gevstat
Generalized extreme value mean and variance
Syntax
[M,V] = gevstat(k,sigma,mu)
Description
[M,V] = gevstat(k,sigma,mu)
returns
the mean of and variance for the generalized extreme value (GEV) distribution
with shape parameter k
, scale parameter sigma
,
and location parameter, mu
. The sizes of M
and V
are
the common size of the input arguments. A scalar input functions
as a constant matrix of the same size as the other inputs.
When k < 0
, the GEV is the type III extreme
value distribution. When k > 0
, the GEV distribution
is the type II, or Frechet, extreme value distribution. If w
has
a Weibull distribution as computed by the wblstat
function, then -w
has a type III extreme value
distribution and 1/w
has a type II extreme value
distribution. In the limit as k
approaches 0,
the GEV is the mirror image of the type I extreme value distribution
as computed by the evstat
function.
The mean of the GEV distribution is not finite when k
≥ 1
,
and the variance is not finite when k
≥ 1/2
.
The GEV distribution has positive density only for values of X
such
that k*(X-mu)/sigma > -1
.
References
[1] Embrechts, P., C. Klüppelberg, and T. Mikosch. Modelling Extremal Events for Insurance and Finance. New York: Springer, 1997.
[2] Kotz, S., and S. Nadarajah. Extreme Value Distributions: Theory and Applications. London: Imperial College Press, 2000.
Extended Capabilities
Version History
Introduced before R2006a