Swarm Intelligence

in other regions of the landscape. Where the function is not random—

and therefore impossible to optimize—a good optimization algorithm

should be able to capitalize on regularities of the fitness landscape.

Multimodal functions have more than one optimum. A simple one-

dimensional example is the equation x

2

= 100. The fitness landscape has

a peak at x = 10 and another at x =−10. Note that there is a kind of

bridge or “saddle” between the two optima, where fitness drops until it

gets to x = 0, then whichever way we go it increases again. The fitness of

x = 0 is not nearly so bad as, say, the fitness of x = 10,000. No matter

where you started a trial-and-error ...