Principle components analysis
Algorithm: 1. Assign data points to a group 2. Iterate through until no change: 1. Find centroid 2. Find the point that is closest to the centroids. Assign that data point to the corresponding group of the centroids. .. admonition:: How Many Groups :class: warning The art of chosing K. Hierarchical Clustering
Bottom-up hierarchical groups can be read out from dendrogram.