Introduction to the Agent Approach
Résumé
When we need to study a real system made up of interconnected elements, where each of these systems has its own dynamics, it is often impossible to foresee the emergence of a global dynamics for the system. In this case, what is in question is a complex system, because any one modification, even if it is marginal in terms of its one or several constituent elements, may lead to a dramatic change in overall operation of the system. It becomes clear that these phenomena may well be understood and observed only through the construction of a model. Even if in certain particular cases the model may be resolved analytically, as is the case for the Lotka–Voltera prey-predator models, computer simulation is indispensable in all other cases, i.e. in most thematically interesting cases. As such, agent modeling is one possible response for studying complex spatial systems.