Strange, i have ~400.000 lines in my input file (~2500 users) ...
On 10/04/2012 05:52 PM, Sean Owen wrote:
This is something fixed in trunk, but you can ignore it. It means your eval is on too little data and the result is not meaningful. On Oct 4, 2012 4:50 PM, "yamo93" <[email protected]> wrote:Hi, I try to evaluate a boolean data model with RecommenderIRStatsEvaluator (mahout 0.7). I always get this exception : Exception in thread "main" java.lang.**IllegalArgumentException: Illegal nDCG: NaN at com.google.common.base.**Preconditions.checkArgument(** Preconditions.java:92) at org.apache.mahout.cf.taste.**impl.eval.IRStatisticsImpl.<** init>(IRStatisticsImpl.java:**38) at org.apache.mahout.cf.taste.**impl.eval.** GenericRecommenderIRStatsEvalu**ator.evaluate(** GenericRecommenderIRStatsEvalu**ator.java:212) at net.bluekiwi.bluekarma.**recommender.Evaluate.main(** Evaluate.java:36) I saw that an issue (https://issues.apache.org/**jira/browse/MAHOUT-1015<https://issues.apache.org/jira/browse/MAHOUT-1015>) was fixed in this area, is it a collateral issue ? Rgds, Yann.
