Create a new layer

Usage

layer(geom = NULL, stat = NULL, data = NULL, mapping = NULL, position = NULL, params = list(), inherit.aes = TRUE, subset = NULL, show.legend = NA)

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.
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.
subset
DEPRECATED. An older way of subsetting the dataset used in a layer.
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.

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.

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) )