3. Numerical aspects of simulation

Simulation involves both the modeling and the use of models, in a process similar to that used in experimental work. In the case of numerical simulation, the formalization of mathematical models has consequences for numerical operation, which are manifested in more or less severe resolution difficulties.

The different levels of modelling can be distinguished from the following point of view:

• functional level: discrete systems in space and time ;

• system level: discrete-space and continuous-time systems;

• network level: discrete-space and continuous-time systems;

• geometric level: continuous systems in time and space.