What's new in Weka 3.8.1 and 3.9.1
In core weka:
Package manager now handles redirects generated by SourceForge
Package manager now employs a new class loading mechanism that attempts to avoid third-party library clashes by isolating the third-party libraries in each package
new RelationNameModifier, SendToPerspective, WriteWekaLog, Job, StorePropertiesInEnvironment, SetPropertiesFromEnvironment, WriteDataToResult and GetDataFromResult steps in Knowledge Flow
RandomForest now has an option for computing the mean impurity decrease variable importance scores
JRip now prunes redundant numeric attribute-value tests from rules
Knowledge Flow now offers an additional executor service that uses a single worker thread; steps can, if necessary, declare programatically that they should run in the single-threaded executor.
GUIs with result lists now support multi-entry delete
GUIs now support copying/pasting of array configurations to/from the clipboard
In packages:
Multi-class FLDA in the discriminantAnalysis package
New implementations in the ensemblesOfNestedDichotomies package
distributedWekaBase now includes the latest version of Ted Dunning's t-digest quantile estimator, bringing a factor of 4 speedup over the old implementation
New streamingUnivariateStats package
RPlugin package updated to support the latest version of MLR
New wekaDeepLearning4j package - provides a MLP classifier built using the DL4J library. Can work with either CPU-based or GPU-based native libraries
New logarithmicErrorMetrics package
New RankCorrelation package, courtesy of Quan Sun. Provides rank correlation metrics, Kendall tau and Spearman rho, for evaluating regression schemes
New AffectiveTweets package, courtesy of Felipe Bravom. Provides text filters for sentiment analysis of tweets
New AnalogicalModeling package, courtesy of Nathan Glenn. Provides an exemplar-based approach to modeling
New MultiObjectiveEvolutionaryFuzzyClassifier package, courtesy of Carlos Martinez Cortes. Provides a fuzzy rule-based classifier
New MultiObjectiveEvolutionarySearch package, courtesy of Carlos Martinez Cortes. Provides a search method that uses the ENORA multi-objective evolutionary algorithm