Visualizing categorical information using bar charts

We saw how the Table visualization is perfect for showing and ordering detailed information. It's quite similar to a spreadsheet. The Bar Chart visualization is very good for visualizing categorical information, that is, where you have categories with supporting hard numbers—sales by region, for example. The region is the category, whereas the sales is the hard number or fact.

Bar charts are typically used to show a distribution. Depending on your data or your analytic requirement, the bars can be ordered by value, placed side by side, stacked on top of each other, or arranged vertically or horizontally.

There is a special case of the category and value combination and that is where you want to plot the frequencies of a set of numerical values. This type of bar chart is referred to as a histogram, and although it is number against number, it is still, in essence, a distribution plot. It is very common in fact to transform the...