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

[Peter Dalgaard]

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.