Precomputation

[Mark]

I've just created some precomputed item-similarities using 
ItemSimilarityJob (LogLikelihoodSimilarity w/ boolean prefs). My 
understanding is that I can create a similarity class using 
FileItemSimilarity but what recommender should I be using with this? All 
the recommenders that I know of take a DataModel and it seems kind of 
redundant to create a FileDataModel using the same precomputed 
item-similarities.

Can someone please explain to me how to use precomputed similarities? 
Also what are some other similarities/recommendations I can precompute 
ahead of time?

Thanks