Re: Q: what is the name of that density function?

Axel Vogt wrote:
I already tried sci.math, but may be this is the proper NG:

With appropriate parameters and up to norming let be f:= x -> exp(-c*x-beta)*(1/2*exp(a*x+alpha)+1/2*exp(-a*x-alpha))^(-b)
for x arbitrary real.

Is there name for that ( and references (on the www ...) ) ?

I would be glad to get some hints ...

You can rewrite the p.d.f. as:

exp(-c*x-beta)*(1/2*exp(a*x+alpha)+1/2*exp(-a*x-alpha))^(-b)

= exp(-c*x-beta)* sech(a*x + alpha)^b

This looks similar to the "hyperbolic secant distribution" or "Perks' distribution".

Mike
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