Not sure who the target audience of this is.
At some point I wanted to get closer to Machine Learning/Computer Vision, and I found out that I had to compute eigenvalues and eigenvectors for PCA, and then I wanted to find out how they are computed, and then I found out I might need to compute QR decomposition for a matrix, and soon I’ve entered in a linear algebra rabbit hole.
So I’ve documented my findings and wrote this article. Somehow just calling methods from a python library was not satisfying for me, I wanted to understand the underlyings.
The target audience would be people who are just starting with this, or undergrad students who are taking numerical analysis / linear algebra classes and have to implement LU/QR decomposition or algorithms for Row Echelon.