Re: Random Forest possible error

2013-12-15 Thread Ted Dunning
Finding problems is never bad, even if misdiagnosed the first time around. On Sat, Dec 14, 2013 at 4:05 PM, sam wu swu5...@gmail.com wrote: Hi Ted, some more debugging, my previous statement is not correct, please dis-regards. There is problem i am sure. I am using InMemeoryMapper, one of

Random Forest possible error

2013-12-14 Thread sam wu
Hi, I am using random forest of Mahout. It works well when I don't use feature descriptor with Ignore feature ( No I flag). If using Ignore flag, the returned feature value is -1 (for in the code dataset.valueOf(aId, token) return -1). I did some investigation, and found that there some

Re: Random Forest possible error

2013-12-14 Thread Ted Dunning
Can you file a JIRA at https://issues.apache.org/jira/browse/MAHOUT ? It sounds like you have a test case in mind along with your fix. If you could package that work up as a patch file, then it would be much appreciated. On Sat, Dec 14, 2013 at 9:24 AM, sam wu swu5...@gmail.com wrote: Hi,

Re: Random Forest possible error

2013-12-14 Thread sam wu
Hi Ted, some more debugging, my previous statement is not correct, please dis-regards. There is problem i am sure. I am using InMemeoryMapper, one of the ways to load data. And I found problem there. I am going to compare with other approach (partial, Breiman) to see what's the difference. My

Re: Random Forest possible error

2013-12-14 Thread sam wu
Running random forest, when loading feature descriptor from JSON file with ignored features , algorithm fails. The root cause is in Dataset.java , fromJSON(String json) function --- public static Dataset fromJSON(String json) { ListMapString, Object fromJSON; try