ggplot2: layer – R documentation

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layer

Create a new layer

Description

A layer is a combination of data, stat and geom with a potential position adjustment. Usually layers are created using geom_* or stat_* calls but it can also be created directly using this function.

Usage

layer(
  geom = NULL,
  stat = NULL,
  data = NULL,
  mapping = NULL,
  position = NULL,
  params = list(),
  inherit.aes = TRUE,
  check.aes = TRUE,
  check.param = TRUE,
  show.legend = NA,
  key_glyph = NULL,
  layer_class = Layer
)

Arguments

`geom`	The geometric object to use display the data
`stat`	The statistical transformation to use on the data for this layer, as a string.
`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)`).
`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.
`position`	Position adjustment, either as a string, or the result of a call to a position adjustment function.
`params`	Additional parameters to the `geom` and `stat`.
`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()`.
`check.aes, check.param`	If `TRUE`, the default, will check that supplied parameters and aesthetics are understood by the `geom` or `stat`. Use `FALSE` to suppress the checks.
`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.
`key_glyph`	A legend key drawing function or a string providing the function name minus the `draw_key_` prefix. See draw_key for details.
`layer_class`	The type of layer object to be constructued. This is intended for ggplot2 internal use only.

Examples

# geom calls are just a short cut for layer
ggplot(mpg, aes(displ, hwy)) + geom_point()
# shortcut for
ggplot(mpg, aes(displ, hwy)) +
  layer(geom = "point", stat = "identity", position = "identity",
    params = list(na.rm = FALSE)
  )

# use a function as data to plot a subset of global data
ggplot(mpg, aes(displ, hwy)) +
  layer(geom = "point", stat = "identity", position = "identity",
    data = head, params = list(na.rm = FALSE)
  )

ggplot2

Create Elegant Data Visualisations Using the Grammar of Graphics

v3.3.3

MIT + file LICENSE

Authors

Hadley Wickham [aut] (<https://orcid.org/0000-0003-4757-117X>), Winston Chang [aut] (<https://orcid.org/0000-0002-1576-2126>), Lionel Henry [aut], Thomas Lin Pedersen [aut, cre] (<https://orcid.org/0000-0002-5147-4711>), Kohske Takahashi [aut], Claus Wilke [aut] (<https://orcid.org/0000-0002-7470-9261>), Kara Woo [aut] (<https://orcid.org/0000-0002-5125-4188>), Hiroaki Yutani [aut] (<https://orcid.org/0000-0002-3385-7233>), Dewey Dunnington [aut] (<https://orcid.org/0000-0002-9415-4582>), RStudio [cph, fnd]

Initial release