k-Means Clustering

James MacQueen et al., 1967

k-means formalized by James MacQueen in 1967 (building on Lloyd’s quantization method) minimizes within-cluster squared distance by alternating Voronoi assignment and centroid recomputation—here on nine toy 2-D points with k = 3. Cross markers show centroid locations; teal, blue, and violet clusters tighten over iterations.