/* nag_monotonic_deriv(e01bgc) Example Program
 *
 * Copyright 1991 Numerical Algorithms Group.
 *
 * Mark 2, 1991.
 */

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nage01.h>

#define MMAX 21
#define NMAX 50

int main(void)
{
  Integer i, m, n, r;
  double x[NMAX], pd[MMAX], pf[MMAX], px[MMAX], f[NMAX], d[NMAX], step;

  Vprintf("e01bgc Example Program Results\n");
  Vscanf("%*[^\n]");  /* Skip heading in data file */
  Vscanf("%ld",&n);
  if (n>0 && n<=NMAX)
    {
      for (r=0; r<n; r++)
        Vscanf("%lf%lf%lf",&x[r], &f[r], &d[r]);
      Vscanf("%ld",&m);
      if (m>0 && m<=MMAX)
        {
          /* compute m equally spaced points from x[0] to x[n-1]. */
          step = (x[n-1]-x[0]) / (double)(m-1);
          for (i=0; i<m; i++)
            px[i] = MIN(x[0]+i*step,x[n-1]);
          e01bgc(n, x, f, d, m, px, pf, pd, NAGERR_DEFAULT);
          Vprintf("                            Interpolated");
          Vprintf("      Interpolated\n");
          Vprintf("       Abscissa                Value");
          Vprintf("           Derivative\n");
          for (i=0; i<m; i++)
            Vprintf("%15.4f      %15.4f      %15.3e\n",px[i],pf[i],pd[i]);
          return EXIT_SUCCESS;
        }
      else
        {
          Vfprintf(stderr, "m is out of range: m = %ld\n",m);
          return EXIT_FAILURE;
        }
    }
  else
    {
      Vfprintf(stderr, "n is out of range: n = %ld\n",n);
      return EXIT_FAILURE;
    }
}