# R-alpha: R 0.50.a1 problems with lm/glm methods

**Kurt Hornik
**
Kurt.Hornik@ci.tuwien.ac.at

*Mon, 28 Jul 1997 15:23:48 +0200*

Thanks for fixing formula() and update().
Here are some open problems.
* effects:
** There is no help available for effects()
** The lm() help page has effects(lm.obj), but from the code it is clear
that the one-arg version cannot work.
Shouldn't it simply return z$effects?
** The two-arg version only works for factors (?) ... otherwise,
z$model.frame[factors & pattern != 0]
gives an error. Can someone explain to me what this is doing?
* plot:
There should be a plot.lm() function which reports that useful
diagnostic plots have not been implemented yet.
Perhaps we should do something like
unimplemented <- function () {
stop("Not implemented yet ... sorry.")
}
plot.lm <- function (...) unimplemented()
plot.glm <- function (...) unimplemented()
and similarly for other stuff which is known to be missing? (This would
also help improving the TASK handling :-))
* predict:
** There is no help available for predict()
** The one-arg version of predict.default() cannot work. For objects
of class "lm", it should simply return the fitted values, right?
** The two-arg version of predict.default() cannot work because no
fitted object has a "covmat" component. Anyway, shouldn't the general
form be something like
predict(object, newdata, ...)
???
Thanks,
-k
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !) To: r-devel-request@stat.math.ethz.ch
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-