ggforce (version 0.1.1)

geom_arc_bar: Arcs and wedges as polygons

Description

This set of stats and geoms makes it possible to draw arcs and wedges as known from pie and donut charts as well as more specialized plottypes such as sunburst plots.

Usage

stat_arc_bar(mapping = NULL, data = NULL, geom = "arc_bar", position = "identity", n = 360, na.rm = FALSE, show.legend = NA, inherit.aes = TRUE, ...)
stat_pie(mapping = NULL, data = NULL, geom = "arc_bar", position = "identity", n = 360, sep = 0, na.rm = FALSE, show.legend = NA, inherit.aes = TRUE, ...)
geom_arc_bar(mapping = NULL, data = NULL, stat = "arc_bar", position = "identity", n = 360, na.rm = FALSE, show.legend = NA, inherit.aes = TRUE, ...)

Arguments

mapping

Set of aesthetic mappings created by aes or aes_. If specified and inherit.aes = TRUE (the default), is combined with the default mapping at the top level of the plot. You only need to supply mapping if there isn't a mapping defined for the plot.

data

A data frame. If specified, overrides the default data frame defined at the top level of the plot.

geom,

stat Override the default connection between geom_arc_bar and stat_arc_bar.

position

Position adjustment, either as a string, or the result of a call to a position adjustment function.

n

The number of points used to draw a full circle. The number of points on each arc will then be calculated as n / span-of-arc

na.rm

If FALSE (the default), removes missing values with a warning. If TRUE silently removes missing values.

show.legend

logical. Should this layer be included in the legends? NA, the default, includes if any aesthetics are mapped. FALSE never includes, and TRUE always includes.

inherit.aes

If FALSE, overrides the default aesthetics, rather than combining with them. This is most useful for helper functions that define both data and aesthetics and shouldn't inherit behaviour from the default plot specification, e.g. borders.

...

other arguments passed on to layer. There are three types of arguments you can use here:

• Aesthetics: to set an aesthetic to a fixed value, like color = "red" or size = 3.
• Other arguments to the layer, for example you override the default stat associated with the layer.
• Other arguments passed on to the stat.

sep

The separation between arcs in pie/donut charts

stat

The statistical transformation to use on the data for this layer, as a string.

Aesthetics

geom_arc_bar understand the following aesthetics (required aesthetics are in bold):

• x0
• y0
• r0
• r
• start - when using stat_arc_bar
• end - when using stat_arc_bar
• amount - when using stat_pie
• explode
• color
• fill
• size
• linetype
• alpha

Computed variables

Details

An arc bar is the thick version of an arc; that is, a circle segment drawn as a polygon in the same way as a rectangle is a thick version of a line. A wedge is a special case of an arc where the inner radius is 0. As opposed to applying coord_polar to a stacked bar chart, these layers are drawn in cartesian space, which allows for transformations not possible with the native ggplot2 approach. Most notable of these are the option to explode arcs and wedgets away from their center point, thus detaching it from the main pie/donut.

See Also

geom_arc for drawing arcs as lines

Examples

# If you know the angle spans to plot it is easy
arcs <- data.frame(
  start = seq(0, 2*pi, length.out=11)[-11],
  end = seq(0, 2*pi, length.out=11)[-1],
  r = rep(1:2, 5)
)

# Behold the arcs
ggplot() + geom_arc_bar(aes(x0=0, y0=0, r0=r-1, r=r, start=start, end=end,
                        fill = r),
                    data=arcs)

# If you got values for a pie chart, use stat_pie
states <- c('eaten', "eaten but said you didn't", 'cat took it', 'for tonight',
            'will decompose slowly')
pie <- data.frame(
  state = factor(rep(states, 2), levels = states),
  type = rep(c('Pie', 'Donut'), each = 5),
  r0 = rep(c(0, 0.8), each = 5),
  focus=rep(c(0.2, 0, 0, 0, 0), 2),
  amount = c(4,3, 1, 1.5, 6, 6, 1, 2, 3, 2),
  stringsAsFactors = FALSE
)

# Look at the cakes
ggplot() + geom_arc_bar(aes(x0=0, y0=0, r0=r0, r=1, amount=amount,
                            fill=state, explode=focus),
                        data=pie, stat='pie') +
  facet_wrap(~type, ncol=1) +
  coord_fixed() +
  theme_no_axes() +
  scale_fill_brewer('', type='qual')