But I got this when no preference data: ====== java.lang.IllegalArgumentException: size is less than 1
at org.apache.mahout.cf.taste.impl.model.GenericItemPreferenceArray.<init>( GenericItemPreferenceArray.java:49) at org.apache.mahout.cf.taste.impl.model.GenericItemPreferenceArray.<init>( GenericItemPreferenceArray.java:56) at org.apache.mahout.cf.taste.impl.model.jdbc.AbstractJDBCDataModel.getPreferencesForItem( AbstractJDBCDataModel.java:441) at org.apache.mahout.cf.taste.impl.recommender.GenericItemBasedRecommender.doMostSimilarItems( GenericItemBasedRecommender.java:169) at org.apache.mahout.cf.taste.impl.recommender.GenericItemBasedRecommender.mostSimilarItems( GenericItemBasedRecommender.java:128) at org.apache.mahout.cf.taste.impl.recommender.GenericItemBasedRecommender.mostSimilarItems( GenericItemBasedRecommender.java:121) at net.gamestreamer.recommendation.SimilarItemsFinder.find( SimilarItemsFinder.java:18) at net.gamestreamer.recommendation.test.RecommenderTest.testSimilarItemsFinder( RecommenderTest.java:45) at net.gamestreamer.recommendation.test.RecommenderTest.main( RecommenderTest.java:85) ========= When create a preference data for the item,GenericItemBasedRecommender.mostSimilarItems() works well. On Sun, Sep 26, 2010 at 9:49 PM, Sean Owen <[email protected]> wrote: > GenericItemBasedRecommender.mostSimilarItems() does not care. It just > uses your ItemSimilarity to do its work. > You'd have to be more specific to get more feedback. Are you sure your > ItemSimilarity is working, not returning NaN? > > On Sun, Sep 26, 2010 at 2:40 PM, Sam Yang <[email protected]> wrote: > > I have custom implementation of ItemSimilarity.Does > > GenericItemBasedRecommender.mostSimilarItems() > > need preference data? > > I new GenericItemBasedRecommender with the preference data model and > > implementation > > of ItemSimilarity,but seems mostSimilarItems() return no results. > -- I'm samsam.
