org.debellor.weka
Class WekaFilter

java.lang.Object
  org.debellor.core.Cell
      org.debellor.weka.WekaFilter

public class WekaFilter
extends Cell

Debellor wrapper for Weka filters - subclasses of weka.filters.Filter. Weka class implementing the filter is identified by its name given in long (with package specification) or short form. This name must exactly match (including case) the corresponding Weka class name. Available names can be found by running Weka GUI (Explorer or Experimenter) and opening the selection list of filters. Alternatively, you can browse Weka code (subpackages of weka.filters package).

Parameters (or options in Weka's terminology) can be passed to the Weka filter in a standard Debellor's way, by calling Cell.set(java.lang.String, java.lang.String) or Cell.setParameters(org.debellor.core.Parameters). Parameters should have names of corresponding Weka options, exactly in the same form as is printed in Weka GUI in the dialog for setting filter options.

Filter is applied to Weka Instances created by concatenation of data and decision fields of input samples (if both are present, as indicated by Sample.SampleType; otherwise only one of the fields is used). Decision is placed as the last attribute of the instances and marked as class attribute.

After filtering, if output instances have class attribute specified, this attribute is extracted as a sample decision.

All input data are first buffered and then passed together to the filter. Thus, filters do not work in on-line fashion.

Author:

Marcin Wojnarski

See Also:

WekaClassifier

Nested Class Summary

Nested classes/interfaces inherited from class org.debellor.core.Cell

Cell.CellMethod, Cell.State, Cell.Stream

Field Summary

protected Cell.Stream

input

Fields inherited from class org.debellor.core.Cell

parameters, random

Constructor Summary

WekaFilter(java.lang.String className)

Method Summary

protected void	onClose() Called by Cell.Stream.close().
protected Sample	onNext() Called by Cell.Stream.next().
protected Sample.SampleType	onOpen() Called by Cell.open().

Methods inherited from class org.debellor.core.Cell

close, erase, getAvailableParams, getParameters, learn, newThread, newThread, next, onErase, onLearn, open, openInputStream, set, set, set, set, setAvailableParams, setParameters, setRandomSeed, setSource, state, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

input

protected Cell.Stream input

Constructor Detail

WekaFilter

public WekaFilter(java.lang.String className)
           throws AmbiguousClassNameException

Parameters:

className - Name of Weka class implementing the filter algorithm, given in long (with package specification) or short form.

Throws:

AmbiguousClassNameException

Method Detail

onOpen

protected Sample.SampleType onOpen()
                            throws java.lang.Exception

Description copied from class: Cell

Called by Cell.open(). Performs the actual opening of communication session, while open checks only against access violation and handles exceptions. Must be overridden in subclasses if open is to be used. Overriders may assume that the cell is in Cell.State.CLOSED state.

Overrides:

onOpen in class Cell

Throws:

java.lang.Exception

onNext

protected Sample onNext()
                 throws java.lang.Exception

Description copied from class: Cell

Called by Cell.Stream.next(). Performs the actual generation of the next output sample, while Stream.next() checks only against access violation and handles exceptions. Must be overridden in the subclass if next is to be used, i.e. if the subclass should generate some output data. Overriders may assume that the cell is in Cell.State.OPEN state.

Overrides:

onNext in class Cell

Throws:

java.lang.Exception

onClose

protected void onClose()
                throws java.lang.Exception

Description copied from class: Cell

Called by Cell.Stream.close(). Performs the actual closing of communication session, while close checks only against access violation and handles exceptions. Must be overridden in subclasses if close is to be used. Usually the overrider will use onClose to release resources, to let them be garbage-collected. Overriders may assume that the cell is in Cell.State.OPEN state.

Overrides:

onClose in class Cell

Throws:

java.lang.Exception