[R] empty array

Gabor Csardi csardi at rmki.kfki.hu
Sat Mar 15 16:42:13 CET 2008


On Sat, Mar 15, 2008 at 04:33:32PM +0100, Christophe Genolini wrote:
> Hi the list
> 
> Is it possible to create an empty matrix ? I do not mean an matrix with 
> a single value that is NA (which is not empty) but a real empty one, 
> with length=0.

Sure:

> matrix(nrow=0, ncol=5)
     [,1] [,2] [,3] [,4] [,5]
> a <- array( dim=c(5,4,0) )
> dim(a)
[1] 5 4 0
> length(a)
[1] 0

> I do not understand why we have length(numeric()), length(factor()) and 
> length(character()) to zero, and length(array()) to one... Any rason for 
> that ?

That i don't know, maybe someone else does.

G.

> Thanks
> 
> Christophe
> 
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-- 
Csardi Gabor <csardi at rmki.kfki.hu>    UNIL DGM



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