The most central point in a cluster is often referred to as a medoid (similar to median, but multi-dimensional).
The Mahout code does not compute medoids. In general, they are difficult to compute and implementing a full k-medoid clustering algorithm even more so. On Mon, Jul 20, 2015 at 6:25 PM, Ankit Goel <ankitgoel2...@gmail.com> wrote: > Oh, I thought kmeans gave me a point vector as a centroid, not a calculated > point central to a cluster. I guess in this case I would be looking for the > most central point vector (from the index ) that I can use as a > representative of the cluster. > > On Tue, Jul 21, 2015 at 6:41 AM, Andrew Musselman < > andrew.mussel...@gmail.com> wrote: > > > I'm not sure centroid id is even a defined thing, especially since the > > centroid, in my understanding, is just a point in space, not necessarily > a > > point in your data. > > > > Are you trying to find the most-central point in a given cluster? > > > > On Mon, Jul 20, 2015 at 5:18 PM, Ankit Goel <ankitgoel2...@gmail.com> > > wrote: > > > > > Hi, > > > I've been messing with mahout 0.10 and kmeans clustering with a solr > > 4.6.1 > > > index. The data is news articles. The --field option for kmeans is set > to > > > "content". The idField is set to "title" (just so i can analyse it > > faster). > > > The clusterdump of the kmeans result gives me a proper output, but I > cant > > > figure out the id of the vector chosen as the center. There are only > > 14-15 > > > articles so I am not hung up about the cluster performance at this > time. > > > > > > I used random seeds for the kmeans commandline. > > > For reference, this is the commandline cluster dump I am executing > > > > > > bin/mahout clusterdump -i $MAHOUT_HOME/testCluster/clusters-3-final > > > -p $MAHOUT_HOME/testCluster/clusteredPoints -d $MAHOUT_HOME/dict.txt > -b 5 > > > > > > The output I get is off the form > > > > > > :{"r": > > > > > > top terms > > > > > > xxxxx==>xxxxx > > > > > > Weight : [props - optional]: Point: > > > > > > 1.0 : [distance=0.0]: [{"account":0.026}.......other features] > > > > > > 1.0 : [distance=0.3963903651622338]: [....] > > > > > > > > > So how exactly do I get the centroid id? I have even tried accessing it > > > with java > > > > > > ClusterWritable value.getValue().getCenter() but this just gives me the > > > features and values of the centroid. > > > > > > Also, please do explain the meaning of "account":0.026 (just making > sure > > I > > > know it right). I used tfidf. > > > > > > -- > > > Regards, > > > Ankit Goel > > > http://about.me/ankitgoel > > > > > > > > > -- > Regards, > Ankit Goel > http://about.me/ankitgoel >