Different persistence can also be exhibited in the way an animal chooses its targets over time. Our design of the intention generator and focusser simplifies the modification of existing personalities and behaviors and the addition of new ones. For example, we can create artificial fishes with different persistences by augmenting the focusser with a positive valued threshold. Suppose the current intention of a predator fish is to eat and let the distance to some currently targeted prey be and the distance to some other prey be . If is greater than the threshold, the fish will target the new prey. Varying the threshold will vary the fish's level of persistence. The same heuristic can be applied to mates when the fish is trying to mate. One can make the fish ``fickle'' by setting the value of the threshold close to zero or make it ``devoted'' by setting a large value.
|Xiaoyuan Tu||January 1996|