C# Class Accord.Genetic.GPTreeChromosome

Tree chromosome represents a tree of genes, which is is used for different tasks of Genetic Programming (GP).

This type of chromosome represents a tree, where each node is represented by GPTreeNode containing IGPGene. Depending on type of genes used to build the tree, it may represent different types of expressions aimed to solve different type of tasks. For example, a particular implementation of IGPGene interface may represent simple algebraic operations and their arguments.

See documentation to IGPGene implementations for additional information about possible Genetic Programming trees.

Inheritance: ChromosomeBase

Show file Open project: accord-net/framework Class Usage Examples

Public Methods

Method	Description
Clone ( ) : IChromosome	Clone the chromosome. The method clones the chromosome returning the exact copy of it.
CreateNew ( ) : IChromosome	Create new random chromosome with same parameters (factory method). The method creates new chromosome of the same type, but randomly initialized. The method is useful as factory method for those classes, which work with chromosome's interface, but not with particular chromosome type.
Crossover ( IChromosome pair ) : void	Crossover operator. The method performs crossover between two chromosomes – interchanging randomly selected sub trees.
GPTreeChromosome ( IGPGene ancestor ) : System	Initializes a new instance of the GPTreeChromosome class. This constructor creates a randomly generated genetic tree, which has all genes of the same type and properties as the specified ancestor.
Generate ( ) : void	Generate random chromosome value. Regenerates chromosome's value using random number generator.
Mutate ( ) : void	Mutation operator. The method performs chromosome's mutation by regenerating tree's randomly selected node.
ToString ( ) : string	Get string representation of the chromosome by providing its expression in reverse polish notation (postfix notation). The method returns string representation of the tree's root node (see GPTreeNode.ToString).

Protected Methods

Method	Description
GPTreeChromosome ( GPTreeChromosome source ) : System	Initializes a new instance of the GPTreeChromosome class. This constructor creates new genetic tree as a copy of the specified source tree.
Generate ( GPTreeNode node, int level ) : void	Generate chromosome's subtree of specified level.

Private Methods

Method	Description
RandomSwap ( GPTreeNode source ) : GPTreeNode	Crossover helper routine - selects random node of chromosomes tree and swaps it with specified node.
Trim ( GPTreeNode node, int level ) : void	Trim tree node, so its depth does not exceed specified level.

Method Details

Clone() public method

Clone the chromosome.

The method clones the chromosome returning the exact copy of it.

public Clone ( ) : IChromosome
return	IChromosome

CreateNew() public method

Create new random chromosome with same parameters (factory method).

The method creates new chromosome of the same type, but randomly initialized. The method is useful as factory method for those classes, which work with chromosome's interface, but not with particular chromosome type.

public CreateNew ( ) : IChromosome
return	IChromosome

Crossover() public method

Crossover operator.

The method performs crossover between two chromosomes – interchanging randomly selected sub trees.

public Crossover ( IChromosome pair ) : void
pair	IChromosome	Pair chromosome to crossover with.
return	void

GPTreeChromosome() protected method

Initializes a new instance of the GPTreeChromosome class.

This constructor creates new genetic tree as a copy of the specified source tree.

protected GPTreeChromosome ( GPTreeChromosome source ) : System
source	GPTreeChromosome	Source genetic tree to clone from.
return	System

GPTreeChromosome() public method

Initializes a new instance of the GPTreeChromosome class.

This constructor creates a randomly generated genetic tree, which has all genes of the same type and properties as the specified ancestor.

public GPTreeChromosome ( IGPGene ancestor ) : System
ancestor	IGPGene	A gene, which is used as generator for the genetic tree.
return	System

Generate() public method

Generate random chromosome value.

Regenerates chromosome's value using random number generator.

public Generate ( ) : void
return	void

Generate() protected method

Generate chromosome's subtree of specified level.

protected Generate ( GPTreeNode node, int level ) : void
node	GPTreeNode	Sub tree's node to generate.
level	int	Sub tree's level to generate.
return	void

Mutate() public method

Mutation operator.

The method performs chromosome's mutation by regenerating tree's randomly selected node.

public Mutate ( ) : void
return	void

ToString() public method

Get string representation of the chromosome by providing its expression in reverse polish notation (postfix notation).

The method returns string representation of the tree's root node (see GPTreeNode.ToString).

public ToString ( ) : string
return	string