geom_rule: Rulers through or offset from the origin

In gggda: A 'ggplot2' Extension for Geometric Data Analysis

Rulers through or offset from the origin

Description

geom_rule() renders segments through or orthogonally translated from the origin.

Usage

geom_rule(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  axis_labels = TRUE,
  axis_ticks = TRUE,
  axis_text = TRUE,
  by = NULL,
  num = NULL,
  snap_rule = TRUE,
  tick_length = 0.025,
  text_dodge = 0.03,
  label_dodge = 0.03,
  ...,
  axis.linewidth = sync(),
  axis.linetype = sync(),
  axis.colour = sync(),
  axis.color = NULL,
  axis.alpha = sync(),
  label.size = sync(),
  label.angle = 0,
  label.hjust = sync(),
  label.vjust = sync(),
  label.family = sync(),
  label.fontface = sync(),
  label.colour = sync(),
  label.color = NULL,
  label.alpha = sync(),
  tick.linewidth = 0.25,
  tick.linetype = "solid",
  tick.colour = sync(),
  tick.color = NULL,
  tick.alpha = sync(),
  text.size = 2.6,
  text.angle = 0,
  text.hjust = sync(),
  text.vjust = sync(),
  text.family = sync(),
  text.fontface = sync(),
  text.colour = sync(),
  text.color = NULL,
  text.alpha = sync(),
  parse = FALSE,
  check_overlap = FALSE,
  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)).
stat	The statistical transformation to use on the data for this layer. When using a ⁠geom_*()⁠ function to construct a layer, the stat argument can be used to override the default coupling between geoms and stats. The stat argument accepts the following: A Stat ggproto subclass, for example StatCount. A string naming the stat. To give the stat as a string, strip the function name of the stat_ prefix. For example, to use stat_count(), give the stat as "count". For more information and other ways to specify the stat, see the layer stat documentation.
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.
axis_labels, axis_ticks, axis_text	Logical; whether to include labels, tick marks, and text value marks along the axes.
by, num	Intervals between elements or number of elements; specify only one.
snap_rule	Logical; whether to snap rule segments to grid values.
tick_length	Numeric; the length of the tick marks, as a proportion of the minimum of the plot width and height.
text_dodge	Numeric; the orthogonal distance of tick mark text from the axis, as a proportion of the minimum of the plot width and height.
label_dodge	Numeric; the orthogonal distance of the axis label from the axis, as a proportion of the minimum of the plot width and height.
...	Additional arguments passed to ggplot2::layer().
axis.linewidth, axis.linetype, axis.colour, axis.color, axis.alpha	Default aesthetics for axes. Set to NULL to inherit from the data's aesthetics.
label.size, label.angle, label.hjust, label.vjust, label.family, label.fontface, label.colour, label.color, label.alpha	Default aesthetics for labels. Set to NULL to inherit from the data's aesthetics.
tick.linewidth, tick.linetype, tick.colour, tick.color, tick.alpha	Default aesthetics for tick marks. Set to NULL to inherit from the data's aesthetics.
text.size, text.angle, text.hjust, text.vjust, text.family, text.fontface, text.colour, text.color, text.alpha	Default aesthetics for tick mark labels. Set to NULL to inherit from the data's aesthetics.
parse	If TRUE, the labels will be parsed into expressions and displayed as described in ?plotmath.
check_overlap	If TRUE, text that overlaps previous text in the same layer will not be plotted. check_overlap happens at draw time and in the order of the data. Therefore data should be arranged by the label column before calling geom_text(). Note that this argument is not supported by geom_label().
na.rm	Passed to ggplot2::layer().
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().

Details

As implemented here, a rule is just an axis that has a fixed range, usually the limits of the data. geom_rule() defaults to stat = "identity" to avoid the problem of failing to pass referent data to the referential stat_rule(). Therefore, the user must provide the lower and upper aesthetics, which are used as euclidean lengths in the plotting window. Meanwhile, stat_rule() defaults to geom = "rule"; see stat_rule() for details on this pairing.

Value

A ggproto layer.

Aesthetics

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

• x

• y

• lower

• upper

• yintercept or xintercept or xend and yend

• linetype

• linewidth

• size

• hjust

• vjust

• colour

• alpha

• label

• family

• fontface

• center, scale

• group

See Also

Other geom layers: geom_axis(), geom_bagplot(), geom_isoline(), geom_lineranges(), geom_text_radiate(), geom_vector()

Examples

USJudgeRatings %>% 
  subset(select = -c(1, 12)) %>% 
  dist(method = "maximum") %>% 
  cmdscale() %>% 
  as.data.frame() %>% 
  setNames(c("PCo1", "PCo2")) %>% 
  transform(name = rownames(USJudgeRatings)) ->
  judge_mds
USJudgeRatings %>% 
  subset(select = c(CONT, RTEN)) %>% 
  setNames(c("contacts", "recommendation")) ->
  judge_meta
lm(as.matrix(judge_meta) ~ as.matrix(judge_mds[, seq(2)])) %>% 
  getElement("coefficients") %>% 
  unname() %>% t() %>% as.data.frame() %>% 
  setNames(c("Intercept", "PCo1", "PCo2")) %>% 
  transform(variable = names(judge_meta)) ->
  judge_lm
ggplot(judge_mds, aes(x = PCo1, y = PCo2)) +
  coord_equal() +
  theme_void() +
  geom_text(aes(label = name), size = 3) +
  stat_rule(
    data = judge_lm, referent = judge_mds,
    aes(center = Intercept, label = variable)
  )

gggda documentation built on July 18, 2026, 5:07 p.m.