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That symbol is easy to remember, it is Grade Up and when pointing the other way it is Grade Down -and yes I did remember that from sight and did not have to loo

That symbol is easy to remember, it is Grade Up and when pointing the other way it is Grade Down -and yes I did remember that from sight and did not have to look it up. See https://aplwiki.com/wiki/Grade-Up https://aplwiki.com/wiki/Grade-Up

amluto 3y ago
Now I know what that particular symbol means! Except that it looks kind of like a down arrow, and that link suggests it’s Grade Down. Would writing argsort(name_of_array, reverse=True) really be so much worse? Or argsort[reverse] (made up syntax) if you want a point-free function form?
- shrubble 3y ago
  You are correct, it is "Grade Down". Some people prefer terseness, think of this as "advanced next-level Perl one-liners" if that helps ...
- lokedhs 3y ago
  It's not sort. In Kap, sort down is ∨. The grade functions returns a sorted index. Basically ⍒ 3 1 2 1 1 returns 0 2 1 3 4. So yes, it performs a sort, but it returns an index that can be used to later look up the respective elements. You can read more about it here if you're interested: https://www.aplwiki.com/wiki/Grade https://www.aplwiki.com/wiki/Grade And here's a silly example where a random array is created, then an array lookup is performed on the sorted indexes: https://kapdemo.dhsdevelopments.com/clientweb2/#a%20%E2%86%90%20%3F20%E2%8D%B4100%20%20%20%20%20%20%20%E2%8D%9D%20Create%20a%20random%20array%20of%2020%20numbers%20between%200%20and%2099%0Ab%20%E2%86%90%20a%5B%E2%8D%8Ba%5D%20%20%20%20%20%20%20%20%20%E2%8D%9D%20Look%20up%20values%20in%20a%20based%20on%20the%20graded%20index%0An%20%E2%86%90%20(%3Ca)%20%E2%8D%AA%20b%20%20%20%20%20%20%E2%8D%9D%20Increase%20the%20rank%20of%20a%20(turning%20it%20into%20a%202-dimensional%20array)%20and%20attach%20b%20below%20it%2C%20creating%20a%202-by-20%20array%0Achart%3Abar%20n%20%20%20%20%20%20%20%E2%8D%9D%20Display%20the%20result%20in%20a%20bar%20chart%0An%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%E2%8D%9D%20Return%20n%20so%20it's%20printed%20after%20the%20chart https://kapdemo.dhsdevelopments.com/clientweb2/#a%20%E2%86%9...
  - amluto 3y ago
    That’s why I said argsort :) https://numpy.org/doc/stable/reference/generated/numpy.argsort.html https://numpy.org/doc/stable/reference/generated/numpy.argso... I assume this name derives from argmin and argmax, which go back at least to MATLAB. But MATLAB has sort returning indices too.

amluto 3y ago

Now I know what that particular symbol means! Except that it looks kind of like a down arrow, and that link suggests it’s Grade Down. Would writing argsort(name_of_array, reverse=True) really be so much worse? Or argsort[reverse] (made up syntax) if you want a point-free function form?

shrubble 3y ago
You are correct, it is "Grade Down". Some people prefer terseness, think of this as "advanced next-level Perl one-liners" if that helps ...
lokedhs 3y ago
It's not sort. In Kap, sort down is ∨. The grade functions returns a sorted index. Basically ⍒ 3 1 2 1 1 returns 0 2 1 3 4. So yes, it performs a sort, but it returns an index that can be used to later look up the respective elements. You can read more about it here if you're interested: https://www.aplwiki.com/wiki/Grade https://www.aplwiki.com/wiki/Grade And here's a silly example where a random array is created, then an array lookup is performed on the sorted indexes: https://kapdemo.dhsdevelopments.com/clientweb2/#a%20%E2%86%90%20%3F20%E2%8D%B4100%20%20%20%20%20%20%20%E2%8D%9D%20Create%20a%20random%20array%20of%2020%20numbers%20between%200%20and%2099%0Ab%20%E2%86%90%20a%5B%E2%8D%8Ba%5D%20%20%20%20%20%20%20%20%20%E2%8D%9D%20Look%20up%20values%20in%20a%20based%20on%20the%20graded%20index%0An%20%E2%86%90%20(%3Ca)%20%E2%8D%AA%20b%20%20%20%20%20%20%E2%8D%9D%20Increase%20the%20rank%20of%20a%20(turning%20it%20into%20a%202-dimensional%20array)%20and%20attach%20b%20below%20it%2C%20creating%20a%202-by-20%20array%0Achart%3Abar%20n%20%20%20%20%20%20%20%E2%8D%9D%20Display%20the%20result%20in%20a%20bar%20chart%0An%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%E2%8D%9D%20Return%20n%20so%20it's%20printed%20after%20the%20chart https://kapdemo.dhsdevelopments.com/clientweb2/#a%20%E2%86%9...
- amluto 3y ago
  That’s why I said argsort :) https://numpy.org/doc/stable/reference/generated/numpy.argsort.html https://numpy.org/doc/stable/reference/generated/numpy.argso... I assume this name derives from argmin and argmax, which go back at least to MATLAB. But MATLAB has sort returning indices too.