Explorer+prediction+visualization+plugins

toc

= Introduction = As of Weka version >3.5.2 one can easily add visualization plugins in the Explorer (Classify panel). This makes it easy to implement custom visualizations, if the ones Weka offers are not sufficient.


 * Note:** This is also covered in chapter //Extending WEKA// of the WEKA manual in versions later than 3.6.1/3.7.0 or snapshots of the stable-3.6/developer version later than 10/01/2010.

= Requirements = > >
 * custom visualization class must implement the following **interface**
 * the class must **either** reside in the following **package** (visualization classes are automatically discovered during run-time)
 * or the class' package must be listed in the key of the  file (only available in 3.5.7 or later).

= Implementation = The visualization interface contains the following four methods > This method returns the //minimal// version (inclusive) of Weka that is necessary to execute the plugin, e.g.,. > This method returns the //maximal// version (exclusive) of Weka that is necessary to execute the plugin, e.g.,. > Returns the actual version of Weka this plugin was designed for, e.g., > The that is returned via this method will be added to the plugins menu in the popup in the Explorer. The ActionListener for clicking the menu item will most likely open a new frame containing the visualized data.
 * **getMinVersion**
 * **getMaxVersion**
 * **getDesignVersion**
 * **getVisualizeMenuItem**

= Examples =

Table with predictions
The example simply displays the //actual// class label and the one predicted by the classifier. In addition to that, it lists whether it was an incorrect prediction and the class probability for the correct class label.



Bar plot with probabilities
The example uses the [|JMathTools] library (needs the  in the CLASSPATH) to display a simple bar plot of the predictions. The correct predictions are displayed in //blue//, the incorrect ones in //red//. In both cases the class probability that the classifier returned for the correct class label is displayed on the y axis. The x axis is simply the index of the prediction starting with 0.



= Downloads =
 * [[file:PredictionTable.java]]
 * [[file:PredictionError.java]]

= See also =
 * Use Weka in your Java code - general overview of the basic Weka API
 * Explorer visualization plugins

= Links =
 * [|JMathTools homepage]