The Why and How of Dynamic Modeling - Dynamic Modeling of Diseases and Pests - page 9

Fig. 1.2
The Diagram Layer displays the following symbols, “building blocks,” for
stocks, flows, converters, and connectors (information arrows), shown in Figure 1.3:
Fig. 1.3
Click on the globe (Figure 1.4) to access the modeling mode:
Fig. 1.4
In the modeling mode you can specify your model's initial conditions and func-
tional relationships. The following symbol (Figure 1.5) indicates that you are now
in the modeling mode:
Fig. 1.5
Begin with the first tool, a stock (rectangle). In this example model, the stock will
represent the number of fish in your pond. Click on the rectangle with your mouse,
drag it to the center of the screen, and click again. Type in the word SICK. This is
what you see (Figure 1.6):
Fig. 1.6