org.moeaframework.algorithm.pisa
Class PISAAlgorithm

java.lang.Object
  org.moeaframework.algorithm.AbstractAlgorithm
      org.moeaframework.algorithm.pisa.PISAAlgorithm

All Implemented Interfaces:

Algorithm

public class PISAAlgorithm
extends AbstractAlgorithm

Algorithm for interfacing with an external PISA selector. The PISA framework is a platform and programming language independent interface for search algorithms. PISA separates search algorithms into selectors, describing the optimization algorithm, and variators, describing the optimization problem. PISA uses a file-based communication channel between selectors and variators, which may result in excessive communication costs, file system bottlenecks and file name collisions. See the PISA homepage for detailed instructions.

Note that some PISA selectors parse the command line arguments using sscanf

   sscanf(argv[2], "%s", filenamebase);
 

On some operating systems, this will not work if the files used by PISA contain whitespace in the filename. It may be necessary to set the JVM property java.io.tmpdir to a folder with no whitespace in the filename.

See Also:

PISA Homepage

Field Summary

Fields inherited from class org.moeaframework.algorithm.AbstractAlgorithm

initialized, numberOfEvaluations, problem, terminated

Constructor Summary

PISAAlgorithm(String name, Problem problem, Variation variation, Properties properties)
Constructs an adapter for a PISA selector.

Method Summary

NondominatedPopulation	getResult() Returns the current best-known result.
void	initialize() Performs any initialization that is required by this algorithm.
void	iterate() Performs one iteration of the algorithm.
void	terminate() Implementations should always invoke super.terminate() to ensure the hierarchy is terminated correctly.

Methods inherited from class org.moeaframework.algorithm.AbstractAlgorithm

evaluate, evaluateAll, evaluateAll, finalize, getNumberOfEvaluations, getProblem, getState, isInitialized, isTerminated, setState, step

Methods inherited from class java.lang.Object

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

Constructor Detail

PISAAlgorithm

public PISAAlgorithm(String name,
                     Problem problem,
                     Variation variation,
                     Properties properties)
              throws IOException

Constructs an adapter for a PISA selector.

Parameters:

name - the name of the PISA selector

problem - the problem being solved

variation - the variation operator

properties - additional properties for the PISA selector configuration file

Throws:

IOException - if an I/O error occurred

Method Detail

initialize

public void initialize()

Description copied from class: AbstractAlgorithm

Performs any initialization that is required by this algorithm. This method is called automatically by the first invocation of AbstractAlgorithm.step(), but may also be called manually prior to any invocations of step. Implementations should always invoke super.initialize() to ensure the hierarchy is initialized correctly.

Overrides:

initialize in class AbstractAlgorithm

terminate

public void terminate()

Description copied from class: AbstractAlgorithm

Implementations should always invoke super.terminate() to ensure the hierarchy is terminated correctly. This method is automatically invoked during finalization, and need only be called directly if non-Java resources are in use.

Specified by:

terminate in interface Algorithm

Overrides:

terminate in class AbstractAlgorithm

iterate

public 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

getResult

public NondominatedPopulation getResult()

Description copied from interface: Algorithm

Returns the current best-known result.

Returns:

the current best-known result