I committed something for this. Along the way of figuring out the corner case here, I realized that there are about 8 similar versions of this code elsewhere that could be standardized, and simplified, mostly by not trying to lazy-load the data.
Give it a spin. On Sat, Sep 25, 2010 at 10:44 AM, Sean Owen <[email protected]> wrote: > This is a different issue. I see it and will put in a fix today. > > On Fri, Sep 24, 2010 at 9:07 PM, Stanley Ipkiss <[email protected]> > wrote: >> >> I did that change yesterday in my code, but forgot to post the update here. >> The error that I get sometimes is - >> >> Caused by: java.lang.NullPointerException >> at >> org.apache.mahout.cf.taste.impl.similarity.file.FileItemSimilarity.itemSimilarities(FileItemSimilarity.java:108) >> at >> org.apache.mahout.cf.taste.impl.recommender.GenericItemBasedRecommender.doEstimatePreference(GenericItemBasedRecommender.java:195) >> at >> org.apache.mahout.cf.taste.impl.recommender.GenericItemBasedRecommender.estimatePreference(GenericItemBasedRecommender.java:126) >> at >> org.apache.mahout.cf.taste.impl.recommender.CachingRecommender$EstimatedPrefRetriever.get(CachingRecommender.java:214) >> at >> org.apache.mahout.cf.taste.impl.recommender.CachingRecommender$EstimatedPrefRetriever.get(CachingRecommender.java:1) >> at >> org.apache.mahout.cf.taste.impl.common.Cache.getAndCacheValue(Cache.java:127) >> at org.apache.mahout.cf.taste.impl.common.Cache.get(Cache.java:96) >> at >> org.apache.mahout.cf.taste.impl.recommender.CachingRecommender.estimatePreference(CachingRecommender.java:128) >> >> I am still looking into for what particular case, does the >> FileItemSimilarity go crazy. >> -- >> View this message in context: >> http://lucene.472066.n3.nabble.com/Possible-multi-thread-issue-in-AbstractDifferenceRecommenderEvaluator-tp1571411p1576371.html >> Sent from the Mahout User List mailing list archive at Nabble.com. >> >
