Visualizing Data

Chapter 5. Connections and Correlations

Data that varies across multiple dimensions is common, and it can be difficult to represent in traditional charts that exploit only the two dimensions of the screen or printed page. In particular, you often have an independent variable and a dependent variable that change over time. Many techniques for representing change exist, but one of the most engaging ways is animation.

In this chapter, we’ll create a display of baseball results to explore how relationships can be instantly and powerfully conveyed through the spatial arrangement of data, visual elements such as icons and lines, and most significantly, the use of animation. You don’t have to understand baseball to understand this chapter; it’s less about the game than it is about the numbers and depicting those numbers.

The display used in this chapter is uniquely suited to the baseball data provided and the relationships within that data. You might choose to use a different sort of display for your data, but you can learn a lot by following the use of font, color, stroke weight, and other parameters shown here. The example demonstrates how to keep the basic goal of a display in mind and how to choose each element to meet that goal. Along the way, we’ll see how to parse text data and convert it from simple plain-text files to internal formats that are easy for our program to mine. We’ll also study how to mix text data (including numeric data) with lines and other visual elements and how ...