Package org.moeaframework.algorithm

Class RandomSearch

java.lang.Object

org.moeaframework.algorithm.AbstractAlgorithm

org.moeaframework.algorithm.RandomSearch

All Implemented Interfaces:

Algorithm, Extensible, Configurable, Named, Stateful

public class RandomSearch
extends AbstractAlgorithm
implements Configurable

Random search implementation. An Initialization instance is used to generate random solutions, which are evaluated and all non-dominated solutions retained. The result is the set of all non-dominated solutions.

Field Summary

Fields inherited from class org.moeaframework.algorithm.AbstractAlgorithm

initialized, numberOfEvaluations, problem, terminated

Constructor Summary

Constructors

Constructor	Description
RandomSearch(Problem problem)	Constructs a new random search procedure with default settings.
RandomSearch(Problem problem, int sampleSize, Initialization generator, NondominatedPopulation archive)	Constructs a new random search procedure for the given problem.

Method Summary

Modifier and Type	Method	Description
String	getName()	Returns the name of this algorithm.
NondominatedPopulation	getResult()	Returns the current best-known result.
int	getSampleSize()	Returns the number of solutions sampled each iteration.
void	initialize()	Performs any initialization that is required by this algorithm.
protected void	iterate()	Performs one iteration of the algorithm.
void	loadState(ObjectInputStream stream)	Loads the state of this object from the stream.
void	saveState(ObjectOutputStream stream)	Writes the state of this object to the stream.
void	setSampleSize(int sampleSize)	Sets the number of solutions sampled each iteration.

Methods inherited from class org.moeaframework.algorithm.AbstractAlgorithm

assertNotInitialized, evaluate, getExtensions, getNumberOfEvaluations, getProblem, isInitialized, isTerminated, step, terminate

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.moeaframework.algorithm.Algorithm

evaluateAll, evaluateAll, run, run

Methods inherited from interface org.moeaframework.core.configuration.Configurable

applyConfiguration, getConfiguration

Methods inherited from interface org.moeaframework.algorithm.extension.Extensible

addExtension, removeExtension

Constructor Details

RandomSearch

public RandomSearch(Problem problem)

Constructs a new random search procedure with default settings.

Parameters:

problem - the problem being solved

RandomSearch

public RandomSearch(Problem problem,
 int sampleSize,
 Initialization generator,
 NondominatedPopulation archive)

Constructs a new random search procedure for the given problem.

Parameters:

problem - the problem being solved

sampleSize - the number of solutions sampled each iteration

generator - the initialization routine used to generate random solutions

archive - the archive of non-dominated solutions

Method Details

getName

public String getName()

Description copied from interface: Algorithm

Returns the name of this algorithm. Whenever possible, this name should match the name recognized by AlgorithmFactory.

Specified by:

getName in interface Algorithm

Specified by:

getName in interface Named

Returns:

the name of this algorithm

getSampleSize

public int getSampleSize()

Returns the number of solutions sampled each iteration.

Returns:

the sample size

setSampleSize

public void setSampleSize(int sampleSize)

Sets the number of solutions sampled each iteration. The main reason to set the sample size is when distributed solution evaluations, as the sample size at least the number of threads. The default value is 100.

Parameters:

sampleSize - the sample size

getResult

public NondominatedPopulation getResult()

Description copied from interface: Algorithm

Returns the current best-known result.

Specified by:

getResult in interface Algorithm

Returns:

the current best-known result

initialize

public void initialize()

Description copied from interface: Algorithm

Performs any initialization that is required by this algorithm. This method should only be called once, though the specific implementation may choose to no-op or throw AlgorithmInitializationException if called multiple times.

Implementations should always call super.initialize() to ensure the algorithm is initialized correctly.

Specified by:

initialize in interface Algorithm

Overrides:

initialize in class AbstractAlgorithm

iterate

protected void iterate()

Description copied from class: AbstractAlgorithm

Performs one iteration of the algorithm. This method should be overridden by implementations to perform each logical iteration of the algorithm.

Specified by:

iterate in class AbstractAlgorithm

saveState

public void saveState(ObjectOutputStream stream)
               throws IOException

Description copied from interface: Stateful

Writes the state of this object to the stream. The order that objects are written to the stream is important. We recommend first calling super.saveState(stream) followed by writing each field.

Specified by:

saveState in interface Stateful

Overrides:

saveState in class AbstractAlgorithm

Parameters:

stream - the stream

Throws:

IOException - if an I/O error occurred

loadState

public void loadState(ObjectInputStream stream)
               throws IOException,
ClassNotFoundException

Description copied from interface: Stateful

Loads the state of this object from the stream. The order for reading objects from the stream must match the order they are written to the stream in Stateful.saveState(ObjectOutputStream).

Specified by:

loadState in interface Stateful

Overrides:

loadState in class AbstractAlgorithm

Parameters:

stream - the stream

Throws:

IOException - if an I/O error occurred

ClassNotFoundException - if the stream referenced a class that is not defined