bbox_to_poly function

Coerce a bounding box to a sfc POLYGON object

Create a sfc object from the coordinates of a bounding box.

bbox_to_poly(bbox = NA, xmin = NA, ymin = NA, xmax = NA, ymax = NA, crs = 4326)

Arguments

• bbox: Numeric vector of 4 elements representing the coordinates of the bounding box. Values should be c(xmin, ymin, xmax, ymax).
• xmin, ymin, xmax, ymax: Alternatively, you can use these named parameters instead of bbox.
• crs: coordinate reference system, something suitable as input to st_crs

Returns

A sfc object of class POLYGON.

Details

Bounding boxes can be located using different online tools, as Bounding Box Tool.

Examples

# bounding box of Germany
bbox_GER <- c(5.86631529, 47.27011137, 15.04193189, 55.09916098)

bbox_GER_sf <- bbox_to_poly(bbox_GER)

library(ggplot2)

ggplot(bbox_GER_sf) +
  geom_sf()

# Extract the bounding box of a sf object
sfobj <- geo_lite_sf("seychelles", points_only = FALSE)

sfobj

# Need at least one non-empty object
if (any(!sf::st_is_empty(sfobj))) {
  bbox <- sf::st_bbox(sfobj)

  bbox

  bbox_sfobj <- bbox_to_poly(bbox)

  ggplot(bbox_sfobj) +
    geom_sf(fill = "lightblue", alpha = 0.5) +
    geom_sf(data = sfobj, fill = "wheat")
}

See Also

sf::st_as_sfc() and sf::st_sfc().

Get sf objects: geo_address_lookup_sf(), geo_amenity_sf(), geo_lite_sf(), geo_lite_struct_sf(), reverse_geo_lite_sf()