text: //  (C) Copyright John Maddock 2006.
  //  Use, modification and distribution are subject to the
  //  Boost Software License, Version 1.0. (See accompanying file
  //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  
  #include "mp_t.hpp"
  #include <boost/math/special_functions/gamma.hpp>
  #include <boost/math/constants/constants.hpp>
  #include <boost/math/tools/test_data.hpp>
  #include <fstream>
  
  using namespace boost::math::tools;
  
  struct beta_data_generator
  {
     mp_t operator()(mp_t a, mp_t b)
     {
        if(a < b)
           throw std::domain_error("");
        // very naively calculate spots:
        mp_t g1, g2, g3;
        int s1, s2, s3;
        g1 = boost::math::lgamma(a, &s1);
        g2 = boost::math::lgamma(b, &s2);
        g3 = boost::math::lgamma(a+b, &s3);
        g1 += g2 - g3;
        g1 = exp(g1);
        g1 *= s1 * s2 * s3;
        return g1;
     }
  };
  
  
  int main()
  {
     parameter_info<mp_t> arg1, arg2;
     test_data<mp_t> data;
  
     std::cout << "Welcome.\n"
        "This program will generate spot tests for the beta function:\n"
        "  beta(a, b)\n\n";
  
     bool cont;
     std::string line;
  
     do{
        get_user_parameter_info(arg1, "a");
        get_user_parameter_info(arg2, "b");
        data.insert(beta_data_generator(), arg1, arg2);
  
        std::cout << "Any more data [y/n]?";
        std::getline(std::cin, line);
        boost::algorithm::trim(line);
        cont = (line == "y");
     }while(cont);
  
     std::cout << "Enter name of test data file [default=beta_data.ipp]";
     std::getline(std::cin, line);
     boost::algorithm::trim(line);
     if(line == "")
        line = "beta_data.ipp";
     std::ofstream ofs(line.c_str());
     ofs << std::scientific << std::setprecision(40);
     write_code(ofs, data, "beta_data");
     
     return 0;
  }
  
  