perimeter: Compute the perimeter of a longitude/latitude polygon
Description
Compute the perimeter of a polygon (or the length of a line) with longitude/latitude coordinates, on an ellipsoid (WGS84 by default)
Usage
# S4 method for matrix
perimeter(x, a=6378137, f=1/298.257223563, ...)
# S4 method for SpatialPolygons
perimeter(x, a=6378137, f=1/298.257223563, ...)
# S4 method for SpatialLines
perimeter(x, a=6378137, f=1/298.257223563, ...)
Value
Numeric. The perimeter or length in m.
Arguments
x
Longitude/latitude of the points forming a polygon or line; Must be a matrix of 2 columns (first one is longitude, second is latitude) or a SpatialPolygons* or SpatialLines* object
a
major (equatorial) radius of the ellipsoid. The default value is for WGS84
f
ellipsoid flattening. The default value is for WGS84
...
Additional arguments. None implemented
Author
This function calls GeographicLib code by C.F.F. Karney