eaLib API Docs
Last Modified : January 7 2002

mss.ea.sel
Class PercentageTruncationSelection

java.lang.Object
  |
  +--mss.ea.core.GeneticOperator
        |
        +--mss.ea.sel.Selection
              |
              +--mss.ea.sel.TruncationSelection
                    |
                    +--mss.ea.sel.PercentageTruncationSelection
All Implemented Interfaces:
SingleStreamProcessor, StreamProcessor

public class PercentageTruncationSelection
extends TruncationSelection

Truncation selection by fixed percentage. This operator selects all individuals that are ranked in their population between 0% and or in other words it selects the best % of all individuals. The default percentage is 50%, which is also used, if an invalid percentage is given.

Since:
0.1
Version:
0.1 (06-03-2001)
Author:
Andreas Rummler

Field Summary
protected  java.lang.Float threshold
          Threshold percentage.
 
Fields inherited from class mss.ea.sel.TruncationSelection
rand
 
Fields inherited from class mss.ea.sel.Selection
multSelection, numberPerSelection
 
Fields inherited from class mss.ea.core.GeneticOperator
description, ID, name
 
Constructor Summary
PercentageTruncationSelection(int numberPerSelection)
          Constructor with number per selection.
PercentageTruncationSelection(int numberPerSelection, float threshold)
          Constructor number per selection and threshold.
 
Method Summary
 float getThreshold()
          Gets the threshold.
protected  int getThresholdIndex(IndividualStream is)
           
 void setThreshold(float t)
          Sets the threshold.
 
Methods inherited from class mss.ea.sel.TruncationSelection
select
 
Methods inherited from class mss.ea.sel.Selection
getSelectionSize, process, setSelectionSize
 
Methods inherited from class mss.ea.core.GeneticOperator
getDescription, getID, getName, toString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface mss.ea.core.StreamProcessor
getName
 

Field Detail

threshold

protected java.lang.Float threshold
Threshold percentage.
Constructor Detail

PercentageTruncationSelection

public PercentageTruncationSelection(int numberPerSelection)
Constructor with number per selection. The threshold is set to 0.5.
Parameters:
numberPerSelection - number how many individuals are selected

PercentageTruncationSelection

public PercentageTruncationSelection(int numberPerSelection,
                                     float threshold)
Constructor number per selection and threshold.
Parameters:
numberPerSelection - number how many individuals are selected
threshold - threshold percentage
Method Detail

setThreshold

public void setThreshold(float t)
Sets the threshold.
Parameters:
t - new threshold

getThreshold

public float getThreshold()
Gets the threshold.
Returns:
current threshold

getThresholdIndex

protected int getThresholdIndex(IndividualStream is)
Overrides:
getThresholdIndex in class TruncationSelection

eaLib API Docs
Last Modified : January 7 2002

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