Thank you, In fact, I need the similarity in database to be able to give the neighborhood and similar users and similar items.
Right now, for my users, I have this table : user_a_id, user_b_id, similarity And I have the same for items. I would like to do some implicit recommendation, and I know that an user is linked to some topics, and an item too. A topic is what I call my subject. That's why I have a link between users and subjects and items and subjects. srowen wrote: > > It sounds like you want to pre-compute, and then save, the similarity > between each pair of items, and each pair of users? Yes you can do > that. You don't have to do that if you don't want to. Already you are > using things like TanimotoCoefficientSimilarity, which compute > similarity dynamically based on the data tables. > > If you did want to make your own table to store these things, you > would also have to write a custom UserSimilarity or ItemSimilarity > class to read from that table. That is fairly easy. > > But I think your table would be more like this: > > user_a_id, user_b_id, similarity > > right? > > > I may be misunderstanding what you are trying to do, since it seems > like you are doing something a little non-standard. Normally you have > one data table, like: > > user_id, item_id, preference > > You have this extra notion of 'subject'. If you explain how this fits > in, maybe I can provide some better advice. > > > Sean > > > On Mon, Jun 22, 2009 at 4:15 PM, charlysf<[email protected]> wrote: >> >> Hello, >> >> I would like some advice, now I have these tables in MYSQL : >> >> User_subject >> user_id, subject_id, relevance >> >> Item_subject >> item_id, subject_id >> >> I would like some advice to have some recommendations. >> >> Now, to compute the user similarity, I made a JDBCDataModel for the table >> User_subject. >> To compute the item similarity, I made the same, for the table >> item_subject. >> >> Now, I have my similarity between users, and between items. >> Do I need to make a table like that : >> >> user_item >> user_id, item_id, relevance >> >> I will have millions of rows, and I think it could be very slow no ? >> >> Thank you very much, >> -- >> View this message in context: >> http://www.nabble.com/Would-like-some-recommendation%2C-need-advice-tp24154572p24154572.html >> Sent from the Mahout User List mailing list archive at Nabble.com. >> >> > > -- View this message in context: http://www.nabble.com/Would-like-some-recommendation%2C-need-advice-tp24154572p24154737.html Sent from the Mahout User List mailing list archive at Nabble.com.
