drasys.or.graph.vrp
Class ClarkeWright

java.lang.Object
  |
  +--drasys.or.graph.vrp.Randomizer
        |
        +--drasys.or.graph.vrp.ClarkeWright

public class ClarkeWright

extends Randomizer

implements ConstructI

A randomized greedy VRP construction algorithm based on the algorithm described by Clarke and Wright.

References:

Local Search in Combinatorial Optimization
    Jan Karel Lenstra (Editor), Emile Aarts (Editor) / Paperback / Published 1997
The Traveling Salesman Problem : A Guided Tour of Combinatorial Optimization
    E.L. Lawler (Editor) / Paperback / Published 1985

Constructor Summary

ClarkeWright()           Constructs a randomized version of the ClarkeWright algorithm using the Randomizer object.

ClarkeWright(int count)           Constructs a randomized version of the ClarkeWright algorithm using the Randomizer object.

ClarkeWright(int count, int strength)           Constructs a randomized version of the ClarkeWright algorithm using the Randomizer object.

ClarkeWright(int count, int strength, ImproveI improveSubalgorithm)           Constructs a randomized version of the ClarkeWright algorithm using the Randomizer object.

 

Methods inherited from class drasys.or.graph.vrp.Randomizer

addIterations, constructClosedTours, constructInboundTours, constructOutboundTours, getCost, getCosts, getLoads, getRandom, getTours, selectVertex, selectVertex, selectVertex, setCapacityConstraint, setCostConstraint, setEdgeKey, setGraph, setProperties, setRandom, setVehicleCost

 

Methods inherited from class java.lang.Object

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

 

Constructor Detail

ClarkeWright

public ClarkeWright()
             throws VRPException

Constructs a randomized version of the ClarkeWright algorithm using the Randomizer object. There are no initial iterations added to the randomizer, so they must be added before use. The random number generator defaults to 'MultiplicativeCongruential'.

ClarkeWright

public ClarkeWright(int count)
             throws VRPException

Constructs a randomized version of the ClarkeWright algorithm using the Randomizer object. One iteration is added at strength '0' and 'count' iterations are added at strength '4'. The random number generator defaults to 'MultiplicativeCongruential'.

ClarkeWright

public ClarkeWright(int count,
                    int strength)
             throws VRPException

Constructs a randomized version of the ClarkeWright algorithm using the Randomizer object. One iteration is added at strength '0' and 'count' iterations are added at strength 'strength'. The random number generator defaults to 'MultiplicativeCongruential'.

ClarkeWright

public ClarkeWright(int count,
                    int strength,
                    ImproveI improveSubalgorithm)
             throws VRPException

Constructs a randomized version of the ClarkeWright algorithm using the Randomizer object. One iteration is added at strength '0' and 'count' iterations are added at strength 'strength'. The random number generator defaults to 'MultiplicativeCongruential'. The subalgorithm is set to 'improveSubalgorithm'.