/* nag_opt_one_var_no_deriv (e04abc) Example Program.
 *
 * Copyright 1998 Numerical Algorithms Group.
 *
 * Mark 5, 1998.
 * Mark 7 revised, 2001.
 * Mark 8 revised, 2004.
 *
 */

#include <nag.h>
#include <nagx04.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <math.h>
#include <nage04.h>

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

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

int main(int argc, char *argv[])
{
  FILE     *fpout;
  Integer  exit_status = 0, max_fun;
  NagError fail;
  Nag_Comm comm;
  double   a, b, e1, e2, f, x;

  INIT_FAIL(fail);

  /* Check for command-line IO options */
  fpout = nag_example_file_io(argc, argv, "-results", NULL);


  fprintf(fpout,
          "nag_opt_one_var_no_deriv (e04abc) Example Program Results\n\n");

  /* e1 and e2 are set to zero so that nag_opt_one_var_no_deriv (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;
  /* nag_opt_one_var_no_deriv (e04abc).
   * Minimizes a function of one variable, using function values only.
   */
  nag_opt_one_var_no_deriv(funct, e1, e2, &a, &b, max_fun, &x, &f, &comm,
                           &fail);
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_opt_one_var_no_deriv (e04abc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  fprintf(fpout, "The minimum lies in the interval %7.5f to %7.5f.\n", a, b);
  fprintf(fpout, "Its estimated position is %7.5f,\n", x);
  fprintf(fpout, "where the function value is %13.4e.\n", f);
  fprintf(fpout, "%1ld function evaluations were required.\n", comm.nf);

 END:
  if (fpout != stdout) fclose(fpout);
  return exit_status;
}