jmetal.qualityIndicator.util
Class MetricsUtil

java.lang.Object
  jmetal.qualityIndicator.util.MetricsUtil

public class MetricsUtil
extends java.lang.Object

This class provides some utilities to compute quality indicators.

Constructor Summary

MetricsUtil()

Method Summary

double	distance(double[] a, double[] b) This method returns the distance (taken the euclidean distance) between two points given as double []
double	distanceToClosedPoint(double[] point, double[][] front) Gets the distance between a point and the nearest one in a given front (the front is given as double [][])
double	distanceToNearestPoint(double[] point, double[][] front) Gets the distance between a point and the nearest one in a given front, and this distance is greater than 0.0
double[]	getMaximumValues(double[][] front, int noObjectives) Gets the maximum values for each objectives in a given pareto front
double[]	getMinimumValues(double[][] front, int noObjectives) Gets the minimum values for each objectives in a given pareto front
double[][]	getNormalizedFront(double[][] front, double[] maximumValue, double[] minimumValue) This method receives a pareto front and two points, one whit maximum values and the other with minimum values allowed, and returns a the normalized Pareto front.
double[]	hvContributions(int numberOfobjectives, double[][] front) Calculates how much hypervolume each point dominates exclusively.
double[]	hvContributions(SolutionSet[] populations) Calculates the hv contribution of different populations.
double[]	hvContributions(SolutionSet archive, SolutionSet[] populations) Calculates the hv contribution of different populations.
double[][]	invertedFront(double[][] front) This method receives a normalized pareto front and return the inverted one.
double[][]	readFront(java.lang.String path) This method reads a Pareto Front for a file.
SolutionSet	readNonDominatedSolutionSet(java.lang.String path) Reads a set of non dominated solutions from a file
void	readNonDominatedSolutionSet(java.lang.String path, NonDominatedSolutionList solutionSet) Reads a set of non dominated solutions from a file and store it in a existing non dominated solution set
SolutionSet	readSolutionSet(java.lang.String path) Reads a set of non dominated solutions from a file

Methods inherited from class java.lang.Object

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

Constructor Detail

MetricsUtil

public MetricsUtil()

Method Detail

readFront

public double[][] readFront(java.lang.String path)

This method reads a Pareto Front for a file.

Parameters:

path - The path to the file that contains the pareto front

Returns:

double [][] whit the pareto front

getMaximumValues

public double[] getMaximumValues(double[][] front,
                                 int noObjectives)

Gets the maximum values for each objectives in a given pareto front

Parameters:

front - The pareto front

noObjectives - Number of objectives in the pareto front

Returns:

double [] An array of noOjectives values whit the maximun values for each objective

getMinimumValues

public double[] getMinimumValues(double[][] front,
                                 int noObjectives)

Gets the minimum values for each objectives in a given pareto front

Parameters:

front - The pareto front

noObjectives - Number of objectives in the pareto front

Returns:

double [] An array of noOjectives values whit the minimum values for each objective

distance

public double distance(double[] a,
                       double[] b)

This method returns the distance (taken the euclidean distance) between two points given as double []

Parameters:

a - A point

b - A point

Returns:

The euclidean distance between the points

distanceToClosedPoint

public double distanceToClosedPoint(double[] point,
                                    double[][] front)

Gets the distance between a point and the nearest one in a given front (the front is given as double [][])

Parameters:

point - The point

front - The front that contains the other points to calculate the distances

Returns:

The minimun distance between the point and the front

distanceToNearestPoint

public double distanceToNearestPoint(double[] point,
                                     double[][] front)

Gets the distance between a point and the nearest one in a given front, and this distance is greater than 0.0

Parameters:

point - The point

front - The front that contains the other points to calculate the distances

Returns:

The minimun distances greater than zero between the point and the front

getNormalizedFront

public double[][] getNormalizedFront(double[][] front,
                                     double[] maximumValue,
                                     double[] minimumValue)

This method receives a pareto front and two points, one whit maximum values and the other with minimum values allowed, and returns a the normalized Pareto front.

Parameters:

front - A pareto front.

maximumValue - The maximum values allowed

minimumValue - The minimum values allowed

Returns:

the normalized pareto front

invertedFront

public double[][] invertedFront(double[][] front)

This method receives a normalized pareto front and return the inverted one. This operation needed for minimization problems

Parameters:

front - The pareto front to inverse

Returns:

The inverted pareto front

readSolutionSet

public SolutionSet readSolutionSet(java.lang.String path)

Reads a set of non dominated solutions from a file

Parameters:

path - The path of the file containing the data

Returns:

A solution set

readNonDominatedSolutionSet

public SolutionSet readNonDominatedSolutionSet(java.lang.String path)

Reads a set of non dominated solutions from a file

Parameters:

path - The path of the file containing the data

Returns:

A solution set

readNonDominatedSolutionSet

public void readNonDominatedSolutionSet(java.lang.String path,
                                        NonDominatedSolutionList solutionSet)

Reads a set of non dominated solutions from a file and store it in a existing non dominated solution set

Parameters:

path - The path of the file containing the data

hvContributions

public double[] hvContributions(int numberOfobjectives,
                                double[][] front)

Calculates how much hypervolume each point dominates exclusively. The points have to be transformed beforehand, to accommodate the assumptions of Zitzler's hypervolume code.

Parameters:

front - transformed objective values

Returns:

HV contributions

hvContributions

public double[] hvContributions(SolutionSet[] populations)

Calculates the hv contribution of different populations. Receives an array of populations and computes the contribution to HV of the population consisting in the union of all of them

Parameters:

populations, - consisting in all the populatoins

Returns:

HV contributions of each population

hvContributions

public double[] hvContributions(SolutionSet archive,
                                SolutionSet[] populations)

Calculates the hv contribution of different populations. Receives an array of populations and computes the contribution to HV of the population consisting in the union of all of them

Parameters:

populations, - consisting in all the populatoins

Returns:

HV contributions of each population