From p.dalgaard at biostat.ku.dk  Thu Mar 29 23:05:30 2007
From: p.dalgaard at biostat.ku.dk (Peter Dalgaard)
Date: Thu, 29 Mar 2007 23:05:30 +0200
Subject: [Rd] small bug in ansari.test
In-Reply-To: <200703292149.39133.thomas.friedrichsmeier@ruhr-uni-bochum.de>
	(Thomas Friedrichsmeier's message of "Thu,
	29 Mar 2007 21:49:35 +0200")
References: <200703292139.21253.thomas.friedrichsmeier@ruhr-uni-bochum.de>
	<200703292149.39133.thomas.friedrichsmeier@ruhr-uni-bochum.de>
Message-ID: <x2r6r7kbfp.fsf@viggo.kubism.ku.dk>

Thomas Friedrichsmeier <thomas.friedrichsmeier at ruhr-uni-bochum.de>
writes:

> On Thursday 29 March 2007 21:39, Thomas Friedrichsmeier wrote:
>> The help page for ansari.test() says (emphasis added):
>>
>> 	By default (if exact is not specified), an exact p-value is computed if
>> both samples contain less than 50 finite values **and there are no ties**.
>> Otherwise, a normal approximation is used.
>>
>> However, this does not appear to be the case in R 2.4.1 or R 2.5.0.
>
> Well, to be precise, the exact p-value really isn't computed in this case, but 
> there's still the warning, as though exact=TRUE had been specified, which I 
> don't believe is intended.

Yes?

Those samples contain less than 50 values but there are ties, so you
get the normal approximation with a warning.  If you specify
exact=FALSE, you get the same result without the warning. 

Where's the bug??


-- 
   O__  ---- Peter Dalgaard             ?ster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907



[Rd] small bug in ansari.test
Peter Dalgaard