exprtk_montecarlo_pi.cpp File Reference

#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <string>
#include "exprtk.hpp"

Include dependency graph for exprtk_montecarlo_pi.cpp:

Go to the source code of this file.

Classes
struct	rnd_01< T >

Functions
template<typename T >
void	monte_carlo_pi ()
int	main ()

Function Documentation

main()

int main

(

)

Definition at line 83 of file exprtk_montecarlo_pi.cpp.

{
   monte_carlo_pi<double>();
   return 0;
}

monte_carlo_pi()

template<typename T >

void monte_carlo_pi

(

)

Definition at line 45 of file exprtk_montecarlo_pi.cpp.

{
   typedef exprtk::symbol_table<T> symbol_table_t;
   typedef exprtk::expression<T>   expression_t;
   typedef exprtk::parser<T>       parser_t;
 
   const std::string monte_carlo_pi_program =
      " var max_samples := 5 * 10^7;              "
      " var count       := 0;                     "
      "                                           "
      " for (var i := 0; i < max_samples; i += 1) "
      " {                                         "
      "    if ((rnd_01^2 + rnd_01^2) <= 1)        "
      "       count += 1;                         "
      " };                                        "
      "                                           "
      " (4 * count) / max_samples;                ";
 
   rnd_01<T> rnd01;
 
   symbol_table_t symbol_table;
   symbol_table.add_function("rnd_01",rnd01);
 
   expression_t expression;
   expression.register_symbol_table(symbol_table);
 
   parser_t parser;
   parser.compile(monte_carlo_pi_program,expression);
 
   const T approximate_pi = expression.value();
 
   const T real_pi = T(3.141592653589793238462643383279502); // or close enough...
 
   printf("pi ~ %20.17f\terror: %20.17f\n",
          approximate_pi,
          std::abs(real_pi - approximate_pi));
}