IAMRate {xegaPopulation}R Documentation

Individually adaptive mutation rate.

Description

The probability of applying a mutation operator to a gene. The idea is that a gene selected for reproduction whose fitness is below a threshold value is mutated with a higher probability to give it a chance.

Usage

IAMRate(fit, lF)

Arguments

fit

Fitness of gene.

lF

Local configuration.

Details

The probability of applying a mutation operator is determined by a threshold: If the fitness of a gene is higher than lF$CutoffFit()*lF$CBestFitness(), than return lF$MutationRate1() else lF$MutationRate2().

Note that the idea is also applicable to gene specific local mutation operators. For example, the bit mutation rate of mutation operators for binary genes.

Value

Mutation rate of a gene depending on its fitness.

References

Stanhope, Stephen A. and Daida, Jason M. (1996) An Individually Variable Mutation-rate Strategy for Genetic Algorithms. In: Koza, John (Ed.) Late Breaking Papers at the Genetic Programming 1996 Conference. Stanford University Bookstore, Stanford, pp. 177-185. (ISBN:0-18-201-031-7)

See Also

Other Adaptive Rates: IACRate()

Examples

parm<-function(x){function() {return(x)}}
lF<-list()
lF$MutationRate1<-parm(0.20)
lF$MutationRate2<-parm(0.40)
lF$CutoffFit<-parm(0.60)
lF$CBestFitness=parm(105)
IAMRate(100, lF)
IAMRate(50, lF)

[Package xegaPopulation version 1.0.0.0 Index]