PS you might find it useful to pinch a bit of this code to implement convergence checking and grid search... not quite the same code base but maps quite directly:
https://code.google.com/p/myrrix-recommender/source/browse/trunk/online/src/net/myrrix/online/factorizer/als/AlternatingLeastSquares.java#226 https://code.google.com/p/myrrix-recommender/source/browse/trunk/online/src/net/myrrix/online/eval/ParameterOptimizer.java#111 On Sat, Jun 8, 2013 at 6:05 PM, Sebastian Schelter <[email protected]> wrote: > Hi Saikat, > > Great that you want to work on the ALS code. I think it is very > important to make it easier to use, ideally no knowledge of the papers > and formulas should be necessary. > > As you know, the ALS code has a hyperparameter lambda that needs to be > tuned in order to get a good factorization. Are you familiar with grid > search and cross validation? It would be awesome to add some tooling for > them to Mahout that helps users to easily find a good lambda. > > Another important new feature would be to check the training error of > the factorization during the computation to make it automatically detect > convergence. Thereby users would not have to give the number of > iterations to execute as parameter. > > What do you think, does this sound reasonable to you? > > Best, > Sebastian > > > On 08.06.2013 01:15, Saikat Kanjilal wrote: >> Sebastien et al, >> Per the latest comments on mahout-974 I'd like to get a deeper understanding >> on what future improvements or architectural changes are desired on the ALS >> subsection of the codebase. I'd love to help with the development efforts >> on this codebase and on the clustering subsection as well. >> >> Regards >> >> Sent from my iPhone >> >
