What is the bug?
This is the same model: the `intercept' term affects the null model, not
the actual model. Just look at all the output.
On Thu, 16 Jun 2005 jyzz88 at gmail.com wrote:
> glm.fit() gave me the same AIC's regardless of TRUE or FALSE intercept
option.
>
>> myX <- as.matrix(1:10)
>> myY <- 3+5*myX
>> foo <- glm.fit(x=myX, y=myY, family = gaussian(link =
"identity"), intercept=TRUE)
>> foo$aic
> [1] 38.94657
>> foo <- glm.fit(x=myX, y=myY, family = gaussian(link =
"identity"), intercept=FALSE)
>> foo$aic
> [1] 38.94657
>> AIC(lm(myY~0+myX, data=data.frame(myY,myX)))
> [1] 38.94657
>> AIC(lm(myY~1+myX, data=data.frame(myY,myX)))
> [1] -650.9808
--
Brian D. Ripley, ripley at 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