Thanks to Prof. Brian Ripley, Marc, and Andy. match.call() is what i need. After spending a weekend away from email, I stumbled on a thread on exactly the same topic this morning,
http://finzi.psych.upenn.edu/R/Rhelp02a/archive/101445.html Horace >>> "Liaw, Andy" <[EMAIL PROTECTED]> 7/30/2007 9:57:47 AM >>> Here's one possibility: R> f <- function(...) { call <- match.call(); sapply(as.list(call[-1]), deparse) } R> f(x, y) [1] "x" "y" R> f(x=x, y=y) x y "x" "y" You basically need to know how to manipulate call objects. The relevant section in the R Language Definition should help. Andy From: Horace Tso > > Folks, > > I've entered into an R programming territory I'm not very > familiar with, thus this probably very elementary question > concerning the mechanic of a function call. > > I want to know from within a function the name of the > variables I pass down. The function makes use of the "..." to > allow for multiple unknown arguments, > > myfun = function(...) { do something } > > In the body I put, > > { > nm <- names(list(...)) > nm > } > > When the function is called with two vectors x, and y > > myfun(x, y) > > It returns NULL. However, when the call made is, > > >myfun(x=x, y=y) > > The result is > [1] "x" "y" > > Question : how do i get the names of the unknown variables > without explicitly saying x=x... > > Thanks in advance. > > Horace > > ______________________________________________ > R-help@stat.math.ethz.ch 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. > > > ------------------------------------------------------------------------------ Notice: This e-mail message, together with any attachments,...{{dropped}} ______________________________________________ R-help@stat.math.ethz.ch 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.
