A question regarding R scoping
Hi,
Perhaps I have to rephrase a bit my question. If we have the following:
i = 10
f1 = function(i){
i <<- 1
}
after calling f1, the value of i becomes 1. Now, suppose that f1 is called in another function f2, and i is initialized in f2 as well, i.e:
f2 = function(n){
i = n
f1(i)
}
The intention is, after executing f2, i=1 (not i=n).
--- On Thu, 8/6/09, Steve Lianoglou <mailinglist.honeypot at gmail.com> wrote:
From: Steve Lianoglou <mailinglist.honeypot at gmail.com> Subject: Re: [R] A question regarding R scoping To: "Ivo Shterev" <idc318 at yahoo.com> Cc: r-help at r-project.org Date: Thursday, August 6, 2009, 10:23 PM Howdy, On Aug 6, 2009, at 4:11 PM, Ivo Shterev wrote:
Hi, The intention is that after executing f2, the value of
i to become 1.
f1 = function(i){i = 1}
f2 = function(n){? i = length(n)
f1(i)
print(i)}
i.e. f2 should print 1, not length(n).
Yeah, you can using parent.frame()'s and such:
f1 <- function(i) assign('i', 10, envir=parent.frame())
f2 <- function(n) {
? i <- length(n)
? f1(i)
? print(i)
}
R> f2(1:20)
[1] 10
Honestly, this just smells like a *really* bad idea, though
... just have f1() return a value that you use in f2.
-steve
--
Steve Lianoglou
Graduate Student: Computational Systems Biology
? |? Memorial Sloan-Kettering Cancer Center
? |? Weill Medical College of Cornell University
Contact Info: http://cbio.mskcc.org/~lianos/contact