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


double *anderson_darling_exp  (double *x, int n)
{
  static double y[2];
  double sqrt2, mean = 0.0, *xcopy, fx, sum3 = 0.0;
  int i;

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

  sqrt2 = sqrt ((double) 2.0);

  for (i = 0; i < n; ++i)
  {
    xcopy[i]= x[i];
    mean += x[i];
  }
  mean /= n;
  qsort (xcopy, n, sizeof (double), dcmp);

  for (i = 0; i < n; ++i)
  {
    fx = 1-exp(-xcopy[i]/mean);
    sum3 += (2.0 * i + 1) * (log (fx) -xcopy[n-i-1]/mean);
  }

  y[0] = (1.0+0.3/n)*(-n-sum3/n);
#ifdef NOISY
  fprintf (stdout,"  TEST20 AD(E)  =%10.4f\n", y[0]);
#endif				/* NOISY */

  free(xcopy);

  return y;
}
