poisson_distribution::mean

傳回表示發出參數。

RealType mean() const;

備註

成員函式會傳回已儲存的值 stored_mean。

範例

 

// std_tr1__random__poisson_distribution_mean.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); 
    } 
 

需求

標題: <random>

命名空間: std

請參閱

參考

<random>

poisson_distribution Class