Returns a random value.
template<class Engine>
result_type operator()(Engine& eng);
template<class Engine>
result_type operator()(Engine& eng,
const param_type& par0);
Parameters
Engine
The type of the random engine.eng
The random engine.par0
The parameter package used to return the random value.
Remarks
The first member function uses the engine eng as a source of uniformly distributed random integral values and returns integral values with each value i occurring with probability pr(i) = comb(stored_t, i) * stored_p^i * (1 - stored_p)^(stored_t-i), where comb(t, i) is the number of possible combinations of t objects taken i at a time.
The second member function behaves the same, except that it uses the parameters stored in par0.
Example
// std_tr1__random__binomial_distribution_operator_fn.cpp
// compile with: /EHsc
#include <random>
#include <iostream>
typedef std::mt19937 Myeng;
typedef std::binomial_distribution<int, double> Mydist;
int main()
{
Myeng eng;
Mydist dist(2, 0.6);
Mydist::input_type engval = eng();
Mydist::result_type distval = dist(eng);
distval = distval; // to quiet "unused" warnings
engval = engval;
std::cout << "p == " << dist.p() << std::endl;
std::cout << "t == " << dist.t() << std::endl;
dist.reset(); // discard any cached values
std::cout << "a random value == " << dist(eng) << std::endl;
std::cout << "a random value == " << dist(eng) << std::endl;
std::cout << "a random value == " << dist(eng) << std::endl;
return (0);
}
p == 0.6 t == 2 a random value == 1 a random value == 0 a random value == 1
Requirements
Header: <random>
Namespace: std