Abstract: It is crucial to determine optimal number of clusters for the duality of clustering in cluster analysis. Based on Affinity Propagation clustering algorithm, a method for determining optimal number of clusters was proposed to analyze the clustering validity and determine optimal number of clusters by using six clustering validity index These clustering validity indexes were analyzed concretely and the method of using IGP index to determine optimal number of clusters was improved. In connection with eight datasets, the performances of these indexes were compared by simulation experimenu. The results of analysis and experiments show that IGP index is the best to determine optimal number of clusters based on Affinity Propagation clustering.

Key words: Affinity propagation, Number of clusters, Clustering validity index, Cluster analysis