geom_chernoff {ggChernoff}

Chernoff faces in ggplot2

Description

The Chernoff geom is used to create data visualisations in the shape of human-like faces. By mapping to the relevant aesthetics, faces can appear to vary in happiness, anger, size, colour and so on.

Usage

geom_chernoff(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  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

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)).

stat

The statistical transformation to use on the data for this layer, either as a ggproto Geom subclass or as a string naming the stat stripped of the stat_ prefix (e.g. "count" rather than "stat_count")

position

Position adjustment, either as a string naming the adjustment (e.g. "jitter" to use 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.

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.

Value

A Geom layer object for use with ggplot2.

Aesthetics

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

• x

• y

• colour

• fill

• size

The following aesthetics are unique to geom_chernoff:

• smile

• brow

• nose

• eyes

For details, see chernoffGrob.

References

Chernoff, H. (1973). The use of faces to represent points in k-dimensional space graphically. Journal of the American Statistical Association, 68(342), 361–368.

See Also

chernoffGrob

Examples

library(ggplot2)
ggplot(iris, aes(Sepal.Width, Sepal.Length, smile = Petal.Length, fill = Species)) +
  geom_chernoff()

ggplot(data.frame(x = 1:4,
                  y = c(3:1, 2.5),
                  z = factor(1:4),
                  w = rnorm(4),
                  n = c(rep(FALSE, 3), TRUE)
                  )) +
    aes(x, y, fill = z, size = x, nose = n, smile = w) +
    geom_chernoff()