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 exponential_distribution
17 // template<class _URNG> result_type operator()(_URNG& g);
36 typedef std::exponential_distribution<> D;
37 typedef D::param_type P;
38 typedef std::mt19937 G;
41 const int N = 1000000;
42 std::vector<D::result_type> u;
43 for (int i = 0; i < N; ++i)
45 D::result_type v = d(g);
49 double mean = std::accumulate(u.begin(), u.end(), 0.0) / u.size();
53 for (std::size_t i = 0; i < u.size(); ++i)
55 double dbl = (u[i] - mean);
62 double dev = std::sqrt(var);
63 skew /= u.size() * dev * var;
64 kurtosis /= u.size() * var * var;
66 double x_mean = 1/d.lambda();
67 double x_var = 1/sqr(d.lambda());
69 double x_kurtosis = 6;
70 assert(std::abs((mean - x_mean) / x_mean) < 0.01);
71 assert(std::abs((var - x_var) / x_var) < 0.01);
72 assert(std::abs((skew - x_skew) / x_skew) < 0.01);
73 assert(std::abs((kurtosis - x_kurtosis) / x_kurtosis) < 0.01);
76 typedef std::exponential_distribution<> D;
77 typedef D::param_type P;
78 typedef std::mt19937 G;
81 const int N = 1000000;
82 std::vector<D::result_type> u;
83 for (int i = 0; i < N; ++i)
85 D::result_type v = d(g);
89 double mean = std::accumulate(u.begin(), u.end(), 0.0) / u.size();
93 for (std::size_t i = 0; i < u.size(); ++i)
95 double dbl = (u[i] - mean);
102 double dev = std::sqrt(var);
103 skew /= u.size() * dev * var;
104 kurtosis /= u.size() * var * var;
106 double x_mean = 1/d.lambda();
107 double x_var = 1/sqr(d.lambda());
109 double x_kurtosis = 6;
110 assert(std::abs((mean - x_mean) / x_mean) < 0.01);
111 assert(std::abs((var - x_var) / x_var) < 0.01);
112 assert(std::abs((skew - x_skew) / x_skew) < 0.01);
113 assert(std::abs((kurtosis - x_kurtosis) / x_kurtosis) < 0.01);
116 typedef std::exponential_distribution<> D;
117 typedef D::param_type P;
118 typedef std::mt19937 G;
121 const int N = 1000000;
122 std::vector<D::result_type> u;
123 for (int i = 0; i < N; ++i)
125 D::result_type v = d(g);
129 double mean = std::accumulate(u.begin(), u.end(), 0.0) / u.size();
133 for (std::size_t i = 0; i < u.size(); ++i)
135 double dbl = (u[i] - mean);
136 double d2 = sqr(dbl);
142 double dev = std::sqrt(var);
143 skew /= u.size() * dev * var;
144 kurtosis /= u.size() * var * var;
146 double x_mean = 1/d.lambda();
147 double x_var = 1/sqr(d.lambda());
149 double x_kurtosis = 6;
150 assert(std::abs((mean - x_mean) / x_mean) < 0.01);
151 assert(std::abs((var - x_var) / x_var) < 0.01);
152 assert(std::abs((skew - x_skew) / x_skew) < 0.01);
153 assert(std::abs((kurtosis - x_kurtosis) / x_kurtosis) < 0.01);