ROULETTE WHEEL

Parents are selected according to their fitness.The individuals with a better fitness have more probability to survive. This operator dividies the population according to their fitness. This selection will have problems when the fitnesses differs very much.

 

LINEAR RANKING

First, it ranks the individual according to their fitness, and then it assigns to every one a new fitness depending on their position in the ordened list. The worst individual will have fitness 0, second worst 1 etc. and the best will have fitness N-1(number of individuals in population). This method can lead to slower convergence, because the best individual doesn't differ so much from other ones.

RANDOM

This operator selects randomly a individual from the population.

BEST INDIVIDUAL

It selects the best individual from the population.