Forum 04/28/2005

“Beyond Pairwise Clustering”

Sameer Agarwal – Computer Science Dept, UCSD

We consider the problem of clustering in domains where the affinity relations are not dyadic (pairwise), but rather triadic, tetradic or higher. The problem is  an instance of the hypergraph partitioning problem. We propose a two-step algorithm for solving this problem. In the first step we use a novel scheme to approximate the hypergraph using a weighted graph. In the second step a spectral partitioning algorithm is used to partition the vertices of this graph. The algorithm  is capable of handling hyperedges of all orders including order two, thus incorporating>information of all orders simultaneously. We present a theoretical analysis that relates  our algorithm to an existing hypergraph partitioning algorithm and explain the reasons for its superior performance. We report the performance of our algorithm on a variety of computer vision problems and compare it to several existing hypergraph partitioning algorithms.