This *is* a documented feature: see ?Extract. I am afraid your `of course' is completely non-obvious to me. I would object strongly to code written to use a documented feature issuing a warning.
On Tue, 20 Apr 2004, Wilhelm B. Kloke wrote: > Yesterday I was biten by a feature, which I find too dangerous. > > I wanted to use a factor `Subject� as index into a data frame, whose row > names were the levels of this factor. So there a 2 different possible > interpretations of this: Either Subject is coerced to numeric or to > character. The intended interpretation was, of course, `as.character(Subject)'. > R did `as.numeric(Subject)�. This will not cause a semantic error, when > the levels of Subject happen to be in numeric order; so it will be > unnoticed quite often. > > I propose to issue a warning whenever a factor is implicitly coerced, > at least in an ambiguous context. -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
