You are right, π times is the monadic "circle" function... Still trying to learn fluently all operators. And indeed, it's not a specially good example, but I do

You are right, π times is the monadic "circle" function... Still trying to learn fluently all operators. And indeed, it's not a specially good example, but I don't have a lot of APL code written (the "nicest" being a Mandelbrot set one-liner), the "longest" being this one and a function to generate histograms, but way harder to read, since it uses quite a few operators: ∇a←n hist x ⍝ Histogram data from x in n buckets s←x[⍋ x] mx←¯1 ↑ s mn←1 ↑ s bk←mn+(⍳n)×(mx-mn)÷n a←+/(~(↑bk)<s) s←((↑bk)<s)/s bk←1↓bk LOOP:→(0=⍴bk)/END a←a,+/(~(↑bk)<s) s←((↑bk)<s)/s bk←1↓bk →LOOP END: ∇ Not brilliant, and even at the time of writing (5 or 6 months ago) I had the feeling it may be possible to write it loopless or close enough. Variables in this one are still "global" since (even if it works) I was still checking it for possible bugs.