The filtering algorithms in the following paper look interesting: Slope One Predictors for Online Rating-Based Collaborative Filtering by Daniel Lemire and Anna Maclachlan http://www.daniel-lemire.com/fr/abstracts/SDM2005.html
Implementation(s) in J can get linked on that page, once written. Normally I'd just add this to my list of possible-things-to-do, but instead I'm putting it before the J community. Should others code it in J before I get around to it, after all, it will make the paper easier for me to read! Also, these formulas are presently getting attention from programmers of other functional languages, so there could be benefits to having a J solution show up sooner rather than later. Tracy ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
