Message-ID: <31605.170.54.59.167.1113850524.squirrel@170.54.59.167>
Date: 2005-04-18T20:55:35Z
From: Kevin Wright
Subject: Why no BIC.default function?
In-Reply-To: <Pine.LNX.4.61.0504181925230.17897@gannet.stats>
> R does not have a BIC S3 generic function: it is in package nlme!
> (There is one for S4 classes in package stats4.)
Sorry, I should have noticed that. Maybe my question should have been:
Since the stats package has generics for logLik and AIC, could it include
a generic for BIC?
Kevin Wright
>> I'm using R 2.0.1.
>>
>> I looked in the email archives but didn't see anything on this topic.
>>
>> I've noticed a surprising (to me) difference between AIC and BIC:
>>
>>> methods("AIC")
>> [1] AIC.default* AIC.logLik*
>>
>>> methods("BIC")
>> [1] BIC.gls* BIC.lm* BIC.lme* BIC.lmList* BIC.logLik* BIC.nls*
>>
>> The BIC.gls BIC.lm BIC.lme BIC.lmList and BIC.nls functions appear to
>> have
>> exactly the same definition. (I didn't check with 'diff' though.)
>>
>> Would it make sense to treat BIC similarly to AIC and have just
>> BIC.default and BIC.logLik?
>
> --
> Brian D. Ripley, ripley@stats.ox.ac.uk
> Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
> University of Oxford, Tel: +44 1865 272861 (self)
> 1 South Parks Road, +44 1865 272866 (PA)
> Oxford OX1 3TG, UK Fax: +44 1865 272595
>