scale_continuous_diverging: Diverging continuous scales for diverging bar charts with...

In ggsurveillance: Tools for Outbreak Investigation/Infectious Disease Surveillance

Diverging continuous scales for diverging bar charts with symmetrical limits

Description

These scales automatically create symmetrical limits around a centre point (zero by default). They're useful for diverging continuous variables where the visual encoding should be balanced around a center point, such as positive and negative values. They are intended to be used with geom_bar_diverging(), geom_area_diverging() and stat_diverging().

Usage

scale_x_continuous_diverging(
  name = waiver(),
  limits = NULL,
  labels = NULL,
  transform = "identity",
  ...,
  breaks = waiver(),
  n.breaks = NULL,
  expand = waiver(),
  position = "bottom"
)

scale_y_continuous_diverging(
  name = waiver(),
  limits = NULL,
  labels = NULL,
  transform = "identity",
  ...,
  breaks = waiver(),
  n.breaks = NULL,
  expand = waiver(),
  position = "left"
)

Arguments

name	The name of the scale. Used as the axis or legend title. If waiver(), the default, the name of the scale is taken from the first mapping used for that aesthetic. If NULL, the legend title will be omitted.
limits	Numeric vector of length two providing limits of the scale. If NULL (the default), limits are automatically computed to be symmetrical around zero.
labels	Either waiver(), a character vector or a function that takes the breaks as input and returns labels as output. By default, absolute values are displayed or passed to the label function.
transform	Defaults to "identity". Use "reverse" to invert the scale. Especially useful to flip the direction of diverging bar charts.
...	Other arguments passed on to ⁠scale_(x|y)_continuous()⁠
breaks	One of: NULL for no breaks waiver() for the default breaks computed by the transformation object A numeric vector of positions A function that takes the limits as input and returns breaks as output (e.g., a function returned by scales::extended_breaks()). Note that for position scales, limits are provided after scale expansion. Also accepts rlang lambda function notation.
n.breaks	An integer guiding the number of major breaks. The algorithm may choose a slightly different number to ensure nice break labels. Will only have an effect if breaks = waiver(). Use NULL to use the default number of breaks given by the transformation.
expand	For position scales, a vector of range expansion constants used to add some padding around the data to ensure that they are placed some distance away from the axes. Use the convenience function expansion() to generate the values for the expand argument. The defaults are to expand the scale by 5% on each side for continuous variables, and by 0.6 units on each side for discrete variables.
position	For position scales, The position of the axis. left or right for y axes, top or bottom for x axes.

Value

A ggplot2 scale object that can be added to a plot.

See Also

geom_bar_diverging(), geom_area_diverging(), stat_diverging()

Examples

library(ggplot2)

# Create sample data with positive and negative values
df <- data.frame(
  x = c(-5, -2, 0, 3, 7),
  y = c(2, -1, 0, -3, 5)
)

# Basic usage
ggplot(df, aes(x, y)) +
  geom_point() +
  scale_x_continuous_diverging() +
  scale_y_continuous_diverging()

ggsurveillance documentation built on June 8, 2025, 10:38 a.m.