Download piechartmp.

piechartMP
Drawing pie-charts with MetaPost
Jens-Uwe Morawski
The piechartMP package is an easy way to draw pie-charts with METAPOST. The package implements an interface that enables even users
with few METAPOST experience to draw their charts. A highlight of
piechartMP is that the user can hide defined segments from drawing
or making them invisible in order to draw multiple different pie-charts
from one data-set. For example a presentation can be made, whereby
every slide has one more segment visible. The special support for presentations was the chief purpose for the piechartMP development.