/* stat.c -- statistical tests of random number sequences. */

/*
Copyright 1999, 2000 Free Software Foundation, Inc.

This file is part of the GNU MP Library.

The GNU MP Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version.

The GNU MP Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
License for more details.

You should have received a copy of the GNU Lesser General Public License
along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA.
*/

/* Examples:

  $ gen 1000 | stat
Test 1000 real numbers.

  $ gen 30000 | stat -2 1000
Test 1000 real numbers 30 times and then test the 30 results in a 
``second level''.

  $ gen -f mpz_urandomb 1000 | stat -i 0xffffffff
Test 1000 integers 0 <= X <= 2^32-1.

  $ gen -f mpz_urandomb -z 34 1000 | stat -i 0x3ffffffff
Test 1000 integers 0 <= X <= 2^34-1.

*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <math.h>
#include "gmp.h"
#include "gmpstat.h"

#if !HAVE_DECL_OPTARG
extern char *optarg;
extern int optind, opterr;
#endif

#define FVECSIZ (100000L)

int g_debug = 0;

static void
print_ks_results (mpf_t f_p, mpf_t f_p_prob,
		  mpf_t f_m, mpf_t f_m_prob,
		  FILE *fp)
{
  double p, pp, m, mp;

  p = mpf_get_d (f_p);
  m = mpf_get_d (f_m);
  pp = mpf_get_d (f_p_prob);
  mp = mpf_get_d (f_m_prob);
  
  fprintf (fp, "%.4f (%.0f%%)\t", p, pp * 100.0);
  fprintf (fp, "%.4f (%.0f%%)\n", m, mp * 100.0);
}

static void
print_x2_table (unsigned int v, FILE *fp)
{
  double t[7];
  int f;


  fprintf (fp, "Chi-square table for v=%u\n", v);
  fprintf (fp, "1%%\t5%%\t25%%\t50%%\t75%%\t95%%\t99%%\n");
  x2_table (t, v);
  for (f = 0; f < 7; f++)
    fprintf (fp, "%.2f\t", t[f]);
  fputs ("\n", fp);
}



/* Pks () -- Distribution function for KS results with a big n (like 1000
   or so):  F(x) = 1 - pow(e, -2*x^2) [Knuth, vol 2, p.51]. */
/* gnuplot: plot [0:1] Pks(x), Pks(x) = 1-exp(-2*x**2)  */

static void
Pks (mpf_t p, mpf_t x)
{
  double dt;			/* temp double */

  mpf_set (p, x);
  mpf_mul (p, p, p);		/* p = x^2 */
  mpf_mul_ui (p, p, 2);		/* p = 2*x^2 */
  mpf_neg (p, p);		/* p = -2*x^2 */
  /* No pow() in gmp.  Use doubles. */
  /* FIXME: Use exp()? */
  dt = pow (M_E, mpf_get_d (p));
  mpf_set_d (p, dt);
  mpf_ui_sub (p, 1, p);
}

/* f_freq() -- frequency test on real numbers 0<=f<1*/
static void
f_freq (const unsigned l1runs, const unsigned l2runs,
	mpf_t fvec[], const unsigned long n)
{
  unsigned f;
  mpf_t f_p, f_p_prob;
  mpf_t f_m, f_m_prob;
  mpf_t *l1res;			/* level 1 result array */

  mpf_init (f_p);  mpf_init (f_m);
  mpf_init (f_p_prob);  mpf_init (f_m_prob);

  
  /* Allocate space for 1st level results. */
  l1res = (mpf_t *) malloc (l2runs * 2 * sizeof (mpf_t));
  if (NULL == l1res)
    {
      fprintf (stderr, "stat: malloc failure\n");
      exit (1);
    }
  
  printf ("\nEquidistribution/Frequency test on real numbers (0<=X<1):\n");
  printf ("\tKp\t\tKm\n");

  for (f = 0; f < l2runs; f++)
    {
      /*  f_printvec (fvec, n); */
      mpf_freqt (f_p, f_m, fvec + f * n, n);

      /* what's the probability of getting these results? */
      ks_table (f_p_prob, f_p, n);
      ks_table (f_m_prob, f_m, n);

      if (l1runs == 0)
	{
	  /*printf ("%u:\t", f + 1);*/
	  print_ks_results (f_p, f_p_prob, f_m, f_m_prob, stdout);
	}
      else
	{
	  /* save result */
	  mpf_init_set (l1res[f], f_p);
	  mpf_init_set (l1res[f + l2runs], f_m);
	}
    }

  /* Now, apply the KS test on the results from the 1st level rounds
     with the distribution
     F(x) = 1 - pow(e, -2*x^2)	[Knuth, vol 2, p.51] */

  if (l1runs != 0)
    {
      /*printf ("-------------------------------------\n");*/

      /* The Kp's. */
      ks (f_p, f_m, l1res, Pks, l2runs);
      ks_table (f_p_prob, f_p, l2runs);
      ks_table (f_m_prob, f_m, l2runs);
      printf ("Kp:\t");
      print_ks_results (f_p, f_p_prob, f_m, f_m_prob, stdout);

      /* The Km's. */
      ks (f_p, f_m, l1res + l2runs, Pks, l2runs);
      ks_table (f_p_prob, f_p, l2runs);
      ks_table (f_m_prob, f_m, l2runs);
      printf ("Km:\t");
      print_ks_results (f_p, f_p_prob, f_m, f_m_prob, stdout);
    }

  mpf_clear (f_p);  mpf_clear (f_m);
  mpf_clear (f_p_prob);  mpf_clear (f_m_prob);
  free (l1res);
}  

/* z_freq(l1runs, l2runs, zvec, n, max) -- frequency test on integers
   0<=z<=MAX */
static void
z_freq (const unsigned l1runs,
	const unsigned l2runs,
	mpz_t zvec[],
	const unsigned long n,
	unsigned int max)
{
  mpf_t V;			/* result */
  double d_V;			/* result as a double */

  mpf_init (V);


  printf ("\nEquidistribution/Frequency test on integers (0<=X<=%u):\n", max);
  print_x2_table (max, stdout);

  mpz_freqt (V, zvec, max, n);

  d_V = mpf_get_d (V);
  printf ("V = %.2f (n = %lu)\n", d_V, n);
  
  mpf_clear (V);
}

unsigned int stat_debug = 0;

int 
main (argc, argv)
     int argc;
     char *argv[];
{
  const char usage[] =
    "usage: stat [-d] [-2 runs] [-i max | -r max] [file]\n" \
    "       file     filename\n" \
    "       -2 runs  perform 2-level test with RUNS runs on 1st level\n" \
    "       -d       increase debugging level\n" \
    "       -i max   input is integers 0 <= Z <= MAX\n" \
    "       -r max   input is real numbers 0 <= R < 1 and use MAX as\n" \
    "                maximum value when converting real numbers to integers\n" \
    "";
  
  mpf_t fvec[FVECSIZ];
  mpz_t zvec[FVECSIZ];
  unsigned long int f, n, vecentries;
  char *filen;
  FILE *fp;
  int c;
  int omitoutput = 0;
  int realinput = -1;		/* 1: input is real numbers 0<=R<1;
				   0: input is integers 0 <= Z <= MAX. */
  long l1runs = 0,		/* 1st level runs */
    l2runs = 1;			/* 2nd level runs */
  mpf_t f_temp;
  mpz_t z_imax;			/* max value when converting between
                                   real number and integer. */
  mpf_t f_imax_plus1;		/* f_imax + 1 stored in an mpf_t for
                                   convenience */
  mpf_t f_imax_minus1;		/* f_imax - 1 stored in an mpf_t for
                                   convenience */


  mpf_init (f_temp);
  mpz_init_set_ui (z_imax, 0x7fffffff);
  mpf_init (f_imax_plus1);
  mpf_init (f_imax_minus1);

  while ((c = getopt (argc, argv, "d2:i:r:")) != -1)
    switch (c)
      {
      case '2':
	l1runs = atol (optarg);
	l2runs = -1;		/* set later on */
	break;
      case 'd':			/* increase debug level */
	stat_debug++;
	break;
      case 'i':
	if (1 == realinput)
	  {
	    fputs ("stat: options -i and -r are mutually exclusive\n", stderr);
	    exit (1);
	  }
	if (mpz_set_str (z_imax, optarg, 0))
	  {
	    fprintf (stderr, "stat: bad max value %s\n", optarg);
	    exit (1);
	  }
	realinput = 0;
	break;
      case 'r':
	if (0 == realinput)
	  {
	    fputs ("stat: options -i and -r are mutually exclusive\n", stderr);
	    exit (1);
	  }
	if (mpz_set_str (z_imax, optarg, 0))
	  {
	    fprintf (stderr, "stat: bad max value %s\n", optarg);
	    exit (1);
	  }
	realinput = 1;
	break;
      case 'o':
	omitoutput = atoi (optarg);
	break;
      case '?':
      default:
	fputs (usage, stderr);
	exit (1);
      }
  argc -= optind;
  argv += optind;

  if (argc < 1)
    fp = stdin;
  else
    filen = argv[0]; 

  if (fp != stdin)
    if (NULL == (fp = fopen (filen, "r")))
      {
	perror (filen);
	exit (1);
      }

  if (-1 == realinput)
    realinput = 1;		/* default is real numbers */

  /* read file and fill appropriate vec */
  if (1 == realinput)		/* real input */
    {
      for (f = 0; f < FVECSIZ ; f++)
	{
	  mpf_init (fvec[f]);
	  if (!mpf_inp_str (fvec[f], fp, 10))
	    break;
	}
    }
  else				/* integer input */
    {
      for (f = 0; f < FVECSIZ ; f++)
	{
	  mpz_init (zvec[f]);
	  if (!mpz_inp_str (zvec[f], fp, 10))
	    break;
	}
    }    
  vecentries = n = f;		/* number of entries read */
  fclose (fp);

  if (FVECSIZ == f)
    fprintf (stderr, "stat: warning: discarding input due to lazy allocation "\
	     "of only %ld entries.  sorry.\n", FVECSIZ);

  printf ("Got %lu numbers.\n", n);

  /* convert and fill the other vec */
  /* since fvec[] contains 0<=f<1 and we want ivec[] to contain
     0<=z<=imax and we are truncating all fractions when
     converting float to int, we have to add 1 to imax.*/
  mpf_set_z (f_imax_plus1, z_imax);
  mpf_add_ui (f_imax_plus1, f_imax_plus1, 1);
  if (1 == realinput)		/* fill zvec[] */
    {
      for (f = 0; f < n; f++)
	{
	  mpf_mul (f_temp, fvec[f], f_imax_plus1);
	  mpz_init (zvec[f]);
	  mpz_set_f (zvec[f], f_temp); /* truncating fraction */
	  if (stat_debug > 1)
	    {
	      mpz_out_str (stderr, 10, zvec[f]);
	      fputs ("\n", stderr);
	    }
	}
    }
  else				/* integer input; fill fvec[] */
    {
      /*    mpf_set_z (f_imax_minus1, z_imax); 
	    mpf_sub_ui (f_imax_minus1, f_imax_minus1, 1);*/
      for (f = 0; f < n; f++)
	{
	  mpf_init (fvec[f]);
	  mpf_set_z (fvec[f], zvec[f]);
	  mpf_div (fvec[f], fvec[f], f_imax_plus1);
	  if (stat_debug > 1)
	    {
	      mpf_out_str (stderr, 10, 0, fvec[f]);
	      fputs ("\n", stderr);
	    }
	}
    }
  
  /* 2 levels? */
  if (1 != l2runs)
    {
      l2runs = n / l1runs;
      printf ("Doing %ld second level rounds "\
	      "with %ld entries in each round", l2runs, l1runs);
      if (n % l1runs)
	printf (" (discarding %ld entr%s)", n % l1runs,
		n % l1runs == 1 ? "y" : "ies");
      puts (".");
      n = l1runs;
    }

#ifndef DONT_FFREQ
  f_freq (l1runs, l2runs, fvec, n);
#endif
#ifdef DO_ZFREQ
  z_freq (l1runs, l2runs, zvec, n, mpz_get_ui (z_imax));
#endif

  mpf_clear (f_temp); mpz_clear (z_imax); 
  mpf_clear (f_imax_plus1);
  mpf_clear (f_imax_minus1);
  for (f = 0; f < vecentries; f++)
    {
      mpf_clear (fvec[f]);
      mpz_clear (zvec[f]);
    }

  return 0;
}