Re: [R] fisher exact for > 2x2 table

From: Thomas Lumley <>
Date: Fri, 29 Apr 2011 08:12:21 +1200

On Fri, Apr 29, 2011 at 8:01 AM, Mike Miller <> wrote:
> On Thu, 28 Apr 2011, viostorm wrote:
>> I'm using fisher.exact on a 4x2 table and it seems to work.
>> Does anyone know exactly what is going on?  I thought fisher.exact is only
>> for 2x2 tables.
> You were wrong.  I'm sure there's nothing wrong with the program.  You will
> find that with bigger tables and larger sample sizes the computational cost
> becomes quite enormous.

In fact, with large tables, roundoff error becomes significant before computational cost becomes prohibitive.


Thomas Lumley
Professor of Biostatistics
University of Auckland

______________________________________________ mailing list
PLEASE do read the posting guide
and provide commented, minimal, self-contained, reproducible code.
Received on Thu 28 Apr 2011 - 20:14:04 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Thu 28 Apr 2011 - 21:40:34 GMT.

Mailing list information is available at Please read the posting guide before posting to the list.

list of date sections of archive