Peter Alspach wrote:
Tena koe
Try either
L[foo()]
or
L[[foo()]]
These return subtly (or not so subtly depending on your point of view)
different results.
which is quite important, hence read the documentation. [] returns a
list of length 1 (or a vector of length 1 of type list) where [[]]
returns the value of the corresponding list element.
This also means that mutpiple indices are interpreted recursively in
[[]] but will select the corresponding list elements in [].
Best,
Uwe Ligges
HTH ....
Peter Alspach
-----Original Message-----
From: r-help-boun...@r-project.org
[mailto:r-help-boun...@r-project.org] On Behalf Of Ning Ma
Sent: Thursday, 27 August 2009 3:35 p.m.
To: r-help@r-project.org
Subject: [R] how to index a list with a string?
Hi, everybody. I have a list obj L, sth like
$`aaa`
[1] "5753"
if the string 'aaa' is a returned value of a function foo().
what is the right syntax form of L$foo()
I'm new to R, thanks in advance.
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______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
______________________________________________
R-help@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.
