X must be a scalar or vector of depth ≤2, of integers each ≥⎕IO. Y may be any array. K is a simple scalar or vector specifying axes of Y. The length of K must be the same as the length of X:
(⍴,X) ≡ ⍴,K
In general, the result R is similar to that obtained by square-bracket indexing with elided subscripts. Items of K distribute items of X along the axes of Y. For example:
I J ⌷[1 3] Y ←→ Y[I;;J]
Note that index with axis may be used with selective specification. ⎕IO is an implicit argument of index with axis.
⎕IO←1 ⎕←CUBE←10⊥¨⍳2 3 4 111 112 113 114 121 122 123 124 131 132 133 134 211 212 213 214 221 222 223 224 231 232 233 234 2⌷[1]CUBE 211 212 213 214 221 222 223 224 231 232 233 234 2⌷[3]CUBE 112 122 132 212 222 232 CUBE[;;2] ≡ 2⌷[3]CUBE 1 (1 3)4⌷[2 3]CUBE 114 134 214 234 CUBE[;1 3;4] ≡ (1 3)4⌷[2 3]CUBE 1
(2(1 3)⌷[1 3]CUBE)←0 ⋄ CUBE ⍝ Selective assignment. 111 112 113 114 121 122 123 124 131 132 133 134 0 212 0 214 0 222 0 224 0 232 0 234