1. Initial value of centroids: Suppose we use medicine A and medicine B as the first centroids. Let 1 c
and 2 c denote the coordinate of the centroids, then 1 c = (1,1) and 2 c = (2,1)
2. Objects-Centroids distance: we calculate the distance between cluster centroid to each object. Let us
use Euclidean distance, then we have distance matrix at iteration 0 is