one document is not enough to make the ConfusionMatrix, try to put all of your documents there and see whether that works.
Regards, Xiaomeng Wan On Wed, Nov 10, 2010 at 7:20 PM, siddharth chhabra <[email protected]> wrote: > > Can somebody point me in the right direction ? > Any help would be greatly appreciated. > > Thanks > -Sid >> From: [email protected] >> To: [email protected] >> Subject: RE: NPE while running testclassifier >> Date: Mon, 8 Nov 2010 18:09:11 +0000 >> >> >> Hi >> I ran the following commands after setting the MAHOUT_HOME and running mvn >> install in the base folder - >> $MAHOUT_HOME/bin/mahout >> org.apache.mahout.classifier.bayes.PrepareTwentyNewsgroups \ >> -p examples/bin/work/20news-bydate/20news-bydate-train \ >> -o examples/bin/work/20news-bydate/bayes-train-input \ >> -a org.apache.mahout.vectorizer.DefaultAnalyzer \ >> -c UTF-8 >> >> $MAHOUT_HOME/bin/mahout trainclassifier \ >> -i examples/bin/work/20news-bydate/bayes-train-input \ >> -o examples/bin/work/20news-bydate/bayes-model \ >> -type bayes \ >> -ng 1 \ >> -source hdfs >> >> $MAHOUT_HOME/bin/mahout testclassifier \ >> -m examples/bin/work/20news-bydate/bayes-model \ >> -d examples/bin/work/20news-bydate/bayes-test-input \ >> -type bayes \ >> -ng 1 \ >> -source hdfs \ >> -method sequential >> >> I created the bayes-test-input folder before running the last command >> (testclassifier) and dropped a document in there for classification. >> -Sid >> > From: [email protected] >> > Date: Mon, 8 Nov 2010 15:57:00 +0530 >> > Subject: Re: NPE while running testclassifier >> > To: [email protected] >> > >> > Please give full details of what you did. Command line wise >> > >> > On Mon, Nov 8, 2010 at 12:54 PM, siddharth chhabra < >> > [email protected]> wrote: >> > >> > > >> > > Hi >> > > I am new to mahout and am using the trunk which I was able to >> > > successfully >> > > build with maven. >> > > I tried to run the newsgroup example and was able to train the classifier >> > > successfully. >> > > But while running the testclassifier I got a NPE as follows - >> > > >> > > Exception in thread "main" java.lang.NullPointerException >> > > at >> > > org.apache.mahout.classifier.ConfusionMatrix.getCount(ConfusionMatrix.java:102) >> > > at >> > > org.apache.mahout.classifier.ConfusionMatrix.incrementCount(ConfusionMatrix.java:118) >> > > at >> > > org.apache.mahout.classifier.ConfusionMatrix.incrementCount(ConfusionMatrix.java:122) >> > > at >> > > org.apache.mahout.classifier.ConfusionMatrix.addInstance(ConfusionMatrix.java:90) >> > > at >> > > org.apache.mahout.classifier.ResultAnalyzer.addInstance(ResultAnalyzer.java:68) >> > > at >> > > org.apache.mahout.classifier.bayes.TestClassifier.classifySequential(TestClassifier.java:266) >> > > at >> > > org.apache.mahout.classifier.bayes.TestClassifier.main(TestClassifier.java:186) >> > > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) >> > > at >> > > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) >> > > at >> > > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) >> > > at java.lang.reflect.Method.invoke(Method.java:597) >> > > at >> > > org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:68) >> > > at org.apache.hadoop.util.ProgramDriver.driver(ProgramDriver.java:139) >> > > at org.apache.mahout.driver.MahoutDriver.main(MahoutDriver.java:184) >> > > >> > > I am running this locally without hadoop. >> > > I tried following the instructions here - >> > > https://cwiki.apache.org/confluence/display/MAHOUT/Twenty+Newsgroups >> > > I created the folder bayes-test-input and dropped in a document there for >> > > testing purposes but that didnt seem to work. >> > > >> > > Any pointers will be appreciated. >> > > >> > > Thanks >> > > -Sid >> > > >> >
