[R] Loss of dimensions in subsetting arrays

[Markku Karhunen]

Hi all,

I've been wondering for a long time why R drops the dimensions of an  
array/matrix when you try to take a subset of one column. I mean this:

dim(A)
[1] 2 5 2
B=A[1,,]
dim(B)
5 2 # so now dim(B)[3] doesn't work
C=B[2,]
dim(C)
NULL # so now nrow(C) doesn't work

Typically, you can get rid of this by writing as.matrix, as.array(...)  
but that generates extra lines of code. This is really annoying. Does  
anybody know how to turn this behaviour off?

best,
Markku Karhunen
Uni. Helsinki