So I must use the UserSimilarity objects and the UserBasedRecommender
although I would prefer the ItemBasedRecommender.
OK so use CachingUserSimilarity then. There are versions for both.
Hello,
today I rewrite the code of my recommender-system and use the
CachingUserSimilarity and a UserBasedRecommender.
Of course the memory consumption is no longer significantly and there
are no more 8 GB in Ram. Otherwise the speed of the recommender-system
naturally slows down a little bit. But the first goal is achieved and
with that memory usage the system could run at an application server.
Later I have to think about the speed and why it is so slow - but first
there is another problem:
The UserBasedRecommender don't work for me! In comparative with the
Itembased-Recommender the Recommendations of the Userbase-Recommender
are really bad. Only/mostly popular Items will be recommended.
I think this is because I had a lot of Items and a lot of Users - but
the most Users occupied only a few Items and the overlap of Users is
sparse. Now there are a few other Users which occupied a lot of Items
and randomly own a Item of the User the recommendation is made for - so
Items were be recommended that have nothing in common with the profile
of the user.
So I have to use a recommender which bases only on the Item-Item-Matrix
and the Userprofile from the User the Recommendation is made for: The
ItemBasedRecommender. But I compute my Item-Item-Matrix with a
UserSimilarity. Is there a way to get a UserSimilarity in a
Item-Based-Recommender? Cast it somehow - so that I could compute the
Item-Item-Similarity "on the fly" like I do this now?
Otherwise I would precompute the whole Item-Item-Matrix like I do it
before and put the Data with Sean's brand new MySQLJDBCItemSimilarity in
the ItemBased - System. (I will test this now). Thank you for that!
Regards Thomas
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___________________________________________________________
Thomas Rewig, MusicFinder Developer Team
mufin GmbH - Dresden office email: [email protected]
August-Bebel-Str. 36 phone: +49 (0)351 / 4794 670
01219 Dresden fax: +49 (0)351 / 4794 765
Germany www: http://business.mufin.com
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