ultra::gp::individual Class Reference

#include <individual.h>

Inheritance diagram for ultra::gp::individual:

Public Types
enum	crossover_t {   one_point , two_points , tree , uniform ,   dependency , NUM_CROSSOVERS }
using	const_exon_iterator = internal::basic_exon_iterator<true>
using	exon_iterator = internal::basic_exon_iterator<false>
Public Types inherited from ultra::individual
using	age_t = unsigned

Public Member Functions
	individual (const problem &)
	individual (const std::vector< gene > &)
symbol::category_t	categories () const noexcept
bool	empty () const noexcept
locus::index_t	size () const noexcept
const gene &	operator[] (const locus &) const noexcept
locus	start () const noexcept
unsigned	mutation (const problem &, double=1.0)
void	apply_decision_vector (const decision_vector &)
crossover_t	active_crossover_type () const noexcept
matrix< unsigned >	analyse_importance (const std::vector< locus > &) const
const_exon_view	cexons () const
auto	begin () const noexcept
auto	end () const noexcept
bool	operator== (const individual &) const noexcept
bool	is_valid () const
Public Member Functions inherited from ultra::individual
age_t	age () const noexcept
void	inc_age (unsigned=1) noexcept
bool	load (std::istream &, const symbol_set &={})
bool	save (std::ostream &) const
hash_t	signature () const noexcept
std::string	format (out::print_format_t) const

Additional Inherited Members
Protected Member Functions inherited from ultra::individual
void	set_if_older_age (age_t) noexcept
Protected Attributes inherited from ultra::individual
hash_t	signature_ {}

Detailed Description

A single member of a genetic programming population.

Straight Line Program (SLP) is the encoding / data structure used to represent the individual.

Note

This class implements a value type with no internal synchronisation. Any operation that mutates the individual is not thread-safe and must not run concurrently with any member function unless externally synchronised.

Examples

symbolic_regression03.cc.

Constructor & Destructor Documentation

individual() [1/2]

ultra::gp::individual::individual ( const problem & p )

explicit

Generates the initial, random expressions that make up an individual.

Parameters

[in]

p

base problem

The constructor is implemented so as to ensure that there is no violation of the type system's constraints.

individual() [2/2]

ultra::gp::individual::individual ( const std::vector< gene > & gv )

explicit

Creates a new individual containing genes from gv.

Parameters

[in]

gv

vector of genes

Precondition

gv is not empty

the final gene produces the default category

This is useful for debugging purpose (i.e. setup ad-hoc individuals).

Member Function Documentation

active_crossover_type()

individual::crossover_t ultra::gp::individual::active_crossover_type ( ) const

nodiscardnoexcept

Returns

the active crossover type for this individual

analyse_importance()

matrix< unsigned > ultra::gp::individual::analyse_importance ( const std::vector< locus > & loci ) const

nodiscard

Calculates the importance of genes contributing to selected loci.

Parameters

[in]

loci

loci from which dependency analysis starts

Returns

a matrix containing the importance of every gene

Precondition

every locus must belong to this individual

Importance is the number of dependency paths from the selected loci to each gene. Counts saturate at the maximum value of unsigned.

apply_decision_vector()

void ultra::gp::individual::apply_decision_vector

(

const decision_vector &

v

)

Applies a decision vector to this individual.

Parameters

[in]

v

decision vector previously extracted from a compatible individual

Precondition

• v.is_valid();
• v must have been obtained from an individual with the same structure (same active exons, loci, and argument layout). Applying a decision vector to a structurally different individual results in undefined behaviour.

Each entry of the decision vector is written back to the corresponding argument in the genome, as identified by decision_vector::coordinate. Real-valued parameters are copied directly, while integer parameters are reconstructed by rounding the provided value to the nearest integer (std::lround).

categories()

symbol::category_t ultra::gp::individual::categories ( ) const

nodiscardnoexcept

Returns

the total number of categories the individual is using

cexons()

const_exon_view ultra::gp::individual::cexons ( ) const

nodiscard

Returns

a const range to iterate through exons (active genes).

empty()

bool ultra::gp::individual::empty ( ) const

nodiscardnoexcept

Returns

true if the individual isn't initialized

is_valid()

bool ultra::gp::individual::is_valid ( ) const

nodiscard

Returns

true if the individual passes the internal consistency check

mutation()

unsigned ultra::gp::individual::mutation	(	const problem &	prb,
		double	temperature = 1.0 )

A new individual is created mutating this.

Parameters

[in]	prb	the current problem
[in]	temperature	mutation intensity (1.0 preserves the configured probability)

Returns

number of mutations performed

Note

External parameters: evolution.p_mutation

operator==()

bool ultra::gp::individual::operator== ( const individual & rhs ) const

nodiscardnoexcept

Parameters

[in]

rhs

second term of comparison

Returns

true if the two individuals are equal (symbol by symbol, including introns)

Note

Age is not checked.

operator[]()

const gene & ultra::gp::individual::operator[] ( const locus & l ) const

nodiscardnoexcept

Parameters

[in]

l

locus of a gene

Returns

the l-th gene of this individual

size()

locus::index_t ultra::gp::individual::size ( ) const

nodiscardnoexcept

Returns

the total size of the individual (effective size + introns)

Remarks

Size is constant for any individual (it's chosen at initialization time).

See also

eff_size()

start()

locus ultra::gp::individual::start ( ) const

nodiscardnoexcept

Returns

the first gene of the individual (the first instruction of the program)

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The documentation for this class was generated from the following files:

• gp/individual.h
• gp/individual.cc