org.jgap.gp.impl
Class GPPopulation

java.lang.Object
  org.jgap.gp.impl.GPPopulation

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable

public class GPPopulation
extends java.lang.Object
implements java.io.Serializable, java.lang.Comparable

Population for GP programs.

Since:

3.0

See Also:

Serialized Form

Field Summary

static double

DELTA

Constructor Summary

GPPopulation()
Default constructor, only for dynamic instantiation.

GPPopulation(GPConfiguration a_config, int a_size)

GPPopulation(GPPopulation a_pop)

GPPopulation(GPPopulation a_pop, boolean a_keepPrograms)

Method Summary

void	addFittestProgram(IGPProgram a_toAdd) Adds a GP program to this Population.
void	clear() Clears the list of programs.
int	compareTo(java.lang.Object a_pop) This method is not producing symmetric results as -1 is more often returned than 1 (see description of return value).
protected boolean	containedInArray(IGPProgram[] a_progs, IGPProgram a_prog) Checks if a program is contained within an array of programs.
void	copyGPPrograms(GPPopulation a_pop) Sets the GPPrograms of the given population to this population.
void	create(java.lang.Class[] a_types, java.lang.Class[][] a_argTypes, CommandGene[][] a_nodeSets, int[] a_minDepths, int[] a_maxDepths, int a_maxNodes, boolean[] a_fullModeAllowed) Creates a population.
void	create(java.lang.Class[] a_types, java.lang.Class[][] a_argTypes, CommandGene[][] a_nodeSets, int[] a_minDepths, int[] a_maxDepths, int a_maxNodes, boolean[] a_fullModeAllowed, IProgramCreator a_programCreator) Creates a population.
void	create(java.lang.Class[] a_types, java.lang.Class[][] a_argTypes, CommandGene[][] a_nodeSets, int[] a_minDepths, int[] a_maxDepths, int a_maxNodes, boolean[] a_fullModeAllowed, IProgramCreator a_programCreator, int a_offset) Creates a population.
IGPProgram	create(java.lang.Class[] a_types, java.lang.Class[][] a_argTypes, CommandGene[][] a_nodeSets, int[] a_minDepths, int[] a_maxDepths, int a_depth, boolean a_grow, int a_maxNodes, boolean[] a_fullModeAllowed, int a_tries) Creates a population.
IGPProgram	create(int a_programIndex, java.lang.Class[] a_types, java.lang.Class[][] a_argTypes, CommandGene[][] a_nodeSets, int[] a_minDepths, int[] a_maxDepths, int a_depth, boolean a_grow, int a_maxNodes, boolean[] a_fullModeAllowed, int a_tries)
IGPProgram	create(int a_programIndex, java.lang.Class[] a_types, java.lang.Class[][] a_argTypes, CommandGene[][] a_nodeSets, int[] a_minDepths, int[] a_maxDepths, int a_depth, boolean a_grow, int a_maxNodes, boolean[] a_fullModeAllowed, int a_tries, IProgramCreator a_programCreator) Creates a valid IGPProgram.
protected java.lang.String	decode(java.lang.String a_string)
java.util.List	determineFittestChromosomes(int a_numberOfPrograms) Sorts the GPPrograms list and returns the fittest n GPPrograms in the population.
IGPProgram	determineFittestProgram() Determines the fittest GPProgram in the population (the one with the highest fitness value) and memorizes it.
IGPProgram	determineFittestProgramComputed() Determines the fittest GPProgram in the population, but only considers programs with already computed fitness value.
protected java.lang.String	encode(java.lang.String a_string)
boolean	equals(java.lang.Object a_pop) The equals-method.
float	getFitnessRank(int a_index)
float[]	getFitnessRanks()
GPConfiguration	getGPConfiguration()
IGPProgram	getGPProgram(int a_index)
IGPProgram[]	getGPPrograms()
java.lang.String	getPersistentRepresentation()
int	getPopSize()
boolean	isChanged()
boolean	isFirstEmpty()
protected void	setChanged(boolean a_changed) Mark that for the population the fittest program may have changed.
void	setGPProgram(int a_index, IGPProgram a_program) Sets the given GPProgram at the given index in the list of GPProgram's.
void	setGPPrograms(GPPopulation a_pop) Sets the GPPrograms of the given population to this population.
void	setGPPrograms(IGPProgram[] a_progs) Sets the GPPrograms of the given array to this population.
void	setGPPrograms(java.util.List a_pop) Sets the GPPrograms of the given population to this population.
protected void	setSorted(boolean a_sorted) Mark the population as sorted.
int	size()
void	sort(java.util.Comparator c) Sorts the population into "ascending" order using some criterion for "ascending".
void	sortByFitness() Sorts the programs within the population according to their fitness value using GPProgramFitnessComparator.

Methods inherited from class java.lang.Object

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

Field Detail

DELTA

public static final double DELTA

See Also:

Constant Field Values

Constructor Detail

GPPopulation

public GPPopulation()
             throws java.lang.Exception

Default constructor, only for dynamic instantiation.

Throws:

java.lang.Exception

Since:

3.3.4

GPPopulation

public GPPopulation(GPConfiguration a_config,
                    int a_size)
             throws InvalidConfigurationException

Throws:

InvalidConfigurationException

GPPopulation

public GPPopulation(GPPopulation a_pop)
             throws InvalidConfigurationException

Throws:

InvalidConfigurationException

GPPopulation

public GPPopulation(GPPopulation a_pop,
                    boolean a_keepPrograms)
             throws InvalidConfigurationException

Parameters:

a_pop - the population to retrieve the parameters from

a_keepPrograms - true copy programs of given population to this one

Throws:

InvalidConfigurationException

Method Detail

sort

public void sort(java.util.Comparator c)

Sorts the population into "ascending" order using some criterion for "ascending". A Comparator is given which will compare two individuals, and if one individual compares lower than another individual, the first individual will appear in the population before the second individual.

Parameters:

c - the Comparator to use

Since:

3.0

create

public void create(java.lang.Class[] a_types,
                   java.lang.Class[][] a_argTypes,
                   CommandGene[][] a_nodeSets,
                   int[] a_minDepths,
                   int[] a_maxDepths,
                   int a_maxNodes,
                   boolean[] a_fullModeAllowed)
            throws InvalidConfigurationException

Creates a population.

Parameters:

a_types - the type for each chromosome, the length of the array represents the number of chromosomes

a_argTypes - the types of the arguments to each chromosome, must be an array of arrays, the first dimension of which is the number of chromosomes and the second dimension of which is the number of arguments to the chromosome

a_nodeSets - the nodes which are allowed to be used by each chromosome, must be an array of arrays, the first dimension of which is the number of chromosomes and the second dimension of which is the number of nodes

a_minDepths - contains the minimum depth allowed for each chromosome

a_maxDepths - contains the maximum depth allowed for each chromosome

a_maxNodes - reserve space for a_maxNodes number of nodes

a_fullModeAllowed - array of boolean values. For each chromosome there is one value indicating whether the full mode for creating chromosome generations during evolution is allowed (true) or not (false)

Throws:

InvalidConfigurationException

Since:

3.0

create

public void create(java.lang.Class[] a_types,
                   java.lang.Class[][] a_argTypes,
                   CommandGene[][] a_nodeSets,
                   int[] a_minDepths,
                   int[] a_maxDepths,
                   int a_maxNodes,
                   boolean[] a_fullModeAllowed,
                   IProgramCreator a_programCreator)
            throws InvalidConfigurationException

Creates a population.

Parameters:

a_types - the type for each chromosome, the length of the array represents the number of chromosomes

a_argTypes - the types of the arguments to each chromosome, must be an array of arrays, the first dimension of which is the number of chromosomes and the second dimension of which is the number of arguments to the chromosome

a_nodeSets - the nodes which are allowed to be used by each chromosome, must be an array of arrays, the first dimension of which is the number of chromosomes and the second dimension of which is the number of nodes

a_minDepths - contains the minimum depth allowed for each chromosome

a_maxDepths - contains the maximum depth allowed for each chromosome

a_maxNodes - reserve space for a_maxNodes number of nodes

a_fullModeAllowed - array of boolean values. For each chromosome there is one value indicating whether the full mode for creating chromosome generations during evolution is allowed (true) or not (false)

a_programCreator - service to create new programs with

Throws:

InvalidConfigurationException

Since:

3.2.2

create

public void create(java.lang.Class[] a_types,
                   java.lang.Class[][] a_argTypes,
                   CommandGene[][] a_nodeSets,
                   int[] a_minDepths,
                   int[] a_maxDepths,
                   int a_maxNodes,
                   boolean[] a_fullModeAllowed,
                   IProgramCreator a_programCreator,
                   int a_offset)
            throws InvalidConfigurationException

Creates a population.

Parameters:

a_types - the type for each chromosome, the length of the array represents the number of chromosomes

a_argTypes - the types of the arguments to each chromosome, must be an array of arrays, the first dimension of which is the number of chromosomes and the second dimension of which is the number of arguments to the chromosome

a_nodeSets - the nodes which are allowed to be used by each chromosome, must be an array of arrays, the first dimension of which is the number of chromosomes and the second dimension of which is the number of nodes

a_minDepths - contains the minimum depth allowed for each chromosome

a_maxDepths - contains the maximum depth allowed for each chromosome

a_maxNodes - reserve space for a_maxNodes number of nodes

a_fullModeAllowed - array of boolean values. For each chromosome there is one value indicating whether the full mode for creating chromosome generations during evolution is allowed (true) or not (false)

a_programCreator - service to create new programs with

a_offset - start index for new programs to put into the configuration

Throws:

InvalidConfigurationException

Since:

3.3.3

create

public IGPProgram create(java.lang.Class[] a_types,
                         java.lang.Class[][] a_argTypes,
                         CommandGene[][] a_nodeSets,
                         int[] a_minDepths,
                         int[] a_maxDepths,
                         int a_depth,
                         boolean a_grow,
                         int a_maxNodes,
                         boolean[] a_fullModeAllowed,
                         int a_tries)
                  throws InvalidConfigurationException

Creates a population.

Parameters:

a_types - Class[]

a_argTypes - Class[][]

a_nodeSets - CommandGene[][]

a_minDepths - int[]

a_maxDepths - int[]

a_depth - int

a_grow - boolean

a_maxNodes - int

a_fullModeAllowed - boolean[]

a_tries - int

Returns:

IGPProgram

Throws:

InvalidConfigurationException

Since:

3.2.2

create

public IGPProgram create(int a_programIndex,
                         java.lang.Class[] a_types,
                         java.lang.Class[][] a_argTypes,
                         CommandGene[][] a_nodeSets,
                         int[] a_minDepths,
                         int[] a_maxDepths,
                         int a_depth,
                         boolean a_grow,
                         int a_maxNodes,
                         boolean[] a_fullModeAllowed,
                         int a_tries)
                  throws InvalidConfigurationException

Parameters:

a_programIndex - int

a_types - Class[]

a_argTypes - Class[][]

a_nodeSets - CommandGene[][]

a_minDepths - int[]

a_maxDepths - int[]

a_depth - int

a_grow - boolean

a_maxNodes - int

a_fullModeAllowed - boolean[]

a_tries - int

Returns:

IGPProgram

Throws:

InvalidConfigurationException

Since:

3.3

create

public IGPProgram create(int a_programIndex,
                         java.lang.Class[] a_types,
                         java.lang.Class[][] a_argTypes,
                         CommandGene[][] a_nodeSets,
                         int[] a_minDepths,
                         int[] a_maxDepths,
                         int a_depth,
                         boolean a_grow,
                         int a_maxNodes,
                         boolean[] a_fullModeAllowed,
                         int a_tries,
                         IProgramCreator a_programCreator)
                  throws InvalidConfigurationException

Creates a valid IGPProgram. No fitness computation is initiated here!

Parameters:

a_programIndex - index of the program in the population

a_types - the type of each chromosome, the length is the number of chromosomes

a_argTypes - the types of the arguments to each chromosome, must be an array of arrays, the first dimension of which is the number of chromosomes and the second dimension of which is the number of arguments to the chromosome

a_nodeSets - the nodes which are allowed to be used by each chromosome, must be an array of arrays, the first dimension of which is the number of chromosomes and the second dimension of which is the number of nodes

a_minDepths - contains the minimum depth allowed for each chromosome

a_maxDepths - contains the maximum depth allowed for each chromosome

a_depth - the maximum depth of the program to create

a_grow - true: grow mode, false: full mode

a_maxNodes - reserve space for a_maxNodes number of nodes

a_fullModeAllowed - array of boolean values. For each chromosome there is one value indicating whether the full mode for creating chromosomes during evolution is allowed (true) or not (false)

a_tries - maximum number of tries to get a valid program

a_programCreator - strategy class to create programs for the population

Returns:

valid program

Throws:

InvalidConfigurationException

Since:

3.0

getPopSize

public int getPopSize()

Returns:

fixed size of the population

Since:

3.0

getGPConfiguration

public GPConfiguration getGPConfiguration()

Returns:

the GPConfiguration set

Since:

3.0

setGPProgram

public void setGPProgram(int a_index,
                         IGPProgram a_program)

Sets the given GPProgram at the given index in the list of GPProgram's. If the given index is exceeding the list by one, the chromosome is appended.

Parameters:

a_index - the index to set the GPProgram in

a_program - the GPProgram to be set

Since:

3.0

getGPProgram

public IGPProgram getGPProgram(int a_index)

setGPPrograms

public void setGPPrograms(GPPopulation a_pop)

Sets the GPPrograms of the given population to this population.

Parameters:

a_pop - the population to use as template

Since:

3.3.3

setGPPrograms

public void setGPPrograms(IGPProgram[] a_progs)

Sets the GPPrograms of the given array to this population.

Parameters:

a_progs - the programs to set

Since:

3.3.3

copyGPPrograms

public void copyGPPrograms(GPPopulation a_pop)

Sets the GPPrograms of the given population to this population.

Parameters:

a_pop - the population to use as template

Since:

3.3.3

setGPPrograms

public void setGPPrograms(java.util.List a_pop)

Sets the GPPrograms of the given population to this population.

Parameters:

a_pop - the population to use as template

Since:

3.3.3

getGPPrograms

public IGPProgram[] getGPPrograms()

size

public int size()

determineFittestProgram

public IGPProgram determineFittestProgram()

Determines the fittest GPProgram in the population (the one with the highest fitness value) and memorizes it. This is an optimized version compared to calling determineFittesPrograms(1).

Returns:

the fittest GPProgram of the population

Since:

3.0

determineFittestProgramComputed

public IGPProgram determineFittestProgramComputed()

Determines the fittest GPProgram in the population, but only considers programs with already computed fitness value.

Returns:

the fittest GPProgram of the population

Since:

3.2

determineFittestChromosomes

public java.util.List determineFittestChromosomes(int a_numberOfPrograms)

Sorts the GPPrograms list and returns the fittest n GPPrograms in the population.

Parameters:

a_numberOfPrograms - number of top performer GPPrograms to be returned

Returns:

list of the fittest n GPPrograms of the population, or the fittest x GPPrograms with x = number of GPPrograms in case n > x.

Since:

3.0

sortByFitness

public void sortByFitness()

Sorts the programs within the population according to their fitness value using GPProgramFitnessComparator.

Since:

3.0

getFitnessRanks

public float[] getFitnessRanks()

getFitnessRank

public float getFitnessRank(int a_index)

setChanged

protected void setChanged(boolean a_changed)

Mark that for the population the fittest program may have changed.

Parameters:

a_changed - true: population's fittest program may have changed, false: fittest program evaluated earlier is still valid

Since:

3.0

isChanged

public boolean isChanged()

Returns:

true: population's programs (maybe) were changed, false: not changed for sure

Since:

3.0

setSorted

protected void setSorted(boolean a_sorted)

Mark the population as sorted.

Parameters:

a_sorted - true: mark population as sorted

Since:

3.0

compareTo

public int compareTo(java.lang.Object a_pop)

This method is not producing symmetric results as -1 is more often returned than 1 (see description of return value).

Specified by:

compareTo in interface java.lang.Comparable

Parameters:

a_pop - the other population to compare

Returns:

1: a_pop is null or having fewer programs or equal number of programs but at least one not contained. 0: both populations containing exactly the same programs. -1: this population contains fewer programs than a_pop

Since:

2.6

containedInArray

protected boolean containedInArray(IGPProgram[] a_progs,
                                   IGPProgram a_prog)

Checks if a program is contained within an array of programs. Assumes that in the array no element will follow after the first null element.

Parameters:

a_progs - the array to search thru

a_prog - the program to find

Returns:

true: program found in array via equals-method

Since:

3.0

equals

public boolean equals(java.lang.Object a_pop)

The equals-method.

Overrides:

equals in class java.lang.Object

Parameters:

a_pop - the population instance to compare with

Returns:

true: given object equal to comparing one

Since:

3.0

addFittestProgram

public void addFittestProgram(IGPProgram a_toAdd)

Adds a GP program to this Population. Does nothing when given null. The injection is actually executed in method create(..)

Parameters:

a_toAdd - the program to add

Since:

3.2

clear

public void clear()

Clears the list of programs. Normally, this should not be necessary. But especially in distributed computing, a fresh population has to be provided sometimes.

Since:

3.2

isFirstEmpty

public boolean isFirstEmpty()

getPersistentRepresentation

public java.lang.String getPersistentRepresentation()

Returns:

the persistent representation of the population, including all GP programs

Since:

3.2.3

encode

protected java.lang.String encode(java.lang.String a_string)

decode

protected java.lang.String decode(java.lang.String a_string)