[R] Vector indices and minus sign

Liaw, Andy
Fri, 14 Nov 2003 16:38:03 -0000

> From: Thomas Lumley [mailto:tlumley at u.washington.edu]
>
> On Fri, 14 Nov 2003, David Orme wrote:
>
> > Hi,
> >
> > I got caught out by this behaviour in 1.8.0 and I wondered why this
> > happens:
> >
>
> Some anomaly of this sort is unavoidable because R allows
> positive or negative numeric indices. It can't distinguish
> between a vector of no positive numbers and a vector of no
> negative numbers.
>
> 	-thomas

I guess this can only work if "-" is treated specially in the subset
operators, so that, e.g., x[-"Andy"] would also work.  (This would be
nice,
IMHO.)

[A bit OT: I remembered that among the list of bugs fixed in Splus 3.2 for
Windows is -0 == 0 is F...]

Andy