I'm trying to run the taste-web example using mahout 0.1 and the grouplens dataset. All the steps here went fine:
http://lucene.apache.org/mahout/taste.html#demo But now I get: Problem accessing /mahout-taste-webapp/RecommenderServlet. Reason: size must be at least 1 Caused by:java.lang.IllegalArgumentException: size must be at least 1 at org.apache.mahout.cf.taste.impl.common.FastSet.(FastSet.java:68) at org.apache.mahout.cf.taste.impl.recommender.slopeone.MemoryDiffStorage.(MemoryDiffStorage.java:110) at org.apache.mahout.cf.taste.impl.recommender.slopeone.SlopeOneRecommender.(SlopeOneRecommender.java:65) at org.apache.mahout.cf.taste.example.grouplens.GroupLensRecommender.(GroupLensRecommender.java:57) at org.apache.mahout.cf.taste.example.grouplens.GroupLensRecommender.(GroupLensRecommender.java:46) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:532) at java.lang.Class.newInstance0(Class.java:372) at java.lang.Class.newInstance(Class.java:325) at org.apache.mahout.cf.taste.web.RecommenderSingleton.(RecommenderSingleton.java:51) at org.apache.mahout.cf.taste.web.RecommenderSingleton.initializeIfNeeded(RecommenderSingleton.java:42) at org.apache.mahout.cf.taste.web.RecommenderServlet.init(RecommenderServlet.java:76) at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:431) at org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:339) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:478) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:389) at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:417) at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230) at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114) at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) at org.mortbay.jetty.Server.handle(Server.java:324) at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:535) at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:865) at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:539) at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212) at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404) at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409) at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:520) _________________________________________________________________ Hotmail® has ever-growing storage! Don’t worry about storage limits. http://windowslive.com/Tutorial/Hotmail/Storage?ocid=TXT_TAGLM_WL_HM_Tutorial_Storage1_052009
