Re: (no object) aka gammaln

[Jody Goldberg <jody gnome org>]

On Thu, Nov 13, 2003 at 12:58:40PM +0100, frerejacque wrote:
> Jody Goldberg a ?crit :
> > On Wed, Nov 12, 2003 at 11:32:27AM +0800, chengj wrote:
> > > Hi !
> > > who know the method of implemention of Excel's Function gammaln()?
> >
> > I doubt anyone knows the exact implementation of MS Excel's gammaln
> > routine, but we do have a version in gnumeric can appears to produce
> > comperable results.
> >
> >     gnumeric/plugins/fn-eng/functions.c:gnumeric_gammaln
> > _______________________________________________
> > gnumeric-list mailing list
> > gnumeric-list gnome org
> > http://mail.gnome.org/mailman/listinfo/gnumeric-list
> ------------------------------------------------------------
> Beeing not involved in the maintenance nor development,
> I feel I have few rights on gnumeric,
> but the problem rised by the email from chengj seems fundamental:

I suspect we interpreted that mail differently.  My assumption was
that chengj was requesting a reference to the algorithm XL uses, and
I responded with a reference to ours.

> If Excel is wrong on something,
> there is no point to mimic that mistake.
>                   ----------------------

We agree.  My comment was meant to indicate only that gnumeric had
the function and where to find it.  In situations of numeric
accuracy Gnumeric does not now, nor will it break things to match Ms
Excel.  There are situations where we have two implementations of a
function whose semantics seem broken in some way, eg PRODUCT.  In
this instance gnumeric uses the standard lgamma function in libm.