Whew, figured it out through trial and error. In case anyone else runs into this problem, the issue ended up being with the data in one of the columns. I knew I didn't have any actual missing values, but one of the columns is a text field which can have the literal value of "NA". I guess R was interpreting those as a special case and then running into problems later. When I replaced the NA with another value, the classifier now sees the right number of rows, and I can run a summary() function fine.
> From: d.dasc...@hotmail.com > To: r-help@r-project.org > Date: Wed, 7 Apr 2010 18:44:34 -0400 > Subject: [R] RWeka - Error when attempting to summary() model > > > I'm a big fan of both Weka and R (quite new at R :) ), and jumped at the > chance to use them together. Unfortunately, I'm running into what is probably > a dumb error when trying to view info about my model. A Google search turned > up 0 hits for the actual error I got (last line), but you all are smarter! > > My code is below, but basically my data frame (q) is imported via RODBC and > has 1586 rows (as you can see from nrow() ). q$Site is the column I hope to > classify by using the JRip classifier. When I view the m object, the model > seems to have been trained on a lot fewer rows than expected (10 vs 1586?), > and the summary() command fails with the error I mentioned I haven't seen > anyone run into. My guess is something is wrong with the specification of the > training set, but when I add control=Weka_control(F=1) to specify only one > fold, the end result is the same with the degenerate confusion matrix error. > Is there some other way I should be forcing it to train on more rows? Is that > issue related to not being able to generate a confusion matrix? > > > > > attach(q) > > > nrow(q) > > [1] 1586 > > > summary(Site) > > A B C D E F > > 265 190 260 344 329 198 > > > m <- JRip(Site~.,data=q) > > > m > > JRIP rules: > > =========== > > > > (Dinosaur = TRex) => Site=A (3.0/0.0) > > => Site=B (5.0/2.0) > > > > Number of Rules : 2 > > > > > summary(m) > > Error in evaluate_Weka_classifier(object, ...) : > > Cannot set dimnames on degenerate confusion matrix. > > > > > _________________________________________________________________ > Hotmail is redefining busy with tools for the New Busy. Get more from your > inbox. > > N:WL:en-US:WM_HMP:042010_2 > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. _________________________________________________________________ The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with Hotmail. PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_5 [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
