I was translating some code from C to R and found that I would really like to be able to pass some parameters to an R function by reference (i.e., have the function make changes in the variables that then propagate back to the calling environment). I have some vague knowledge of the whole assign(substitute(deparse())) framework, but I was just wondering if there is some simpler/more accepted idiom ... To make this concrete, suppose I want to write a swap() function that swaps the values of two variables: swap <- function(a,b) { tmp <- a; a <- b; b <- tmp } clearly doesn't work. Is there something simple and bulletproof that would work? (Just a little more context: I'm translating some Numerical Recipes optimization code to R for a class I'm teaching. I could do it with a call to C code, but I'd like the students to be able to play around with the code easily. For the time being I've worked around this problem, but it left me wondering.) thanks, Ben Bolker Benjamin Bolker Dep't of Ecology and Evolutionary Biology, ben at eno.princeton.edu Princeton University tel: (609) 258-6886, fax: (609) 258-1334 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help 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-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._