Fitness proportionate selection

Fitness proportionate selection, also known as roulette wheel selection, is a genetic operator used in genetic algorithms for selecting potentially useful solutions for recombination.

In fitness proportionate selection, as in all selection methods, the fitness function assigns a fitness to possible solutions or chromosomes. This fitness level is used to associate a probability of selection with each individual chromosome. If ${\displaystyle f_{i}}$ is the fitness of individual ${\displaystyle i}$ in the population, its probability of being selected is ${\displaystyle p_{i}={\frac {f_{i}}{\Sigma _{j=1}^{N}f_{j}}}}$, where ${\displaystyle N}$ is the number of individuals in the population.

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