/* nag_opt_simplex (e04ccc) Example Program.
 *
 * Copyright 1996 Numerical Algorithms Group.
 *
 * Mark 4, 1996.
 * Mark 6 revised, 2000.
 * Mark 7 revised, 2001.
 * Mark 7b revised, 2004.
 * Mark 8 revised, 2004.
 */

#include <math.h>
#include <stdio.h>
#include <string.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nage04.h>
#include <nagx02.h>
#include <nagx04.h>

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

int main(int argc, char *argv[])
{
  FILE        *fpout;
  char        *optionsfile = 0;
  char        *outfile = 0;
  Nag_Boolean print;
  Integer     exit_status = 0, n;
  Nag_Comm    comm;
  Nag_E04_Opt options;
  double      objf, *x = 0;
  NagError    fail;

  INIT_FAIL(fail);

  /* Check for command-line IO options */
  fpout = nag_example_file_io(argc, argv, "-results", NULL);
  (void) nag_example_file_io(argc, argv, "-options", &optionsfile);
  (void) nag_example_file_io(argc, argv, "-nag_write", &outfile);
  if (!outfile)
    {
      outfile = NAG_ALLOC(7, char);
      strcpy(outfile, "stdout");
    }


  fprintf(fpout, "nag_opt_simplex (e04ccc) Example Program Results\n");
  n = 2;
  if (n >= 1)
    {
      if (!(x = NAG_ALLOC(n, double)))
        {
          fprintf(fpout, "Allocation failure\n");
          exit_status = -1;
          goto END;
        }
    }
  else
    {
      fprintf(fpout, "Invalid n.\n");
      exit_status = 1;
      return exit_status;
    }
  /* nag_opt_init (e04xxc).
   * Initialization function for option setting
   */
  nag_opt_init(&options);
  strcpy(options.outfile, outfile);
  /* Read remaining option value from file */
  print = Nag_TRUE;
  /* nag_opt_read (e04xyc).
   * Read options from a text file
   */
  if (strcmp(outfile, "stdout"))
    fclose(fpout);
  nag_opt_read("e04ccc", optionsfile, &options, print, options.outfile, &fail);
  if (strcmp(outfile, "stdout"))
    {
      fpout = fopen(outfile, "a");
    }
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_opt_read (e04xyc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

  /* Starting values */
  x[0] = -1.0;
  x[1] = 1.0;

  /* nag_opt_simplex (e04ccc), see above. */
  if (strcmp(outfile, "stdout"))
    fclose(fpout);
  nag_opt_simplex(n, funct, x, &objf, &options, &comm, &fail);
  if (strcmp(outfile, "stdout"))
    {
      fpout = fopen(outfile, "a");
    }
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_opt_simplex (e04ccc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

 END:
  if (fpout != stdout) fclose(fpout);
  if (x) NAG_FREE(x);
  if (optionsfile) NAG_FREE(optionsfile);
  if (outfile) NAG_FREE(outfile);

  return exit_status;
}

static void NAG_CALL funct(Integer n, double *xc, double *objf, Nag_Comm *comm)
{
  *objf = exp(xc[0]) * (xc[0] * 4.0 * (xc[0] + xc[1]) +
                        xc[1] * 2.0 * (xc[1] + 1.0) + 1.0);
}