Dot Plots

Dot plots represent individual observations in a batch of data with symbols, usually circular dots. They have been used for more than 100 years to depict distributions in detail. Hand-drawn examples show their authors' efforts to arrange symbols so that they are as near as possible to their proper locations on a scale without overlapping enough to obscure each other. Recent computer programs that attempt to reproduce these historical plots have unfortunately resorted to simple histogram binning instead of using methods that follow the rules for the hand-drawn examples. This article introduces an algorithm that more accurately represents the dot plots cited in the literature.