Frequently+Asked+Questions

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General

 * What are the principal release branches of Weka?
 * Where can I get old versions of WEKA?
 * How do I get the latest bugfixes?
 * Can I check my CLASSPATH from within WEKA?
 * Where is my home directory located?
 * Can I check how much memory is available for WEKA?
 * Can I use WEKA in commercial applications?

Basic usage

 * Can I use CSV files?
 * How do I perform CSV file conversion?
 * How do I divide a dataset into training and test set?
 * How do I generate compatible train and test sets that get processed with a filter?
 * How do I perform attribute selection?
 * How do I perform clustering?
 * Where do I find visualization of classifiers, etc.?
 * How do I perform text classification?
 * How can I perform multi-instance learning in WEKA?
 * How do I perform cost-sensitive classification?
 * How do I make predictions with a trained model?
 * Why am I missing certain nominal or string values from sparse instances?
 * Can I use WEKA for time series analysis?
 * Does WEKA support multi-label classification?
 * How do I perform one-class classification?
 * Can I make a screenshot of a plot or graph directly in WEKA?
 * How do I use the package manager?
 * What do I do if the package manager does not start?

Advanced usage

 * How can I track instances in WEKA?
 * How do I use ID attributes?
 * How do I connect to a database?
 * How do I use WEKA from command line?
 * Can I tune the parameters of a classifier?
 * How do I generate Learning curves?
 * Where can I find information regarding ROC curves?
 * I have unbalanced data - now what?
 * Can I run an experiment using clusterers in the Experimenter?
 * How can I use transactional data in Weka?
 * How can I use Weka with Matlab or Octave?

Customizing Weka

 * Can I change the colors (background, axes, etc.) of the plots in WEKA?
 * How do I add a new classifier, filter, kernel, etc

Using third-party tools

 * How do I use libsvm in WEKA?
 * The snowball stemmers don't work, what am I doing wrong?

Developing with WEKA

 * Where can I get WEKA's source code?
 * How do I compile WEKA?
 * What is CVS and what do I need to do to access it?
 * What is Subversion and what do I need to do to access it?
 * How do I use WEKA's classes in my own code?
 * How do I write a new classifier or filter?
 * Can I compile WEKA into native code?
 * Can I use WEKA from C#?
 * Can I use WEKA from Python?
 * Can I use WEKA from Groovy?
 * Serialization is nice, but what about generating actual Java code from WEKA classes?
 * How are packages structured for the package management system?
 * Pluggable evaluation metrics for classification/regression
 * How can I contribute to WEKA?

Windows

 * How do I modify the CLASSPATH?
 * How do I modify the RunWeka.bat file?
 * Can I process UTF-8 datasets or files?
 * How do I run the Windows Weka installer in silent mode?

Troubleshooting

 * I have Weka download problems - what's going wrong?
 * My ARFF file doesn't load - why?
 * What does nominal value not declared in header, read Token[X], line Y mean?
 * How do I get rid of this OutOfMemoryException?
 * How do I deal with a StackOverflowError?
 * Why do I get the error message 'training and test set are not compatible'?
 * Couldn't read from database: unknown data type
 * Trying to add JDBC driver: ... - Error, not in CLASSPATH?
 * I cannot process large datasets - any ideas?
 * See Troubleshooting article for more troubleshooting.