Stochastic universal sampling

[1] SUS is a development of fitness proportionate selection (FPS) which exhibits no bias and minimal spread.

Where FPS chooses several solutions from the population by repeated random sampling, SUS uses a single random value to sample all of the solutions by choosing them at evenly spaced intervals.

This gives weaker members of the population (according to their fitness) a chance to be chosen.

Using a comb-like ruler, SUS starts from a small random number, and chooses the next candidates from the rest of population remaining, not allowing the fittest members to saturate the candidate space.

Described as an algorithm, pseudocode for SUS looks like: Where Population[0..I] is the set of individuals with array-index 0 to (and including) I.

SUS example