One technical tip: .csv (comma separated values) and .txt (text) formats are the same data encoding. The difference is the file extensions can tell the operating system what types of programs should open the files by default. The matlab ecosystem has a csvread function that should help you avoid having to write parsing code in the future.

I hope this helps! Your article is a nice walkthrough. My only other recommendation is to add some high level comments in the code samples on the intent behind the code, but thats more personal taste as I skip to check these out first!