Get a coatline for any region on Earth.
coastline(extent = NULL, ..., dimension = c(1024, 1024), projection = NULL)Arguments
- extent
extent xmin, xmax, ymin, ymax
- ...
argumetns passed to [elevation()]
- dimension
optional size of matrix to contour (a default is used)
- projection
provide this for custom extents in a given projection
Value
matrix of coordinates in longlat (or whatever projection is specified)
Details
This uses the [elevation()] function to get a coastline by contouring elevation data at 0. (This might return nothing.)
For 'extent' not provided it will be derived from a plot extent if one exists. It's the user's job to ensure the projection is appropriate (we don't have a graphics mechanism to record a current projection string.)
If no device is open and no extent given, a coastline for longlat is given.
