Package org.cicirello.permutations.distance

Class SquaredDeviationDistance

  • All Implemented Interfaces:
    NormalizedPermutationDistanceMeasurer, NormalizedPermutationDistanceMeasurerDouble, PermutationDistanceMeasurer, PermutationDistanceMeasurerDouble
    public final class SquaredDeviationDistance
extends Object
implements NormalizedPermutationDistanceMeasurer
    Squared Deviation Distance:

    Squared Deviation distance is the sum of the squares of the positional deviations of the permutation elements. The positional deviation of an element is the difference in its location in the two permutations.

    For example, consider p1 = [0, 1, 2, 3, 4, 5] and p2 = [1, 0, 5, 2, 4, 3]. Element 0 is displaced by 1 position. Likewise for elements 1 and 2. Element 3 is displaced by 2 positions. Element 4 is in the same position in both. Element 5 is displaced by 3 positions.

    Sum the squared deviations: 1^2 + 1^2 + 1^2 + 2^2 + 0^2 + 3^2 = 1 + 1 + 1 + 4 + 9 = 16.

    Runtime: O(n), where n is the permutation length.

    Squared deviation distance is described in:
    M. Sevaux and K. Sorensen, "Permutation distance measures for memetic algorithms with population management," The 6th Metaheuristics International Conference, August, 2005.

    • Constructor Detail

      • SquaredDeviationDistance

        public SquaredDeviationDistance()
        Constructs the distance measurer as specified in the class documentation.