1// { dg-options "-std=gnu++11" }
2// Use smaller statistics when running on simulators, so it takes less time.
3// For powerpc-eabi, SAMPLES=30000 fails.
4// { dg-options "-std=gnu++11 -DSAMPLES=35000" { target simulator } }
5
6// Copyright (C) 2010-2015 Free Software Foundation, Inc.
7//
8// This file is part of the GNU ISO C++ Library.  This library is free
9// software; you can redistribute it and/or modify it under the
10// terms of the GNU General Public License as published by the
11// Free Software Foundation; either version 3, or (at your option)
12// any later version.
13//
14// This library is distributed in the hope that it will be useful,
15// but WITHOUT ANY WARRANTY; without even the implied warranty of
16// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17// GNU General Public License for more details.
18//
19// You should have received a copy of the GNU General Public License
20// along with this library; see the file COPYING3.  If not see
21// <http://www.gnu.org/licenses/>.
22
23#include "chi2_quality.h"
24
25// Tests chi^2 for a distribution of uniformly generated random strings.
26void
27test_uniform_random()
28{
29  bool test __attribute__((unused)) = true;
30  std::srand(137);
31  std::unordered_set<std::string> set;
32  std::string s;
33  const unsigned long N = SAMPLES;
34  const unsigned long k = N/100;
35  const unsigned int len = 25;
36  while (set.size() < N)
37    {
38      s.clear();
39      for (unsigned int i = 0; i < len; ++i)
40       s.push_back(rand() % 128);
41      set.insert(s);
42    }
43
44  double chi2 = chi2_hash(set, k);
45  VERIFY( chi2 < k*1.1 );
46}
47
48int
49main()
50{
51  test_uniform_random();
52  return 0;
53}
54