ceph/src/boost/libs/random/test/test_bernoulli.cpp

   1 /* test_bernoulli.cpp
   2  *
   3  * Copyright Steven Watanabe 2011
   4  * Distributed under the Boost Software License, Version 1.0. (See
   5  * accompanying file LICENSE_1_0.txt or copy at
   6  * http://www.boost.org/LICENSE_1_0.txt)
   7  *
   8  * $Id$
   9  *
  10  */
  11
  12 #include <boost/random/bernoulli_distribution.hpp>
  13 #include <boost/random/uniform_int.hpp>
  14 #include <boost/random/uniform_01.hpp>
  15 #include <boost/random/mersenne_twister.hpp>
  16 #include <boost/math/distributions/binomial.hpp>
  17 #include <boost/lexical_cast.hpp>
  18 #include <boost/exception/diagnostic_information.hpp>
  19 #include <vector>
  20 #include <iostream>
  21 #include <numeric>
  22
  23 #include "chi_squared_test.hpp"
  24
  25 bool do_test(double p, long long max) {
  26     std::cout << "running bernoulli(" << p << ")" << " " << max << " times: " << std::flush;
  27
  28     boost::math::binomial expected(static_cast<double>(max), p);
  29
  30     boost::random::bernoulli_distribution<> dist(p);
  31     boost::mt19937 gen;
  32     long long count = 0;
  33     for(long long i = 0; i < max; ++i) {
  34         if(dist(gen)) ++count;
  35     }
  36
  37     double prob = cdf(expected, count);
  38
  39     bool result = prob < 0.99 && prob > 0.01;
  40     const char* err = result? "" : "*";
  41     std::cout << std::setprecision(17) << prob << err << std::endl;
  42
  43     std::cout << std::setprecision(6);
  44
  45     return result;
  46 }
  47
  48 bool do_tests(int repeat, long long trials) {
  49     boost::mt19937 gen;
  50     boost::uniform_01<> rdist;
  51     int errors = 0;
  52     for(int i = 0; i < repeat; ++i) {
  53         if(!do_test(rdist(gen), trials)) {
  54             ++errors;
  55         }
  56     }
  57     if(errors != 0) {
  58         std::cout << "*** " << errors << " errors detected ***" << std::endl;
  59     }
  60     return errors == 0;
  61 }
  62
  63 int usage() {
  64     std::cerr << "Usage: test_bernoulli_distribution -r <repeat> -t <trials>" << std::endl;
  65     return 2;
  66 }
  67
  68 template<class T>
  69 bool handle_option(int& argc, char**& argv, char opt, T& value) {
  70     if(argv[0][1] == opt && argc > 1) {
  71         --argc;
  72         ++argv;
  73         value = boost::lexical_cast<T>(argv[0]);
  74         return true;
  75     } else {
  76         return false;
  77     }
  78 }
  79
  80 int main(int argc, char** argv) {
  81     int repeat = 10;
  82     long long trials = 1000000ll;
  83
  84     if(argc > 0) {
  85         --argc;
  86         ++argv;
  87     }
  88     while(argc > 0) {
  89         if(argv[0][0] != '-') return usage();
  90         else if(!handle_option(argc, argv, 'r', repeat)
  91              && !handle_option(argc, argv, 't', trials)) {
  92             return usage();
  93         }
  94         --argc;
  95         ++argv;
  96     }
  97
  98     try {
  99         if(do_tests(repeat, trials)) {
 100             return 0;
 101         } else {
 102             return EXIT_FAILURE;
 103         }
 104     } catch(...) {
 105         std::cerr << boost::current_exception_diagnostic_information() << std::endl;
 106         return EXIT_FAILURE;
 107     }
 108 }