System dynamics is an approach to understanding the behaviour of complex systems over time. It deals with internal feedback loops and time delays that affect the behaviour of the entire system. What makes using system dynamics different from other approaches to studying complex systems is the use of feedback loops and stocks and flows. These elements help describe how even seemingly simple systems display baffling nonlinearity
Here is how a system diagram looks like:
The downside, as I understand it, is that each different use of a System Dynamics symbol requires its own entry in the library. For example, a stock with one inflow and one outflow requires a different Modelica symbol from one with one inflow and 2 outflows. Also (again, as I understand it), every separate equation requires its own symbol to be defined and added to the library before it can be used.
¿Anyone here can confirm or deny this? ¿Is this a limitation inherent in all Modelica enviroments? ¿or it is an implementation limitation on this particular library?
and, going back to the original aim of this question: Is there a less expensive way (than System Modeler) to do this in Mathematica, without System Modeler?