You are invoking it incorrectly but I’d suggest using the newer Spark version. It’s easier to use and about 10x faster.
You’ll need to install Spark alongside Mahout then invoke with: mahout spark-itemsimilarity -i input -o output …. The driver is documented here: http://mahout.apache.org/users/algorithms/intro-cooccurrence-spark.html On Apr 11, 2015, at 12:34 AM, lastarsenal <lastarse...@163.com> wrote: Hi, I'm a rookie for mahout. Recently when I tried to run ItemSimilarityJob with my own hadoop, I met a problem. The command is: hadoop jar mahout-core-0.9-job.jar org.apache.mahout.cf.taste.hadoop.similarity.item.ItemSimilarityJob -i /home/hadoop/itembased/user_item -o /home/hadoop/itembased/output -s SIMILARITY_EUCLIDEAN_DISTANCE -mp 0 -b true --startPhase 0 --endPhase 0 There are 1 errors: 15/04/10 15:06:02 ERROR common.AbstractJob: Unexpected 0 while processing Job-Specific Options: Unexpected 0 while processing Job-Specific Options: Usage: [--input <input> --output <output> --similarityClassname <similarityClassname> --maxSimilaritiesPerItem <maxSimilaritiesPerItem> --maxPrefs <maxPrefs> --minPrefsPerUser <minPrefsPerUser> --booleanData <booleanData> --threshold <threshold> --randomSeed <randomSeed> --help --tempDir <tempDir> --startPhase <startPhase> --endPhase <endPhase>] What's the resaon for this situation? Thank you! Best Regards, lastarsenal
