OpenEuphoria

Re: New proposal for math.e

• Posted by CChris <christian.cuvier at agricu?ture.gouv.fr> Aug 03, 2007
• 540 views

Juergen Luethje wrote:
> 
> CChris wrote:
> 
> <snip>
> 
> > Since no one replied to my first proposal, I'll repeat it: add a gamma()
> > function
> > and an erf() function, since they re very commonly used in analysis and
> > statistics.
> > Note that an incomplete gamma function could be an even better idea than
> > erf(),
> > as erf() is a special, very frequent occurrence of incomplete_gamma(x,z)
> > after
> > a trivial transform. The general incomplete_gamma() arises in physics
> > rather.
> > The value of the Euler constant (=-gamma'(1)) would be a logical addition
> > then
> > too.
> > 
> > 1/sqrt(2*PI) is a very common normalisation constant as well, both in
> > statistics
> > and in Fourier series calculations, so it may not hurt to have it on board
> > as
> > well.
> > 
> > The most difficult thing here could be to port some Fortran code to Eu to do
> > the above, assuming the C compiler don't have this as standard. There is
> > ample
> > supply of such free code.
> 
> I do not even know the meaning of a gamma() and an erf() function, so I
> can't provide code for them. But you probably can do so. 
> 
> Regards,
>    Juergen

The Cephes C/C++ numericall library at www.moshier.net has more than what we
need, and doesn't seem to have any licensing issue, apart from reproducing the
copyright notice.

CChris