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.
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, expand = 0, radius = 0, na.rm = FALSE, show.legend = NA, inherit.aes = TRUE, ... )
Set of aesthetic mappings created by
aes(). If specified and
inherit.aes = TRUE (the default), it is combined with the default mapping
at the top level of the plot. You must supply
mapping if there is no plot
The data to be displayed in this layer. There are three options:
NULL, the default, the data is inherited from the plot
data as specified in the call to
data.frame, or other object, will override the plot
data. All objects will be fortified to produce a data frame. See
fortify() for which variables will be created.
function will be called with a single argument,
the plot data. The return value must be a
will be used as the layer data. A
function can be created
~ head(.x, 10)).
The geometric object to use to display the data, either as a
Geom subclass or as a string naming the geom stripped of the
geom_ prefix (e.g.
"point" rather than
Position adjustment, either as a string naming the adjustment
"jitter" to use
position_jitter), or the result of a call to a
position adjustment function. Use the latter if you need to change the
settings of the adjustment.
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
FALSE, the default, missing values are removed with
a warning. If
TRUE, missing values are silently removed.
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.
It can also be a named logical vector to finely select the aesthetics to
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.
Other arguments passed on to
layer(). These are
often aesthetics, used to set an aesthetic to a fixed value, like
colour = "red" or
size = 3. They may also be parameters
to the paired geom/stat.
The separation between arcs in pie/donut charts
The statistical transformation to use on the data for this
layer, either as a
Geom subclass or as a string naming the
stat stripped of the
stat_ prefix (e.g.
"count" rather than
A numeric or unit vector of length one, specifying the expansion amount. Negative values will result in contraction instead. If the value is given as a numeric it will be understood as a proportion of the plot area width.
expand but specifying the corner radius.
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.
geom_arc_bar understand the following aesthetics (required aesthetics are in bold):
start - when using stat_arc_bar
end - when using stat_arc_bar
amount - when using stat_pie
x and y coordinates for the polygon
The start coordinates for the segment
geom_arc() for drawing arcs as lines
# 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(arcs) + geom_arc_bar(aes(x0 = 0, y0 = 0, r0 = r - 1, r = r, start = start, end = end, fill = r)) # geom_arc_bar uses geom_shape to draw the arcs, so you have all the # possibilities of that as well, e.g. rounding of corners ggplot(arcs) + geom_arc_bar(aes(x0 = 0, y0 = 0, r0 = r - 1, r = r, start = start, end = end, fill = r), radius = unit(4, 'mm')) # 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) ) # 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')