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https://issues.apache.org/jira/browse/MAHOUT-1030?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13404737#comment-13404737
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Pat Ferrel commented on MAHOUT-1030:
------------------------------------
A couple other thoughts:
1) With non-partitioning clustering like fuzzy kmeans the weight is used to
communicate the probability of inclusion in the cluster. I'd expect it is
required. Whatever you do can't change the meaning of the weight for anything
but kmeans.
2) Strictly speaking the probability of a vectors inclusion in a cluster for
kmeans is always 1.0 or 0. Therefore if you attach the underlying pdf to the
clusteredPoints aren't you actually turning kmeans into fkmeans, at least by
some loose definition? or is the weight calculated differently for fkmeans--see
#1.
> Regression: Clustered Points Should be WeightedPropertyVectorWritable not
> WeightedVectorWritable
> ------------------------------------------------------------------------------------------------
>
> Key: MAHOUT-1030
> URL: https://issues.apache.org/jira/browse/MAHOUT-1030
> Project: Mahout
> Issue Type: Bug
> Components: Clustering, Integration
> Affects Versions: 0.7
> Reporter: Jeff Eastman
> Assignee: Jeff Eastman
> Fix For: 0.8
>
> Attachments: MAHOUT-1030.patch, MAHOUT-1030.patch, MAHOUT-1030.patch
>
>
> Looks like this won't make it into this build. Pretty widespread impact on
> code and tests and I don't know which properties were implemented in the old
> version. I will create a JIRA and post my interim results.
> On 6/8/12 12:21 PM, Jeff Eastman wrote:
> > That's a reversion that evidently got in when the new
> > ClusterClassificationDriver was introduced. It should be a pretty easy fix
> > and I will see if I can make the change before Paritosh cuts the release
> > bits tonight.
> >
> > On 6/7/12 1:00 PM, Pat Ferrel wrote:
> >> It appears that in kmeans the clusteredPoints are now written as
> >> WeightedVectorWritable where in mahout 0.6 they were
> >> WeightedPropertyVectorWritable? This means that the distance from the
> >> centroid is no longer stored here? Why? I hope I'm wrong because that is
> >> not a welcome change. How is one to order clustered docs by distance from
> >> cluster centroid?
> >>
> >> I'm sure I could calculate the distance but that would mean looking up the
> >> centroid for the cluster id given in the above WeightedVectorWritable,
> >> which means iterating through all the clusters for each clustered doc. In
> >> my case the number of clusters could be fairly large.
> >>
> >> Am I missing something?
> >>
> >>
> >
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