On Mon, Aug 6, 2012 at 9:03 PM, Schoenfeld, David Alan,Ph.D.,Biostatistics <dschoenf...@partners.org> wrote: > Thank you both, this was very helpful. I need to study environments more. Do > either of you know a good source?
Disclaimer: I really have no idea what I'm talking about. They are a somewhat subtle, but exceptionally powerful concept: see, inter alia, cran.r-project.org/doc/contrib/Fox-Companion/appendix-scope.pdf http://www.lemnica.com/esotericR/Introducing-Closures/ If you know a little bit of C, it will go a long way in understanding environments in R. You'll want to (eventually) start to associate R names with C pointers and environments with symbol tables (hence the fact the printed environment is just a memory address) , but that's perhaps a little bit down the road. Environments are different in their fundamental behavior because of this though: they're the best way to get pass by reference in R. Best, Michael ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
