Out of bounds negative index
On 5/2/2008 3:29 PM, hadley wickham wrote:
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
But NA and -NA are different: the first is logical, the latter is an integer. Duncan Murdoch