2.1 Introduction

There are many ways to use Ptolemy II. It can be used as a framework for assembling software components, as a modeling and simulation tool, as a block-diagram editor, as a system-level rapid prototyping application, as a toolkit supporting research in component-based design, or as a toolkit for building Java applications. This chapter introduces its use as a modeling and simulation tool.

In this chapter, we describe how to graphically construct models using Vergil, a graphical user interface (GUI) for Ptolemy II. Figure 2.1 shows a simple Ptolemy II model in Vergil, showing the graph editor, one of several editors available in Vergil. Keep in mind as you read this document that graphical entry of models is only one of several possible entry mechanisms available in Ptolemy II. For example, you can define models in Java, as shown in figure 1.5, or in XML, as shown in figure 1.3 of the previous chapter. Moreover, only some of the execution engines (called domains) are described here. A major emphasis of Ptolemy II is to provide a framework for the construction of modeling and design tools, so the specific modeling and design tools described here should be viewed as representative of our efforts.