#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "local_proto.h"


double *dagostino_d  (double *x, int n)
{
  int i;
  static double y[2];
  double d, s, t = 0., *xcopy, m2, s1 = 0., s2, mn = 0.0;

  if ((xcopy = (double *) malloc (n * sizeof (double))) == NULL)
  {
    fprintf (stderr, "Memory allocation error\n");
    exit (EXIT_FAILURE);
  }

  for (i = 0; i < n; ++i)
    xcopy[i] = x[i];

  qsort (xcopy, n, sizeof (double), dcmp);

  for (i = 0; i < n; ++i)
  {
    t += xcopy[i] * ((i + 1) - 0.5 * (n + 1));
    mn += xcopy[i];
  }

  m2 = mn / n;
  for (i = 0; i < n; ++i)
    s1 += (xcopy[i] - m2) * (xcopy[i] - m2);

  s2 = s1 / n;
  s = sqrt (s2);
  d = t / (n * n * s);

  /* y[0] = (d - 1. / (2*sqrt (M_PI))) * sqrt ((double)n) / 0.02998598; */
  y[0] = d;
  y[1] = sqrt((double)n)*(y[0]-0.28209479)/0.02998598;

#ifdef NOISY
  fprintf (stdout,"  TEST4  DAGN   =%10.4f\n", y[0]);
#endif /* NOISY */

  return y;
}
