layer(geom = NULL, stat = NULL, data = NULL, mapping = NULL, position = NULL, params = list(), inherit.aes = TRUE, subset = NULL, show.legend = NA)
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
fortifyfor which variables will be created. A
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.
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.
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.
NA, the default, includes if any aesthetics are mapped.
FALSEnever includes, and
A layer is a combination of data, stat and geom with a potential position
adjustment. Usually layers are created using
calls but it can also be created directly using this function.
# 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) )