Gaussian Process Regression in 9,000 Google Sheets Cell Formulas

What is the most cursed environment for numerical linear algebra? You could write a matrix solver in Bash. You could implement gradient descent in CSS. But if you want to truly suffer while building something that looks deceptively useful, you have to use Google Sheets cell formulas. I decided to implement a fully functional Gaussian Process (GP) regression pipeline—complete with Matérn 5/2 kernel…