Y may be any array.  The axis specification is optional.  If present, K must be a simple integer scalar or one-element vector.  The value of K must be an axis of Y.  If absent, the last axis is implied.

The items of R are the sub-arrays of Y along the Kth axis.  R is a scalar if Y is a scalar.  Otherwise R is an array whose rank is ¯1+⍴⍴Y and whose shape is (K≠⍳⍴⍴Y)/⍴Y.

Examples

      ↓3 4⍴'MINDTHATSTEP'
 MIND  THAT  STEP
 
      ↓2 5⍴⍳10
 1 2 3 4 5  6 7 8 9 10
 
      ↓[1]2 5⍴⍳10
 1 6  2 7  3 8  4 9  5 10