jenes.population

Class Fitness<C extends Chromosome>

java.lang.Object

jenes.population.Fitness<C>

All Implemented Interfaces:

java.lang.Cloneable

Direct Known Subclasses:

EntropyFitness, FitnessFunction, FitnessFunction, ImageMatchingFitness, MultiObjectiveProblem.ProblemFitness, PatternGA.PatternFitness, TSPGA.TSPFitness, WeekFitness

public abstract class Fitness<C extends Chromosome>
extends java.lang.Object
implements java.lang.Cloneable

This class aims at implementing the scoring and sorting of individuals.

Socring of individuals is obtained by implementing the abstract method evaluate. The class supports multi-objective optimizazion, so that a vector of scores can be associated to each individual. Flags have to be given at construction. Each flag should be true if the related objective is to maximize, otherwise false.

Sorting is performed according to objectives, so that better individuals come first. In order to keep sorting efficient, there are four modes, namely PARTIAL, HIERACHICAL, DOMINANCE, and CROWDING.

In PARTIAL mode, sorting is perfomed using only the first objective. HIERARCHICAL mode considers objectives in sequence. DOMINANCE is used to sort individuals according to dominance. CROWDING sorts elements by dominance first, and by crowding distance after, as suggested by Deb for NSGA2.

Cloning is necessary for multithreading.

Since:

2.0

Version:

2.2

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Fitness.SortingMode Sorting modes

Constructor Summary

Constructors

Constructor and Description
Fitness(boolean... bis) Creates a new fitness where the number of objectives is derived by the lenght of array given as argument.
Fitness(int m, boolean maximize) Creates a new fitness with the defined number of objectives imposing all to maximize or minimize solutions.

Method Summary

Methods

Modifier and Type	Method and Description
void	adjust(Population<C> pop, Individual<C>[] elite) Adjust the evaluation after elistim is applied.
Fitness<C>	clone()
static int	dominance(Individual<?> i1, Individual<?> i2, boolean... bis) Returns a positive, negative or zero value according to dominance relation between individuals i1 and i2, given the objective flag array.
int	dominance(Individual<C> i1, Individual<C> i2) Returns a positive, negative or zero value according to dominance relation between individuals i1 and i2
static boolean	dominates(Individual<?> i1, Individual<?> i2, boolean... bis) Checks if individuals i1 dominates i2.
boolean	dominates(Individual<C> i1, Individual<C> i2) Checks if individuals i1 dominates i2.
protected Fitness<C>	duplicate() Builds a copy instance.
abstract void	evaluate(Individual<C> individual) Evaluates a single Individual.
boolean[]	getBiggerIsBetter() Returns the objective flag array.
int	getNumOfObjectives() Returns the number of objectives
void	init(Individual<C> ind) Initializes the Individual given as parameter by resetting its scores.
void	init(Population<C> pop) Initializes the Population given as parameter by resetting the scores of all individuals.
void	partialsort(java.util.List<Individual<C>> list, int dim) Sorts the list of Individual given as argument.
static <K extends Chromosome> void	partialsort(java.util.List<Individual<K>> list, int dim, boolean bib) Sorts the list of Individual given as argument.
void	prepare(Population<C> pop) Prepares the evaluation.
Fitness.SortingMode	setSortingMode(Fitness.SortingMode sortingMode) Sets the Fitness.SortingMode of Population
void	sort(Fitness.SortingMode mode, java.util.List<Individual<C>> list) Sorts the list of individuals given as argument using the Fitness.SortingMode given as argument
static <K extends Chromosome> void	sort(Fitness.SortingMode sortingMode, java.util.List<Individual<K>> list, boolean... bis) Sorts the list given as argument using the Fitness.SortingMode and the array given as arguments.
void	sort(Fitness.SortingMode mode, Population<C> pop) Sorts the Population given as argument using the Fitness.SortingMode given as argument
static <K extends Chromosome> void	sort(Fitness.SortingMode sortingMode, Population<K> pop, boolean... bis) Sorts the Population given as argument using the Fitness.SortingMode and the array given as arguments.
void	sort(java.util.List<Individual<C>> list) Sorts the list of individuals given as argument
static <K extends Chromosome> void	sort(java.util.List<Individual<K>> list, boolean... bis) Sorts the list given as argument using the array given as argument.
void	sort(Population<C> pop) Sorts the Population given as argument
static <K extends Chromosome> void	sort(Population<K> pop, boolean... bis) Sorts the Population given as argument using the array given as argument.

Methods inherited from class java.lang.Object

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

Constructor Detail

Fitness

public Fitness(int m,
       boolean maximize)

Creates a new fitness with the defined number of objectives imposing all to maximize or minimize solutions.

Parameters:

m - numbers of objective

maximize - when true the algorithm will find solution with maximum score; false otherwise

Fitness

public Fitness(boolean... bis)

Creates a new fitness where the number of objectives is derived by the lenght of array given as argument. Each cell of array represent a flag for maximize or minimize that objective

Parameters:

bis - a boolean array. When a cell contains a true value the algorithm will find solution with maximum score; false otherwise

Method Detail

clone

public final Fitness<C> clone()

Overrides:

clone in class java.lang.Object

duplicate

protected Fitness<C> duplicate()
                                           throws java.lang.CloneNotSupportedException

Builds a copy instance. It can be overwritten by subclasses.

Returns:

copy instance

Throws:

java.lang.CloneNotSupportedException

evaluate

public abstract void evaluate(Individual<C> individual)

Evaluates a single Individual. This evaluation of individuals is specifically related to the problem to solve.

Parameters:

individual - the individual to be evaluated

prepare

public void prepare(Population<C> pop)

Prepares the evaluation. Callback used to prepare the evaluation. It can be overridden to provide a specific task.

Parameters:

pop - population to evaluate.

adjust

public void adjust(Population<C> pop,
          Individual<C>[] elite)

Adjust the evaluation after elistim is applied. Callback used to adjust the scores after the elitism is applied. It can be overridden to provide a specific task.

Parameters:

pop - population to evaluate.

elite - individuals entered because of elitism

init

public void init(Individual<C> ind)

Initializes the Individual given as parameter by resetting its scores.

Parameters:

ind - individual to be initialize

init

public void init(Population<C> pop)

Initializes the Population given as parameter by resetting the scores of all individuals.

Parameters:

pop - population to initialize

setSortingMode

public final Fitness.SortingMode setSortingMode(Fitness.SortingMode sortingMode)

Sets the Fitness.SortingMode of Population

Parameters:

sortingMode - sorting mode

sort

public final void sort(Population<C> pop)

Sorts the Population given as argument

Parameters:

pop - population to be sorted

sort

public final void sort(Fitness.SortingMode mode,
        Population<C> pop)

Sorts the Population given as argument using the Fitness.SortingMode given as argument

Parameters:

mode - sorting mode

pop - population to be sorted

sort

public final void sort(java.util.List<Individual<C>> list)

Sorts the list of individuals given as argument

Parameters:

list - list of individual to be sorted

sort

public final void sort(Fitness.SortingMode mode,
        java.util.List<Individual<C>> list)

Sorts the list of individuals given as argument using the Fitness.SortingMode given as argument

Parameters:

mode - sorting mode

list - list of individual to be sorted

sort

public static <K extends Chromosome> void sort(Population<K> pop,
                               boolean... bis)

Sorts the Population given as argument using the array given as argument. Each cell of array represent a flag for maximize or minimize that objective

Parameters:

pop - population to be sorted

bis - a boolean array. Each cell contains a true if the corresponding score to be maximized; false otherwise

sort

public static <K extends Chromosome> void sort(Fitness.SortingMode sortingMode,
                               Population<K> pop,
                               boolean... bis)

Sorts the Population given as argument using the Fitness.SortingMode and the array given as arguments. Each cell of array represent a flag for maximize or minimize that objective

Parameters:

sortingMode - sorting mode

pop - population to be sorted

bis - a boolean array. Each cell contains a true if the corresponding score to be maximized; false otherwise

sort

public static <K extends Chromosome> void sort(java.util.List<Individual<K>> list,
                               boolean... bis)

Sorts the list given as argument using the array given as argument. Each cell of array represent a flag for maximize or minimize that objective

Parameters:

pop - population to be sorted

bis - a boolean array. Each cell contains a true if the corresponding score to be maximized; false otherwise

sort

public static <K extends Chromosome> void sort(Fitness.SortingMode sortingMode,
                               java.util.List<Individual<K>> list,
                               boolean... bis)

Sorts the list given as argument using the Fitness.SortingMode and the array given as arguments. Each cell of array represent a flag for maximize or minimize that objective

Parameters:

sortingMode - sorting mode

pop - population to be sorted

bis - a boolean array. Each cell contains a true if the corresponding score to be maximized; false otherwise

partialsort

public final void partialsort(java.util.List<Individual<C>> list,
               int dim)

Sorts the list of Individual given as argument. Individuals are sorted by score in position dim .

Parameters:

list - list to be ordered

dim - index score to sort

partialsort

public static <K extends Chromosome> void partialsort(java.util.List<Individual<K>> list,
                                      int dim,
                                      boolean bib)

Sorts the list of Individual given as argument. Individuals are sorted by score in position dim . Sort direction is set by bib

Type Parameters:

K - extends Chromosome

Parameters:

list - list to be ordered

dim - index score to sort

bib - Sorting is ascending if bib is true ; sorting is descending if bib is false

getNumOfObjectives

public final int getNumOfObjectives()

Returns the number of objectives

Returns:

number of objective

getBiggerIsBetter

public final boolean[] getBiggerIsBetter()

Returns the objective flag array. Each element is true is the corresponding objective is to maximize, false if it is to minimize. Values should not be changed.

Returns:

the array

dominance

public final int dominance(Individual<C> i1,
            Individual<C> i2)

Returns a positive, negative or zero value according to dominance relation between individuals i1 and i2

Parameters:

i1 - individual

i2 - individual

Returns:

+1 if i1 dominates i2, -1 if i2 dominates i2, 0 otherwise

dominates

public boolean dominates(Individual<C> i1,
                Individual<C> i2)

Checks if individuals i1 dominates i2.

Parameters:

i1 - individual

i2 - individual

Returns:

true, if i1 dominates i2

dominance

public static int dominance(Individual<?> i1,
            Individual<?> i2,
            boolean... bis)

Returns a positive, negative or zero value according to dominance relation between individuals i1 and i2, given the objective flag array.

Parameters:

i1 - individual

i2 - individual

bis - objective flag array

Returns:

+1 if i1 dominates i2, -1 if i2 dominates i2, 0 otherwise

dominates

public static boolean dominates(Individual<?> i1,
                Individual<?> i2,
                boolean... bis)

Checks if individuals i1 dominates i2.

Parameters:

i1 - individual

i2 - individual

bis - objective flag array

Returns:

true, if i1 dominates i2