Hi,
I am trying to understand the Kmeans implementation in Mahout.
Few questions appear in my mind:
1. In the ClusterIteration.IterateMR(), no combiner class has been declared.
Looking at CIMapper and CIReducer, I could not find out where the new centroids
are computed at the end of each iteration?
* I expected at some point the "SUM" (as in Cluster.S1) of the points
assigned to a cluster will be divided by the number of points (Cluster.S0). The
computeCentroid() method in AbstractCluster class does that but I could not
find whether it was called or not.
2. While generating the cluster centroids as initial guess i.e
RandomSeedGenerator.buildRandom(), why the observer() method was called for
each cluster? I noticed this observe() method records the sum of points
assigned to that cluster. Then, is not that point (which was chosen as
clusterCenter) counted twice ?
Can someone please help me answering these questions.
Regards,
Aniruddha
