Takes a geographic object or bounding box as an input and outputs a bounding box, represented as a bounding box, corner points or rectangular polygon.
geo_bb(
shp,
scale_factor = 1,
distance = 0,
output = c("polygon", "points", "bb")
)Arguments
- shp
Spatial object (from sf or sp packages)
- scale_factor
Numeric vector determining how much the bounding box will grow or shrink. Two numbers refer to extending the bounding box in x and y dimensions, respectively. If the value is 1, the output size will be the same as the input.
- distance
Distance in metres to extend the bounding box by
- output
Type of object returned (polygon by default)
See also
bb_scale
Other geo:
bbox_scale(),
geo_bb_matrix(),
quadrant(),
reproject()
Examples
# Simple features implementation:
shp <- routes_fast_sf
shp_bb <- geo_bb(shp, distance = 100)
#> Assuming a geographical (lat/lon) CRS (EPSG:4326)
#> Transforming to CRS +proj=aeqd +lat_0=53.816446 +lon_0=-1.5309755 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs
#> Warning: CRS object has comment, which is lost in output; in tests, see
#> https://cran.r-project.org/web/packages/sp/vignettes/CRS_warnings.html
plot(shp_bb, col = "red", reset = FALSE)
plot(geo_bb(routes_fast_sf, scale_factor = 0.8), col = "green", add = TRUE)
plot(geo_bb(routes_fast_sf, output = "points"), add = TRUE)
plot(routes_fast_sf$geometry, add = TRUE)
