Editing Selection (evolutionary algorithm) (section)

=== Roulette wheel selection ===
In the [[Fitness_proportionate_selection|roulette wheel selection]], the probability of choosing an individual for breeding of the next generation is proportional to its fitness, the better the fitness is, the higher chance for that individual to be chosen.
Choosing individuals can be depicted as spinning a roulette that has as many pockets as there are individuals in the current generation, with sizes depending on their probability.
Probability of choosing individual <math>i</math> is equal to <math>p_i = \frac{f_i}{\Sigma_{j=1}^{N} f_j}</math>, where <math>f_i</math> is the fitness of <math>i</math> and <math>N</math> is the size of current generation (note that in this method one individual can be drawn multiple times).

====Stochastic universal sampling====
[[Stochastic universal sampling]] is a development of roulette wheel selection with minimal spread and no bias.