[Gretl-users] Factorial

[Riccardo (Jack) Lucchetti]

On Tue, October 10, 2006 16:43, Ignacio Díaz-Emparanza wrote:
> Is there a way to use a factorial of a number in a "genr" formula?
> I do not find it in the manual.
>
> I mean for example
> genr F = 4! 			(=4x3x2x1)
>

you can use the gamma() function, as in

genr a = 4
genr F = gamma(a+1)

If you need it for things like hypergeometric functions, which involve ratios,
we also have the lngamma() function, which gives numerically better results.

Riccardo (Jack) Lucchetti
Dipartimento di Economia
Facoltà di Economia "G. Fuà"
Ancona