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eval_param.pass.cpp (5910B)


      1 //===----------------------------------------------------------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is dual licensed under the MIT and the University of Illinois Open
      6 // Source Licenses. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // REQUIRES: long_tests
     11 
     12 // <random>
     13 
     14 // template<class RealType = double>
     15 // class weibull_distribution
     16 
     17 // template<class _URNG> result_type operator()(_URNG& g, const param_type& parm);
     18 
     19 #include <random>
     20 #include <cassert>
     21 #include <vector>
     22 #include <numeric>
     23 #include <cstddef>
     24 
     25 template <class T>
     26 inline
     27 T
     28 sqr(T x)
     29 {
     30     return x * x;
     31 }
     32 
     33 int main()
     34 {
     35     {
     36         typedef std::weibull_distribution<> D;
     37         typedef D::param_type P;
     38         typedef std::mt19937 G;
     39         G g;
     40         D d(0.5, 2);
     41         P p(1, .5);
     42         const int N = 1000000;
     43         std::vector<D::result_type> u;
     44         for (int i = 0; i < N; ++i)
     45         {
     46             D::result_type v = d(g, p);
     47             assert(d.min() <= v);
     48             u.push_back(v);
     49         }
     50         double mean = std::accumulate(u.begin(), u.end(), 0.0) / u.size();
     51         double var = 0;
     52         double skew = 0;
     53         double kurtosis = 0;
     54         for (std::size_t i = 0; i < u.size(); ++i)
     55         {
     56             double dbl = (u[i] - mean);
     57             double d2 = sqr(dbl);
     58             var += d2;
     59             skew += dbl * d2;
     60             kurtosis += d2 * d2;
     61         }
     62         var /= u.size();
     63         double dev = std::sqrt(var);
     64         skew /= u.size() * dev * var;
     65         kurtosis /= u.size() * var * var;
     66         kurtosis -= 3;
     67         double x_mean = p.b() * std::tgamma(1 + 1/p.a());
     68         double x_var = sqr(p.b()) * std::tgamma(1 + 2/p.a()) - sqr(x_mean);
     69         double x_skew = (sqr(p.b())*p.b() * std::tgamma(1 + 3/p.a()) -
     70                         3*x_mean*x_var - sqr(x_mean)*x_mean) /
     71                         (std::sqrt(x_var)*x_var);
     72         double x_kurtosis = (sqr(sqr(p.b())) * std::tgamma(1 + 4/p.a()) -
     73                        4*x_skew*x_var*sqrt(x_var)*x_mean -
     74                        6*sqr(x_mean)*x_var - sqr(sqr(x_mean))) / sqr(x_var) - 3;
     75         assert(std::abs((mean - x_mean) / x_mean) < 0.01);
     76         assert(std::abs((var - x_var) / x_var) < 0.01);
     77         assert(std::abs((skew - x_skew) / x_skew) < 0.01);
     78         assert(std::abs((kurtosis - x_kurtosis) / x_kurtosis) < 0.01);
     79     }
     80     {
     81         typedef std::weibull_distribution<> D;
     82         typedef D::param_type P;
     83         typedef std::mt19937 G;
     84         G g;
     85         D d(1, .5);
     86         P p(2, 3);
     87         const int N = 1000000;
     88         std::vector<D::result_type> u;
     89         for (int i = 0; i < N; ++i)
     90         {
     91             D::result_type v = d(g, p);
     92             assert(d.min() <= v);
     93             u.push_back(v);
     94         }
     95         double mean = std::accumulate(u.begin(), u.end(), 0.0) / u.size();
     96         double var = 0;
     97         double skew = 0;
     98         double kurtosis = 0;
     99         for (std::size_t i = 0; i < u.size(); ++i)
    100         {
    101             double dbl = (u[i] - mean);
    102             double d2 = sqr(dbl);
    103             var += d2;
    104             skew += dbl * d2;
    105             kurtosis += d2 * d2;
    106         }
    107         var /= u.size();
    108         double dev = std::sqrt(var);
    109         skew /= u.size() * dev * var;
    110         kurtosis /= u.size() * var * var;
    111         kurtosis -= 3;
    112         double x_mean = p.b() * std::tgamma(1 + 1/p.a());
    113         double x_var = sqr(p.b()) * std::tgamma(1 + 2/p.a()) - sqr(x_mean);
    114         double x_skew = (sqr(p.b())*p.b() * std::tgamma(1 + 3/p.a()) -
    115                         3*x_mean*x_var - sqr(x_mean)*x_mean) /
    116                         (std::sqrt(x_var)*x_var);
    117         double x_kurtosis = (sqr(sqr(p.b())) * std::tgamma(1 + 4/p.a()) -
    118                        4*x_skew*x_var*sqrt(x_var)*x_mean -
    119                        6*sqr(x_mean)*x_var - sqr(sqr(x_mean))) / sqr(x_var) - 3;
    120         assert(std::abs((mean - x_mean) / x_mean) < 0.01);
    121         assert(std::abs((var - x_var) / x_var) < 0.01);
    122         assert(std::abs((skew - x_skew) / x_skew) < 0.01);
    123         assert(std::abs((kurtosis - x_kurtosis) / x_kurtosis) < 0.03);
    124     }
    125     {
    126         typedef std::weibull_distribution<> D;
    127         typedef D::param_type P;
    128         typedef std::mt19937 G;
    129         G g;
    130         D d(2, 3);
    131         P p(.5, 2);
    132         const int N = 1000000;
    133         std::vector<D::result_type> u;
    134         for (int i = 0; i < N; ++i)
    135         {
    136             D::result_type v = d(g, p);
    137             assert(d.min() <= v);
    138             u.push_back(v);
    139         }
    140         double mean = std::accumulate(u.begin(), u.end(), 0.0) / u.size();
    141         double var = 0;
    142         double skew = 0;
    143         double kurtosis = 0;
    144         for (std::size_t i = 0; i < u.size(); ++i)
    145         {
    146             double dbl = (u[i] - mean);
    147             double d2 = sqr(dbl);
    148             var += d2;
    149             skew += dbl * d2;
    150             kurtosis += d2 * d2;
    151         }
    152         var /= u.size();
    153         double dev = std::sqrt(var);
    154         skew /= u.size() * dev * var;
    155         kurtosis /= u.size() * var * var;
    156         kurtosis -= 3;
    157         double x_mean = p.b() * std::tgamma(1 + 1/p.a());
    158         double x_var = sqr(p.b()) * std::tgamma(1 + 2/p.a()) - sqr(x_mean);
    159         double x_skew = (sqr(p.b())*p.b() * std::tgamma(1 + 3/p.a()) -
    160                         3*x_mean*x_var - sqr(x_mean)*x_mean) /
    161                         (std::sqrt(x_var)*x_var);
    162         double x_kurtosis = (sqr(sqr(p.b())) * std::tgamma(1 + 4/p.a()) -
    163                        4*x_skew*x_var*sqrt(x_var)*x_mean -
    164                        6*sqr(x_mean)*x_var - sqr(sqr(x_mean))) / sqr(x_var) - 3;
    165         assert(std::abs((mean - x_mean) / x_mean) < 0.01);
    166         assert(std::abs((var - x_var) / x_var) < 0.01);
    167         assert(std::abs((skew - x_skew) / x_skew) < 0.01);
    168         assert(std::abs((kurtosis - x_kurtosis) / x_kurtosis) < 0.03);
    169     }
    170 }