1 //===----------------------------------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // REQUIRES: long_tests
14 // template<class RealType = double>
15 // class normal_distribution
17 // template<class _URNG> result_type operator()(_URNG& g, const param_type& parm);
36 typedef std::normal_distribution<> D;
37 typedef D::param_type P;
38 typedef std::minstd_rand G;
42 const int N = 1000000;
43 std::vector<D::result_type> u;
44 for (int i = 0; i < N; ++i)
46 double mean = std::accumulate(u.begin(), u.end(), 0.0) / u.size();
50 for (std::size_t i = 0; i < u.size(); ++i)
52 double dbl = (u[i] - mean);
59 double dev = std::sqrt(var);
60 skew /= u.size() * dev * var;
61 kurtosis /= u.size() * var * var;
63 double x_mean = p.mean();
64 double x_var = sqr(p.stddev());
66 double x_kurtosis = 0;
67 assert(std::abs((mean - x_mean) / x_mean) < 0.01);
68 assert(std::abs((var - x_var) / x_var) < 0.01);
69 assert(std::abs(skew - x_skew) < 0.01);
70 assert(std::abs(kurtosis - x_kurtosis) < 0.01);