Re: st: RE: Hypergeometric Distribution

[Marcello Pagano <pagano@hsph.harvard.edu>]

Just concerned with the accuracy.

m.p.

Nick Cox wrote:
> Roger's posting includes what I presume is an allusion to 
> an -egen- function _ghyper.ado that I wrote in 1999. 
> I withdrew this program as redundant some years ago, 
> given that you can use something like 
> comb(K, k) * comb(N - K, n - k) / comb(N, n)
>
> wherever you want. In context N, K, n, k may be 
> variables, scalars or placeholders for numeric
> constants, or any mixture thereof. 
> This might need a wrapper to yield zeros where 
> appropriate, or it might need care whenever 
> individual terms get very large, but otherwise
> does it raise any problems? 
> Nick 
> n.j.cox@durham.ac.uk 
> Marcello Pagano
>  
>   
> > I looked at --ssizebi-- but it seems to be focused on power 
> > and sample 
> > sizes.
> >     
>  
> Newson, Roger B wrote:
>
>   
> > > Thanks to Marcello for telling us all about this recently-published
> > > algorithm, which looks very useful. A search on
> > >
> > > findit hypergeometric
> > >
> > > in Stata finds a single reference (to a SSC package), which was
> > > distributed as long ago as 1999. This suggests that the new 
> > >       
> > algorithm
> >     
> > > might be a good candidate for implementation in Mata by 
> > >       
> > Marcello, or by
> >     
> > > anybody else with the time and inclination to do so.
> > >       
> Marcello Pagano
>
>   
> > Does anyone have or know of Stata code to calculate the Hypergeometric 
> > Distribution accurately?
> >
> > See Journal of Discrete Algorithms ,  Volume 5 ,  Issue 2  (June 2007) 
> > Pages: 341-347 for an article by Berkopec, HyperQuick algorithm for 
> > discrete hypergeometric distribution 
> > <http://portal.acm.org/citation.cfm?id=1240586&coll=GUIDE&dl=GUIDE&CFID=
> > 27443384&CFTOKEN=80678482>.
> >     
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