/* nag_opt_one_var_deriv(e04bbc) Example Program.
 *
 * Copyright 1998 Numerical Algorithms Group.
 *
 * Mark 5, 1998.
 * Mark 7 revised, 2001.
 *
 */

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <math.h>
#include <nage04.h>

#ifdef __cplusplus
extern "C" {
#endif
static void funct(double xc, double *fc, double *gc, Nag_Comm *comm);
#ifdef __cplusplus
}
#endif

static void funct(double xc, double *fc, double *gc, Nag_Comm *comm)
{
  *fc = sin(xc) / xc;
  *gc = (cos(xc) - *fc) / xc;
}
/* funct */

int main(void)
{
  double a, b;
  double e1, e2;
  double x, f, g;
  Integer max_fun;
  Nag_Comm comm;
  static NagError fail;

  Vprintf("e04bbc Example Program Results.\n\n");

  /* e1 and e2 are set to zero so that e04abc will reset them to
   *  their default values
   */
  e1 = 0.0;
  e2 = 0.0;
  /* The minimum is known to lie in the range (3.5, 5.0) */
  a = 3.5;
  b = 5.0;
  /* Allow 30 calls of funct */
  max_fun = 30;
  fail.print = TRUE;
  e04bbc(funct, e1, e2, &a, &b, max_fun, &x, &f, &g, &comm, &fail);

  Vprintf("The minimum lies in the interval %7.5f to %7.5f.\n", a, b);
  Vprintf("Its estimated position is %7.5f,\n", x);
  Vprintf("where the function value is %9.4e\n",f);
  Vprintf("and the gradient is %9.4e.\n",g);
  Vprintf("%1ld function evaluations were required.\n", comm.nf);

  return EXIT_SUCCESS;
}