[SPARK-20790] ALS with implicit feedback ignores negative values

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.3.1, 1.4.0, 1.4.1, 1.5.0, 1.5.1, 1.5.2, 1.6.0, 1.6.1, 1.6.2, 1.6.3, 2.0.0, 2.0.1, 2.0.2, 2.1.0, 2.1.1
• Fix Version/s: 2.2.0
• Component/s: ML, MLlib
• Assignee: David Eis
• Reporter: David Eis
• Created: 17/May/17 19:38
• Updated: 02/Jun/17 14:01
• Resolved: 31/May/17 12:53

Description

The refactorization that was done in https://github.com/apache/spark/pull/5314/files introduced a bug, whereby for implicit feedback negative ratings just get ignored. Prior to that commit they were not ignored, but the absolute value was used as the confidence and the preference was set to 0. The preservation of comments and absolute value indicate that this was unintentional.

Issue Links

• links to: [Github] Pull Request #18022 (davideis)
• links to: [Github] Pull Request #18188 (davideis)