R: Plot data ellipses.

stat_ellipse {ggplot2}

R Documentation

Plot data ellipses.

Description

Plot data ellipses.

Usage

stat_ellipse(mapping = NULL, data = NULL, geom = "path",
  position = "identity", type = "t", level = 0.95, segments = 51,
  na.rm = FALSE, ...)

Arguments

`mapping`	The aesthetic mapping, usually constructed with `aes` or `aes_string`. Only needs to be set at the layer level if you are overriding the plot defaults.
`data`	A layer specific dataset - only needed if you want to override the plot defaults.
`geom`	The geometric object to use display the data
`position`	The position adjustment to use for overlappling points on this layer
`type`	The type of ellipse. The default `"t"` assumes a multivariate t-distribution, and `"norm"` assumes a multivariate normal distribution. `"euclid"` draws a circle with the radius equal to `level`, representing the euclidian distance from the center. This ellipse probably won't appear circular unless `coord_fixed()` is applied.
`level`	The confidence level at which to draw an ellipse (default is 0.95), or, if `type="euclid"`, the radius of the circle to be drawn.
`segments`	The number of segments to be used in drawing the ellipse.
`na.rm`	If `FALSE` (the default), removes missing values with a warning. If `TRUE` silently removes missing values.
`...`	other arguments passed on to `layer`. This can include aesthetics whose values you want to set, not map. See `layer` for more details.

Details

The method for calculating the ellipses has been modified from car::ellipse (Fox and Weisberg, 2011)

References

John Fox and Sanford Weisberg (2011). An R Companion to Applied Regression, Second Edition. Thousand Oaks CA: Sage. URL: http://socserv.socsci.mcmaster.ca/jfox/Books/Companion

Examples

ggplot(faithful, aes(waiting, eruptions))+
  geom_point()+
  stat_ellipse()

ggplot(faithful, aes(waiting, eruptions, color = eruptions > 3))+
  geom_point()+
  stat_ellipse()

ggplot(faithful, aes(waiting, eruptions, color = eruptions > 3))+
  geom_point()+
  stat_ellipse(type = "norm", linetype = 2)+
  stat_ellipse(type = "t")

ggplot(faithful, aes(waiting, eruptions, color = eruptions > 3))+
  geom_point()+
  stat_ellipse(type = "norm", linetype = 2)+
  stat_ellipse(type = "euclid", level = 3)+
  coord_fixed()

ggplot(faithful, aes(waiting, eruptions, color = eruptions > 3))+
  stat_ellipse(geom = "polygon")

[Package ggplot2 version 1.0.1 Index]