Module org.cicirello.jpt

Package org.cicirello.permutations.distance

Class ReversalIndependentDistance

java.lang.Object

org.cicirello.permutations.distance.ReversalIndependentDistance

All Implemented Interfaces:

PermutationDistanceMeasurer, PermutationDistanceMeasurerDouble

public final class ReversalIndependentDistance
extends Object
implements PermutationDistanceMeasurer

This class implements the concept of a reversal independent distance measure. This is relevant if the permutation and its reverse have the same problem dependent interpretation.

In this case, this class computes the minimum of distance(p1,p2) and distance(p1,reverse(p2)) for a given distance measure passed as a parameter to the constructor.

Constructor Summary

Constructors

Constructor	Description
ReversalIndependentDistance(PermutationDistanceMeasurer d)	Constructs a distance measure for measuring distance with reversal independence, such that distance = min { distance(p1,p2), distance(p1,reverse(p2)) }

Method Summary

Modifier and Type	Method	Description
int	distance(Permutation p1, Permutation p2)	Measures the distance between two permutations, with reversal independence: distance = min { distance(p1,p2), distance(p1,reverse(p2)) }

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.cicirello.permutations.distance.PermutationDistanceMeasurer

distancef

Constructor Details

ReversalIndependentDistance

public ReversalIndependentDistance(PermutationDistanceMeasurer d)

Constructs a distance measure for measuring distance with reversal independence, such that distance = min { distance(p1,p2), distance(p1,reverse(p2)) }

Parameters:

d - A distance measure.

Method Details

distance

public int distance(Permutation p1,
 Permutation p2)

Measures the distance between two permutations, with reversal independence: distance = min { distance(p1,p2), distance(p1,reverse(p2)) }

Specified by:

distance in interface PermutationDistanceMeasurer

Parameters:

p1 - first permutation

p2 - second permutation

Returns:

distance between p1 and p2

Throws:

IllegalArgumentException - if p1.length() is not equal to p2.length().