A Greedy Algorithm for Hierarchical Complete Linkage Clustering

We are interested in the greedy method to compute an hierarchical complete linkage clustering. There are two known methods for this problem, one having a running time of O(n(3)) with a space requirement of O(n) and one having a running time of O(n(2) log n) with a space requirement of circle minus(n(2)), where n is the number of points to be clustered. Both methods are not capable to handle large point sets. In this paper, we give an algorithm with a space requirement of O(n) which is able to cluster one million points in a day on current commodity hardware.