On Tue, 2004-11-09 at 02:07, Martin Maechler wrote: <SNIP>
> > Further note that many of us try to avoid attach()ing data frames > (most of the time; not always) and we have provided the nice alternative > with( <data> , <expression_body> ) > > So, for the current example, you could also say > > with(trees, plot(Girth ~ Height)) > > The main advantage of with(): Only inside it, the components of > 'trees' are visible - no need to remember to detach() ; > see also help(with) and its examples. Right. Thanks Martin. After sending my reply, I kicked myself a few times for not mentioning with()...especially because it also enables a standardized mechanism for accessing data frame variables across functions (not all of which have a 'data = ' argument). Also, there is a substantial savings with respect to overhead by not attaching and detaching (manipulating the search path), which I had noted and benchmarked previously in a post, earlier this year I believe, that I cannot locate at the moment. This can become very important if one is looping (in some fashion) over data frames or subsets of data frames and therefore avoids the repeated calls to attach() and detach(). Best regards, Marc ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
