I've created an issue here - https://issues.apache.org/jira/browse/MAHOUT-1004
Best, Kris 2012/5/1 Sebastian Schelter <[email protected]> > Hi Kris, > > this sounds great, could you open a JIRA issue for that? > > --sebastian > > On 01.05.2012 11:17, Kris Jack wrote: > > Hello, > > > > I recently implemented a distributed user-based collaborative filtering > > algorithm. I've tested it experimentally and found that it is better > suited > > to Mendeley's data set for generating recommendations than the item-based > > implementation > > ( > http://www.slideshare.net/KrisJack/mahout-becomes-a-researcher-large-scale-recommendations-at-mendeley > ). > > This is mostly because Mendeley's data set has far more items than users. > > > > I'd like to contribute this code to the Mahout project. This will be the > > first patch that I write for Mahout so I'm following the instructions at > > https://cwiki.apache.org/MAHOUT/how-to-contribute.html > > > > In brief, so far I've taken the code for the existing > > org.apache.mahout.cf.taste.hadoop.item.RecommenderJob and created a new > > org.apache.mahout.cf.taste.hadoop.user.RecommenderJob. With help from > Sean > > Owen, I followed a similar approach to the item-based implementation, but > > multiplied a user-user matrix with a user-item vector rather than an > > item-item matrix with an item-user vector. The result of the > multiplication > > then needs to be transposed in order to output recommendations by user > id. > > > > Rather than changing the item-based code, I've created new classes for > the > > user-based version, which tend to be modified versions of the originals. > It > > would be much tidier to merge these together, where possible, and to > > parametrise them. I didn't want to change the item-based code straight > off, > > however, without consulting you all. > > > > Would be great to get some feedback. > > > > Best, > > Kris > > > > -- > > View this message in context: > http://lucene.472066.n3.nabble.com/Distributed-User-based-Collaborative-Filtering-tp3952692.html > > Sent from the Mahout Developer List mailing list archive at Nabble.com. > > -- Dr Kris Jack, http://www.mendeley.com/profiles/kris-jack/
