop();
 
 
 clrscrn();
 
 n = 10000.0;
  
 printf(" Heun's method to approximate the solution\n" 
        " of the differential equation\n\n" 
        "  y' = %s,\n\n with n = %.0f \n\n",Y_peq, n);


 printf("                    y_n = %.10f\n\n",
          Heun_s_Method(a,
                        b,
                        n,
                        y0,
                        (*P_f))
        );

 printf(" The exact value is y   = 5.790805\n\n");

 stop();
 return 0;
}