Fitness proportional (and inverse proportional) individual selection operator. More...

Inheritance diagram for SelFitnessProportionalOp:

Public Member Functions
bool	initialize (StateP)
	Selection operator initialization. Must be called before individual selection. More...

IndividualP	select (const std::vector< IndividualP > &)
	Select one individual from a set. More...

std::vector< IndividualP >	selectMany (const std::vector< IndividualP > &, uint)
	Repeatedly select from the same pool (duplicates allowed) More...

bool	setSelPressure (double)
	Set selection pressure value. More...

virtual bool	initialize (StateP)=0
	Selection operator initialization. Must be called before individual selection. More...

virtual IndividualP	select (const std::vector< IndividualP > &)=0
	Select one individual from a set. More...

Protected Attributes
double	selPressure_
	the ratio of selection probability of the best and worst individual in the set More...

Protected Attributes inherited from SelectionOperator
StateP	state_

Detailed Description

Fitness proportional (and inverse proportional) individual selection operator.

Functionality: The selection operator assigns a positive value 'S' to each individual, and chooses an individual with proportion to the value 'S'. The selection pressure parameter 'P' states how much is the best individual 'better' than the worst, i.e. how greater chance of selection has the best individual related to the worst one. (the worst individual always has S = 1, and the best S = P)

Inverse proportional selection: For elimination purpose, the P may be set to a value lower than 1; in that case, the worst individual will have the greatest chance of selection, and the best individual the lowest chance.

Examples

if P = 10, then the best individual has the selection value 10 and worst value 1
if P = 0.1, then the best individual has the selection value 0.1 (i.e. has 10 times lesser chance to be selected than the worst individual!)

Definition at line 26 of file SelFitnessProportionalOp.h.