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access sublists by a variable

4 messages · Antje Gruner, R. Michael Weylandt, David Winsemius +1 more

#
Dear list,

I'd like to access the elements of a list within another list with the
help of a variable.

dict <- list(  "24" = c(1,2,3,6,12,24,48,72,96,120,144,168,720),
          "168" = c(1,12,24,48,72,96,120,144,168,336,504,672),
         "8760" = c(1,24,168,730,4380,8760)
        )

dict$"24" works fine, but

a <- "24"
dict$a

returns  NULL

Unfortunately dict[a] does not work for me, because I see no possibility
to access the inner elements of list "24" in that case
i.e. dict[a][1] returns the whole list and not the first element.

What is the correct syntax to access those elements with the help of a
variable?
Thanks in advance

Antje
#
dict[[a]]

? `[[`

Michael
On Wed, Nov 16, 2011 at 10:16 AM, Antje Gruner <ntj at allesjetzt.net> wrote:
#
On Nov 16, 2011, at 10:16 AM, Antje Gruner wrote:

            
I can't remember if this is a FAQ but it is certainly discussed on the  
page you would ge with

?"$"

dict[[a]]
David Winsemius, MD
West Hartford, CT
#
Hi:

Try dict[[a]] rather than dict$a, and read the section on lists in the
Introduction to R manual to learn how to properly index them.

HTH,
Dennis
On Wed, Nov 16, 2011 at 7:16 AM, Antje Gruner <ntj at allesjetzt.net> wrote: