[jira] Updated: (MAHOUT-109) Implementation of Cosine distance measure, plus unit test.

["Jeff Eastman (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/MAHOUT-109?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Jeff Eastman updated MAHOUT-109:
--------------------------------

    Resolution: Fixed
        Status: Resolved  (was: Patch Available)

Committed to trunk r774521

> Implementation of Cosine distance measure, plus unit test.
> ----------------------------------------------------------
>
>                 Key: MAHOUT-109
>                 URL: https://issues.apache.org/jira/browse/MAHOUT-109
>             Project: Mahout
>          Issue Type: Improvement
>    Affects Versions: 0.2
>            Reporter: Richard Tomsett
>            Assignee: Grant Ingersoll
>            Priority: Trivial
>         Attachments: CosineDistanceMeasurePatch.patch
>
>
> This is a class implementing a cosine distance measure. In various places I've seen cosine *similarity* defined as being the cosine of the angle between vectors - cos(a,b) - and cosine *distance* being (1 - cos(a,b)), so in keeping with the other distance measures, this returns 1-cos(angle) as the distance.
> Made a new test class rather than using the default distance measure check as the vectors in the current default test class all have a cosine distance of zero between them ([1,1,1,1,1,1], [3,3,3,3,3,3] and [6,6,6,6,6,6]). The test checks the cosine distances between [1,0,0,0,0,0], [1,1,1,0,0,0] and [1,1,1,1,1,1].

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.