Package org.moeaframework.algorithm

Class Checkpoints

java.lang.Object

org.moeaframework.core.PeriodicAction

org.moeaframework.algorithm.Checkpoints

All Implemented Interfaces:

Algorithm, Stateful

public class Checkpoints
extends PeriodicAction

Decorates an Algorithm to periodically save checkpoint files from which the algorithm can resume itself if unexpectedly terminated.

   File stateFile = new File("last.state");
 
   Algorithm algorithm = new Checkpoints(new NSGAII(...), stateFile, 100);
 
   while (!algorithm.isTerminated()) {
     algorithm.step();
   }
 

Nested Class Summary

Nested classes/interfaces inherited from class org.moeaframework.core.PeriodicAction

PeriodicAction.FrequencyType

Field Summary

Fields inherited from class org.moeaframework.core.PeriodicAction

algorithm, frequency, frequencyType, iteration, lastInvocation

Constructor Summary

Constructors

Constructor	Description
Checkpoints(Algorithm algorithm, File stateFile, int checkpointFrequency)	Decorates an algorithm to periodically save checkpoints from which the algorithm can resume itself if unexpectedly terminated.

Method Summary

Modifier and Type	Method	Description
void	doAction()	Invoked periodically by this class to perform some function.
void	terminate()	Terminates this algorithm.

Methods inherited from class org.moeaframework.core.PeriodicAction

evaluate, getAlgorithm, getNumberOfEvaluations, getProblem, getResult, isTerminated, loadState, saveState, step

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.moeaframework.core.Algorithm

run, run

Constructor Details

Checkpoints

public Checkpoints(Algorithm algorithm,
 File stateFile,
 int checkpointFrequency)

Decorates an algorithm to periodically save checkpoints from which the algorithm can resume itself if unexpectedly terminated.

Parameters:

algorithm - the algorithm

stateFile - the file containing the checkpoint states

checkpointFrequency - the number of objective function evaluations between checkpoints

Method Details

doAction

public void doAction()

Description copied from class: PeriodicAction

Invoked periodically by this class to perform some function. This function should not depend on the frequency that it is invoked, since it is not guaranteed that this method is invoked at any specific frequency and, in some cases, may not be invoked at all.

Specified by:

doAction in class PeriodicAction

terminate

public void terminate()

Description copied from interface: Algorithm

Terminates this algorithm. Implementations should use this method to free any underlying resources; however, the Algorithm.getResult() and Algorithm.getNumberOfEvaluations() methods are still required to work after termination.

Specified by:

terminate in interface Algorithm

Overrides:

terminate in class PeriodicAction