Other displays of categorical data

Two variations of the standard bar chart of categorical data are often encountered. A stacked bar chart is simply a bar chart in which the bars are stacked on top of each other. It is particularly useful when comparing several distributions since the stacked bar charts can be drawn side by side.

In a pie chart, a circle is split into segments according to the proportion of data values in each category. The angle for each category is given by the proportion.

Although pie charts seem visually different from the two types of bar chart, they are closely related.

In bar charts, stacked bar charts and pie charts, the area of ink for any category is proportional to the number of values in that category


Richest people under 40

Fortune magazine regularly publishes various lists of the world's biggest corporations and richest individuals, and in September 2002 it published a list of the world's richest people who were under 40. The following table shows where those with personal fortunes over US$136 billion are based.

Region Number of people
USA 30
Europe 18
Asia 16
Other 6

It should be noted that

The diagram below shows these data.

Drag the slider to the right to stack the bars of the bar chart.


In the diagram below, drag the slider to change the stacked bar chart into a pie chart.