On Sun, Jun 14, 2015 at 2:45 PM, Sebastian Schelter (JIRA) <[email protected]>
wrote:

>
>     [
> https://issues.apache.org/jira/browse/MAHOUT-1739?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14585002#comment-14585002
> ]
>
> Sebastian Schelter commented on MAHOUT-1739:
> --------------------------------------------
>
> The FileItemSimilarity class reads the output of ItemSimilarityJob. You
> can then use the resulting ItemSimilarity with Mahout's recommenders.
>
> [1]
> https://github.com/apache/mahout/blob/master/mr/src/main/java/org/apache/mahout/cf/taste/impl/similarity/file/FileItemSimilarity.java
>
> > maxSimilarItemsPerItem param of ItemSimilarityJob doesn't behave correct
> > ------------------------------------------------------------------------
> >
> >                 Key: MAHOUT-1739
> >                 URL: https://issues.apache.org/jira/browse/MAHOUT-1739
> >             Project: Mahout
> >          Issue Type: Bug
> >          Components: Collaborative Filtering
> >    Affects Versions: 0.10.0
> >            Reporter: lariven
> >              Labels: easyfix, patch
> >         Attachments: fix_maxSimilarItemsPerItem_incorrect_behave.patch
> >
> >
> > the output similar items of ItemSimilarityJob for each target item may
> exceed the number of similar items we set to maxSimilarItemsPerItem
> parameter. the following code of ItemSimilarityJob.java about line NO. 200
> may affect:
> >         if (itemID < otherItemID) {
> >           ctx.write(new EntityEntityWritable(itemID, otherItemID), new
> DoubleWritable(similarItem.getSimilarity()));
> >         } else {
> >           ctx.write(new EntityEntityWritable(otherItemID, itemID), new
> DoubleWritable(similarItem.getSimilarity()));
> >         }
> > Don't know why need to switch itemID with otherItemID, but I think a
> single line is enough:
> >           ctx.write(new EntityEntityWritable(itemID, otherItemID), new
> DoubleWritable(similarItem.getSimilarity()));
>
>
>
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