Re: [Bug-apl] Non-bug: Help comparing solutions

[Elias Mårtenson]

Referencing yesterday's discussion about ⍤, I realised that I can use it to get the indexes like this:

      X

┌→─┐

↓xz│

│zx│

│ab│

│ba│

└──┘

      ⍋⍤1 X

┌→──┐

↓1 2│

│2 1│

│1 2│

│2 1│

└───┘

However, I can't figure out a good way to apply it to the original array. Really, what is th ebest solution to this problem?

Regards,

Elias

On 5 March 2014 13:06, Elias Mårtenson <address@hidden> wrote:

I was looking at the APL idiom library and found this solution to sort rows in a matrix X:

A←(⍋,X)-⎕IO ◊ (⍴X)⍴(,X)[⎕IO+A[⍋⌊A÷¯1↑⍴X]]

It looked a bit excessive to me, and I wanted to make a more clear version so I came up with this:

⊃p⌷¨⍨⊂¨⍋¨p←⊂[2]X

Are there any benefits to the previous one?

As a side note, since I'm a big fan of lambda functions, I find my second solution to be even better, but the idiom library doesn't use lambdas so it'd be a bit of apples vs. oranges:

⊃ {⍵[⍋⍵]}¨ ⊂[2]X

Opinions?

Regards,

Elias