geom_boxplot: Box and whiskers plot.

Description

The lower and upper "hinges" correspond to the first and third quartiles (the 25th and 75th percentiles). This differs slightly from the method used by the boxplot function, and may be apparent with small samples. See boxplot.stats for for more information on how hinge positions are calculated for boxplot.

Usage

geom_boxplot(mapping = NULL, data = NULL, stat = "boxplot",
  position = "dodge", outlier.colour = NULL, outlier.shape = 19,
  outlier.size = 1.5, outlier.stroke = 0.5, notch = FALSE,
  notchwidth = 0.5, varwidth = FALSE, na.rm = FALSE, show.legend = NA,
  inherit.aes = TRUE, ...)
stat_boxplot(mapping = NULL, data = NULL, geom = "boxplot",
  position = "dodge", coef = 1.5, 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 le

data

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

position

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

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

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

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 (default 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), 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.

...

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, likecolor = "red"orsize = 3.

geom, stat

Use to override the default connection between geom_boxplot and stat_boxplot.

coef

length of the whiskers as multiple of IQR. Defaults to 1.5

Details

The upper whisker extends from the hinge to the highest value that is within 1.5 * IQR of the hinge, where IQR is the inter-quartile range, or distance between the first and third quartiles. The lower whisker extends from the hinge to the lowest value within 1.5 * IQR of the hinge. Data beyond the end of the whiskers are outliers and plotted as points (as specified by Tukey).

In a notched box plot, the notches extend 1.58 * IQR / sqrt(n). This gives a roughly 95See McGill et al. (1978) for more details.