use “mahout itemsimilarity …”
But be aware that you have to convert all your user and item ids into non-negative ints. Basically inside Mahout-MapReduce they are assumed to be row and column numbers in a big matrix of all input. BTW no need to move data, Mahout-Spark reads anything Mahout-MapReduce can read without the ID restrictions. On Apr 12, 2015, at 8:04 PM, lastarsenal <lastarse...@163.com> wrote: Hi, Pat, I think it would better to follow the existing system instead of making a large scale data transfer. So, I will be very appreciated if somebody can give the advice based on hadoop, Thank you. 在 2015-04-13 00:33:48，"Pat Ferrel" <p...@occamsmachete.com> 写道： > 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 >
