A New Agglomerative 2–3 Hierarchical Clustering Algorithm

Abstract

We studied a new general clustering procedure, that we call here Agglomerative 2–3 Hierarchical Clustering (2–3 AHC), which was proposed in Bertrand (2002a, 2002b). The three main contributions of this paper are: first, the theoretical study has led to reduce the complexity of the algorithm from $\mathcal{O}$>(n³) to $\mathcal{O}$(n²logn). Secondly, we proposed a new 2–3 AHC algorithm that simplifies the one proposed in 2002 (its principle is closer to the principle of the classical AHC). Finally, we proposed a first implementation of a 2–3 AHC algorithm.