ggforce: geom_ellipse – R documentation

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geom_ellipse

Draw (super)ellipses based on the coordinate system scale

Description

This is a generalisation of geom_circle() that allows you to draw ellipses at a specified angle and center relative to the coordinate system. Apart from letting you draw regular ellipsis, the stat is using the generalised formula for superellipses which can be utilised by setting the m1 and m2 aesthetics. If you only set the m1 the m2 value will follow that to ensure a symmetric appearance.

Usage

stat_ellip(
  mapping = NULL,
  data = NULL,
  geom = "circle",
  position = "identity",
  n = 360,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE,
  ...
)

geom_ellipse(
  mapping = NULL,
  data = NULL,
  stat = "ellip",
  position = "identity",
  n = 360,
  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), 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)`).
`geom`	The geometric object to use display the data
`position`	Position adjustment, either as a string, or the result of a call to a position adjustment function.
`n`	The number of points to sample along the ellipse.
`na.rm`	If `FALSE`, the default, missing values are removed with a warning. If `TRUE`, missing values are silently removed.
`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.
`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()`. 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.
`stat`	The statistical transformation to use on the data for this layer, as a string.

Aesthetics

geom_arc understand the following aesthetics (required aesthetics are in bold):

x0
y0
a
b
angle
m1
m2
color
fill
size
linetype
alpha
lineend

Computed variables

x, y: The coordinates for the points along the ellipse

Examples

# Basic usage
ggplot() +
  geom_ellipse(aes(x0 = 0, y0 = 0, a = 10, b = 3, angle = 0)) +
  coord_fixed()

# Rotation
# Note that it expects radians and rotates the ellipse counter-clockwise
ggplot() +
  geom_ellipse(aes(x0 = 0, y0 = 0, a = 10, b = 3, angle = pi / 4)) +
  coord_fixed()

# Draw a super ellipse
ggplot() +
  geom_ellipse(aes(x0 = 0, y0 = 0, a = 6, b = 3, angle = -pi / 3, m1 = 3)) +
  coord_fixed()

ggforce

Accelerating 'ggplot2'

v0.3.3

MIT + file LICENSE

Authors

Thomas Lin Pedersen [cre, aut] (<https://orcid.org/0000-0002-5147-4711>), RStudio [cph]

Initial release