geom_boxploth {ggstance}

Horizontal box and whiskers plot.

Description

Horizontal version of geom_boxplot().

Usage

geom_boxploth(
  mapping = NULL,
  data = NULL,
  stat = "boxploth",
  position = "dodge2v",
  ...,
  outlier.colour = NULL,
  outlier.color = NULL,
  outlier.fill = NULL,
  outlier.shape = 19,
  outlier.size = 1.5,
  outlier.stroke = 0.5,
  outlier.alpha = NULL,
  notch = FALSE,
  notchwidth = 0.5,
  varwidth = FALSE,
  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), it is combined with the default mapping at the top level of the plot. You must supply mapping if there is no plot mapping.

data

The data to be displayed in this layer. There are three options:

If NULL, the default, the data is inherited from the plot data as specified in the call to ggplot().

A 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.

A function will be called with a single argument, the plot data. The return value must be a data.frame, and will be used as the layer data. A function can be created from a formula (e.g. ~ head(.x, 10)).

stat

Use to override the default connection between geom_boxplot and stat_boxplot.

position

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

...

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.

outlier.colour, outlier.color, outlier.shape, outlier.size, outlier.stroke

Default aesthetics for outliers. Set to NULL to inherit from the aesthetics used for the box.

In the unlikely event you specify both US and UK spellings of colour, the US spelling will take precedence.

outlier.fill

Default aesthetics for outliers. Set to NULL to inherit from the aesthetics used for the box.

In the unlikely event you specify both US and UK spellings of colour, the US spelling will take precedence.

Sometimes it can be useful to hide the outliers, for example when overlaying the raw data points on top of the boxplot. Hiding the outliers can be achieved by setting outlier.shape = NA. Importantly, this does not remove the outliers, it only hides them, so the range calculated for the y-axis will be the same with outliers shown and outliers hidden.

outlier.alpha

Default aesthetics for outliers. Set to NULL to inherit from the aesthetics used for the box.

In the unlikely event you specify both US and UK spellings of colour, the US spelling will take precedence.

Sometimes it can be useful to hide the outliers, for example when overlaying the raw data points on top of the boxplot. Hiding the outliers can be achieved by setting outlier.shape = NA. Importantly, this does not remove the outliers, it only hides them, so the range calculated for the y-axis will be the same with outliers shown and outliers hidden.

notch

If FALSE (default) make a standard box plot. If TRUE, make a notched box plot. Notches are used to compare groups; if the notches of two boxes do not overlap, this suggests that the medians are significantly different.

notchwidth

For a notched box plot, width of the notch relative to the body (defaults to notchwidth = 0.5).

varwidth

If FALSE (default) make a standard box plot. If TRUE, boxes are drawn with widths proportional to the square-roots of the number of observations in the groups (possibly weighted, using the weight aesthetic).

na.rm

If FALSE, the default, missing values are removed with a warning. If TRUE, missing values are silently removed.

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. It can also be a named logical vector to finely select the aesthetics to display.

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().

Aesthetics

geom_boxploth() understands the following aesthetics (required aesthetics are in bold):

• y

• xlower

• xupper

• xmiddle

• xmin

• xmax

• alpha

• colour

• fill

• group

• linetype

• shape

• size

• weight

Learn more about setting these aesthetics in vignette("ggplot2-specs").

Examples

library("ggplot2")

# With ggplot2 we need coord_flip():
ggplot(mpg, aes(class, hwy, fill = factor(cyl))) +
  geom_boxplot() +
  coord_flip()

# With ggstance we use the h-suffixed version:
ggplot(mpg, aes(hwy, class, fill = factor(cyl))) +
  geom_boxploth()

# With facets ggstance horizontal layers are often the only way of
# having all ggplot features working correctly, for instance free
# scales:
df <- data.frame(
  Group = factor(rep(1:3, each = 4), labels = c("Drug A", "Drug B", "Control")),
  Subject = factor(rep(1:6, each = 2), labels = c("A", "B", "C", "D", "E", "F")),
  Result = rnorm(12)
)

ggplot(df, aes(Result, Subject))+
  geom_boxploth(aes(fill = Group))+
  facet_grid(Group ~ ., scales = "free_y")