poisson_distribution::poisson_distribution
Constructs the distribution.
poisson_distribution(RealType mean0 = RealType(1.0));
explicit binomial_distribution(const param_type& par0);
Parameters
mean0
The mean distribution parameter.par0
The parameter package used to construct the distribution.
Remarks
Precondition: 0.0 < mean0
The first constructor constructs an object whose stored value stored_mean holds the value mean0.
The second constructor constructs an object whose stored parameters are initialized from par0.
Example
// std_tr1__random__poisson_distribution_construct.cpp
// compile with: /EHsc
#include <random>
#include <iostream>
typedef std::mt19937 Myeng;
typedef std::poisson_distribution<int, double> Mydist;
int main()
{
Myeng eng;
Mydist dist(3.5);
Mydist::input_type engval = eng();
Mydist::result_type distval = dist(eng);
distval = distval; // to quiet "unused" warnings
engval = engval;
std::cout << "mean == " << dist.mean() << 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);
}
mean == 3.5 a random value == 5 a random value == 2 a random value == 11
Requirements
Header: <random>
Namespace: std