[R] control enviromnet

[facS93@hampshire.edu]

thanks Roger, 
this doesn't do exactly what I want, which I didn't explain clearly enough in 
the original post. I want to have a check mechanism to find whether there are 
variables in the function that are not "locally" defined, in which case I 
wouldn't know in advance what they are - well, I probably should because I am 
writing the function. It's just that when the function gets kind of large, and 
I am testing it as I am building it, it's easy to lose track of all these 
variables.

thanks,

Fang

Quoting "Roger D. Peng" <rpeng at jhsph.edu>:

> I think you want something like
> 
> exists("x", where = environment(), inherits = FALSE)
> 
> -roger
> 
> facS93 at hampshire.edu wrote:
> > Hi all:
> > 
> > I would like to implement an option in my function so that it warns me of
> any 
> > variables that are not defined in the current environment - if it needs to
> 
> > look up variables in the parent frame, it tells me so. 
> > 
> > The following is an example and it does what I want, and I'd rather have
> the 
> > environment control option inside this function instead of outside. Any
> help 
> > would be greatly appreciated.
> > 
> > x = 1
> > test = function(y) {
> >  ans = y + x;
> >  return(ans);
> > }
> > environment(test)=NULL
> > test(y = 1)
> > 
> > Thanks much!
> > 
> > Fang
> > 
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