rgeos (version 0.3-5)

gSymdifference: Geometry Symmetric Difference

Description

Function for determining the symmetric difference between the two given geometries

Usage

gSymdifference(spgeom1, spgeom2, byid=FALSE, id=NULL, drop_not_poly=FALSE)

Arguments

spgeom1, spgeom2

sp objects as defined in package sp

byid

Logical vector determining if the function should be applied across ids (TRUE) or the entire object (FALSE) for spgeom1 and spgeom2

id

Character vector defining id labels for the resulting geometries, if unspecified returned geometries will be labeled based on their parent geometries' labels.

drop_not_poly

default FALSE, if TRUE and spgeom1, spgeom2 both inherit from SpatialPolygons, POINT and LINESTRING objects will be dropped from output GEOMETRYCOLLECTION objects to simplify output.

Details

Returns the regions of spgeom1 and spgeom2 that do not intersect. If the geometries do not intersect then spgeom1 and spgeom2 will be returned as separate subgeometries.

See Also

gDifference gIntersection gUnion

Examples

x = readWKT("POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))")
y = readWKT("POLYGON ((5 5, 15 5, 15 15, 5 15, 5 5))")

d = gSymdifference(x,y)
plot(d,col='red',pbg='white')