The para quoted dates from before the stats package was split off in
2003, and is historical (it was true at one point, but not in R
2.0.0, the earliest running version I have).
There is however still some truth lurking there: the code is
offset <- if (!is.null(off.num <- attr(tt, "off
Hi Ken,
First of all, whether you specify the offset by the argument or in the
formula, your code requires that q25 is the same length as the variable
Contr. You can set this up by defining your new data as follows:
nd <- data.frame( Contr = cc , q25 = qlogis(0.25))
This sorts out the problem of
Hi,
I have run into another problem using offsets, this time with
the predict function, where there seems to be a contradiction
again between the behavior and the help page.
On the man page for predict.lm, it says
Offsets specified by offset in the fit by lm will not be included in
predictions,
