Pro Data Visualization using R and JavaScript

CHAPTER 7

Bar Charts

Chapter 6 explored using time series charts to look at defect data over time, and this chapter looks at bar charts, which display ordinal or ranked data relative to a specific data set. They usually consist of an x- and y-axis, and have bars or colored rectangles to indicate values of categories.

William Playfair created the bar chart in the first edition of The Commercial and Political Atlas in 1786 to show Scotland’s import and export data to and from different parts of the world (see Figure 7-1). He created it out of necessity; the other charts in the atlas were time series charts demonstrating hundreds of years’ worth ...