sig
type elt
type t
val mean : Distributions.Features.S.t -> Distributions.Features.S.elt
val variance : Distributions.Features.S.t -> Distributions.Features.S.elt
val skewness : Distributions.Features.S.t -> Distributions.Features.S.elt
val kurtosis : Distributions.Features.S.t -> Distributions.Features.S.elt
end