A comparison of four “classic” types of charts: a bar chart, a pie chart, a treemap and a diagram based on a circle packing layout (sometimes called “bubble chart”, not to be confused with this one, which encodes instead three dimensions of data).
Seven classes, represented by color, are each assigned a random value, that is then encoded with the four different techniques. Bars use their length to represent quantity, while the pie chart uses angles. Both the treemap and the bubbles uses area instead. The four layouts are also instructed to try to preserve the ordering of classes.