Pie charts, as mediums of data representation, have been widely used in news media, corporate presentations, and research papers. Pie charts have been used in the past to compare data between two time periods as well as to represent parts of a whole in a single pie. However, even with such widespread use, they have been criticized by statisticians. The blog post at http://www.r-chart.com/2010/07/pie-charts-in-ggplot2.html summarizes the main criticism as follows:
The relative size of each slice is difficult to interpret. Studies have shown that pie charts are hard to read
Pie charts require too much space to present too little information
They are frequently rendered in 3D (this makes the previous two issues worse)
The main criticism of pie charts is that they are difficult to interpret, especially when the difference between two slices of a pie is small. Human beings are not trained well to observe angles; hence, many times, pie charts might even be interpreted wrongly. Even...