Whenever Optimax is about to add a new a individual to the population, it first checks to see if that individual already exists in the population. This is call a clone check. The clone check ensures that trials are not duplicated within the same generation, increases diversity and forces exploration of the nearby fitness terrain.
If the clone check determines that a clone exists, Optimax will use one of the changeling methods you select to modify the current individual so that it is no longer a clone.
These are the changeling methods available in the optimization settings.
When using Random, Optimax creates a new individual by mutation. A single, randomly chosen gene is mutated to a new, valid value for that gene.
When using Rival, roughly one-half of the genes of the individual are shifted up or down by one step to create a near likeness, or a rival to the existing individual. Each gene has a 50% chance of being shifted, and there is a 50% chance of an upward or downward shift. If, after shifting all genes and creating a rival, it is found that there is a clone in the population for this new individual, then the process is repeated until a clone is not found.
When using Random, Optimax generates and entirely new, entirely random individual.
After applying any changeling method, Optimax performs the clone check again. If the changeling is itself determined to be a clone, the current method is repeated until the changeling is found not to be a clone.
If you select more than one changeling method, Optimax chooses between all of the selected methods at random each time it needs to create a changeling.