geom_tukey: Tukey's HSD intervals

In adas.utils: Design of Experiments and Factorial Plans Utilities

Tukey's HSD intervals

Description

stat_tukey() fits a one-way aov(response ~ factor) per group and computes Tukey's HSD pairwise differences with stats::TukeyHSD(). geom_tukey() draws them as horizontal error bars with points, plus a red reference line at zero, and labels the y axis with the comparisons. Groups (e.g. a colour mapping) are dodged, and facets work as usual.

Usage

geom_tukey(
  mapping = NULL,
  data = NULL,
  ...,
  conf.level = 0.95,
  dodge = 0.5,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

stat_tukey(
  mapping = NULL,
  data = NULL,
  geom = "pointrange",
  position = "identity",
  ...,
  conf.level = 0.95,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

Arguments

mapping	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 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)).
...	Other arguments passed on to layer()'s params argument. These arguments broadly fall into one of 4 categories below. Notably, further arguments to the position argument, or aesthetics that are required can not be passed through .... Unknown arguments that are not part of the 4 categories below are ignored. Static aesthetics that are not mapped to a scale, but are at a fixed value and apply to the layer as a whole. For example, colour = "red" or linewidth = 3. The geom's documentation has an Aesthetics section that lists the available options. The 'required' aesthetics cannot be passed on to the params. Please note that while passing unmapped aesthetics as vectors is technically possible, the order and required length is not guaranteed to be parallel to the input data. When constructing a layer using a ⁠stat_*()⁠ function, the ... argument can be used to pass on parameters to the geom part of the layer. An example of this is stat_density(geom = "area", outline.type = "both"). The geom's documentation lists which parameters it can accept. Inversely, when constructing a layer using a ⁠geom_*()⁠ function, the ... argument can be used to pass on parameters to the stat part of the layer. An example of this is geom_area(stat = "density", adjust = 0.5). The stat's documentation lists which parameters it can accept. The key_glyph argument of layer() may also be passed on through .... This can be one of the functions described as key glyphs, to change the display of the layer in the legend.
conf.level	Family-wise confidence level, passed to stats::TukeyHSD().
dodge	Dodging width between groups.
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. To include legend keys for all levels, even when no data exists, use TRUE. If NA, all levels are shown in legend, but unobserved levels are omitted.
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. annotation_borders().
geom	The geometric object to use display the data.
position	A position adjustment to use on the data for this layer. This can be used in various ways, including to prevent overplotting and improving the display. The position argument accepts the following: The result of calling a position function, such as position_jitter(). This method allows for passing extra arguments to the position. A string naming the position adjustment. To give the position as a string, strip the function name of the position_ prefix. For example, to use position_jitter(), give the position as "jitter". For more information and other ways to specify the position, see the layer position documentation.

Details

The input variables are given through the non-positional response and factor aesthetics, because ggplot2 maps a discrete x to integers before the stat runs. For the same reason the comparisons are placed on a continuous y axis: y is the comparison index, x = diff, xmin/xmax = lwr/upr. The stat also returns comparison (the label) and p.adj. geom_tukey() adds the matching y axis labels; with stat_tukey() alone the y axis shows the indices.

Value

A ggplot2 layer (stat_tukey()) or a set of layers (geom_tukey()).

See Also

ggTukey()

Examples

library(ggplot2)
ggplot(battery, aes(response = Response, factor = Material, colour = Temperature)) +
  geom_tukey(conf.level = 0.99) +
  labs(x = "Difference", y = "Material")

adas.utils documentation built on Nov. 12, 2026, 5:07 p.m.