Package org.uma.jmetal.util

Class AdaptiveGrid<S extends Solution<?>>

java.lang.Object

org.uma.jmetal.util.AdaptiveGrid<S>

public class AdaptiveGrid<S extends Solution<?>>
extends Object

This class defines an adaptive grid over a list of solutions as the one used by algorithm PAES.

Author:

Antonio J. Nebro, Juan J. Durillo

Constructor Summary

Constructors

Constructor	Description
AdaptiveGrid(int bisections, int objectives)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	addSolution(int location)	Increases the number of solutions into a specific hypercube.
void	calculateOccupied()	Calculates the number of hypercubes having one or more solutions.
double	getAverageOccupation()	Return the average number of solutions in the occupied hypercubes
int	getBisections()	Returns the number of bi-divisions performed in each objective.
int[]	getHypercubes()
int	getLocationDensity(int location)	Returns the number of solutions into a specific hypercube.
int	getMostPopulatedHypercube()	Returns the value of the most populated hypercube.
int	location(S solution)	Calculates the hypercube of a solution
int	occupiedHypercubes()	Returns the number of hypercubes with more than zero solutions.
int	randomOccupiedHypercube()	Returns a random hypercube that has more than zero solutions.
int	randomOccupiedHypercube(BoundedRandomGenerator<Integer> randomGenerator)	Returns a random hypercube that has more than zero solutions.
void	removeSolution(int location)	Decreases the number of solutions into a specific hypercube.
int	rouletteWheel()	Returns a random hypercube using a rouleteWheel method.
int	rouletteWheel(BoundedRandomGenerator<Double> randomGenerator)	Returns a random hypercube using a rouletteWheel method.
String	toString()	Returns a String representing the grid.
void	updateGrid(List<S> solutionList)	Updates the grid limits and the grid content adding the solutions contained in a specific solutionList.
void	updateGrid(S solution, List<S> solutionSet)	Updates the grid limits and the grid content adding a new Solution.

Methods inherited from class java.lang.Object

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

Constructor Details

AdaptiveGrid

public AdaptiveGrid(int bisections,
 int objectives)

Constructor. Creates an instance of AdaptiveGrid.

Parameters:

bisections - Number of bi-divisions of the objective space.

objectives - Number of numberOfObjectives of the problem.

Method Details

updateGrid

public void updateGrid(List<S> solutionList)

Updates the grid limits and the grid content adding the solutions contained in a specific solutionList.

Parameters:

solutionList - The solutionList.

updateGrid

public void updateGrid(S solution,
 List<S> solutionSet)

Updates the grid limits and the grid content adding a new Solution. If the solution falls out of the grid bounds, the limits and content of the grid must be re-calculated.

Parameters:

solution - Solution considered to update the grid.

solutionSet - SolutionSet used to update the grid.

location

public int location(S solution)

Calculates the hypercube of a solution

Parameters:

solution - The Solution.

getMostPopulatedHypercube

public int getMostPopulatedHypercube()

Returns the value of the most populated hypercube.

Returns:

The hypercube with the maximum number of solutions.

getLocationDensity

public int getLocationDensity(int location)

Returns the number of solutions into a specific hypercube.

Parameters:

location - Number of the hypercube.

Returns:

The number of solutions into a specific hypercube.

removeSolution

public void removeSolution(int location)

Decreases the number of solutions into a specific hypercube.

Parameters:

location - Number of hypercube.

addSolution

public void addSolution(int location)

Increases the number of solutions into a specific hypercube.

Parameters:

location - Number of hypercube.

getBisections

public int getBisections()

Returns the number of bi-divisions performed in each objective.

Returns:

the number of bi-divisions.

toString

public String toString()

Returns a String representing the grid.

Overrides:

toString in class Object

Returns:

The String.

rouletteWheel

public int rouletteWheel()

Returns a random hypercube using a rouleteWheel method.

Returns:

the number of the selected hypercube.

rouletteWheel

public int rouletteWheel(BoundedRandomGenerator<Double> randomGenerator)

Returns a random hypercube using a rouletteWheel method.

Parameters:

randomGenerator - the BoundedRandomGenerator to use for the roulette

Returns:

the number of the selected hypercube.

calculateOccupied

public void calculateOccupied()

Calculates the number of hypercubes having one or more solutions. return the number of hypercubes with more than zero solutions.

occupiedHypercubes

public int occupiedHypercubes()

Returns the number of hypercubes with more than zero solutions.

Returns:

the number of hypercubes with more than zero solutions.

randomOccupiedHypercube

public int randomOccupiedHypercube()

Returns a random hypercube that has more than zero solutions.

Returns:

The hypercube.

randomOccupiedHypercube

public int randomOccupiedHypercube(BoundedRandomGenerator<Integer> randomGenerator)

Returns a random hypercube that has more than zero solutions.

Parameters:

randomGenerator - the BoundedRandomGenerator to use for selecting the hypercube

Returns:

The hypercube.

getAverageOccupation

public double getAverageOccupation()

Return the average number of solutions in the occupied hypercubes

getHypercubes

public int[] getHypercubes()