Package ec.multiobjective.nsga2

Class NSGA2MultiObjectiveFitness

java.lang.Object
ec.Fitness
ec.multiobjective.MultiObjectiveFitness
ec.multiobjective.nsga2.NSGA2MultiObjectiveFitness
All Implemented Interfaces:
Prototype, Setup, Serializable, Cloneable, Comparable<Object>
public class NSGA2MultiObjectiveFitness extends MultiObjectiveFitness
NSGA2MultiObjectiveFitness is a subclass of MultiObjeciveFitness which adds auxiliary fitness measures (sparsity, rank) largely used by MultiObjectiveStatistics. It also redefines the comparison measures to compare based on rank, and break ties based on sparsity.
See Also:

  • Field Details

    • NSGA2_RANK_PREAMBLE

      public static final String NSGA2_RANK_PREAMBLE
      See Also:

    • NSGA2_SPARSITY_PREAMBLE

      public static final String NSGA2_SPARSITY_PREAMBLE
      See Also:

    • rank

      public int rank
      Pareto front rank measure (lower ranks are better)

    • sparsity

      public double sparsity
      Sparsity along front rank measure (higher sparsity is better)

  • Constructor Details

    • NSGA2MultiObjectiveFitness

      public NSGA2MultiObjectiveFitness()

  • Method Details

    • getAuxilliaryFitnessNames

      public String[] getAuxilliaryFitnessNames()
      Description copied from class: MultiObjectiveFitness
      Returns auxilliary fitness value names to be printed by the statistics object. By default, an empty array is returned, but various algorithms may override this to provide additional columns.
      Overrides:
      getAuxilliaryFitnessNames in class MultiObjectiveFitness

    • getAuxilliaryFitnessValues

      public double[] getAuxilliaryFitnessValues()
      Description copied from class: MultiObjectiveFitness
      Returns auxilliary fitness values to be printed by the statistics object. By default, an empty array is returned, but various algorithms may override this to provide additional columns.
      Overrides:
      getAuxilliaryFitnessValues in class MultiObjectiveFitness

    • fitnessToString

      public String fitnessToString()
      Description copied from class: Fitness
      Print to a string the fitness in a fashion intended to be parsed in again via readFitness(...). The fitness and evaluated flag should not be included. The default form simply calls toString(), which is almost certainly wrong, and you'll probably want to override this to something else. When overriding, you may wish to check to see if the 'trials' variable is non-null, and issue an error if so.
      Overrides:
      fitnessToString in class MultiObjectiveFitness

    • fitnessToStringForHumans

      public String fitnessToStringForHumans()
      Description copied from class: Fitness
      Print to a string the fitness in a fashion readable by humans, and not intended to be parsed in again. The default form simply calls toString(), but you'll probably want to override this to something else.
      Overrides:
      fitnessToStringForHumans in class MultiObjectiveFitness

    • readFitness

      public void readFitness(EvolutionState state, LineNumberReader reader) throws IOException
      Description copied from class: Fitness
      Reads in the fitness from a form outputted by fitnessToString() and thus printFitnessForHumans(...). The default version of this method exits the program with an "unimplemented" error.
      Overrides:
      readFitness in class MultiObjectiveFitness
      Throws:
      IOException

    • writeFitness

      public void writeFitness(EvolutionState state, DataOutput dataOutput) throws IOException
      Description copied from class: Fitness
      Writes the binary form of an individual out to a DataOutput. This is not for serialization: the object should only write out the data relevant to the object sufficient to rebuild it from a DataInput. The default version exits the program with an "unimplemented" error; you should override this, and be certain to also write the 'trials' variable as well.
      Overrides:
      writeFitness in class MultiObjectiveFitness
      Throws:
      IOException

    • readFitness

      public void readFitness(EvolutionState state, DataInput dataInput) throws IOException
      Description copied from class: Fitness
      Reads the binary form of an individual from a DataInput. This is not for serialization: the object should only read in the data written out via printIndividual(state,dataInput). The default version exits the program with an "unimplemented" error; you should override this, and be certain to also write the 'trials' variable as well.
      Overrides:
      readFitness in class MultiObjectiveFitness
      Throws:
      IOException

    • equivalentTo

      public boolean equivalentTo(Fitness _fitness)
      Description copied from class: MultiObjectiveFitness
      Returns true if I'm equivalent in fitness (neither better nor worse) to _fitness. The rule I'm using is this: If one of us is better in one or more criteria, and we are equal in the others, then equivalentTo is false. If each of us is better in one or more criteria each, or we are equal in all criteria, then equivalentTo is true. Multiobjective optimization algorithms may choose to override this to do something else.
      Overrides:
      equivalentTo in class MultiObjectiveFitness

    • betterThan

      public boolean betterThan(Fitness _fitness)
      We specify the tournament selection criteria, Rank (lower values are better) and Sparsity (higher values are better)
      Overrides:
      betterThan in class MultiObjectiveFitness