If you have no ratings, how are you using RMSE? this typically measures error in reconstructing ratings. I think you are probably measuring something meaningless.
On Mon, May 6, 2013 at 10:17 AM, William <icswilliam2...@gmail.com> wrote: > I have a dataset about user and movie(no rate).But I want to get some > recommendations from this dataset. > I just know the users see or not see some movie.So I set the rating matrix > like: seen movies are 1, not seen movies are missing. > I use parallelALS function to decompose this matrix with three > parameters(numfeatures ,numIterations, lambda). And I would like to get the > best combination to reduce the RMSE. > I my experiment, RMSE value decreases with larger numIterations. But it > increases with larger numfeatures. I use the another rating-matrix(from > mahout official website) to experiment, everything is fine. > So How to explain it? Can't I assign all rates are 1?
