[R] 'all' inconsistent?

[Uwe Ligges]

Seth Falcon wrote:

> On 30 Jan 2006, ligges at statistik.uni-dortmund.de wrote:
> 
>>Current behaviour is consistent in so far that identical(all(x),
>>!any(!x)) is TRUE and definition of any() is obvious.
> 
> 
> That helps, thanks.  I'm not sure I've had enough coffee to continue,
> but, for the set analogy I think we are saying:
> 
> logical(0) is the empty set {}.
> Complement of {} is the universal set U.
> 
> Then !logical(0)  == !{} == U.  any(U) is TRUE, isn't it?  

Hmmm, "!" is for *logical* negation, and indeed identical(logical(0), 
!(logical(0))) is TRUE, hence my first statement holds.


> I guess the real message is that you need to protect yourself by
> testing for positive length first.

Yes, indeed.

Uwe



> + seth
> 
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