A very basic k-means clustering implementation in Objective-C. Includes an example app to test it out.

Create an object to cluster (e.g. a point) that inherits from GWClusterObject and implements - (double)calculatePenaltyAgainstObject:(GWClusterObject *)object. Then instantiate a GWCluster with a list of objects, an initial length-k list of means, and a block to calculate the mean of a group of objects.