ggplot2 layer for a delineation object

Creates a list of ggplot2::geom_sf() layers representing the delineation results of a delineation object. The list can be added to a ggplot2::ggplot() object with +, and further layers or themes can be added on top. Base layers (streets, railways, river_centerline, river_surface) are not included and can be added separately with ggplot2::geom_sf().

Usage

geom_delineation(x, extent = "corridor", legend = TRUE)

Arguments

x

An object of class delineation. This is typically the output of the delineate() function.

extent

The delineation layer whose bounding box sets the plot extent. One of "corridor", "valley", "riverspace", or NULL (no restriction, ggplot2 fits all layers). Defaults to "corridor".

legend

Whether the plot should display a legend. Default is TRUE.

Value

A list of ggplot2::geom_sf() and ggplot2::coord_sf() elements to be added to a ggplot2::ggplot() object.

Details

The following layers are included (where present in x), in the following order:

• corridor or riverspace (only when corridor is absent): drawn first to set the plot extent

• valley: light grey, transparent fill, no outlines

• segments: outlined polygons

• corridor: outlined polygon

See also

plot.delineation() for a base R alternative.

Examples

if (FALSE) { # interactive()
library(ggplot2)
bd <- delineate_city_river("Bucharest", "Dâmbovița")
ggplot() + geom_delineation(bd) + theme_void()
ggplot() + geom_delineation(bd, extent = "valley") + theme_void()
}