Compute normal data ellipsesSource:
The method for calculating the ellipses has been modified from
car::dataEllipse (Fox and Weisberg 2011, Friendly and Monette 2013)
stat_ellipse( mapping = NULL, data = NULL, geom = "path", position = "identity", ..., type = "t", level = 0.95, segments = 51, na.rm = FALSE, show.legend = NA, inherit.aes = TRUE )
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
mappingif there is no plot mapping.
The data to be displayed in this layer. There are three options:
NULL, the default, the data is inherited from the plot data as specified in the call to
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.
functionwill 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
functioncan be created from a
~ head(.x, 10)).
The geometric object to use to display the data, either as a
Geomsubclass or as a string naming the geom stripped of the
Position adjustment, either as a string naming the adjustment (e.g.
position_jitter), or the result of a call to a position adjustment function. Use the latter if you need to change the settings of the adjustment.
Other arguments passed on to
layer(). These are often aesthetics, used to set an aesthetic to a fixed value, like
colour = "red"or
size = 3. They may also be parameters to the paired geom/stat.
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 euclidean distance from the center. This ellipse probably won't appear circular unless
The level at which to draw an ellipse, or, if
type="euclid", the radius of the circle to be drawn.
The number of segments to be used in drawing the ellipse.
FALSE, the default, missing values are removed with a warning. If
TRUE, missing values are silently removed.
logical. Should this layer be included in the legends?
NA, the default, includes if any aesthetics are mapped.
FALSEnever includes, and
TRUEalways includes. It can also be a named logical vector to finely select the aesthetics to display.
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.
John Fox and Sanford Weisberg (2011). An R Companion to Applied Regression, Second Edition. Thousand Oaks CA: Sage. URL: https://socialsciences.mcmaster.ca/jfox/Books/Companion/
Michael Friendly. Georges Monette. John Fox. "Elliptical Insights: Understanding Statistical Methods through Elliptical Geometry." Statist. Sci. 28 (1) 1 - 39, February 2013. URL: https://projecteuclid.org/journals/statistical-science/volume-28/issue-1/Elliptical-Insights-Understanding-Statistical-Methods-through-Elliptical-Geometry/10.1214/12-STS402.full
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, fill = eruptions > 3)) + stat_ellipse(geom = "polygon")