[ 
https://issues.apache.org/jira/browse/MATH-1031?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Thorsten Schäfer updated MATH-1031:
-----------------------------------

    Attachment: centroid.patch

Added path with new method and refactored other classes that use variance 
calculation
                
> Refactoring: Move variance calculation of a centroid cluster to its class
> -------------------------------------------------------------------------
>
>                 Key: MATH-1031
>                 URL: https://issues.apache.org/jira/browse/MATH-1031
>             Project: Commons Math
>          Issue Type: Improvement
>    Affects Versions: 3.2
>            Reporter: Thorsten Schäfer
>            Priority: Minor
>         Attachments: centroid.patch
>
>
> Users might be interested in assessing the quality of each cluster in the 
> calculated clustering. This can be performed by calculating its variance. 
> The variance calculation is actually performed in other places (e.g. for the 
> MultiKMeans), but not available to end users. 
> I'd propose to add the functionality into the CentroidCluster. The one issue 
> to consider is that the cluster does not know based on which distance measure 
> it was calculated. In the implementation, I chose to parametrize the method 
> with a distance measure which enables users to also compare the quality based 
> on various distance measures. Alternatively, it would be possible to add the 
> distance measure as a field, which is set by the clustering algorithm.
> In the patch I went for the first method and also changed the 2 other places 
> where variance calculation is performed to use the new feature.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to