| OCR Text |
Show pending on the simulation behavior. They interact with the simulation at different time intervals. A sample set of directors is shown in Figure 3.6. Periodic analysis is a background director that periodically copies the entire simulation and prepares a summary of interesting statistics. The director or its period can be changed anytime. Analysis on demand is a user driven director similar to periodic analysis. It is used by the user to supplement the periodic analysis at the time of particularly fast changes or to perform additional analysis. Change o f parameters is a director that controls global parameters of the simulation. In an artificial life simulation, examples of such parameters could include the rate of growth of artificial organisms, the availability of food and so on. Since the director is a regular computer program, these parameters can be controlled in a complex way. Change o f code is the most powerful director. It is used by the user to dynamically implant new parts of code in the simulation or to modify old code. The main usage of this director is to add new behaviors to artificial organisms. Directors were successfully applied to simulations that ran uninterrupted for weeks. Without introspection, it would be impossible to steer simulations on the executor directors Figure 3.6. An Artificial Life Simulation |
