Hello

I made a new porgram to rotate cartesian coordinates around the origin: Try it online!

I want to simplify the (⊂+/a×(⍴a)⍴1 2○⊃x)⍪⍨⊂-/a×(⍴a)⍴2 1○⊃x part to a shorter one, preferably

-2 bytes

@Razetime some reason you can't take the input as the head & tail separately?

(i still wish there was a simple atan2 in APL, and if BQN ever goes ahead with a trig namespace, i'm definitely having it there)

@dzaima 12○⊣+0J1×⊢ isn't so bad.

@Adám it's pretty bad.

@Razetime also, if using ⎕, you don't need the {…}1

@dzaima uh yes old question

doesn't have flexible input

@Razetime ah, understandable

-4 bytes

is there a better way to rotate coordinates?

@Razetime -1 by using ⍴ in place of ↑…⊆

@dzaima doesn't seem to work.

@Razetime that's not all you have to do to make it work :p

ah

another -2 by using ×⍤1

@dzaima not sure where this one goes

@dzaima got this one tho

@Razetime to multiply each row of the reshaped tail by ⍵○⊃x you're reshaping it. Instead you could use ×⍤1 (just an example of how it works)

confusement

@Razetime ⍵○⊃x is a 2-item vector (i.e. 1 10 in my example); You want to multiply each row of a by it (4 2⍴⍳8 being a in my example)

ye it's just hard to find where it goes

never used atop a lot

@Razetime it's "rank" here. ×⍤1 is "apply × on cells with rank 1", aka multiply each row by the vector

@dzaima Ok is this right

@Razetime yep! but (×⍤1) → ×⍤1⊢ for -1 byte

alright

68 bytes so far

would this be shorter with imaginary coordinates?

@Razetime i haven't tried; in the perfect world, (⊃x)0∘+⍢polar⊢⍬2⍴1↓x would work (i.e. "add (⊃x) to the angle in the polar coordinates)

oh lol

60 bytes

@dzaima (fwiw i have an old file defining pol in dzaima/APL allowing for almost that (difference being it uses a vector of vectors instead of a matrix))

cool

I wasnt sure how to do it with a vector of vectors

@Razetime you probably don't want to

55 bytes

any better way to shorten this?

I feel like I'm done

@Razetime i have 53 using (⊣,',',⊢)/⍕¨ but a completely different approach to actually rotating (no temp function)

cool

I wanted to get it below 58

@Razetime yeah

oh, that's a whole rework

@Razetime yeah; (⊣,',',⊢)/⍕¨ is like the only thing left from your solution

lol

@dzaima 51 by including x←⎕ in the expression instead of a separate statement

yeah now that you got rid of the function you can remove the global var

@dzaima 51 with a different method

you may be able to shorten further with it

@Razetime definitely not what i had, but impressive regardless

oh well

@Razetime 47 with a different formatting strategy (no ⍉ and ,¨ but uses monadic ⍪)

lemme try

@dzaima got mine to 47 too with another different formatting strategy; should probably be able to golf another byte or two off

Btw, webinar happing now at dyalog.tv

@dzaima yep, 46 but now it's a bit more confusing

ok lol

for now I'm gonna stop

@dzaima got 43 by another slightly different method

@dzaima what a gamer

@dzaima (here's that solution)

Try it online!

I'm trying to find the nth hilbert prime

but i need a workaround to assigning stuff in extended

@Razetime i don't think you can without additional bytes. easiest would be ⍭⊢a←

don't know how this never occurred to me

@dzaima (but that's only usable for function variables, and in most cases you'd want arrays)