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:> 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 > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >
On Nov 16, 2011, at 10:16 AM, Antje Gruner wrote:> 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$"24" works fine, but > > a <- "24" > dict$aI can't remember if this is a FAQ but it is certainly discussed on the page you would ge with ?"$" dict[[a]]> > returns NULL> > Unfortunately dict[a] does not work for me, because I see no > possibility > to access the inner elements of list "24" in that case > i.e. dict[a][1] returns the whole list and not the first element. > > What is the correct syntax to access those elements with the help of a > variable? > Thanks in advance > > Antje > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.David Winsemius, MD West Hartford, CT
Hi: Try dict[[a]] rather than dict$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:> 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 > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >