signed_area {rsgeo} | R Documentation |
Calculate the area of a polygon
Description
Functions to calculate different types of area for polygons.
Usage
signed_area(x)
unsigned_area(x)
signed_area_cd(x)
unsigned_area_cd(x)
signed_area_geodesic(x)
unsigned_area_geodesic(x)
Arguments
x |
an object of class |
Details
functions assume counter clock-wise winding in accordance with the simple feature access standard
functions ending in
_cd
use the Chamberlain-Duquette algorithm for spherical areaChamberlain-Duquette and Geodesic areas are returned in meters squared and assume non-planar geometries
See geo docs for more:
Value
a numeric vector of the area contained by the geometry
Examples
x <- c(0, 1, 1, 0, 0)
y <- c(0, 0, 1, 1, 0)
p <- geom_polygon(x, y)
signed_area(p)
unsigned_area(p)
signed_area_cd(p)
unsigned_area_cd(p)
signed_area_geodesic(p)
unsigned_area_geodesic(p)
[Package rsgeo version 0.1.6 Index]