A type of selection operator used in evolutionary algorithms in which a theoretical roulette wheel is spun. Each member of the population is assigned a segment of the wheel, with size proportional to its fitness, such that fitter individuals are more likely to be selected for the next generation and/or reproduction.
Selection is a key element of any type of evolutionary-algorithm. There are many ways to apply selection, but one of the simplest, and therefore most popular, is roulette wheel selection.
In roulette wheel selection, an imaginary dial is spun. It will point to a random location along this circle. The proportion of the circle that is taken up by each member of the population (and therefor the likelihood of each being selected) is determined by that member's fitness.
In practice, it is unnecessary to implement a roulette wheel selector as a circle. Instead, a random number is selected.
