list/matrix chimera

On 4/10/07, Tony Plate <tplate at blackmesacapital.com> wrote:

Aren't you just seeing the effect of drop=TRUE? (at least with the
examples you give below -- they all pick out a submatrix with extent one
on some dimension)

AFAICT, matrices with a list as the underlying data work properly, e.g.:

 > vv <- array(as.list(1:12), 3:4)
 > vv

      [,1] [,2] [,3] [,4]
[1,] 1    4    7    10
[2,] 2    5    8    11
[3,] 3    6    9    12

 > vv[1:2,]

      [,1] [,2] [,3] [,4]
[1,] 1    4    7    10
[2,] 2    5    8    11

 > vv[1,,drop=FALSE]

      [,1] [,2] [,3] [,4]
[1,] 1    4    7    10

 >

It can actually be useful sometimes to have a matrix (or array) of
non-atomic objects -- wouldn't your proposed change remove (or at least
damage) that functionality?

I use this functionality a lot in the reshape package.  I would hate
to see it go!

It would be nice to have some way to remove the [[1]] from vv[1, 2][[1]] though.