draw_key_pie            Legend key for the pie glyphs
geom_pie_glyph          Scatter plot with points replaced by
                        axis-invariant pie-chart glyphs
geom_pie_interactive    Scatter plots with interactive pie-chart glyphs
pieGrob                 Create pie-chart glyph
scale_radius_discrete   Scales for the pie glyph radius
upgradeUnit.unit.list   Upgrading units for a list
