[Jprogramming] Indexing into array

[alexgian]

If I want to index into a (rank 2) array to get the element usually called
the (i,j)th in the big, bad world, is there a better way to do it than
this, which I currently use?

    idx  =: (1 { [) { ] {~ 0 { [

    2 1 idx 4 4 $i.16

9

I notice that if { takes an array as left arg, it merely returns the given
rows of that array, rather than the required indexed element.
So I can't do, for instance,  (2 1) { 4 4 $i.16 and get what I want
Furher, I wander if there is a more generic way of writing this so that it
would work automatically for rank-3 arrays and greater.