@Adám you don't have the "arithmetic mean as least-squares matrix division" idiom in the cart?

@ngn No. Is there any reason to, when +/÷≢ is there and works on all ranks?

@Adám sometimes it leads to shorter code. and it's beautiful

@ngn The APLcart isn't intended as a golf course :-)

@ngn: Adam is busy — he has to write code to append .aplf to file names. SCNR. ;-)

@TorstenGrust .aplf ... what?

@ngn Heh, did you watch the Dyalog webinar last week? (You totally should, it was super interesting.)

@TorstenGrust no. was it recorded for public viewing?

@TorstenGrust will watch, thanks

(Source Code Mgmt with Dyalog 17.1)

I am looking at a piece of code that follows the form {⍵{⍺ g ⍵}¨f ⍵}¨X What would be the idiomatic APL way to express this nested iteration? The nested each doesn't feel right to me.

@TorstenGrust {⍺ g ⍵} is just g

Yes, right. I wanted to make explicit that g can depend on items of X itself as well as those returned by f ⍵.

@TorstenGrust OK, but {⍵ h ⍵} is just h⍨ so the whole thing is g¨∘f⍨¨

Let me process that...

(Thank you!)

Nice, nice! Thanks again!

@TorstenGrust Unless you can redefine your functions g and f to pair-up their arguments appropriately, you can't really get rid of the ¨s, although you could embed them.

@Adám Can you elaborate on the embed?

@TorstenGrust If you have a function f and find yourself using f¨ all the time, just do f←f¨

@Adám Ah, OK.

Noted.

@TorstenGrust ¨ is dangerous, beware of empties

@ngn Yes, thanks for the heads-up. Working out for me here but you are right, of course.

@GregEdwards Hello. Interested in APL?

Announcement: APLcart now includes applicable entries (some of them never released!) from Dyalog's #onelinerwednesday series, and has gained a "clear input button" (×). Next major task is sifting through the 700 FinnAPL idioms…

@ngn re: codegolf.stackexchange.com/questions/187082/… I've never used ⌹ before and I have no idea how that would work for that challenge >.>

@J.Sallé Roger Hui, A History of APL in 50 Functions: 2. A Short Average

@Adám Cool, I'll check it out in a bit

I managed to shave two bytes, not the 3 ngn mentioned |-⌹⊢=⊢

I'm sure one of the tacks is unnecessary, though

@Adám ^

@J.Sallé |- -> ≠

@ngn Ah, I see it now

I'll update the answer

@J.Sallé pity the challenge requires the ≠ version. =⌹=== would have been so beautiful :)

Hah! That'd be funny

@ngn @J.Sallé How about ≠⌹≠÷≠ ?

@Adám yeah, i thought of ≠⌹≠=≠ but it has the same distribution of chars as ≠⌹===

@Adám that'd be cool as well, but it looks less symetric to me

Not that the other one is, it just looks better IMO

@J.Sallé -1 with Extended: ≠⌹1¨ Try it online!

@Adám with extended you can use monadic ≤

@ngn How?

oops, we've got a left arg here...