org.android.activityminer.logic.features.selection
Class SymmetricalUncertainityBasedFeatureSelection

Package class diagram package SymmetricalUncertainityBasedFeatureSelection
java.lang.Object
  extended by org.android.activityminer.logic.features.selection.SymmetricalUncertainityBasedFeatureSelection

public class SymmetricalUncertainityBasedFeatureSelection
extends Object

Implementation of the symmetrical uncertanity filter suggested by Lei Yu, Huan Liu in "Feature Selection for High-Dimensional Data: A Fast Correlation-Based Filter Solution" (In "Proceedings of the Twentieth International Conference on Machine Learning", pages 856-863, 2003). This implementation is an adaption of the reference implementation in Weka, with some computational optimizations and without missing value distribution.


Field Summary
private  AttributeEvaluationResult[] attributeEvalResult
          The results from attribute evaluation
private  EvaluationSamples evalSamples
          The valuation activites
 
Constructor Summary
SymmetricalUncertainityBasedFeatureSelection()
           
 
Method Summary
 AttributeEvaluationResult[] evaluate(EvaluationSamples evalSamples)
          Algorithm for FCBF
private  AttributeEvaluationResult evaluateAttribute(int idxAttribute)
          Evaluates an individual attribute by measuring the symmetrical uncertainty between it and the class.
protected  void prepare(EvaluationSamples evalSamples)
          Preparation
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

evalSamples

private EvaluationSamples evalSamples
The valuation activites


attributeEvalResult

private AttributeEvaluationResult[] attributeEvalResult
The results from attribute evaluation

Constructor Detail

SymmetricalUncertainityBasedFeatureSelection

public SymmetricalUncertainityBasedFeatureSelection()
Method Detail

prepare

protected final void prepare(EvaluationSamples evalSamples)
Preparation

Parameters:
evalSamples - the activity instances with discretized feature values

evaluate

public AttributeEvaluationResult[] evaluate(EvaluationSamples evalSamples)
Algorithm for FCBF

Parameters:
evalSamples - the evaluation training instances with discretized feature values
Returns:
an array (not necessarily ordered) of selected attribute indexes

evaluateAttribute

private AttributeEvaluationResult evaluateAttribute(int idxAttribute)
Evaluates an individual attribute by measuring the symmetrical uncertainty between it and the class.

Parameters:
idxAttribute - the attribute index
Returns:
the evaluation result