I'm not sure the idea of having a generic 'sd' extract the residual standard
deviation from a linear model quite jives with me. Personally, I think a
generic function with name like 'residSD' or something similar would be better.
Either way, I think it would be nice to have some function like t
I have from time to time seen inquiries on r-help in respect of
how to obtain the estimated standard deviation from the output of
fitting a linear model. And have had occasion to want to do this
myself.
The way I currently do it is something like summary(fit)$sigma
(where fit is returned by lm()
