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From charlysf <charles.rue...@gmail.com>
Subject Re: Would like some recommendation, need advice
Date Mon, 22 Jun 2009 20:24:45 GMT

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<charles.ruelle@gmail.com> 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.


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