Create pie charts

Creates a single pie chart or several pie charts

ggpie(data, x, by, offset = 0.5, label.size = 4,
  label.color = "black", facet.label.size = 11,
  border.color = "black", border.width = 0.5, legend = TRUE,
  percent = TRUE, title, digits = 0, nrow = 1)

Arguments

data	A data frame.
x	The variable to be plotted. It will be coerced to a factor.
by	Optional "by" variable (see details).
offset	Distance of pie slice labels from the origin (see details).
label.size	Size of slice label text.
label.color	Color of slice label text.
facet.label.size	Size of the "by" variable labels.
border.color	Color of pie slice borders.
border.width	Width of pie slice borders.
legend	Logical. If TRUE, adds a legend. If FALSE, the legend is omitted and each pie slice is labeled.
percent	Logical. If TRUE, prints percents for each pie slice.
title	Optional title.
digits	Number of decimal digits when printing percents.
nrow	Number of rows for a faceted graph.

Value

a ggplot2 graph

Details

If a by variable is present, a faceted graph is created with one pie chart for each level of the by variable. The nrow option controls the number of rows in the faceted chart. The facet.label.size option controls the size of the facet label for each pie chart.

The offset value controls the distance of the pie slice label from the pie's origin. A value of 0.5 will center the label in each slice. A value of 1.0 will place each label on the pie radius. A value larger than 1.0 will place the label outside the pie slice. You may have to vary this value to get the most attractive spacing.

Examples

library(ggplot2)
ggpie(mpg, class)

ggpie(mpg, class, offset=0.8, label.color="white")

ggpie(mpg, class, offset=1.3,
      title="Auto Class Distribution")

ggpie(mpg, class, offset=1.3, legend=FALSE,
      title="Auto Class Distribution")

ggpie(mpg, class, offset=1.3, percent=FALSE,
      legend=FALSE, title="Auto Class Distribution")

ggpie(mpg, class, year, offset=1.3, label.size=3,
      legend=FALSE, title="Car Class by Year")

ggpie(mpg, drv, cyl, nrow=2, label.size=3.5,
     title="Car Drive Type by Number of Cylinders") +
 scale_fill_brewer(palette="Dark2") +
 theme(legend.position = "top")

ggpie(mpg, drv, trans, nrow=3, border.color="white", border.width=1.5,
      label.color="black", label.size=3, offset=.7,
      title="Auto Drive Type by Transmission\n") +
  theme(legend.position=c(.8, .2)) +
  scale_fill_manual(values=c("yellow", "skyblue", "green"))