org.eclipse.viatra.dse.genetic.selectors

Class NonDominatedAndCrowdingDistanceSelector

java.lang.Object

org.eclipse.viatra.dse.genetic.selectors.NonDominatedAndCrowdingDistanceSelector

All Implemented Interfaces:

ISelectNextPopulation

public class NonDominatedAndCrowdingDistanceSelector
extends java.lang.Object
implements ISelectNextPopulation

Constructor Summary

Constructors

Constructor and Description
NonDominatedAndCrowdingDistanceSelector()

Method Summary

Methods

Modifier and Type	Method and Description
static void	crowdingDistanceAssignment(java.util.List<InstanceData> front, java.util.List<IObjective> objectives) Executes the crowding distance assignment for the specified InstanceDatas (for a Front).
static int	dominates(InstanceData i1, InstanceData i2, ObjectiveComparatorHelper helper) Compares the two instances by the number of constraint violations and the objectives.
boolean	filtersDuplicates()
static java.util.LinkedList<java.util.LinkedList<InstanceData>>	nonDominatedSort(java.util.Collection<InstanceData> population, java.util.List<IObjective> objectives, ObjectiveComparatorHelper helper, boolean calcCrowdingDistanceForEachFront) Makes a fast non-domination sort of the specified InstanceDatas.
java.util.List<InstanceData>	selectNextPopulation(java.util.Collection<InstanceData> currentPopulation, java.util.List<IObjective> objectives, int numberOfSelectedInstances, boolean finalSelection, ObjectiveComparatorHelper helper, boolean calcCrowdingDistanceForEachFront)
static InstanceData[]	sortByCrowdingDistance(java.util.List<InstanceData> InstanceDatas) Returns the specified InstanceDatas sorted in ascending order by the crowding distance value.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NonDominatedAndCrowdingDistanceSelector

public NonDominatedAndCrowdingDistanceSelector()

Method Detail

selectNextPopulation

public java.util.List<InstanceData> selectNextPopulation(java.util.Collection<InstanceData> currentPopulation,
                                                java.util.List<IObjective> objectives,
                                                int numberOfSelectedInstances,
                                                boolean finalSelection,
                                                ObjectiveComparatorHelper helper,
                                                boolean calcCrowdingDistanceForEachFront)

Specified by:

selectNextPopulation in interface ISelectNextPopulation

filtersDuplicates

public boolean filtersDuplicates()

Specified by:

filtersDuplicates in interface ISelectNextPopulation

nonDominatedSort

public static java.util.LinkedList<java.util.LinkedList<InstanceData>> nonDominatedSort(java.util.Collection<InstanceData> population,
                                                                        java.util.List<IObjective> objectives,
                                                                        ObjectiveComparatorHelper helper,
                                                                        boolean calcCrowdingDistanceForEachFront)

Makes a fast non-domination sort of the specified InstanceDatas. The method returns the different domination fronts in ascending order by their rank and sets their rank value.

Parameters:

population - InstanceDatas to sort

Returns:

domination fronts in ascending order by their rank

dominates

public static int dominates(InstanceData i1,
            InstanceData i2,
            ObjectiveComparatorHelper helper)

Compares the two instances by the number of constraint violations and the objectives.

Parameters:

i1 -

i2 -

objectives - The objective comparator helper.

Returns:

-1 if i1 is dominated by i2
+1 if i1 dominates i2
0 if they aren't dominated by each other

crowdingDistanceAssignment

public static void crowdingDistanceAssignment(java.util.List<InstanceData> front,
                              java.util.List<IObjective> objectives)

Executes the crowding distance assignment for the specified InstanceDatas (for a Front).

Parameters:

front - InstanceDatas //all the specified InstanceDatas must belong to the same front

sortByCrowdingDistance

public static InstanceData[] sortByCrowdingDistance(java.util.List<InstanceData> InstanceDatas)

Returns the specified InstanceDatas sorted in ascending order by the crowding distance value.

Parameters:

InstanceDatas - InstanceDatas to sort

Returns:

InstanceDatas sorted in ascending order by the crowding distance value