Fast Affinity Propagation Clustering under Given Number of Clusters

Fast searching the given number of clusters

The searching process is necessary for the Affinity propagation clustering (AP) when one demands a clustering solution under given number of clusters.
The Fast AP uses multi-grid searching to reduce the calling times of AP, and improves the upper bound of preference parameter to reduce the searching scope, so that it can (largely) enhance the speed performance of AP under given number of clusters.