recSBX {ecr}

Simulated Binary Crossover (SBX) recombinator.

Description

The Simulated Binary Crossover was first proposed by [1]. It i suited for float representation only and creates two offspring. Given parents $p_1, p_2$ the offspring are generated as $c_{1/2} = \bar{x} \pm \frac{1}{2}\beta(p_2 - p_1)$ where $\bar{x} = \frac{1}{2}(p_1 + p_2), p_2 > p_1$. This way $\bar{c} = \bar{x}$ is assured.

Usage

recSBX(inds, eta = 5, p = 1, lower, upper)

Arguments

inds

[numeric]
Parents, i.e., list of exactly two numeric vectors of equal length.

eta

[numeric(1)]
Parameter eta, i.e., the distance parameters of the crossover distribution.

p

[numeric(1)]
Crossover probability for each gene. Default is 1.0.

lower

[numeric]
Vector of minimal values for each parameter of the decision space.

upper

[numeric]
Vector of maximal values for each parameter of the decision space.

Value

[ecr_recombinator]

Note

This is the default recombination operator used in the NSGA-II EMOA (see nsga2).

References

[1] Deb, K. and Agrawal, R. B. (1995). Simulated binary crossover for continuous search space. Complex Systems 9(2), 115-148.

See Also

Other recombinators: recCrossover(), recIntermediate(), recOX(), recPMX(), recUnifCrossover()