Item Based Collaborative Filtering Properties Question

2013-09-11 Thread Brian Arnold
Hi, I am currently trying to run the distributed Item Based Collaborative filtering algorithm on our Hadoop cluster, and I have a few questions regarding tweaking the various properties of the algorithm. For the maxPrefsPerUser,maxSimilaritiesPerItem, and maxPrefsPerUserItemSimilarity properties

Re: Item Based Collaborative Filtering Properties Question

2013-09-12 Thread Darius Miliauskas
Hi, Brian, this question is also relevant for me. Perhaps somebody will give more details because I am just learning myself. But, I guess you can try to change the parameters, and check the performance, and write here about it that everybody would get more knowledge! In general, if these values a

Re: Item Based Collaborative Filtering Properties Question

2013-09-12 Thread 林伟
Hi Brian *& *Miliauskas, I am a data mining engineer form Taobao recommendation team. In past one month, I have read all the code of mahout itemCF. So maybe I can answer this question. We consider the input of itemCF for one user is a item vector, like this (the notation is from Json object model

Re: Item Based Collaborative Filtering Properties Question

2013-09-12 Thread Brian Arnold
Hi, Thank you for the response! What you said makes sense. Here is a link to the other property: http://grepcode.com/file/repo1.maven.org/maven2/org.apache.mahout/mahout-core/0.6/org/apache/mahout/cf/taste/hadoop/item/RecommenderJob.java#RecommenderJob.0DEFAULT_MAX_SIMILARITIES_PER_ITEM Supposi

Re: Item Based Collaborative Filtering Properties Question

2013-09-12 Thread 林伟
Hi Brain, The parameter "maxPrefsPerUserInItemSimilarity" is in RecommenderJob, from the text of comment, It is the same as the paramter "maxPrefsPerUser " in ItemSimilarityJob. The second question is not easy to answer. It is decided by your recommendation scenario and input data features. Th

Re: Item Based Collaborative Filtering Properties Question

2013-09-12 Thread Sebastian Schelter
Hi Brian, Happy to give you some details: So, from a matrix A (user x item) that holds user-item interactions, this algorithm first computes a matrix S (item x item) of item similarities and afterwards uses these item similarities to compute recommendations for users. the parameters refer to the

Re: Item Based Collaborative Filtering Properties Question

2013-09-13 Thread Brian Arnold
Hey Sebastian, Thanks for all the information, that was very helpful. One question, when you said "as large as the maximum number of interactions per user or larger" for the macPrefsPerUser property does that refer if the algorithm was comparing your items and my items it would be looking at how m