Hello, I use PearsonCorrelation, and I would like to understand why on my example, I have a NaN. http://www.nabble.com/file/p24175732/Image%2B3.png
http://www.nabble.com/file/p24175732/Image%2B4.png I use PearsonCorrelation for an Item Basis recommender, and I of course expect, to have a similarity between the two items, because they are linked to a same user. But in fact, I have a NaN. I saw that the mean of the data should be 0, but or me, 0 is the neutral score, and I can't be sure that for each user, their mean is 0, is it important ? I don't really understand why. Thank you. -- View this message in context: http://www.nabble.com/Questions-about-PearsonCorrelation-on-a-example-tp24175732p24175732.html Sent from the Mahout User List mailing list archive at Nabble.com.
