Hi Immo,
did you have an extra cluster assignment at the end? Because the KMeans uses
two phases: the first where all points are assigned to a cluster and the second
where the cluster centroids are calculated based on the first assignment. So my
idea is that you could use the clustering flag in order to have a final cluster
assignment.
I didn't do the math though, this is just an educated guess.
Hope this helps,
Christoph
Am 26.07.2011 um 15:05 schrieb Immo Micus:
> Hello,
>
> this is my first email to the mahout-user-list.
> I am trying to do some clustering with mahout and i have a question
> concerning the cluster-center and cluster-radius.
>
> For testing, i clustered 10 points using the KMeansClusterer:
>
> points:
> [13.000, 4455.000]
> [13.000, 5101.000]
> [13.000, 333.000]
> [13.000, 3412.000]
> [13.000, 823.000]
> [13.000, 238.000]
> [13.000 951.000]
> [ 9.000, 311.000]
> [ 9.000, 970.000]
> [10.000, 2885.000]
>
> This is the method i am using:
>
> clusters = KMeansClusterer.clusterPoints(points, initial_clusters, measure,
> 10, 0.001);
>
> initial_clusters are 2 random points of the points above, measure is
> EuclideanDistanceMeasure.
>
>
> And this is the result of the converged clusters VL-0 and VL-1:
>
> VL-0{n=6 c=[11.667, 604.333] r=[1.886, 315.059]}
> VL-1{n=4 c=[12.250, 3963.250] r=[1.299, 866.428]}
>
> If i understand this output right then n is the number of points that are
> assigned to the cluster. c is the cluster-center and r is the radius of the
> cluster.
> So, every point belongs to either cluster 0 or cluster 1. Actually you can
> even guess what points belong to what cluster but i am confused by the
> calculated cluster-center and cluster-radius:
> For example [ 9.000, 970.000] should belong to cluster 0, but 9.000 <
> 9.781 [11.667 -1.886] and 970.000 > 919.392 [604.333 + 315.059]. The point
> is not in range of the cluster, it obviously does not belong to cluster 1 but
> all 10 points are assigned to clusters. Can someone please tell me where the
> mistake is?
>
>
> greetings, Immo
>
>
>
>
>
>
>
>
Christoph Brücke
[email protected]
