Module org.cicirello.jpt
Package org.cicirello.permutations.distance

Class RTypeDistance

  • All Implemented Interfaces:
    NormalizedPermutationDistanceMeasurer, NormalizedPermutationDistanceMeasurerDouble, PermutationDistanceMeasurer, PermutationDistanceMeasurerDouble
    public final class RTypeDistance
extends Object
implements NormalizedPermutationDistanceMeasurer

    RType distance treats the permutations as if they represent sets of directed edges, and counts the number of edges that differ.

    Consider the example permutation: [1, 5, 2, 4, 0, 3]. RType distance treats this as equivalent to the set of directed edges: {(1,5), (5,2), (2,4), (4,0), (0,3)}.

    E.g., distance between [1, 5, 2, 4, 0, 3] and [ 5, 1, 4, 0, 3, 2] is 3. Why? Well, the first permutation has the directed edges: {(1,5), (5,2), (2,4), (4,0), (0,3)}. The second has 2 of these (4,0), and (0,3), but does not include 3 of the edges: (1,5), (5,2), (2,4)

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

    RType distance was introduced in:
    V. Campos, M. Laguna, and R. Marti, "Context-independent scatter and tabu search for permutation problems," INFORMS Journal on Computing, vol. 17, no. 1, pp. 111–122, 2005.

    • Constructor Detail

      • RTypeDistance

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