Hello all, I am looking at the Mahout 0.4 code for MySQLJDBCDiffStorage in the Slope One recommender, and in particular the first two SQL statements.
In the getDiffSQL statement, isn't it missing the stdevColumn in the second SELECT of the UNION, and more importantly, shouldn't the avgColumn in that same second SELECT have a minus sign in front of it? In the getDiffsSQL statement, aren't we simply missing a UNION with a second SELECT that looks for our particular item in the A column rather than the B column like the first SELECT does? I may have got this completely wrong, please do let me know! Regards, Eric.
