pagmo::algorithm::spea2 Class Reference

"Strength Pareto Evolutionary Algorithm (SPEA2)" More...

#include <spea2.h>

Inheritance diagram for pagmo::algorithm::spea2:

Public Member Functions
	spea2 (int gen=100, double cr=0.95, double eta_c=10, double m=0.01, double eta_m=50, int archive_size=0)
	Constructor. More...
base_ptr	clone () const
	Clone method.
void	evolve (population &) const
	Evolve implementation. More...
std::string	get_name () const
	Algorithm name.
Public Member Functions inherited from pagmo::algorithm::base
	base ()
	Default constructor. More...
virtual	~base ()
	Trivial destructor. More...
std::string	human_readable () const
	Return human readable representation of the algorithm. More...
void	set_screen_output (const bool p)
	Setter-Getter for protected m_screen_output data. More...
bool	get_screen_output () const
	Gets screen output. More...
void	reset_rngs (const unsigned int) const
	Resets the seed of the internal rngs using a user-provided seed. More...

Protected Member Functions
std::string	human_readable_extra () const
	Extra human readable algorithm info. More...

Friends
class	boost::serialization::access

Additional Inherited Members
Protected Attributes inherited from pagmo::algorithm::base
bool	m_screen_output
	Indicates to the derived class whether to print stuff on screen.
rng_double	m_drng
	Random number generator for double-precision floating point values.
rng_uint32	m_urng
	Random number generator for unsigned integer values.
unsigned int	m_fevals
	A counter for the number of function evaluations.

Detailed Description

"Strength Pareto Evolutionary Algorithm (SPEA2)"

Strength Pareto Evolutionary Algorithm (SPEA2) is a multi-objective optimization algorithm. The quality of an individual is measured taking into consideration its pareto strenght and its distance to its K-th neighbour, where It uses an external archive in which are stored the non dominated solutions found so far. The size of the archive is kept constant throughout the run by mean of a truncation operator taking into consideration the distance of each individual to its closest neighbours.

Author

Andrea Mambrini (andre.nosp@m.a.ma.nosp@m.mbrin.nosp@m.i@gm.nosp@m.ail.c.nosp@m.om)

Annalisa Riccardi (nina1.nosp@m.983@.nosp@m.gmail.nosp@m..com)

See also

Eckart Zitzler, Marco Laumanns, and Lothar Thiele – "SPEA2: Improving the Strength Pareto Evolutionary Algorithm"

Definition at line 80 of file spea2.h.

Constructor & Destructor Documentation

pagmo::algorithm::spea2::spea2	(	int	gen = 100,
		double	cr = 0.95,
		double	eta_c = 10,
		double	m = 0.01,
		double	eta_m = 50,
		int	archive_size = 0
	)

Constructor.

Constructs a SPEA2 algorithm

Parameters

[in]	gen	Number of generations to evolve.
[in]	cr	Crossover probability
[in]	eta_c	Distribution index for crossover
[in]	m	Mutation probability
[in]	eta_m	Distribution index for mutation
[in]	archive_size	the size of the non_dominated archive. If archive_size=0 then the archive size is set equal to the population size. The population returned after evolve has a size equal to archive_size

Exceptions

value_error

if gen is negative

Definition at line 59 of file spea2.cpp.

Member Function Documentation

void pagmo::algorithm::spea2::evolve ( population &  pop ) const

virtual

Evolve implementation.

Run the SPEA2 algorithm for the number of generations specified in the constructors.

Parameters

[in,out]

pop

input/output pagmo::population to be evolved.

Implements pagmo::algorithm::base.

Definition at line 97 of file spea2.cpp.

std::string pagmo::algorithm::spea2::human_readable_extra ( ) const

protectedvirtual

Extra human readable algorithm info.

Will return a formatted string displaying the parameters of the algorithm.

Reimplemented from pagmo::algorithm::base.

Definition at line 305 of file spea2.cpp.

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

• spea2.h
• spea2.cpp