Active Distance-Based Clustering using K-medoids
This addresses the computational bottleneck in distance-based clustering for applications where obtaining all distances is difficult, though it is an incremental improvement over existing k-medoids methods.
The paper tackles the problem of k-medoids clustering requiring all pairwise distances, which is impractical in many applications, by introducing a method that uses only a small subset of distances and estimates unknown ones via triangle inequality, achieving proper clustering on real-world and synthetic datasets.
k-medoids algorithm is a partitional, centroid-based clustering algorithm which uses pairwise distances of data points and tries to directly decompose the dataset with $n$ points into a set of $k$ disjoint clusters. However, k-medoids itself requires all distances between data points that are not so easy to get in many applications. In this paper, we introduce a new method which requires only a small proportion of the whole set of distances and makes an effort to estimate an upper-bound for unknown distances using the inquired ones. This algorithm makes use of the triangle inequality to calculate an upper-bound estimation of the unknown distances. Our method is built upon a recursive approach to cluster objects and to choose some points actively from each bunch of data and acquire the distances between these prominent points from oracle. Experimental results show that the proposed method using only a small subset of the distances can find proper clustering on many real-world and synthetic datasets.