Read a GPX file. By default, it reads all possible GPX layers, and only returns shapes for layers that have any features. if the layer has any features a sp object is returned.
read_gpx(file, layers = c("waypoints", "tracks", "routes",
"track_points", "route_points"))
a GPX filename (including directory)
vector of GPX layers. Possible options are "waypoints"
, "tracks"
, "routes"
, "track_points"
, "route_points"
. By dedault, all those layers are read.