[R] How to refer to a list member by variable
hadley wickham
h.wickham at gmail.com
Mon Dec 1 20:16:39 CET 2008
On Mon, Dec 1, 2008 at 12:53 PM, Reitsma, Rene - COB
<reitsmar at bus.oregonstate.edu> wrote:
> Dear All,
>
> I'm hoping one of you can help me with the following R problem. I'm
> trying to refer to a member of a list by variable. However, this seems
> not to work:
>
> foo=list(first=c(1:10),second=c(11:20))
>
>> foo$first
> [1] 1 2 3 4 5 6 7 8 9 10
>
>> foo$"first"
> [1] 1 2 3 4 5 6 7 8 9 10
>
>> goo=c("first")
>
>> foo$goo
> NULL
>
>> foo$goo[1]
> NULL
>
foo[[goo]]
which you'll find in ?"$" under the heading "Recursive (list-like) objects"
Hadley
--
http://had.co.nz/
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