net.sourceforge.cilib.algorithm
Class MultistartOptimisationAlgorithm

java.lang.Object
  net.sourceforge.cilib.algorithm.Algorithm
      net.sourceforge.cilib.algorithm.MultistartOptimisationAlgorithm

All Implemented Interfaces:

Serializable, Runnable, ParticipatingAlgorithm, Cloneable

public class MultistartOptimisationAlgorithm
extends Algorithm
implements ParticipatingAlgorithm

MultistartOptimisationAlgorithm is simply a wrapper. The wrapped optimisation algorithm is subject to restart conditions. Each time one of these conditions is satisfied, the wrapped algorithm is re-initialised and execution continues until this algorithm's stopping conditions are satisfied.

This class implements a generalised multistart optimisation algorithm. The original Multistart PSO is due to F. van den Bergh, reference: F. van den Bergh, "An Analysis of Particle Swarm Optimizers," PhD thesis, Department of Computer Science, University of Pretoria, South Africa, 2002.

Author:

Edwin Peer

See Also:

Serialized Form

Field Summary

Fields inherited from class net.sourceforge.cilib.algorithm.Algorithm

optimisationProblem

Constructor Summary

MultistartOptimisationAlgorithm()
Creates a new instance of MultistartOptimisationAlgorithm.

MultistartOptimisationAlgorithm(MultistartOptimisationAlgorithm copy)
Create a copy of the provided instance.

Method Summary

void	addRestartCondition(StoppingCondition condition) Add a stopping condition used to determine when the algorithm should be restarted.
void	algorithmIteration() Perform an algorithm iteration, then restart the Algorithm and increment the number of restarts.
OptimisationSolution	getBestSolution() Get the best current solution.
MultistartOptimisationAlgorithm	getClone() Create a cloned copy of the current object and return it.
Entity	getContribution() Returns contribution to the solution for the co-operative optimisation algorithm.
Fitness	getContributionFitness() Returns the fitness of contribution to the solution.
OptimisationProblem	getOptimisationProblem() Get the specified OptimisationProblem.
int	getRestarts() Returns the number of times that the algorithm has been restarted.
Fitness	getSolutionFitness() Return the fitness of the solution.
List<OptimisationSolution>	getSolutions() Get the collection of best solutions.
void	performInitialisation() Perform the needed initialisation required before the execution of the algorithm starts.
void	removeRestartCondition(StoppingCondition condition) Removes a restart condition.
void	setOptimisationProblem(OptimisationProblem problem) Set the optimisation problem.
void	setTargetAlgorithm(Algorithm algorithm) Sets the target optimisation algorithm that is subject to restarting.
void	updateContributionFitness(Fitness fitness) Updates the new fitness for the solution contribution.

Methods inherited from class net.sourceforge.cilib.algorithm.Algorithm

addAlgorithmListener, addStoppingCondition, get, getAlgorithmList, getIterations, getPercentageComplete, getStoppingConditions, initialise, isFinished, performIteration, performUninitialisation, removeAlgorithmListener, removeStoppingCondition, reset, run, terminate

Methods inherited from class java.lang.Object

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

Constructor Detail

MultistartOptimisationAlgorithm

public MultistartOptimisationAlgorithm()

Creates a new instance of MultistartOptimisationAlgorithm.

MultistartOptimisationAlgorithm

public MultistartOptimisationAlgorithm(MultistartOptimisationAlgorithm copy)

Create a copy of the provided instance.

Parameters:

copy - The instance to copy.

Method Detail

getClone

public MultistartOptimisationAlgorithm getClone()

Create a cloned copy of the current object and return it. In general the created copy will be a deep copy of the provided instance. As a result this operation an be quite expensive if used incorrectly.

Specified by:

getClone in interface Cloneable

Specified by:

getClone in class Algorithm

Returns:

An exact clone of the current object instance.

See Also:

Object.clone()

setTargetAlgorithm

public void setTargetAlgorithm(Algorithm algorithm)

Sets the target optimisation algorithm that is subject to restarting.

Parameters:

algorithm - Any OptimisationAlgorithm that extends Algorithm.

getOptimisationProblem

public OptimisationProblem getOptimisationProblem()

Get the specified OptimisationProblem.

Overrides:

getOptimisationProblem in class Algorithm

Returns:

The specified OptimisationProblem.

getSolutionFitness

public Fitness getSolutionFitness()

Return the fitness of the solution.

Returns:

The current Fitness.

setOptimisationProblem

public void setOptimisationProblem(OptimisationProblem problem)

Set the optimisation problem.

Overrides:

setOptimisationProblem in class Algorithm

Parameters:

problem - The problem to set.

getContribution

public Entity getContribution()

Returns contribution to the solution for the co-operative optimisation algorithm.

Specified by:

getContribution in interface ParticipatingAlgorithm

Returns:

The algorithm's solution contribution.

getContributionFitness

public Fitness getContributionFitness()

Returns the fitness of contribution to the solution.

Specified by:

getContributionFitness in interface ParticipatingAlgorithm

Returns:

The fitness of the solution contribution.

updateContributionFitness

public void updateContributionFitness(Fitness fitness)

Updates the new fitness for the solution contribution.

Specified by:

updateContributionFitness in interface ParticipatingAlgorithm

Parameters:

fitness - The new fitness of the contribution.

addRestartCondition

public void addRestartCondition(StoppingCondition condition)

Add a stopping condition used to determine when the algorithm should be restarted. Equivalent to calling Algorithm.addStoppingCondition(StoppingCondition) on the algorithm set in #setTargetAlgorithm(OptimisationAlgorithm).

Parameters:

indicator - The StoppingCondition to be added.

removeRestartCondition

public void removeRestartCondition(StoppingCondition condition)

Removes a restart condition. Equivalent to calling Algorithm.removeStoppingCondition(StoppingCondition) on the algorithm set in #setTargetAlgorithm(OptimisationAlgorithm).

Parameters:

indicator - The StoppingCondition to be removed.

performInitialisation

public void performInitialisation()

Perform the needed initialisation required before the execution of the algorithm starts.

Overrides:

performInitialisation in class Algorithm

algorithmIteration

public void algorithmIteration()

Perform an algorithm iteration, then restart the Algorithm and increment the number of restarts.

Specified by:

algorithmIteration in class Algorithm

getRestarts

public int getRestarts()

Returns the number of times that the algorithm has been restarted.

Returns:

The number of restarts.

getBestSolution

public OptimisationSolution getBestSolution()

Get the best current solution. This best solution is determined from the personal bests of the particles.

Specified by:

getBestSolution in class Algorithm

Returns:

The OptimisationSolution representing the best solution.

getSolutions

public List<OptimisationSolution> getSolutions()

Get the collection of best solutions. This result does not actually make sense in the normal PSO algorithm, but rather in a MultiObjective optimization.

Specified by:

getSolutions in class Algorithm

Returns:

The Collection<OptimisationSolution> containing the solutions.