[R] Extracting the name of an object into a character string and vice versa

Gabor Grothendieck ggrothendieck at gmail.com
Fri Dec 12 14:41:48 CET 2008


Its a FAQ:

http://cran.r-project.org/doc/FAQ/R-FAQ.html#How-can-I-turn-a-string-into-a-variable_003f

On Fri, Dec 12, 2008 at 8:30 AM, Philip Whittall
<Philip.whittall at detica.com> wrote:
>
> I am still struggling to map a character string to an object name and
> vice versa in R.
> I thought the as.name() function might work, but observe the following
> behaviour ...
>
>> attach(warpbreaks)
>> levels(tension)
> [1] "L" "M" "H"
>> levels(as.name("tension"))
> NULL
>> objectname<-as.name("tension")
>> objectname
> tension
>> levels(objectname)
> NULL
>
> So even though it sets up a symbol, this symbol isn't recognised as an
> object name by functions such as levels().
>
> I need 2 functions, call them A and B such that A("tension") yields the
> object name tension which is recognised by functions and
> B(tension) yields the character result "tension".
>
> Any suggestions would be greatly appreciated,
>
> Philip
>
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