Chapter 3 Venndir Basics

A Venn diagram seems relatively simple and straightforward. It uses circles (or sometimes ellipses) to represent the shared and distinct elements of each set.

Proportional Euler diagrams use areas proportional to the number of elements of each set, and are somewhat unpredictable.

An important feature of any good Venn diagram is clear labeling. Venndir is as much about labeling as it is about the diagram. Adding signed labels only heightens the challenge.

Figure 3.1: Three-way proportional Euler diagram, showing the difficulty of labeling each region. Here, the overlap of set_A and set_C has 2 items. The label is placed outside, connected by a line segment.

Venndir employs a variety of strategies to automate labeling, and adds approaches to allow for manual adjustments. Figure 3.1 demonstrates that sometimes there is no other option but to place a label outside.

Most of this chapter describes basic features of Venndir. Although some techniques may feel advanced, I promise it becomes more "advanced" in the next chapter!