09 Oct 2020
Some introductory notes on a recently popular topic in machine learning research.

26 Feb 2018
Cross-validation is a somewhat tricky problem for PCA, clustering, and other matrix factorization models. This post provides some Python code snippets for fitting these models with held out data.

26 Feb 2018
We show how to fit least squares regression with data missing at random.

27 Mar 2016
This post provides a short introduction to principal components analysis (PCA).

18 Nov 2015
We review some more optimistic results characterizing when clustering is not so hard to accomplish.

01 Oct 2015
A review of a result proved by

Kleinberg (2002).

11 Sep 2015
A brief look into why clustering is a hard problem.