Hello Mahout community, I load first two columns of Group Lens 100K (au.base) data into GenericBooleanPrefDataModel,
1-) Using MemoryIDMigrator, 2-) Using a custom UpdatableIDMigrator, namely IdentityIDMigrator, that simply relies on Long.parseLong(stringID) and Long.toString(longID) method. Where IDs are already numeric/integers. However I am seeing different set of recommendations in each case for the same user. Here is an example for the userID=1. Results of memory migrator 716 1.0 673 1.0 320 1.0 1239 1.0 452 1.0 877 1.0 474 1.0 949 1.0 291 1.0 1213 1.0 Results of identity migrator 273 1.0 33 1.0 61 1.0 117 1.0 155 1.0 160 1.0 171 1.0 189 1.0 202 1.0 265 1.0 Here is the code snippet I was using http://pastebin.com/nvD4wWGg and IdentityMigerator http://pastebin.com/i6jzbGVV Is this expected behavior? The order of recommendations being different, when just {user|item}IDs are transformed/mapped. Thank you. P.S. I obtained the same behavior with GenericItemBasedRecommender and with different userIDs too.
