八 032007
Pie charts are a very bad way of displaying information.
from R-help
The pie chart is invented by Playfair in 1786. Among statisticians, however, the pie chart is generally deprecated in favor of the bar chart, usually on the blief that judgments of relative areas or angles are more difficult than judgment of length. In Tufte’s (1983) view, for example, “the only design worse than a pie chart is several of them … pie charts should never be used”. The prevailing views and the results of influential studies by Cleveland & McGill (1984, 1986) continue to lead statisticians to hold the pie chart in disfavor.
