Adám Brudzewsky
@abrudz.bsky.social
Orthodox Jew working full time as APL programmer and Head of Language Design at Dyalog Ltd.
Much better, but as a professional APLer, I would have written `(100<(+/÷≢)sym(¯3↑⊢)⌸price)/∪sym` which is only 23 tokens. Maybe Python's 26 tokens more doesn't sound like much, but that's over 200% as many tokens!
November 11, 2025 at 4:53 PM
Much better, but as a professional APLer, I would have written `(100<(+/÷≢)sym(¯3↑⊢)⌸price)/∪sym` which is only 23 tokens. Maybe Python's 26 tokens more doesn't sound like much, but that's over 200% as many tokens!
That said, what does "compute a weighted 3-period moving average by symbol, filtering for symbols where average is greater than 100" even mean? Where the average *at some point* was greater than 100? Surely, a moving average is a list, and I don't see how to meaningfully filter by lists > 100.
November 10, 2025 at 12:17 PM
That said, what does "compute a weighted 3-period moving average by symbol, filtering for symbols where average is greater than 100" even mean? Where the average *at some point* was greater than 100? Surely, a moving average is a list, and I don't see how to meaningfully filter by lists > 100.
I'm a confused about example 2. I don't know Q or Python, but the APL code seems iffy even if `,\\` is just a typo, as it doesn't even refer to the symbols; `(⍳3)ר` needs no `¨` unless you meant `∘ר`; `(3÷+/⍳3)×` is just `0.5×`; `{⍵/⍨100<+/⍵}¨` filtes the raw data instead of the symbols; etc.
November 10, 2025 at 12:15 PM
I'm a confused about example 2. I don't know Q or Python, but the APL code seems iffy even if `,\\` is just a typo, as it doesn't even refer to the symbols; `(⍳3)ר` needs no `¨` unless you meant `∘ר`; `(3÷+/⍳3)×` is just `0.5×`; `{⍵/⍨100<+/⍵}¨` filtes the raw data instead of the symbols; etc.
It really should say "given a square numeric matrix".
January 21, 2025 at 7:01 AM
It really should say "given a square numeric matrix".