This layout of a histogram was first suggested by Florence Nightingale to explain the problems of the Crimea.

The figure show the Daisy 'Circular Histograms' example.

The circular histogram is a powerful way to display data.

The great advantage is that when a histogram is to be drawn in great detail for say 200 or more values, the traditional axis for a horizontal form will have a very small increment. Details will suffer badly, when the graph is shown on an A4 sheet of paper.

By drawing the histogram in a circle, the axis is about twice as long, which allows a much larger increment.

The circular form is also more-readable.

See Circular Histogram in the Help for more details.