Coerce a bounding box to a sfc POLYGON object

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

Usage

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

Value

A sfc object of class POLYGON.

Details

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

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()

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()

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

sfobj
#> Simple feature collection with 1 feature and 2 fields
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 45.99888 ymin: -10.46493 xmax: 56.49794 ymax: -3.512
#> Geodetic CRS:  WGS 84
#> # A tibble: 1 × 3
#>   query      address                                                    geometry
#> * <chr>      <chr>                                            <MULTIPOLYGON [°]>
#> 1 seychelles Sesel   (((45.99888 -9.401015, 46.00121 -9.427337, 46.00564 -9.456…

# 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")
}

# }