ceph/src/boost/libs/math/tools/beta_data.cpp

   1 //  (C) Copyright John Maddock 2006.
   2 //  Use, modification and distribution are subject to the
   3 //  Boost Software License, Version 1.0. (See accompanying file
   4 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   5
   6 #include <boost/math/special_functions/gamma.hpp>
   7 #include <boost/math/constants/constants.hpp>
   8 #include <boost/math/tools/test_data.hpp>
   9 #include <fstream>
  10 #include "mp_t.hpp"
  11
  12 using namespace boost::math::tools;
  13
  14 struct beta_data_generator
  15 {
  16    mp_t operator()(mp_t a, mp_t b)
  17    {
  18       if(a < b)
  19          throw std::domain_error("");
  20       // very naively calculate spots:
  21       mp_t g1, g2, g3;
  22       int s1, s2, s3;
  23       g1 = boost::math::lgamma(a, &s1);
  24       g2 = boost::math::lgamma(b, &s2);
  25       g3 = boost::math::lgamma(a+b, &s3);
  26       g1 += g2 - g3;
  27       g1 = exp(g1);
  28       g1 *= s1 * s2 * s3;
  29       return g1;
  30    }
  31 };
  32
  33
  34 int main()
  35 {
  36    parameter_info<mp_t> arg1, arg2;
  37    test_data<mp_t> data;
  38
  39    std::cout << "Welcome.\n"
  40       "This program will generate spot tests for the beta function:\n"
  41       "  beta(a, b)\n\n";
  42
  43    bool cont;
  44    std::string line;
  45
  46    do{
  47       get_user_parameter_info(arg1, "a");
  48       get_user_parameter_info(arg2, "b");
  49       data.insert(beta_data_generator(), arg1, arg2);
  50
  51       std::cout << "Any more data [y/n]?";
  52       std::getline(std::cin, line);
  53       boost::algorithm::trim(line);
  54       cont = (line == "y");
  55    }while(cont);
  56
  57    std::cout << "Enter name of test data file [default=beta_data.ipp]";
  58    std::getline(std::cin, line);
  59    boost::algorithm::trim(line);
  60    if(line == "")
  61       line = "beta_data.ipp";
  62    std::ofstream ofs(line.c_str());
  63    ofs << std::scientific << std::setprecision(40);
  64    write_code(ofs, data, "beta_data");
  65
  66    return 0;
  67 }
  68