A
chi_squared_distribution random number distribution
produces random numbers
x>0
distributed according to
the probability density function
p(x|n)=x(n/2)−1⋅e−x/2Γ(n/2)⋅2n/2 .template<class RealType = double>
class chi_squared_distribution {
public:
using result_type = RealType;
using param_type = unspecified;
chi_squared_distribution() : chi_squared_distribution(1.0) {}
explicit chi_squared_distribution(RealType n);
explicit chi_squared_distribution(const param_type& parm);
void reset();
template<class URBG>
result_type operator()(URBG& g);
template<class URBG>
result_type operator()(URBG& g, const param_type& parm);
RealType n() const;
param_type param() const;
void param(const param_type& parm);
result_type min() const;
result_type max() const;
};