math/tools/hyp_1f1_big_data.cpp

//  (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)

#define BOOST_MATH_MAX_SERIES_ITERATION_POLICY 10000000

#include <boost/math/special_functions/hypergeometric_1f1.hpp>
#include <boost/math/constants/constants.hpp>
#include <boost/lexical_cast.hpp>
#include <fstream>
#include <map>
#include <boost/math/tools/test_data.hpp>
#include <boost/random.hpp>
#define BOOST_MATH_USE_MPFR
#include "mp_t.hpp"

#include <boost/multiprecision/mpfi.hpp>

using namespace boost::math::tools;
using namespace boost::math;
using namespace std;
using namespace boost::multiprecision;

typedef mpfi_float_1000 mpfi_type;

mp_t hypergeometric_1f1_generic_series(mp_t a_, mp_t b_, mp_t z_)
{
   using namespace boost::math::tools;
   using namespace boost::math;
   using namespace std;
   using namespace boost::multiprecision;

   mpfi_type a(a_), b(b_), z(z_), sum(0), term(1), diff, term0(0);
   unsigned n = 0;
   bool cont = true;

   unsigned max_n;
   if (b < 0)
      max_n = itrunc(-b) + 10000;
   else
      max_n = 10000000;

   mpfi_type overflow_limit("1.189731495357231765e+4900");  // a bit less than LDBL_MAX for extended long doubles.

   do
   {
      sum += term;
      term *= (((a + n) / ((b + n) * (n + 1))) * z);
      ++n;
      diff = fabs(term / sum);
      if (n > max_n)
      {
         std::cout << "Aborting series evaluation due to too many iterations...\n";
         throw evaluation_error("");
      }
      if (fabs(upper(sum)) > overflow_limit)
      {
         std::cout << "Aborting series evaluation due to over large sum...\n";
         throw evaluation_error("");
      }
      cont = (fabs(upper(diff)) > 1e-40) || (b + n < 0) || (fabs(term0) < fabs(term));
      term0 = term;
      //std::cout << upper(term) << " " << upper(sum) << " " << upper(diff) << " " << cont << std::endl;
   } while (cont);

   mp_t r = mp_t(width(sum) / median(sum));
   if (fabs(r) > 1e-40)
   {
      std::cout << "Aborting to to error in result of " << r << std::endl;
      throw evaluation_error("");
   }
   std::cout << "Found error in sum was " << r << std::endl;

   return mp_t(median(sum));
}


struct hypergeometric_1f1_gen
{
   mp_t operator()(mp_t a1, mp_t a2, mp_t z)
   {
      mp_t result;
      try {
         result = hypergeometric_1f1_generic_series(a1, a2, z);
         std::cout << a1 << " " << a2 << " " << z << " " << result << std::endl;
      }
      catch (...)
      {
         throw std::domain_error("");
      }
      if (fabs(result) > (std::numeric_limits<double>::max)())
      {
         std::cout << "Rejecting over large value\n";
         throw std::domain_error("");
      }
      return result;
   }
};


int main(int, char* [])
{
   parameter_info<mp_t> arg1, arg2, arg3;
   test_data<mp_t> data;

   std::cout << "Welcome.\n"
      "This program will generate spot tests for 1F1 (Yeh!!):\n";

   std::string line;
   //bool cont;

   std::vector<mp_t> v;
   random_ns::mt19937 rnd;
   random_ns::uniform_real_distribution<float> ur_a(0, 1);

   mp_t p = ur_a(rnd);
   p *= 1e6;
   v.push_back(p);
   v.push_back(-p);
   p = ur_a(rnd);
   p *= 1e5;
   v.push_back(p);
   v.push_back(-p);
   p = ur_a(rnd);
   p *= 1e4;
   v.push_back(p);
   v.push_back(-p);
   p = ur_a(rnd);
   p *= 1e3;
   v.push_back(p);
   v.push_back(-p);
   p = ur_a(rnd);
   p *= 1e2;
   v.push_back(p);
   v.push_back(-p);
   p = ur_a(rnd);
   p *= 1e-5;
   v.push_back(p);
   v.push_back(-p);
   p = ur_a(rnd);
   p *= 1e-12;
   v.push_back(p);
   v.push_back(-p);
   p = ur_a(rnd);
   p *= 1e-30;
   v.push_back(p);
   v.push_back(-p);

   for (unsigned i = 0; i < v.size(); ++i)
   {
      for (unsigned j = 0; j < v.size(); ++j)
      {
         for (unsigned k = 0; k < v.size(); ++k)
         {
            std::cout << i << " " << j << " " << k << std::endl;
            std::cout << v[i] << " " << (v[j] * 3) / 2 << " " << (v[j] * 5) / 4 << std::endl;
            arg1 = make_single_param(v[i]);
            arg2 = make_single_param(mp_t((v[j] * 3) / 2));
            arg3 = make_single_param(mp_t((v[k] * 5) / 4));
            data.insert(hypergeometric_1f1_gen(), arg1, arg2, arg3);
         }
      }
   }


   std::cout << "Enter name of test data file [default=hypergeometric_1f1.ipp]";
   std::getline(std::cin, line);
   boost::algorithm::trim(line);
   if(line == "")
      line = "hypergeometric_1f1.ipp";
   std::ofstream ofs(line.c_str());
   ofs << std::scientific << std::setprecision(40);
   write_code(ofs, data, line.c_str());

   return 0;
}