Pie Charts: A Familiar Way to Show Proportions
The Pie Chart is perhaps the most popular data visualization in the world and is familiar to almost everyone. It displays fractions as "parts of the whole". Although popular, Pie Charts are not usually the most effective visualization technique for displaying data. For a small data set, the Bar Graph is more effective; for a large data set or a hierarchical data set, a Treemap is more useful.
Two distinct styles of Pie Charts
Pie Charts are popular visualization tools for Executive Dashboards and web-based presentations of data. Our data visualization software can produce two different types of Pie Charts:
|Standard Pie Chart — Each slice of the pie represents a numeric variable and its proportional relationship to the total. The color of each slice can represent a category or another numeric variable.||Compare this to a Bar Graph visualization using the same data. You do not need to use color to display an accurate and readable visualization and it's easy to see relative sizes as well as the absolute magnitude for each variable.|
|Multi-Level Pie Chart — These are also known as Sunbursts. They allow you to display a hierarchy within the data using multiple levels in the pie. You can modify the visible depth level to display only those levels in the hierarchy you want to see. You can also drill into a slice to see additional details about that specific subset of data.||Compare the Multi-Level Pie Chart to a standard Treemap data visualization, which allocates all of the available space to the visualization using rectangles rather than slices. Treemaps make more effective use of available space, enable more accurate comparisons and are an excellent way to display information about a large number of data points.|
Pie Charts have a long history
The Pie Chart is one of the oldest documented data visualizations. It first appeared in 1801 in a publication written by William Playfair in England. In his book, The Statistical Breviary, he used a variety of graphs to present geographical areas, populations, and revenues of European states.