jamal sasha 2012-10-22, 02:40
I am trying to do matrix multiplication using pig.
Basically I have data in the form:
item1, item3, 0.4
item1, item5, 0.6
And then I another data in the form
Just to give some context.. I am trying to build a top n recommendation
system.. which is as follows.
Matrix formed by data2.txt
item1 item2 item3 item4 item5
user1 1 1 0 0 1
Matrix formed by data1.txt
item1 item2 item 3 item4 item5
item1 1 0.3 0.4 0 0.6
So recommendations for user1 would be whether user1 is the score
computation as followed
Score for user 1 for item 1 = (ignore item1, item1 score) u12* item_12 +
u13*item_13 + u14*item14 + u15*item15
1 *0.3 + 0*0.4 + 0*0 + 1 * 0.6 = 0.9
And then i find this score for user1 and item2
And then for user 2 .. item 1 and so on.
I understand this is more of an implementation challenge.. and not sure
whether this is the right place to ask this.. But any suggestions will be