Top-N recommendation with matrix factorization

2016-05-20 Thread Mario Levitin
Hi, If one is using a matrix factorization based method, in order to generate a top-N recommendation to a user, all the unknown ratings of that user needs to be predicted (so that highest predicted N items can be recommended). If we are talking about a site with millions of items this means that

Mahout recommender under heavy traffic

2014-05-13 Thread Mario Levitin
Hi, I setup a web service using Mahout. Everything worked fine. However, I anticipate high traffic. That is, the system will produce quite a lot of recommendations every second. I'm quite inexperienced in things like load balancing. Any advice or pointers are greatly appreciated. Thanks

Re: Understanding LogLikelihood Similarity

2014-05-01 Thread Mario Levitin
distribution with an unknown parameter p_A. Likewise with B and p_B. The two binomial distributions may or may not be independent. The LLR is measuring the degree evidence against independence. On Thu, May 1, 2014 at 12:50 AM, Mario Levitin mariolevi...@gmail.com wrote: Ted, I understand how

Re: Understanding LogLikelihood Similarity

2014-04-30 Thread Mario Levitin
not use the contingency table. I hope my question is clear. Thanks. On Mon, Apr 28, 2014 at 2:41 AM, Ted Dunning ted.dunn...@gmail.com wrote: Excellent. Look forward to hearing your reactions. On Mon, Apr 28, 2014 at 1:14 AM, Mario Levitin mariolevi...@gmail.com wrote: Not yet, but I

Re: Understanding LogLikelihood Similarity

2014-04-30 Thread Mario Levitin
, 2014 at 11:31 PM, Mario Levitin mariolevi...@gmail.com wrote: Hi Ted, I have read the paper. I understand the Likelihood Ratio for Binomial Distributions part. However, I cannot make a connection with this part and the contingency table. In order to calculate Likelihood Ratio for two

Understanding LogLikelihood Similarity

2014-04-27 Thread Mario Levitin
Hi, I've used LogLikelihood Similarity in user based nearest neighborhood collaborative filtering and it has given good results (better than the others). I have read the blog post by Ted Dunning ( http://tdunning.blogspot.com.tr/2008/03/surprise-and-coincidence.html) also looked at the

Re: Understanding LogLikelihood Similarity

2014-04-27 Thread Mario Levitin
Not yet, but I will. Thanks On Mon, Apr 28, 2014 at 2:01 AM, Ted Dunning ted.dunn...@gmail.com wrote: On Mon, Apr 28, 2014 at 12:30 AM, Mario Levitin mariolevi...@gmail.com wrote: I'm trying to give it a probabilistic interpretation in order to understand the logic behind. Any

Re: org.apache.mahout.math.IndexException

2014-04-20 Thread Mario Levitin
whether the patch from https://issues.apache.org/ jira/browse/MAHOUT-1517 fixes your problem? Best, Sebastian On 04/18/2014 11:03 PM, Mario Levitin wrote: In my dataset ID's are strings so I use MemoryIDMigrator. This migrator produces large longs. I'm not doing any translation. I could

Re: org.apache.mahout.math.IndexException

2014-04-18 Thread Mario Levitin
ted.dunn...@gmail.com wrote: Are you translating the ID's down into a range that will fit into int's? On Thu, Apr 17, 2014 at 3:02 PM, Mario Levitin mariolevi...@gmail.com wrote: Hi, I'm trying to run the ALS algorithm. However, I get the following error: Exception in thread pool-1

org.apache.mahout.math.IndexException

2014-04-17 Thread Mario Levitin
Hi, I'm trying to run the ALS algorithm. However, I get the following error: Exception in thread pool-1-thread-3 org.apache.mahout.math.IndexException: Index -691877539 is outside allowable range of [0,2147483647) at org.apache.mahout.math.AbstractVector.set(AbstractVector.java:395) at

Re: how to recommend users already consumed items

2014-03-04 Thread Mario Levitin
releases come out you won't have to manage a fork. On Mar 2, 2014, at 12:38 PM, Mario Levitin mariolevi...@gmail.com wrote: Juan, I don't understand your solution, if there are no ratings how can you blend the recommendations from the system and the user's already read news. Anyway, I

Re: how to recommend users already consumed items

2014-03-04 Thread Mario Levitin
you be willing to set up a jira issue and create a patch for this? --sebastian On 03/04/2014 11:58 PM, Mario Levitin wrote: I think we should introduce a new parameter for the recommend() method in the Recommender interface that tells whether already known items should be recommended

Re: how to recommend users already consumed items

2014-03-02 Thread Mario Levitin
Juan, I don't understand your solution, if there are no ratings how can you blend the recommendations from the system and the user's already read news. Anyway, I think, as Pat does, the best way is to remove the mentioned line. It should be the responsibility of the business logic to remove

how to recommend users already consumed items

2014-03-01 Thread Mario Levitin
Hi, Mahout do not recommend items which are already consumed by the user. For example, In the getAllOtherItems method of GenericUserBasedRecommender class there is the following line possibleItemIDs.removeAll(dataModel.getItemIDsFromUser(theUserID)); which removes user's items from the

SVD++ when there are no ratings

2014-01-09 Thread Mario Levitin
Hi, In my dataset there are no ratings. There is information only about which users rented which movies. I think SVD is not suitable in this case. What about SVD++? I heard that it can be used with this kind of data. Are there any other alternatives (other than neighborhood based ones)? Thanks

Re: SVD++ when there are no ratings

2014-01-09 Thread Mario Levitin
ratio as similarity measure or an SVDRecommender with an ALSWRFactorizer with usesImplicitFeedback = true --sebastian On 01/09/2014 01:57 PM, Mario Levitin wrote: Hi, In my dataset there are no ratings. There is information only about which users rented which movies. I think SVD

Re: Mahout Web Service GlassFish 4 Deployment Error

2013-12-04 Thread Mario Levitin
/ManuelB/facebook-recommender-demo If you need more support I would recommend to contact one of the supporting companies like MapF, Cloudera or Apaxo (my own company). /Manuel On 02.12.2013, at 22:49, Mario Levitin wrote: Hi, I'm trying to build a web service for Mahout. If I use

Recommending already consumed items

2013-12-02 Thread Mario Levitin
Hi all, In some recommender applications the system might recommend already consumed items. For example, a hotel recommendation site might recommend hotel A to a user who already stayed at hotel A before. In order to recommend already consumed items we have to rank all of the items (consumed and