Hi, David: That works. Thanks very much. Spencer Graves
On 5/5/2016 7:43 PM, David Winsemius wrote:
On May 5, 2016, at 5:12 PM, Spencer Graves <spencer.gra...@effectivedefense.org> wrote: I want a function to evaluate one argument in the environment of a data.frame supplied as another argument. "attach" works for this, but "with" does not. Is there a way to make "with" work? I'd rather not attach the data.frame. With the following two functions "eval.w.attach" works but "eval.w.with" fails: dat <- data.frame(a=1:2) eval.w.attach <- function(x, dat){ attach(dat) X <- x detach() X } eval.w.with <- function(x, dat){ with(dat, x) } eval.w.attach(a/2, dat) # returns c(.5, 1)How about using eval( substitute( ...))? eval.w.sub <- function(expr, datt){ eval( substitute(expr), env=datt) } eval.w.sub(a/2, dat) #[1] 0.5 1.0
______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
