[R] inconsistent behaviour of add1 and drop1 with a weighted linear model

[Duncan Murdoch]

On 3/13/2007 3:14 PM, hadley wickham wrote:
> On 3/13/07, Peter Dalgaard <p.dalgaard at biostat.ku.dk> wrote:
>> Jenny Hodgson wrote:
>>> I was using Version 2.3.1 for Windows (binary download version). Guess I
>>> should be using the latest version, (but the reason is I'm writing up my
>>> PhD and I thought my results would be more 'repeatable' if I didn't keep
>>> changing my version of the software, I didn't really think there would
>>> be any glitches as big as this). Sorry if this is a waste of your time.
>>> And thanks very much for replying so quickly.
>>>
>>> Jenny
>>>
>>>
>> Always a good idea to check the NEWS file:
>>
>>     o   add1.lm() had been broken by other changes for weighted fits.
> 
> Yes, but a little impractical.  Has any one ever considered a standard
> for the news file so changes could be extracted and included in online
> documentation somewhere?

It's in a structured format, and is online.  The readNEWS() function can
read it.  It would be nice if someone would contribute a more friendly
reader...

Try

readNEWS(url("http://cran.r-project.org/bin/windows/base/NEWS.R-2.5.0dev"),
chop="keepAll")[[c("2.5","2.5.0","BUG FIXES")]]

for the unfriendly but informative version.

Duncan Murdoch