ggpie - A ggplot2 extension to create pie, donut and rose pie plot

ggpie aims to create pie (2D and 3D), donut and rose pie plot with the ggplot2 plotting system which implemented the grammar of graphics. It contains five main functions:

• ggpie: Create 2D pie plot with single group variable.
• ggdonut: Create 2D donut plot with single group variable.
• ggnestedpie: Create 2D nested pie plot with two group variables.
• ggpie3D: Create 3D pie plot with single group variable.
• ggrosepie: Create rose pie plot with single or two group variables.