Thank you Prof. Ripley, for examining this issue. I have two more
questions on this topic, if I may.
(1) Truncated column names
With your explanations I can see that the problem of missing column names
originates in cbind() and the 'deparse.level' bug we have just discovered.
I had tried diff
A few points.
0) This seems a Wishlist item, but it does not say so (see the section
on BUGS in the FAQ).
1) A formula does not need to have an lhs, and it is an assumption
that the response is the first element of 'variables' (an assumption
not made a couple of lines later when 'resp' is us
The model frame shows the response and predictors in a data frame with
nicely labelled columns:
fm <- lm(wt~qsec+log(hp)+sqrt(disp), data=mtcars)
model.frame(fm) # ok
When the left hand side consists of more than one response, those response
variables still look good, inside a matrix:
fm
