double bracket stripping names
Hi Patrick,
On 02/26/2013 02:30 AM, Patrick Burns wrote:
Is it on purpose that `[[` strips the names when used on an atomic vector?
> c(a=1, b=2)[1]
a 1
> c(a=1, b=2)[[1]]
[1] 1
FWIW, here are a couple of other interesting facts about this:
(a) [[ is about twice faster than [ for me (64-bit Ubuntu)
on a named atomic vector.
(b) [[ raises an error if the subscript is out of bounds:
> c(a=1, b=2)[3]
<NA>
NA
> c(a=1, b=2)[[3]]
Error in c(a = 1, b = 2)[[3]] : subscript out of bounds
Can be useful in some contexts.
Cheers,
H.
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