datamodel - Extend Mahout for new dataset -

i want build recommendation model based on mahout. dataset format has columns other userid, itemid, rating , timestamp. thus, think need extend filedatamodel.

i looked jesterdatamodel example. however, have problem logic flow. in buildmodel() method, empty map "data" first constructed. thrown processfile. assume "data" modified in method, since later used construct genericdatamodel however, data local variable instead of class variable, how modified?

processfile(iterator, data, timestamps, false); return new genericdatamodel(genericdatamodel.todatamap(data, true)); 

i see... believe have rewrite major parts datamodel, similarities calculation, , on , on, make work. can @ rescorer allows introduce own logic , filter items out or boost other items based on requirements.

in chapter 5 of mahout in action book there example of how use rescorer class. can see code here (link)