/* nag_robust_m_estim_1var (g07dbc) Example Program.
 *
 * Copyright 1996 Numerical Algorithms Group.
 *
 * Mark 4, 1996.
 *
 * Mark 6 revised, 2000.
 * Mark 8 revised, 2004.
 */

#include <nag.h>
#include <nag_stdlib.h>
#include <nag_string.h>
#include <stdio.h>
#include <nagg07.h>

int main(void)
{
  Integer exit_status=0, i, isigma, maxit, n, nit;
  NagError fail;
  Nag_SigmaSimulEst sigma_enum;
  char sigma_enum_str[20];
  double c, dchi, h1, h2, h3, *rs=0, sigma, sigsav, *sorted_x=0, thesav, theta;
  double tol, *x=0;

  INIT_FAIL(fail);
  Vprintf("nag_robust_m_estim_1var (g07dbc) Example Program Results\n\n");

  /* Skip heading in data file */
  Vscanf("%*[^\n]\n");
  Vscanf("%ld %*[^\n]\n",&n);
  if (n>1)
    {
      if ( !( x = NAG_ALLOC(n, double)) ||
           !( rs = NAG_ALLOC(n, double)) ||
           !( sorted_x = NAG_ALLOC(n, double)) )
        {
          Vprintf("Allocation failure\n");
          exit_status = -1;
          goto END;
        }
    }
  else
    {
      Vprintf("Invalid n.\n");
      exit_status = 1;
      return exit_status;
    }
  for (i = 1; i <= n; ++i)
    Vscanf("%lf", &x[i - 1]);
  Vscanf("%*[^\n]\n");
  Vscanf("%lf %lf %lf %lf %ld %*[^\n]\n", &h1,&h2,&h3,&dchi,&maxit);
  Vprintf("%25sInput parameters     Output parameters\n","");
  Vprintf("   sigma_est         sigma    theta   tol       sigma   theta\n\n");
  while ((scanf("%ld %lf %lf %lf%*[^\n]", &isigma,&sigma,&theta,&tol))
         != EOF)
    {
      if (isigma == 1)
        {
          sigma_enum = Nag_SigmaSimul;
          strcpy(sigma_enum_str, "Nag_SigmaSimul");
        }
      else if (isigma == 0)
        {
          sigma_enum = Nag_SigmaBypas;
          strcpy(sigma_enum_str, "Nag_SigmaBypas");
        }
      sigsav = sigma;
      thesav = theta;
      c = 0.0;

      /* nag_robust_m_estim_1var (g07dbc).
       * Robust estimation, M-estimates for location and scale
       * parameters, standard weight functions
       */
      nag_robust_m_estim_1var(sigma_enum, n, x, Nag_HampelFun, c, h1, h2, h3,
                              dchi, &theta, &sigma, maxit, tol, rs, &nit,
                              sorted_x, &fail);
      if (fail.code != NE_NOERROR)
        {
          Vprintf("Error from nag_robust_m_estim_1var (g07dbc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }

      Vprintf("%s    %8.4f %8.4f %7.4f %9.4f %8.4f\n", sigma_enum_str,
              sigsav, thesav,tol,sigma,theta);
    }
 END:
  if (x) NAG_FREE(x);
  if (rs) NAG_FREE(rs);
  if (sorted_x) NAG_FREE(sorted_x);
  return exit_status;
}