See the Tutorial.pdf for detailed information on obtaining, using and extending MEKA. For a list of included methods and 'quick-start' command line examples, see: http://meka.sourceforge.net/methods.html

Improvements since the last version are as follows.

• MEKA's build has been switched over from Apache Ant to Apache Maven.

  • Note: this change affects people working with the source code.
  • It makes life easier with deploying artifacts to Maven Central automatically
  • Better execution of unit tests.

• The Evaluation framework has been heavily reworked

  • Evaluation output has been improved, as much in the code as the visual text output (now prettier!).
  • Macro and Micro Precision and Recall are added as evaluation metrics
  • AUPRC and AUROC are added as evaluation metrics
  • AUPRC and AUROC can be visualised with the 'Show ...' options under the right-click menu of the History panel.
  • Objects like doubles[] can be stored in Results, rather than just Strings and Doubles.
  • In particular there are improvements to cross validation and incremental validation.
  • Cross-fold evaluation now combines all predictions together and then evaluates it (rather than averaging the statistics afterwards).
  • Incremental evaluation is basic prequential (interleaved train then test) with a GUI option for the number of samples
  • Incremental validation displays metrics in the GUI sampled over time in addition to those overall. These can be plotted with by selecting 'Incremental Performance' from the right-click menu in the History panel.
  • Note the earlier incremental evaluation scheme (which was window-based prequential) is also still available.

• The seed used to randomize a dataset is no longer passed on to Randomizeable classifiers -- they must use their own.

  • This means that the results of the Randomizeable classifiers will be different to earlier versions of MEKA when a dataset is randomized (of course, the result should not be statistically significant).

• It is easier now to add new functionality to Result History objects.

  • The Classify tab now automatically discovers its result history plugins at runtime.
  • These have to be derived from meka.gui.explorer.classify.AbstractClassifyResultHistoryPlugin and placed in the meka.gui.explorer.classify package.
  • New functionality (Show Graph, Save Graph, Save Model, Save CSV, Incremental Performance, Show ROC, Show PRC, etc.) is using this architecture

• The Explorer tabs are now plugins and get discovered dynamically at runtime.

  • This makes it easy for other people to add more tabs (i.e., meka packages), simply derived from meka.gui.explorer.AbstractExplorerTab and placed in the meka.gui.explorer package.

• A GUIChooser class is now available: meka.gui.guichooser.GUIChooser

  • This allows the selection of either the Explorer (the interface which has existed until now) and the new Experimenter interface.
  • It features dynamic discovery of menu items as well:
    • They need to be derived from meka.gui.guichooser.AbstractMenuItemDefinition and placed in package meka.gui.guichooser.
    • If you want a "shortcut" button like the Explorer menu definition has, simply let the isShortcutButton() method return true.
    • See the code for examples.

• Meka now has an Experimenter

  • The experimenter is still 'experimental' at the moment.
  • It is not based directly on WEKA's experimenter, but should be relatively intuitive to people that have used it.
  • See ExperimentExample.java for an example of how to do this on the command line.
  • New documentation on how to use it is in the Tutorial

• The MultilabelClassifier class has been (more appropriately) renamed ProblemTransformationMethod, and there is now a MultiLabelClassifier Interface.

  • Methods like MajorityLabelsetClassifier now implement MultilabelClassifier. Most others are ProblemTransformationMethods

• Tool tips and get/set options thoroughly elabourated throughout classifiers, and respective javadoc comments cleaned up

• Tutorial updated to reflect changes

• A number of minor bug fixes, e.g.,

  • bug fixed in PSt when empty labelset appears
  • some related issues in SNN where also fixed