jopt.csp.search
Class WeightedRandomizedNeighborhood

java.lang.Object
  jopt.csp.search.WeightedRandomizedNeighborhood

All Implemented Interfaces:

Neighborhood

public class WeightedRandomizedNeighborhood

extends java.lang.Object

implements Neighborhood

A wrapper to other neighborhoods that returns neighbors from the wrapped neighborhoods in a random, weighted manner. Differs from the RandomizedNeighborhood in that the specified weights influence the frequency of the neighbors returned from the associated neighborhood. For example, if Neighborhood2 and Neighborhood1 are included with weights of 2.0 and 1.0, respectively, the caller is twice as likely to get a neighbor from Neighborhood2 (assuming the neighbors are requested in numeric order) until Neighborhood2 is exhausted.

Author:

James Boerkoel

Constructor Summary

WeightedRandomizedNeighborhood(Neighborhood[] hoods, double[] weights)
Creates a weighted, random, unified neighborhood based on a collection of other neighborhoods

WeightedRandomizedNeighborhood(Neighborhood[] hoods, double[] weights, long randomSeed)
Creates a weighted, random, unified neighborhood based on a collection of other neighborhoods with a specific randomizer seed

Method Summary

SolverSolution	getNeighbor(int index) Returns the neighboring solution at index i
Neighborhood	getSelectedNeighborhood() Returns the Neighborhood represented by the latest selected Neighborhood
int	getSelectedNeighborhoodOffset() Returns the offset into Neighborhood represented by the latest selected Neighborhood
void	neighborSelected(int i) Indicates that a neighbor has been selected from this neighborhood and is about to be used to update the initial solution.
void	setInitialSolution(SolverSolution initial) Sets the initial solution to which this neighborhood is related
int	size() Returns the number of potential solutions contained in the neighborhood

Methods inherited from class java.lang.Object

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

Constructor Detail

WeightedRandomizedNeighborhood

public WeightedRandomizedNeighborhood(Neighborhood[] hoods,
                                      double[] weights)

Creates a weighted, random, unified neighborhood based on a collection of other neighborhoods

WeightedRandomizedNeighborhood

public WeightedRandomizedNeighborhood(Neighborhood[] hoods,
                                      double[] weights,
                                      long randomSeed)

Creates a weighted, random, unified neighborhood based on a collection of other neighborhoods with a specific randomizer seed

Method Detail

setInitialSolution

public void setInitialSolution(SolverSolution initial)

Description copied from interface: Neighborhood

Sets the initial solution to which this neighborhood is related

Specified by:

setInitialSolution in interface Neighborhood

size

public int size()

Description copied from interface: Neighborhood

Returns the number of potential solutions contained in the neighborhood

Specified by:

size in interface Neighborhood

getNeighbor

public SolverSolution getNeighbor(int index)

Description copied from interface: Neighborhood

Returns the neighboring solution at index i

Specified by:

getNeighbor in interface Neighborhood

Parameters:

index - Index of neighbor within neighborhood

Returns:

Solution given by the neighbor or null if some pre-propagation checks show that the neighbor is invalid (and will fail constraint satisfaction).

getSelectedNeighborhood

public Neighborhood getSelectedNeighborhood()

Description copied from interface: Neighborhood

Returns the Neighborhood represented by the latest selected Neighborhood

Specified by:

getSelectedNeighborhood in interface Neighborhood

Returns:

Neighborhood represented by the latest selected Neighborhood null if no such neighbor has been selected

getSelectedNeighborhoodOffset

public int getSelectedNeighborhoodOffset()

Description copied from interface: Neighborhood

Returns the offset into Neighborhood represented by the latest selected Neighborhood

Specified by:

getSelectedNeighborhoodOffset in interface Neighborhood

Returns:

the offset into Neighborhood represented by the latest selected Neighborhood -1 if no such neighbor has been selected

neighborSelected

public void neighborSelected(int i)

Description copied from interface: Neighborhood

Indicates that a neighbor has been selected from this neighborhood and is about to be used to update the initial solution. This is useful if the neighborhood will adjust the order in which neighbors are produced.

Specified by:

neighborSelected in interface Neighborhood