Re: [R] Adding percentage to Pie Charts (was (no subject))

From: Anupam Tyagi <>
Date: Tue 19 Sep 2006 - 06:51:51 GMT

Greg Snow <Greg.Snow <at>> writes:

> You may want to rethink your whole approach here:
> 1. Pie charts are usually a poor choice of graph, there are better
> choices.
> 2. Adding percentages to a pie chart is a way of admitting that the pie
> chart is not doing the job.
> 3. If you want people to compare percentages, then a table is what is
> needed.
> 4. A pie chart with percentages added is essentially a colorful but
> poorly layed out table.
> Consider using a dotplot instead of a pie chart, it changes the job of
> the viewer from comparing areas/angles (done poorly by humans) to
> comparing positions along a common scale (done well by humans).

I think dot charts (plots) are very useful, but they are not substitutes for a pie chart: they do not show a comparison between the total and the individual value; have a different scale (linear, usually), and are visually not suitable to answer some questions that a pie chart can answer (is the value approximately less than a fourth of the total? Is it less than half?). For some of these questions, even dot-charts require a value label, or the user doing mental calculations to guess approximations.

I think I am quite attuned to getting approximate fractions from a pie-chart in shorter time, than on a linear scale like the dot-chart.

A modification in a pie chart that draws overlapping areas with a common start point at the top of the circle, can make is more informative than a dot-chart. Something like:
* Start drawing at the top of the circle, as zero (degree/area). * Draw the representation of every value starting from the top, as zero, representing it as a labled line from the center of the circle to the boundary (can use colors where possible).
* Use two lables for the circular axis, inside one for percentages, outside for values.

What is the simplest way to draw this in R?

Anupam. mailing list PLEASE do read the posting guide and provide commented, minimal, self-contained, reproducible code. Received on Tue Sep 19 18:28:26 2006

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.1.8, at Tue 19 Sep 2006 - 08:30:05 GMT.

Mailing list information is available at Please read the posting guide before posting to the list.