Forgot to include in the last mail. Again, I do have the Rennie paper which I'll dig in to and see if I can fix it sometime in the near future. I'll also look at the problem with -seq flag to testnb. All the guidelines for submitting patches are on JIRA or the mahout.apache.org pages, correct?
Chandler -----Original Message----- From: Chandler Burgess [mailto:[email protected]] Sent: Friday, March 28, 2014 3:16 PM To: [email protected] Subject: RE: MAHOUT-1369 - Why does theta normalization for naive bayes classification commented out? Well, maybe someone can correct me but this seems disappointing. I uncommented the code in NaiveBayesModel, BayesUtil and TrainNaiveBayesJob, added some trace statements in ComplementaryThetaMapper and ComplementaryNaiveBayesClassifier to verify they were being called, and then ran some tests using trainnb/testnb. There was not a single difference in the classifications when train/testcomplementary was specified vs standard naïve bayes. Also, running testnb with the -seq flag doesn't appear to work. -----Original Message----- From: Chandler Burgess [mailto:[email protected]] Sent: Thursday, March 27, 2014 5:17 PM To: [email protected] Subject: RE: MAHOUT-1369 - Why does theta normalization for naive bayes classification commented out? The program I wrote didn't use a model that was trained with Cbayes. After looking at the scorers in SNB and CNB, I figured they would give different results even on a model not trained with CNB. That could very well be ignorance on my part as to the math. However, I did some command line tests using -c on both training and testing and didn't see any difference in the testnb output. ________________________________________ From: Suneel Marthi <[email protected]> Sent: Thursday, March 27, 2014 5:12 PM To: [email protected] Cc: [email protected] Subject: Re: MAHOUT-1369 - Why does theta normalization for naive bayes classification commented out? Just checking , u r testing Cbayes on a model that's already been trained using Cbayes correct? Also the jira I mentioned earlier was fixed for .9, so u should be good. No code changes were done to naive bayes since .9 Sent from my iPhone > On Mar 27, 2014, at 6:01 PM, Chandler Burgess <[email protected]> > wrote: > > Ok, I'll uncomment those lines and see. I also have plenty of test data > available too (I'm doing document classification with unbalanced classes), > so I'll see if it improves there as well. > > Also, I'll try to make some time in the next week and go over the algorithm > in detail compared with the paper as an extra check. > > Thanks, > Chandler > ________________________________________ > From: Sebastian Schelter <[email protected]> > Sent: Thursday, March 27, 2014 4:01 PM > To: [email protected] > Subject: Re: MAHOUT-1369 - Why does theta normalization for naive bayes > classification commented out? > > Hi Chandler, > > I think a good way to go would be to reenable theta normalization and > run the classification examples that we already have to see how it > affects the result (and make sure it improves the result). > > Would be great to have this fixed. I'm also planning to port NB to our > Spark DSL very soon (should be just a few lines of code). > > --sebastian > > >> On 03/27/2014 09:07 PM, Suneel Marthi wrote: >> Which Mahout version r u running? While its true that ThetaNormalizer is >> still disabled today, Mahout-1389 fixes a bug wherein Complementary NB >> wasn't being called when invoked. >> >> Please test with Mahout 0.9 or trunk. >> >> >> >> >> On Thursday, March 27, 2014 3:53 PM, Chandler Burgess >> <[email protected]> wrote: >> >> Hello all, >> >> It seems Robin Anil hasn't responded, and no one is sure of the status on >> this. What needs to be done on this, and/or what can I do to help? I'm no ML >> expert, but I do have the paper and should be able to verify/fix the >> implementation. I'm REALLY interested in using the CNB classifier, since it >> seems well suited to the problem I'm trying to tackle, before I give up and >> use something else. >> >> I've done tests and see no difference when -c is passed on the command line >> for training or testing. I also wrote a program to print the scores using >> StandardNaiveBayesClassifier and ComplementaryNaiveBayesClassifier in a >> binary classification problem and see no difference between the scores, so >> it seems complementary naïve bayes is completely disabled. >> >> Thanks, >> Chandler Burgess >
