Hi Ted, sure. will keep digging..
About SGD, I dont have an idea about how it works et al. If there is some documentation / reference / quick summary to read about it that'll be gr8. Just saw one reference in https://cwiki.apache.org/confluence/display/MAHOUT/Logistic+Regression. I am assuming we should be able to create a model from wikipedia articles and label the country of a new article. If so, could you please provide a note on how to do this. We already have the wikipedia data being extracted for specific countries using WikipediaDatasetCreatorDriver. How do we go about training the classifier using SGD ? thanks for your help, Joe. On Sun, Sep 19, 2010 at 11:25 PM, Ted Dunning <[email protected]> wrote: > I am watching these efforts with interest, but have been unable to > contribute much to the process. I would encourage Joe and others to keep > whittling this problem down so that we can understand what is causing it. > > In the meantime, I think that the SGD classifiers are close to production > quality. For problems with less than several million training examples, > and > especially problems with many sparse features, I think that these > classifiers might be easier to get started with than the Naive Bayes > classifiers. To make a virtue of a defect, the SGD based classifiers to > not > use Hadoop for training. This makes deployment of a classification > training > workflow easier, but limits the total size of data that can be handled. > > What would you guys need to get started with trying these alternative > models? > > On Sun, Sep 19, 2010 at 8:13 PM, Gangadhar Nittala > <[email protected]>wrote: > > > Joe, > > Even I tried with reducing the number of countries in the country.txt. > > That didn't help. And in my case, I was monitoring the disk space and > > at no time did it reach 0%. So, I am not sure if that is the case. To > > remove the dependency on the number of countries, I even tried with > > the subjects.txt as the classification - that also did not help. > > I think this problem is due to the type of the data being processed, > > but what I am not sure of is what I need to change to get the data to > > be processed successfully. > > > > The experienced folks on Mahout will be able to tell us what is missing I > > guess. > > > > Thank you > > Gangadhar > > > > On Sun, Sep 19, 2010 at 8:06 AM, Joe Kumar <[email protected]> wrote: > > > Gangadhar, > > > > > > I modified $MAHOUT_HOME/examples/src/test/resources/country.txt to just > > have > > > 1 entry (spain) and used WikipediaDatasetCreatorDriver to create the > > > wikipediainput data set and then ran TrainClassifier and it worked. > when > > I > > > ran TestClassifier as below, I got blank results in the output. > > > > > > $MAHOUT_HOME/examples/target/mahout-examples-0.4-SNAPSHOT.job > > > org.apache.mahout.classifier.bayes.TestClassifier -m wikipediamodel -d > > > wikipediainput -ng 3 -type bayes -source hdfs > > > > > > Summary > > > ------------------------------------------------------- > > > Correctly Classified Instances : 0 ?% > > > Incorrectly Classified Instances : 0 ?% > > > Total Classified Instances : 0 > > > > > > ======================================================= > > > Confusion Matrix > > > ------------------------------------------------------- > > > a <--Classified as > > > 0 | 0 a = spain > > > Default Category: unknown: 1 > > > > > > I am not sure if I am doing something wrong.. have to figure out why my > > o/p > > > is so blank. > > > I'll document these steps and mention about country.txt in the wiki. > > > > > > Question to all > > > Should we have 2 country.txt > > > > > > 1. country_full_list.txt - this is the existing list > > > 2. country_sample_list.txt - a list with 2 or 3 countries > > > > > > To get a flavor of the wikipedia bayes example, we can use > > > country_sample.txt. When new people want to just try out the example, > > they > > > can reference this txt file as a parameter. > > > To run the example in a robust scalable infrastructure, we could use > > > country_full_list.txt. > > > any thots ? > > > > > > regards > > > Joe. > > > > > > On Sat, Sep 18, 2010 at 8:57 PM, Joe Kumar <[email protected]> wrote: > > > > > >> Gangadhar, > > >> > > >> After running TrainClassifier again, the map task just failed with the > > same > > >> exception and I am pretty sure it is an issue with disk space. > > >> As the map was progressing, I was monitoring my free disk space > dropping > > >> from 81GB. It came down to 0 after almost 66% through the map task and > > then > > >> the exception happened. After the exception, another map task was > > resuming > > >> at 33% and I got close to 15GB free space (i guess the first map task > > freed > > >> up some space) and I am sure they would drop down to zero again and > > throw > > >> the same exception. > > >> I am going to modify the country.txt to just 1 country and recreate > > >> wikipediainput and run TrainClassifier. Will let you know how it > goes.. > > >> > > >> Do we have any benchmarks / system requirements for running this > example > > ? > > >> Has anyone else had success running this example anytime. Would > > appreciate > > >> your inputs / thots. > > >> > > >> Should we look at tuning the code for handling these situations ? Any > > quick > > >> suggestions on where to start looking at ? > > >> > > >> regards, > > >> Joe. > > >> > > >> > > >> > > >> > > > > > >
