Programming Leftovers

posted by Roy Schestowitz on Sep 10, 2023

• Pearson, Spearman and Kendall correlation coefficients by hand

  In statistics, a correlation is used to evaluate the relationship between two variables.

• Update: zipdump.py Version 0.0.28

  This is an update linked to option -f l to find PKZIP records. When option -E all is used, field externalattributes is parsed now: zipdump_v0_0_28.zip (http)MD5: 288DBCFACB42E6563F417E46BD6081BCSHA256: 4C3AD3A49FCFC1B5A680EAE80CE129A67912BCC03402EC9F46D08F902BC512A1

• My mental model of transducers

  I’ve been programming in Clojure for a long time, but I haven’t been using transducers much. I learned to mechanically transform (into [] (map f coll)) to (into [] (map f) coll) for a slight performance gain, but not much beyond that. Recently, however, I’ve found myself refactoring transducers-based code at work, which prompted me to get back to speed.

  I found Eero Helenius’ article “Grokking Clojure transducers” a great help in that. To me, it’s much more approachable than the official documentation – in a large part because it shows you how to build transducers from the ground up, and this method of learning profoundly resonates with me. I highly recommend it. However, it’s also useful to have a visual intuition of how transducers work, a mental model that hints at the big picture without zooming into the details too much. In this post, I’d like to share mine and illustrate it with a REPL session. (Spoiler alert: there’s core.async ahead, but in low quantities.)

• Linux on ThinkPad X13s Gen 1

  This is to document my ordeal #EmbraceTheSuck journey and work-in-progress of daily driving a Lenovo ThinkPad X13s Gen 1.