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.
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