I think that means you are using the wrong input to #4. It looks like you are trying to evaluate the ALS recs then create a recommender? To use ALS for recs try the CLI first see “mahout recommendfactorized” with input = (userid, itemid, rating). If #4 is to create all recs for all known users then it is independent of all other jobs since it takes interactions or ratings as input. not the output f a previous job.
On Mar 19, 2015, at 7:11 AM, James Parker <[email protected]> wrote: Hi, I try ALS recommender using Java code. This is the steps i follow: 1. I create DatasetSplitter Job 2. I create ParallelALSFactorizationJob Job 3. I create FactorizationEvaluator Job 4. I create RecommenderJob Job Everything is ok for 1 to 3. But when i run the RecommenderJob , i have the following error ------------------------------------------------------------------------------------------------------------------------------- java.lang.Exception: java.lang.RuntimeException: java.lang.ClassCastException: org.apache.mahout.math.map.OpenIntObjectHashMap cannot be cast to org.apache.mahout.common.Pair at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:403) . . ---------------------------------------------------------------------------------------------------------------------------- I'm suprised to see that if i run steps 1 to 3 using my java code, and the last step using the command line "mahout recommendfactorized ........" with the files generates with my java code steps 1 to 3), recommendations are correctly generated. Thanks you very much Evans
