Package org.moeaframework.core.indicator

Class RIndicator

java.lang.Object

org.moeaframework.core.indicator.NormalizedIndicator

org.moeaframework.core.indicator.RIndicator

All Implemented Interfaces:

Indicator

Direct Known Subclasses:

R1Indicator, R2Indicator, R3Indicator

public abstract class RIndicator
extends NormalizedIndicator

Abstract class for implementing R indicator functions.

References:

1. Hansen, M. P. and A. Jaszkiewicz (1998). Evaluating the Quality of Approximations to the Non-dominated Set. IMM Technical Report IMM-REP-1998-7.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	RIndicator.ChebyshevUtility	Chebyshev (also referred to as Chebychev or Tchebycheff) utility function.
static class	RIndicator.LinearWeightedSumUtility	Linear-weighted sum utility function.
static interface	RIndicator.UtilityFunction	Interface for defining utility functions.

Field Summary

Fields

Modifier and Type	Field	Description
protected RIndicator.UtilityFunction	utilityFunction	The utility function used by the R2 calculation.
protected double[][]	weights	The weights, typically uniformly distributed.

Fields inherited from class org.moeaframework.core.indicator.NormalizedIndicator

problem

Constructor Summary

Constructors

Constructor	Description
RIndicator(Problem problem, int subdivisions, NondominatedPopulation referenceSet, Normalizer normalizer, RIndicator.UtilityFunction utilityFunction)	Constructs a new R indicator using the specified utility function.

Method Summary

Modifier and Type	Method	Description
double	expectedUtility(NondominatedPopulation population)	Computes the expected utility for the given population.
static int	getDefaultSubdivisions(Problem problem)	Returns the default number of subdivisions for a given problem.

Methods inherited from class org.moeaframework.core.indicator.NormalizedIndicator

getNormalizedReferenceSet, normalize

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.Indicator

evaluate

Field Details

utilityFunction

protected RIndicator.UtilityFunction utilityFunction

The utility function used by the R2 calculation.

weights

protected double[][] weights

The weights, typically uniformly distributed.

Constructor Details

RIndicator

public RIndicator(Problem problem,
 int subdivisions,
 NondominatedPopulation referenceSet,
 Normalizer normalizer,
 RIndicator.UtilityFunction utilityFunction)

Constructs a new R indicator using the specified utility function.

Parameters:

problem - the problem

subdivisions - the number of subdivisions along each objective

referenceSet - the reference set

normalizer - the user-provided normalizer, or null if the default is used

utilityFunction - the utility function

Method Details

expectedUtility

public double expectedUtility(NondominatedPopulation population)

Computes the expected utility for the given population.

Parameters:

population - the population

Returns:

the expected utility

getDefaultSubdivisions

public static int getDefaultSubdivisions(Problem problem)

Returns the default number of subdivisions for a given problem. The defaults, for an M objective problem, are:

• if M=2, then 500
• if M=3, then 30
• if M=4, then 12
• if M=5, then 8
• else 3

Parameters:

problem - the problem

Returns:

the default number of subdivisions for a given problem