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 weibull_distribution
17 // template<class _URNG> result_type operator()(_URNG& g);
36 typedef std::weibull_distribution<> D;
37 typedef std::mt19937 G;
40 const int N = 1000000;
41 std::vector<D::result_type> u;
42 for (int i = 0; i < N; ++i)
44 D::result_type v = d(g);
48 double mean = std::accumulate(u.begin(), u.end(), 0.0) / u.size();
52 for (std::size_t i = 0; i < u.size(); ++i)
54 double dbl = (u[i] - mean);
61 double dev = std::sqrt(var);
62 skew /= u.size() * dev * var;
63 kurtosis /= u.size() * var * var;
65 double x_mean = d.b() * std::tgamma(1 + 1/d.a());
66 double x_var = sqr(d.b()) * std::tgamma(1 + 2/d.a()) - sqr(x_mean);
67 double x_skew = (sqr(d.b())*d.b() * std::tgamma(1 + 3/d.a()) -
68 3*x_mean*x_var - sqr(x_mean)*x_mean) /
69 (std::sqrt(x_var)*x_var);
70 double x_kurtosis = (sqr(sqr(d.b())) * std::tgamma(1 + 4/d.a()) -
71 4*x_skew*x_var*sqrt(x_var)*x_mean -
72 6*sqr(x_mean)*x_var - sqr(sqr(x_mean))) / sqr(x_var) - 3;
73 assert(std::abs((mean - x_mean) / x_mean) < 0.01);
74 assert(std::abs((var - x_var) / x_var) < 0.01);
75 assert(std::abs((skew - x_skew) / x_skew) < 0.01);
76 assert(std::abs((kurtosis - x_kurtosis) / x_kurtosis) < 0.03);
79 typedef std::weibull_distribution<> D;
80 typedef std::mt19937 G;
83 const int N = 1000000;
84 std::vector<D::result_type> u;
85 for (int i = 0; i < N; ++i)
87 D::result_type v = d(g);
91 double mean = std::accumulate(u.begin(), u.end(), 0.0) / u.size();
95 for (std::size_t i = 0; i < u.size(); ++i)
97 double dbl = (u[i] - mean);
104 double dev = std::sqrt(var);
105 skew /= u.size() * dev * var;
106 kurtosis /= u.size() * var * var;
108 double x_mean = d.b() * std::tgamma(1 + 1/d.a());
109 double x_var = sqr(d.b()) * std::tgamma(1 + 2/d.a()) - sqr(x_mean);
110 double x_skew = (sqr(d.b())*d.b() * std::tgamma(1 + 3/d.a()) -
111 3*x_mean*x_var - sqr(x_mean)*x_mean) /
112 (std::sqrt(x_var)*x_var);
113 double x_kurtosis = (sqr(sqr(d.b())) * std::tgamma(1 + 4/d.a()) -
114 4*x_skew*x_var*sqrt(x_var)*x_mean -
115 6*sqr(x_mean)*x_var - sqr(sqr(x_mean))) / sqr(x_var) - 3;
116 assert(std::abs((mean - x_mean) / x_mean) < 0.01);
117 assert(std::abs((var - x_var) / x_var) < 0.01);
118 assert(std::abs((skew - x_skew) / x_skew) < 0.01);
119 assert(std::abs((kurtosis - x_kurtosis) / x_kurtosis) < 0.01);
122 typedef std::weibull_distribution<> D;
123 typedef std::mt19937 G;
126 const int N = 1000000;
127 std::vector<D::result_type> u;
128 for (int i = 0; i < N; ++i)
130 D::result_type v = d(g);
131 assert(d.min() <= v);
134 double mean = std::accumulate(u.begin(), u.end(), 0.0) / u.size();
138 for (std::size_t i = 0; i < u.size(); ++i)
140 double dbl = (u[i] - mean);
141 double d2 = sqr(dbl);
147 double dev = std::sqrt(var);
148 skew /= u.size() * dev * var;
149 kurtosis /= u.size() * var * var;
151 double x_mean = d.b() * std::tgamma(1 + 1/d.a());
152 double x_var = sqr(d.b()) * std::tgamma(1 + 2/d.a()) - sqr(x_mean);
153 double x_skew = (sqr(d.b())*d.b() * std::tgamma(1 + 3/d.a()) -
154 3*x_mean*x_var - sqr(x_mean)*x_mean) /
155 (std::sqrt(x_var)*x_var);
156 double x_kurtosis = (sqr(sqr(d.b())) * std::tgamma(1 + 4/d.a()) -
157 4*x_skew*x_var*sqrt(x_var)*x_mean -
158 6*sqr(x_mean)*x_var - sqr(sqr(x_mean))) / sqr(x_var) - 3;
159 assert(std::abs((mean - x_mean) / x_mean) < 0.01);
160 assert(std::abs((var - x_var) / x_var) < 0.01);
161 assert(std::abs((skew - x_skew) / x_skew) < 0.01);
162 assert(std::abs((kurtosis - x_kurtosis) / x_kurtosis) < 0.03);