Fold and Other Functional Conjunctions
The Array Cast
The Hidden Tax on the Cache Bandwidth
L2 ll2 is pretty much saturated with reading and writing for the arithmetic operations. If you add on any requirement to cast out cache lines that shows up as a generalized slowdown. The several releases of j would j is pretty good job now reusing operands when it can.
Array Cast - March 31, 2023
Show Notes
Thanks to Bob Therriault, Conor Hoekstra and Marshall Lochbaum for gathering these links:
[01] 00:01:45 Luther J. Woodrum Obituary https://www.fraryfuneralhome.com/obituaries/Luther--J.-Woodrum?obId=27482014#/celebrationWall
https://www.linkedin.com/in/luther-woodrum-b5775a4a?trk=public_profile_browsemap
Lenore Mullin Mathematics of Arrays https://www.linkedin.com/in/lenore-mullin-268b0a13
[02] 00:03:46 Episode 6 https://www.arraycast.com/episodes/episode-06-henry-richs-deep-dive-into-j
Episode 18 https://www.arraycast.com/episodes/episode18-henry-rich-presents-j903
Episode 48 https://www.arraycast.com/episodes/episode48-henry-rich
[03] 00:04:40 Command to run Fold using J Playground - install 'github:jsoftware/dev_fold'
J Fold https://code.jsoftware.com/wiki/Vocabulary/fcap
APL Reduce / https://aplwiki.com/wiki/Reduce
APL Scan \ https://aplwiki.com/wiki/Scan
J Scan /\ https://code.jsoftware.com/wiki/Vocabulary/bslash
https://code.jsoftware.com/wiki/Vocabulary/slash
J Grade /: or \: https://code.jsoftware.com/wiki/Vocabulary/slashco
[04] 00:10:02 Functional Programming Language https://en.wikipedia.org/wiki/Functional_programming
C Programming Language https://en.wikipedia.org/wiki/C_(programming_language)
[05] 00:12:30 Iverson Notation https://www.jsoftware.com/papers/APL.htm
Adjacent Difference C++ https://en.cppreference.com/w/cpp/algorithm/adjacent_difference
[06] 00:14:50 Haskell Programming Language https://en.wikipedia.org/wiki/Haskell
BQN Primitives https://mlochbaum.github.io/BQN/commentary/primitive.html
[07] 00:16:10 Object Oriented Programming https://en.wikipedia.org/wiki/Object-oriented_programming
[08] 00:17:12 J Power Conjunction u^:n https://code.jsoftware.com/wiki/Vocabulary/hatco
NARS 2000 APL https://aplwiki.com/wiki/NARS
J Rank Conjunction " https://code.jsoftware.com/wiki/Vocabulary/quote
J Cut Conjunction ;. https://code.jsoftware.com/wiki/Vocabulary/semidot
J Key Conjunction /. https://code.jsoftware.com/wiki/Vocabulary/slashdot#dyadic
J Recursion $: https://code.jsoftware.com/wiki/Vocabulary/dollarco
[09] 00:24:20 Identity Element https://aplwiki.com/wiki/Identity_element
[10] 00:37:09 J Terminate Z: https://code.jsoftware.com/wiki/Vocabulary/zcapco
J Cap [: https://code.jsoftware.com/wiki/Vocabulary/squarelfco
[11] 00:41:22 J throw. https://code.jsoftware.com/wiki/Vocabulary/throwdot
J catch. https://code.jsoftware.com/wiki/Vocabulary/trydot
[12] 00:45:21 J ^:v^:_ https://code.jsoftware.com/wiki/Vocabulary/hatco#DoWhile
J _3 Z: (Iterations bottom of page) https://code.jsoftware.com/wiki/Vocabulary/zcapco
[13] 00:53:05 BQN Fold https://mlochbaum.github.io/BQN/doc/fold.html
Table from J Fold to K https://code.jsoftware.com/wiki/User:Will_Gajate/FoldVariants
[14] 00:55:13 Arthur Whitney https://en.wikipedia.org/wiki/Arthur_Whitney_(computer_scientist)
APL Partition https://aplwiki.com/wiki/Partition
[15] 00:57:55 J Gerunds https://code.jsoftware.com/wiki/Vocabulary/Glossary#Gerund
[16] 00:59:20 J Rank-Gerund 901 Release Notes https://code.jsoftware.com/wiki/System/ReleaseNotes/J901
[17] 01:01:11 C++ 2019 7 Consecutive Ones Conor talk https://www.youtube.com/watch?v=48gV1SNm3WA
[18] 01:03:10 BQN Each https://mlochbaum.github.io/BQN/doc/map.html
[19] 01:05:25 Dyalog APL Split https://aplwiki.com/wiki/Split
APL2 https://aplwiki.com/wiki/APL2
[20] 01:07:42 J NuVoc Dictionary https://code.jsoftware.com/wiki/NuVoc
[21] 01:11:25 Index Origin https://aplwiki.com/wiki/Index_origin
[22] 01:27:15 CPU Cache https://en.wikipedia.org/wiki/CPU_cache
[23] 01:33:00 ValGrind Tool https://valgrind.org/docs/manual/
Perf linux https://perf.wiki.kernel.org/index.php/Tutorial
[24] 01:35:58 Contact AT ArrayCast DOT Com
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