Calculates the area of the given geometry.

`gArea(spgeom, byid=FALSE)`

## Arguments

- spgeom
sp object as defined in package sp

- byid
Logical determining if the function should be applied across subgeometries (TRUE) or the entire object (FALSE)

## Value

Returns the area of the geometry in the units of the current projection. By definition non-[MULTI]POLYGON geometries have an area of 0. The area of a POLYGON is the area of its shell less the area of any holes. Note that this value may be different from the `area`

slot of the `Polygons`

class as this value does not subtract the area of any holes in the geometry.

## Author

Roger Bivand & Colin Rundel

## Examples

```
gArea(readWKT("POINT(1 1)"))
#> [1] 0
gArea(readWKT("LINESTRING(0 0,1 1,2 2)"))
#> [1] 0
gArea(readWKT("LINEARRING(0 0,3 0,3 3,0 3,0 0)"))
#> [1] 0
p1 = readWKT("POLYGON((0 0,3 0,3 3,0 3,0 0))")
p2 = readWKT("POLYGON((0 0,3 0,3 3,0 3,0 0),(1 1,2 1,2 2,1 2,1 1))")
gArea(p1)
#> [1] 9
p1@polygons[[1]]@area
#> [1] 9
gArea(p2)
#> [1] 8
p2@polygons[[1]]@area
#> [1] 9
```