R help - Aug 2011 - problem deparsing argument

Hi,

I don't know much about R's deparsing "magic", I simply use
the
deparse(substitute(arg)) trick to get the names of the variables
passed as arguments to the function in order to set labels, etc.

The problem is that this doesn't work with nested functions. For
example, 
> foo <- function(x) print(deparse(substitute(x)))
> a=1
> foo(a)
[1] "a"

This is OK. However,
> bar <- function(x) foo(x)
> bar(a)
[1] "x"

this is not what I want. I wanted bar(a) to print "a" not
"x". Is it
possible to do this?

Thanks in advance.

-- 
Ernest

On Aug 18, 2011, at 5:11 PM, Ernest Adrogu? wrote:
> Hi,
>
> I don't know much about R's deparsing "magic", I simply
use the
> deparse(substitute(arg)) trick to get the names of the variables
> passed as arguments to the function in order to set labels, etc.
>
> The problem is that this doesn't work with nested functions. For
> example,
>
>> foo <- function(x) print(deparse(substitute(x)))
>> a=1
>> foo(a)
> [1] "a"
>
> This is OK. However,
>
>> bar <- function(x) foo(x)
>> bar(a)
> [1] "x"
>
> this is not what I want. I wanted bar(a) to print "a" not
"x". Is it
> possible to do this?
 > bar <- function(x) class(substitute(foo(x)))
 > bar(a)
[1] "call

So...

 > bar <- function(x) substitute(foo(x))[[2]]
 > bar(a)
a

-- 

David Winsemius, MD
West Hartford, CT