[Rd] Defining environments within functions

Giles Hooker gjh27 at cornell.edu
Fri Aug 29 12:52:10 CEST 2008


I think I over-emphasized the secondary function, but I can generate the 
scoping problem as follows. First, at the command line, I can get a 
function to access objects that were not in its arguments by

ProfileEnv = new.env()
hello.world = "Hello World"

fn1 = function()
	hw = get('hello.world',envir=ProfileEnv)

and then call

 > fn1()
[1] "Hello World"

Now I want to define a wrapper function

fn2 = function()
	ProfileEnv = new.env()
	hello.world = "Hello World"


and if I try

 > rm(ProfileEnv)                          # Just to be safe
 > rm(hello.world)
 > fn2()
Error in get("hello.world", envir = ProfileEnv) :
   object "ProfileEnv" not found

In my actual code, fn1() is really a call to


and hello.world are quantities that were calculated the last time that 
ProfileErr was called and that I want to keep track of.

As an alternative simple example, how would I keep a counter for the 
number of times that optim (or any other generic optimizer) has called 


>> How can I define environments within a function so that they are visible
>> to calls to a sub-function?
> I think you need to give a simplified, runnable example.  (Or at least 
> runnable until it hits the scoping problem you've got.)  "Sub-function" 
> isn't R terminology, and it's not clear what you mean by it.

Giles Hooker
Assistant Professor:

Department of Biological Statistics and Computational Biology
Department of Statistical Science
1186 Comstock Hall
Cornell University
Ithaca, NY, 14853

Ph:  (+1 607) 255 1638
Fax: (+1 607) 255 4698

Email:  giles.hooker at cornell.edu

More information about the R-devel mailing list