Chapter 9. More Tools
As discussed at the beginning of the book, there are a lot of tools that you will end up using for one or two specific purposes. In this section, I discuss other tools that I find handy for analysis and include a brief explanation about how to use them.
Many of these tools are pretty powerful—far more than in a three-page summary can describe. I will touch on each of these tools very briefly and try to provide an example for each. However, be prepared to look for additional material and supplemental documentation.
While R is my primary tool for graph visualization, there are several additional tools that are handy under specific circumstances. Graphviz is toolkit for visualizing graphs. Gnuplot is the utility knife of plotting tools: powerful, scriptable, and profoundly unfriendly.
Graphviz is a graph layout and visualization package. Originally developed by AT&T Labs, the package is now released under the Eclipse license and is actively maintained.
Graphviz is actually a suite of tools, each of which provides a different mechanism for automatically laying out graphs. With each tool, you provide a graph specification, and the tool automatically lays out the graph based on the specification. Graphs are specified via a language called dot, which specifies nodes of various attributes and then links connecting them. An example dot command and output are shown in Example 9-1, with the results illustrated in Figure 9-1.