28 Numerics library [numerics]

28.5 Random number generation [rand]

28.5.9 Random number distribution class templates [rand.dist]

28.5.9.4 Poisson distributions [rand.dist.pois]

28.5.9.4.5 Class template extreme_value_distribution [rand.dist.pois.extreme]

An extreme_value_distribution random number distribution produces random numbers x distributed according to the probability density function230
namespace std { template<class RealType = double> class extreme_value_distribution { public: // types using result_type = RealType; using param_type = unspecified; // constructor and reset functions extreme_value_distribution() : extreme_value_distribution(0.0) {} explicit extreme_value_distribution(RealType a, RealType b = 1.0); explicit extreme_value_distribution(const param_type& parm); void reset(); // equality operators friend bool operator==(const extreme_value_distribution& x, const extreme_value_distribution& y); // generating functions template<class URBG> result_type operator()(URBG& g); template<class URBG> result_type operator()(URBG& g, const param_type& parm); // property functions RealType a() const; RealType b() const; param_type param() const; void param(const param_type& parm); result_type min() const; result_type max() const; // inserters and extractors template<class charT, class traits> friend basic_ostream<charT, traits>& operator<<(basic_ostream<charT, traits>& os, const extreme_value_distribution& x); template<class charT, class traits> friend basic_istream<charT, traits>& operator>>(basic_istream<charT, traits>& is, extreme_value_distribution& x); }; }
explicit extreme_value_distribution(RealType a, RealType b = 1.0);
Preconditions: .
Remarks: a and b correspond to the respective parameters of the distribution.
RealType a() const;
Returns: The value of the a parameter with which the object was constructed.
RealType b() const;
Returns: The value of the b parameter with which the object was constructed.
230)230)
The distribution corresponding to this probability density function is also known (with a possible change of variable) as the Gumbel Type I, the log-Weibull, or the Fisher-Tippett Type I distribution.