f must be a monadic primitive mixed function taken from those shown in Table 14 below, or a function derived from the operators Reduction (/) or Scan (\). B must be a numeric scalar or vector. Y may be any array whose items are appropriate to function f. Axis does not follow the normal syntax of an operator.
Table 14: Primitive monadic mixed functions with optional axis.
| Function | Name | Range of B |
|---|---|---|
| ⌽ or ⊖ | Reverse | B∊⍳⍴⍴Y |
| ↑ | Mix | (0≠1|B)^(B>⎕IO-1)^(B<⎕IO+⍴⍴Y) |
| ↓ | Split | B∊⍳⍴⍴Y |
| , | Ravel | fraction, or zero or more axes of Y |
| ⊂ | Enclose | (B≡⍳0)∨(^/B∊⍳⍴⍴Y) |
In most cases, B must be an integer which identifies a specific axis of Y. However, when f is the Mix function (↑), B is a fractional value whose lower and upper integer bounds select an adjacent pair of axes of Y or an extreme axis of Y.
For Ravel (,) and Enclose (⊂), B can be a vector of two or more axes.
⎕IO is an implicit argument of the derived function which determines the meaning of B.
Examples
⌽[1]2 3⍴⍳6 4 5 6 1 2 3 ↑[.1]'ONE' 'TWO' OT NW EO