[Rd] Out of bounds negative index

[hadley wickham]

On Fri, May 2, 2008 at 2:23 PM, Vincent Goulet
<vincent.goulet at act.ulaval.ca> wrote:
> Hi,
>
>  From the R Language Definition, Section 3.4.1:
>
>  "If i is positive and exceeds length(x) then the corresponding selection is
> NA. A negative out of bounds value for i causes an error."
>
>  (This is also mentioned in S Programming, footnote of page 24.)
>
>  Can someone please provide an example triggering the error? Looking in
> src/main/subscript.c I could not find exception handling for |i| >
> length(x), unless the negative subscript is mixed with NAs. In other cases,
> out of bounds negative indexes just seem silently ignored.
>
>  Did I missed or misinterpreted something, here?

Well, there's this:

> a <- 1:10
> a[NA]
 [1] NA NA NA NA NA NA NA NA NA NA
> a[-NA]
[1] NA


Hadley

-- 
http://had.co.nz/