I removed the users with a few ratings (<20) and now it works.
My data seems too sparse, thanks a lot for the hint.
On 10/05/2012 09:20 AM, Sean Owen wrote:
It could still be that you're sampling too little test data for
example. Or that the data is too sparse in some parts. This means
there were 0 valid test cases.
On Thu, Oct 4, 2012 at 5:33 PM, yamo93 <[email protected]> wrote:
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.
