3 messages · Reitsma, Rene - COB, Gavin Simpson, Hadley Wickham
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 I'm sure I'm missing something quite elementary. Perhaps you can help? RR
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$goo
NULL
foo[[goo]] See ?`[[` for more details. Not sure if there is an incantation that will work with '$' in this case. HTH G
foo$goo[1]
NULL I'm sure I'm missing something quite elementary. Perhaps you can help? RR
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On Mon, Dec 1, 2008 at 12:53 PM, Reitsma, Rene - COB
Dear All, I'm hoping one of you can help me with the following R problem. I'm trying to refer to a member of a list by variable. However, this seems not to work: foo=list(first=c(1:10),second=c(11:20))
foo$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