Circular insets

Circular insets

Usage

shape_circle(centre, radius)

Arguments

centre

Coordinates of the inset centre. Ideally this should be an sfc object (see sf::st_sfc()) including a coordinate reference system. An sf::st_point() or a vector of longitude and latitude are also accepted. If a CRS cannot be determined, WGS 84 is assumed.

radius

Radius of the inset circle in the units of the inset's crs_working.

Value

A shape definition suitable for use with configure_inset().

See also

configure_inset()

Other shapes: shape_rectangle(), shape_sf()

Examples

library(ggplot2)
nc <- sf::st_read(system.file("shape/nc.shp", package = "sf"), quiet = TRUE)
make_demo <- function(...) {
  ggplot(nc) +
    geom_sf(fill = "grey95", colour = "grey85") +
    # For a filled frame, we want to interleave it between the base layer
    # (above this line) and the target layer (below the following line).
    geom_inset_frame(target.aes = list(fill = "white")) +
    geom_sf_inset(map_base = "none") +
    coord_sf_inset(inset = configure_inset(...)) +
    theme_void()
}
circle <- shape_circle(sf::st_centroid(nc[21,]), radius = 50)
#> Warning: st_centroid assumes attributes are constant over geometries

make_demo(circle, scale = 3, translation = c(-200, -200))

make_demo(circle, scale = 3, translation = c(-100, -100))

make_demo(circle, scale = 3, translation = c(0, 0))

make_demo(circle, scale = 0.5, translation = c(0, 0))