chrisd:

In calculating the Xmeans clustering solution of a dataset, it is necessary (in the algorithm description) to seed the centers properly.

In Weka Xmeans, there is an option to specify the Initial Centers. Additionally, in other Xmeans libraries, the user often has to provide an initial set of centers.

However, there is no indication whether or what the WEKA xmeans library does to create the initial centers if none are provided.

How does WEKA produce initial centers if none are provided? Or, is it necessary to generate the initial centers yourself in order to run the Xmeans algorithm properly?