poisson_distribution::mean
Returns the mean distribution parameter.
RealType mean() const;
Remarks
The member function returns the stored value stored_mean.
Example
// std_tr1__random__poisson_distribution_mean.cpp
// compile with: /EHsc
#include <random>
#include <iostream>
typedef std::tr1::mt19937 Myeng;
typedef std::tr1::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::tr1