C++ Mathematical Expression Toolkit (ExprTk) release
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Classes | Functions
exprtk_simple_example_17.cpp File Reference
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <string>
#include "exprtk.hpp"
Include dependency graph for exprtk_simple_example_17.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 75 of file exprtk_simple_example_17.cpp.

76{
77 monte_carlo_pi<double>();
78 return 0;
79}

◆ monte_carlo_pi()

template<typename T >
void monte_carlo_pi ( )

Definition at line 45 of file exprtk_simple_example_17.cpp.

46{
47 typedef exprtk::symbol_table<T> symbol_table_t;
48 typedef exprtk::expression<T> expression_t;
49 typedef exprtk::parser<T> parser_t;
50
51 const std::string monte_carlo_pi_program =
52 " var samples[2 * 10^8] := [(rnd_01^2 + rnd_01^2) <= 1]; "
53 " 4 * sum(samples) / samples[]; ";
54
55 rnd_01<T> rnd01;
56
57 symbol_table_t symbol_table;
58 symbol_table.add_function("rnd_01",rnd01);
59
60 expression_t expression;
61 expression.register_symbol_table(symbol_table);
62
63 parser_t parser;
64 parser.compile(monte_carlo_pi_program,expression);
65
66 const T approximate_pi = expression.value();
67
68 const T real_pi = T(3.141592653589793238462643383279502); // or close enough...
69
70 printf("pi ~ %20.17f\terror: %20.17f\n",
71 approximate_pi,
72 std::abs(real_pi - approximate_pi));
73}