DistributedEvolutionaryAlgorithmsFramework
Class Population

java.lang.Object
  DistributedEvolutionaryAlgorithmsFramework.Population

All Implemented Interfaces:

java.lang.Comparable<Population>, java.lang.Iterable<Individual>, org.apache.hadoop.io.Writable, org.apache.hadoop.io.WritableComparable<Population>

public class Population
extends java.lang.Object
implements java.lang.Iterable<Individual>, org.apache.hadoop.io.WritableComparable<Population>

Population used in evolutionary algorithms

Nested Class Summary

static class	Population.acceptImmigrantsMethod Determines how immigrating individuals are handled.
static class	Population.expelEmigrantsMethod Determines how emigrating individuals are chosen.

Field Summary

int	dimensions

Constructor Summary

Population()
Parameterless constructor

Population(java.util.ArrayList<Individual> population)
Constructs Population with given Individuals

Method Summary

void	acceptImmigrants(Population immigrants, Population.acceptImmigrantsMethod method) Accepts immigrants into existing population.
void	add(Individual ind) Ads one Individual to population
void	clear() Clears Population by removing all Individuals
Population	clone()
int	compareTo(Population o)
void	drop(int i) Removes one Individual from Population with given index i
double	evaluateIndividual(Individual i)
Individual	get(int j)
int	getBestIndex() Get population index of the best Individual
static int	getBestIndex(java.util.ArrayList<Individual> list) Get population index of the best Individual from ArrayList of Individuals.)
Individual	getBestIndividual()
int	getByIndex(int i) Get Individual by his population index
Population	getEmigrants(int nMigratingIndividuals, Population.expelEmigrantsMethod method) Expels immigrants from evolved population.
int	getKey()
double	getMaxRestriction(int i)
boolean	getMigratingFlag()
double	getMinRestriction(int i)
java.util.ArrayList<Individual>	getPopulation()
java.util.Iterator<Individual>	iterator()
void	randomize() Sets all Individuals to random values
void	readFields(java.io.DataInput in)
void	resetIndividualsPopulation() Set Individuals population to this Population.
void	set(int j, Individual ind) Sets one Individual with index j, rewriting the old one
void	setFitnessFunction(FitnessFunction ff) Sets fitness function of this Population which is later used to create Individuals and determine their fitness
void	setKey(int k) Each population has its unique key given by the framework at initialization by this function.
void	setMigratingFlag() Migrating flag marks if the population is used for evolution or for migration
void	setPopulation(java.util.ArrayList<Individual> individuals) Makes new Population from Individuals given in the individuals parameter
int	size()
void	sort() Sorts the population by fitness
java.lang.String	toString()
void	write(java.io.DataOutput out)

Methods inherited from class java.lang.Object

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

Field Detail

dimensions

public int dimensions

Constructor Detail

Population

public Population(java.util.ArrayList<Individual> population)

Constructs Population with given Individuals

Parameters:

population - ArrayList of Individuals who will become the new Population

Population

public Population()

Parameterless constructor

Method Detail

getMinRestriction

public double getMinRestriction(int i)

Parameters:

i - Dimension from which the restriction is returned

Returns:

lower restriction of given dimension

getMaxRestriction

public double getMaxRestriction(int i)

Parameters:

i - Dimension from which the restriction is returned

Returns:

upper restriction of given dimension

randomize

public void randomize()

Sets all Individuals to random values

evaluateIndividual

public double evaluateIndividual(Individual i)

Parameters:

i - Individual to be evalueated

Returns:

fitness of the Individual

getPopulation

public java.util.ArrayList<Individual> getPopulation()

Returns:

ArrayList of Individuals from Population

setFitnessFunction

public void setFitnessFunction(FitnessFunction ff)

Sets fitness function of this Population which is later used to create Individuals and determine their fitness

Parameters:

ff - FitnessFunction extending class

resetIndividualsPopulation

public void resetIndividualsPopulation()

Set Individuals population to this Population. Needed after adding external Individuals.

setMigratingFlag

public void setMigratingFlag()

Migrating flag marks if the population is used for evolution or for migration

getMigratingFlag

public boolean getMigratingFlag()

Returns:

whether the population is used for migration

setKey

public void setKey(int k)

Each population has its unique key given by the framework at initialization by this function.

Parameters:

k - integer to set the key to.

getKey

public int getKey()

Returns:

the key (id) of the population

add

public void add(Individual ind)

Ads one Individual to population

Parameters:

ind - Individual to add

get

public Individual get(int j)

Parameters:

j - Index of Individual to return

Returns:

Individual with index j

set

public void set(int j,
                Individual ind)

Sets one Individual with index j, rewriting the old one

Parameters:

j - Index of new Individual

ind - Individual to be added

setPopulation

public void setPopulation(java.util.ArrayList<Individual> individuals)

Makes new Population from Individuals given in the individuals parameter

Parameters:

individuals - ArrayList of new Individuals

size

public int size()

Returns:

population size

drop

public void drop(int i)

Removes one Individual from Population with given index i

Parameters:

i - Index of removed Individual

clear

public void clear()

Clears Population by removing all Individuals

sort

public void sort()

Sorts the population by fitness

getBestIndex

public static int getBestIndex(java.util.ArrayList<Individual> list)

Get population index of the best Individual from ArrayList of Individuals.)

Parameters:

list - ArrayList of Individuals to search in.

Returns:

best Individual from given ArrayList

getBestIndividual

public Individual getBestIndividual()

Returns:

best individual of existing population.

acceptImmigrants

public void acceptImmigrants(Population immigrants,
                             Population.acceptImmigrantsMethod method)

Accepts immigrants into existing population.

Parameters:

immigrants - Immigrating Population

method - One of Population.acceptImmigrantsMethod (REPLACE_WORST, REPLACE_BEST, REPLACE_RANDOM, NO_REPLACE).

See Also:

Population.acceptImmigrantsMethod

getEmigrants

public Population getEmigrants(int nMigratingIndividuals,
                               Population.expelEmigrantsMethod method)

Expels immigrants from evolved population.

Parameters:

nMigratingIndividuals - Number of emigrants

method - One of Population.expelEmigrantsMethod (EXPEL_BEST, EXPEL_RANDOM).

See Also:

Population.expelEmigrantsMethod

getByIndex

public int getByIndex(int i)

Get Individual by his population index

Parameters:

i - Order of the Individual by fitness

Returns:

Index of Individual

See Also:

getBestIndex

clone

public Population clone()

Overrides:

clone in class java.lang.Object

iterator

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

Specified by:

iterator in interface java.lang.Iterable<Individual>

write

public void write(java.io.DataOutput out)
           throws java.io.IOException

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

java.io.IOException

readFields

public void readFields(java.io.DataInput in)
                throws java.io.IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

java.io.IOException

compareTo

public int compareTo(Population o)

Specified by:

compareTo in interface java.lang.Comparable<Population>

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getBestIndex

public int getBestIndex()

Get population index of the best Individual

Returns: