An extreme_value_distribution random number distribution
produces random numbers x
distributed according to
the probability density function231 p(x|a,b)=1b⋅exp(a−xb−exp(a−xb)).
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.