Class R2Archive

  extended by jmetal.core.SolutionSet
      extended by jmetal.util.archive.Archive
          extended by jmetal.util.archive.R2Archive
All Implemented Interfaces:

public class R2Archive
extends Archive

This class implements a bounded archive based on crowding distances (as defined in NSGA-II).

See Also:
Serialized Form

Field Summary
Fields inherited from class jmetal.core.SolutionSet
Constructor Summary
R2Archive(int maxSize)
R2Archive(int maxSize, int numberOfObjectives, java.lang.String file)
Method Summary
 boolean add(Solution solution)
          Adds a Solution to the archive.
 Solution getSolution()
          Returns a solution from the archive based on their contribution to the R2 indicator.
Methods inherited from class jmetal.core.SolutionSet
add, best, clear, get, getCapacity, getMaxSize, indexWorst, iterator, printFeasibleFUN, printFeasibleVAR, printObjectives, printObjectivesToFile, printVariablesToFile, remove, replace, setCapacity, size, sort, union, worst, writeObjectivesToMatrix
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail


public R2Archive(int maxSize)
Constructor. Creates an R2Archive for a problem of 2 objectives

maxSize - The maximum size of the archive.


public R2Archive(int maxSize,
                 int numberOfObjectives,
                 java.lang.String file)

maxSize - The maximum size of the archive.
numberOfObjectives - The number of objectives.
Method Detail


public boolean add(Solution solution)
Adds a Solution to the archive. If the Solution is dominated by any member of the archive, then it is discarded. If the Solution dominates some members of the archive, these are removed. If the archive is full and the Solution has to be inserted, the solutions are sorted by crowding distance and the one having the minimum crowding distance value.

add in class SolutionSet
solution - The Solution
true if the Solution has been inserted, false otherwise.


public Solution getSolution()
Returns a solution from the archive based on their contribution to the R2 indicator. The solution is chosen using a binary tournament.