Custom functions that are used in Bayesian Data Analysis for the Behavioral and Neural Sciences: Non-Calculus Fundamentals can be downloaded here:

readme.pdf
installHLfunctions.m.zip
code repository.zip

If you would like to first download instructions for 'installing' them on your computer, download and  read the 'readme' file first.

**Note that all code is written in Matlab (a language similar to Python, but specialized for mathematical computing), using only the base version of the language (no add-ons or 'toolboxes' are required). The Matlab programming language is available for download to students at most universities, or a low-cost student version is available directly from MathWorks.