jenes.population

Class Population<T extends Chromosome>

java.lang.Object

jenes.population.Population<T>

Type Parameters:

T - The class of chromosomes individuals are made of.

All Implemented Interfaces:

java.lang.Iterable<Individual<T>>

public final class Population<T extends Chromosome>
extends java.lang.Object
implements java.lang.Iterable<Individual<T>>

The Population class represents a population of Individuals.

An important property of a population is its size, that is the number of individuals it contains. The DEFAULT_SIZE constant is used as default if the size is not specified.

Population.Statistics collects statistics regarding the population. Statistics can be accessed by the getStatistics() method and updated by the updateStatistics(jenes.population.Population.Statistics).

Since:

1.0

Version:

2.0

See Also:

Individual, Population.Statistics

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Population.Filter The interface provides a method to create filters on individuals
static class	Population.Pareto<K extends Chromosome> This class represents a Pareto front for a multi objective solution
static class	Population.Statistics<T extends Chromosome> The Population.Statistics class is only responsible for storing statistics about a population.

Field Summary

Fields

Modifier and Type	Field and Description
static Population.Filter	ALL Filter that passes all individuals
static Population.Filter	BEST Filter that passes the best individuals
static int	DEFAULT_SIZE The default population size
static Population.Filter	ILLEGALS Filter that passes all illegals individuals
static Population.Filter	LEGALS Filter that passes all legals individuals

Constructor Summary

Constructors

Constructor and Description
Population() Constructs a new empty population
Population(Individual<T> sample) Constructs a new population by cloning the individual sample.
Population(Individual<T> sample, int size) Constructs a new population by cloning the individual sample and specifying the initial size.
Population(java.util.List<Individual<T>> individuals) Constructs a new population with the specified list of individuals
Population(Population<T> population) Constructs a new population from the specified one with the same size

Method Summary

Methods

Modifier and Type	Method and Description
void	add(Individual<T> individual) Adds an individual at the end of this population.
void	add(Individual<T>[] individuals) Adds multiple individuals at the end of this population.
void	add(java.util.List<Individual<T>> individuals) Adds the list of individuals at the end of this population.
void	add(Population<T> pop) Adds all the individuals contained by the specified population at this population.
void	clear() Removes all the individuals from this population.
int	getAge() Returns the age of this population
java.util.List<Individual<T>>	getAllLegalIndividuals() Deprecated.
double[][]	getAllScores() Returns an array with all scores of all the individuals held by this population.
static Pool<?>	getDefaultPool() Returns the default pool
Fitness<T>	getEvaluatedBy() Return the genetic algorithm that has evaluated this population.
Individual<T>	getIndividual(int index) Returns the individual at the specified position.
java.util.List<Individual<T>>	getIndividuals() Returns the (cloned) list of individuals
Population.Pareto	getPareto() Return Population.Pareto of this population
Pool<T>	getPool() Returns the Pool of this population
double[]	getScores(int objIndex) Returns an array with all scores for a specific objective of all the individuals held by this population.
boolean[]	getSortedBy() Return the sort criteria
Population.Statistics	getStatistics() Returns a Population.Statistics of this population
Population.Statistics	getStatistics(boolean collectable) Returns a Statistics of this population
boolean	hasLegals() Checks if the population has legal individuals
void	invalidate() Invalidates the population by setting as not evaluated its individuals.
boolean	isEmpty() Tests if this population is empty.
boolean	isSorted() Check if the individuals order has been evaluated
java.util.Iterator<Individual<T>>	iterator() Returns an interator related the individuals of this population.
java.util.Iterator<Individual<T>>	iterator(int speciem) Returns a new Iterator of Individual that belong to a specific speciem.
java.util.Iterator<Individual<T>>	iterator(Population.Filter filter) Returns a new Iterator of Individual filtered by the Population.Filter given as argument.
Individual<T>	remove(int index) Removes the specified individual from this population.
Individual<T>	replace(int index, Individual<T> individual) Replaces the individual at the specified position with the specified individual.
void	reset(java.util.List<Individual> list, boolean sorted) Reset the individuals belonging to this population
void	resize(int size) Resizes the current population.
void	resizeAs(Population<T> population) Resizes the current population.
void	setAs(Population<T> pop) Sets this population as the specified one.
static void	setDefaultPool(Pool<?> pool) Sets the default poll
void	setEvaluatedBy(Fitness fitness) Specify the fitness that has scored population
Individual<T>	setIndividual(Individual<T> individual, int index) Deprecated.
void	setIndividualAs(int k, Individual<T> individual) Sets the Individual at the specified position equal to the specified one
void	setPool(Pool<T> pool) Sets the Pool for this population.
void	setSortingBy(boolean... bib) Specify the bigger is better
int	size() Returns the population size.
void	sort(boolean... bis) Sorts the individuals of this population in descending order, from highest to lowest score.
void	swap(Population<T> pop) Swaps this population with the speficied one; the age and the individuals will be swapped by this operation.
java.lang.String	toCompleteString() Returns a string complete representation of this population.
java.lang.String	toString() Returns a string representation of this population.
void	trimToSize() Trims the capacity of this Population instance to be the list's current size.
void	updateStatistics(Population.Statistics statistics) Sets the specified statistics according to the statistics of this population

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_SIZE

public static final int DEFAULT_SIZE

The default population size

See Also:

Constant Field Values

ALL

public static final Population.Filter ALL

Filter that passes all individuals

LEGALS

public static final Population.Filter LEGALS

Filter that passes all legals individuals

ILLEGALS

public static final Population.Filter ILLEGALS

Filter that passes all illegals individuals

BEST

public static final Population.Filter BEST

Filter that passes the best individuals

Constructor Detail

Population

public Population()

Constructs a new empty population

Population

public Population(Population<T> population)

Constructs a new population from the specified one with the same size

Parameters:

population - the population used as sample

Population

public Population(java.util.List<Individual<T>> individuals)

Constructs a new population with the specified list of individuals

Parameters:

individuals - the list to be used in the population creation

Population

public Population(Individual<T> sample)

Constructs a new population by cloning the individual sample. The population assumes the default size.

Parameters:

sample - the individual sample

Population

public Population(Individual<T> sample,
          int size)

Constructs a new population by cloning the individual sample and specifying the initial size.

Parameters:

sample - the individual sample

size - the length population

Method Detail

isSorted

public boolean isSorted()

Check if the individuals order has been evaluated

Returns:

setEvaluatedBy

public final void setEvaluatedBy(Fitness fitness)

Specify the fitness that has scored population

Parameters:

fitness -

setSortingBy

public final void setSortingBy(boolean... bib)

Specify the bigger is better

Parameters:

bib -

getEvaluatedBy

public final Fitness<T> getEvaluatedBy()

Return the genetic algorithm that has evaluated this population. If null the population has not been evaluated yet.

Returns:

getSortedBy

public boolean[] getSortedBy()

Return the sort criteria

Returns:

getPool

public final Pool<T> getPool()

Returns the Pool of this population

Returns:

the pool of this population

setPool

public final void setPool(Pool<T> pool)

Sets the Pool for this population. Remove all individuals from old pool and adds them to new pool

Parameters:

pool - the new pool for this population

iterator

public final java.util.Iterator<Individual<T>> iterator()

Returns an interator related the individuals of this population.

Specified by:

iterator in interface java.lang.Iterable<Individual<T extends Chromosome>>

iterator

public final java.util.Iterator<Individual<T>> iterator(int speciem)

Returns a new Iterator of Individual that belong to a specific speciem.

Parameters:

speciem - speciem of individuals

Returns:

new iterator

iterator

public final java.util.Iterator<Individual<T>> iterator(Population.Filter filter)

Returns a new Iterator of Individual filtered by the Population.Filter given as argument.

Parameters:

filter - Filter object

Returns:

new iterator

getAge

public final int getAge()

Returns the age of this population

Returns:

the age of this population

setAs

public final void setAs(Population<T> pop)

Sets this population as the specified one.

Parameters:

pop - the model population

swap

public final void swap(Population<T> pop)

Swaps this population with the speficied one; the age and the individuals will be swapped by this operation. Swap is fast in case of both populations share a common pool, or they don't have one assigned, as not required to move individuals between the pools.

Parameters:

pop - the other population with witch make the individuals swap

add

public final void add(Individual<T> individual)

Adds an individual at the end of this population.

Parameters:

individual - the individual to add.

add

public final void add(Individual<T>[] individuals)

Adds multiple individuals at the end of this population.

Parameters:

individuals - the individuals to be added

add

public final void add(java.util.List<Individual<T>> individuals)

Adds the list of individuals at the end of this population.

Parameters:

individuals - the list of individuals to add

add

public final void add(Population<T> pop)

Adds all the individuals contained by the specified population at this population.

Parameters:

pop - the population to add.

resize

public final void resize(int size)

Resizes the current population. If the new size is bigger than the old size, new individuals will be added cloning random individuals, thus requiring that at least one individual is held. If the new size is smaller than the old size, individuals will be removed from the bottom.

Parameters:

size - the population new size

resizeAs

public final void resizeAs(Population<T> population)

Resizes the current population. If the new size is bigger than the old size, new individuals will be added cloning the corresponding ones in the population argument If the new size is smaller than the old size, individuals will be removed

Parameters:

population - the Population to get the size from

remove

public final Individual<T> remove(int index)

Removes the specified individual from this population.

Parameters:

index - the individual to remove.

Returns:

the removed individual.

clear

public final void clear()

Removes all the individuals from this population.

trimToSize

public final void trimToSize()

Trims the capacity of this Population instance to be the list's current size. An application can use this operation to minimize the storage of a Population instance.

reset

public final void reset(java.util.List<Individual> list,
         boolean sorted)

Reset the individuals belonging to this population

Parameters:

list - list of new individuals

sorted - flag indicating if the new individuals are sorted

setIndividualAs

public final void setIndividualAs(int k,
                   Individual<T> individual)

Sets the Individual at the specified position equal to the specified one

Parameters:

k - the position of the individual to be modify

individual - the Individual model

getIndividual

public final Individual<T> getIndividual(int index)

Returns the individual at the specified position.

Parameters:

index - the index of the desired individual.

Returns:

the desired individual.

setIndividual

public final Individual<T> setIndividual(Individual<T> individual,
                          int index)

Deprecated.

Replaces the individual at the specified position in this population with the specified one. If the individual passed as argument already belongs to some population, operation is aborted returning null.

Parameters:

individual -

index - index of individual to replace.

Returns:

the individual previously at the specified position, or null if the operation cannot have place.

See Also:

replace(int, jenes.population.Individual)

getAllScores

public final double[][] getAllScores()

Returns an array with all scores of all the individuals held by this population.

Returns:

an array with the scores of this population individuals.

getScores

public final double[] getScores(int objIndex)

Returns an array with all scores for a specific objective of all the individuals held by this population. If individuals have a objective the index given as argument is ignored because individuals have one score.

Parameters:

objIndex - index of objective

Returns:

an array with the scores, for a specific objective, of this population individuals. If individuals have a objective the index given as argument is ignored and returns the score at position 0

getAllLegalIndividuals

@Deprecated
public final java.util.List<Individual<T>> getAllLegalIndividuals()

Deprecated.

Returns the list of legal individals held by the population. The list returned is recycled, thus the reference to previous legal individuals could become invalid.

Returns:

the list of legal individuals.

hasLegals

public final boolean hasLegals()

Checks if the population has legal individuals

Returns:

true if and only if exist at least one legal individual

isEmpty

public final boolean isEmpty()

Tests if this population is empty.

Returns:

true if this population is empty; false otherwise.

size

public final int size()

Returns the population size.

Returns:

the number of individuals in the population.

replace

public final Individual<T> replace(int index,
                    Individual<T> individual)

Replaces the individual at the specified position with the specified individual. Note:if a null Individual is passed as argument the individual at index position is removed

Parameters:

index - the position of the individual to replace.

individual - the replacing individual.

Returns:

the individual previously held at that position, null if the opration does not succeed.

toCompleteString

public final java.lang.String toCompleteString()

Returns a string complete representation of this population.

Returns:

a new String complete string representing this population.

toString

public final java.lang.String toString()

Returns a string representation of this population.

Overrides:

toString in class java.lang.Object

Returns:

a new String object representing this population.

sort

public final void sort(boolean... bis)

Sorts the individuals of this population in descending order, from highest to lowest score.

getStatistics

public final Population.Statistics getStatistics(boolean collectable)

Returns a Statistics of this population

Returns:

the statistics of this population

getStatistics

public final Population.Statistics getStatistics()

Returns a Population.Statistics of this population

Returns:

statistic of this population

getPareto

public final Population.Pareto getPareto()

Return Population.Pareto of this population

Returns:

pareto of this population

updateStatistics

public final void updateStatistics(Population.Statistics statistics)

Sets the specified statistics according to the statistics of this population

Parameters:

statistics - the statistics to be set

getIndividuals

public final java.util.List<Individual<T>> getIndividuals()

Returns the (cloned) list of individuals

Returns:

individuals

invalidate

public final void invalidate()

Invalidates the population by setting as not evaluated its individuals.

getDefaultPool

public static Pool<?> getDefaultPool()

Returns the default pool

Returns:

default pool

setDefaultPool

public static void setDefaultPool(Pool<?> pool)

Sets the default poll

Parameters:

pool - new pool