The named tools are the most important tools.
Most applications can have several documents open at the same time and
each document is usually represented by one window. STELLA, however,
can only have one document open but each document can have several windows.
If one model is open, the item "Open" is therefore grayed out
in the "File" menu, while "Close" is not, telling you
that you can't open another model before you close the currently open model.
In STELLA, each document can have several windows. The basic window
where you enter your model is always open, but you can also have windows
with output in table or graph format and these windows you may open and
close as you wish.
Remember to save your work now and then. Although computer crashes are rare, computer hang ups are not. As soon as you have done a few changes to your work, save it. If you are using discettes, be sure to make backup copies (not on the same discette) now and then.
The basic window can show you four different views of your model,
You choose between the views by clicking on the arrows to the left and on the globe/x2 sign (The Map/model toggle). When starting to work with STELLA, the model view is by far the most useful view.
With the model view you can build your model, enter your equations, and
enter comments:
The named tools are the most important tools.
The equation view shows your equations and with this view you can also
change existing equations and comments:
With this view you can build your model and enter comments
With this view you can group your model into submodels (not demonstrated
here)
A STELLA model consists of four basic items
A reservoir is a place where things are stored, e.g. a bathtub is a store of water. A flow defines the inflow/outflow from a reservoir. A converter can hold information like constants, unit conversions, and different kind of variables. A connector is an information flow.
Beside these four basic items STELLA provides some other practical tools: