Create a new layer
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.
layer(geom = NULL, stat = NULL, data = NULL, mapping = NULL, position = NULL, params = list(), inherit.aes = TRUE, check.aes = TRUE, check.param = TRUE, subset = NULL, show.legend = NA)
- The geometric object to use display the data
- The statistical transformation to use on the data for this layer, as a string.
- The data to be displayed in this layer. There are three
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.
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.
- Set of aesthetic mappings created by
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.
- Position adjustment, either as a string, or the result of a call to a position adjustment function.
- Additional parameters to the
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.
- check.aes, check.param
TRUE, the default, will check that supplied parameters and aesthetics are understood by the
FALSEto suppress the checks.
- DEPRECATED. An older way of subsetting the dataset used in a layer.
- logical. Should this layer be included in the legends?
NA, the default, includes if any aesthetics are mapped.
FALSEnever includes, and
# 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) )