Points, jittered to reduce overplotting.

Usage

geom_jitter(mapping = NULL, data = NULL, width = NULL, height = NULL, stat = "identity", position = "jitter", 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 level of the plot. You only need to supply mapping if there isn't a mapping defined for the plot.
data
A data frame. If specified, overrides the default data frame defined at the top level of the plot.
width
Amount of vertical and horizontal jitter. The jitter is added in both positive and negative directions, so the total spread is twice the value specified here. If omitted, defaults to 40% of the resolution of the data: this means the jitter values will occupy 80% of the implied bins. Categorical data is aligned on the integers, so a width or height of 0.5 will spread the data so it's not possible to see the distinction between the categories.
height
Amount of vertical and horizontal jitter. The jitter is added in both positive and negative directions, so the total spread is twice the value specified here. If omitted, defaults to 40% of the resolution of the data: this means the jitter values will occupy 80% of the implied bins. Categorical data is aligned on the integers, so a width or height of 0.5 will spread the data so it's not possible to see the distinction between the categories.
stat
The statistical transformation to use on the data for this layer, as a string.
position
Position adjustment, either as a string, or the result of a call to a position adjustment function.
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. borders.
...
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, like color = "red" or size = 3.
  • Other arguments to the layer, for example you override the default stat associated with the layer.
  • Other arguments passed on to the stat.

Description

The jitter geom is a convenient default for geom_point with position = 'jitter'. It's a useful way of handling overplotting caused by discreteness in smaller datasets.

Aesthetics

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

  • x
  • y
  • alpha
  • colour
  • fill
  • shape
  • size
  • stroke

Examples

p <- ggplot(mpg, aes(cyl, hwy)) p + geom_point()

p + geom_jitter()

# Add aesthetic mappings p + geom_jitter(aes(colour = class))

# Use smaller width/height to emphasise categories ggplot(mpg, aes(cyl, hwy)) + geom_jitter()

ggplot(mpg, aes(cyl, hwy)) + geom_jitter(width = 0.25)

# Use larger width/height to completely smooth away discreteness ggplot(mpg, aes(cty, hwy)) + geom_jitter()

ggplot(mpg, aes(cty, hwy)) + geom_jitter(width = 0.5, height = 0.5)

See also

geom_point for regular, unjittered points, geom_boxplot for another way of looking at the conditional distribution of a variable