bb2bbox function

Convert a bb specification to a bbox specification

In ggmap, all maps (class ggmap) have the bb attribute, a data frame bounding box specification in terms of the bottom left and top right points of the spatial extent. This function converts this specification to a named double vector (with names left, bottom, right, top) specification that is used in some querying functions (e.g. get_stadiamap).

bb2bbox(bb)

Arguments

• bb: a bounding box in bb format (see examples)

Returns

a bounding box in bbox format (see examples)

Examples

## Not run:
# cut down on R CMD check time

# grab a center/zoom map and compute its bounding box
gc <- geocode("white house, washington dc")
map <- get_map(gc)
(bb <- attr(map, "bb"))
(bbox <- bb2bbox(bb))

# use the bounding box to get a Stadia map
stadMap <- get_stadiamap(bbox)

ggmap(map) +
  geom_point(
    aes(x = lon, y = lat),
    data = gc, colour = "red", size = 3
  )

ggmap(stadMap) +
  geom_point(
    aes(x = lon, y = lat),
    data = gc, colour = "red", size = 3
  )
## End(Not run)

Author(s)

David Kahle david@kahle.io