Function produces the Convex Hull of the given geometry, the smallest convex polygon that contains all subgeometries

gConvexHull(spgeom, byid=FALSE, id = NULL)

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)

id

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

Details

Returns the convex hull as a SpatialPolygons object.

Author

Roger Bivand & Colin Rundel

Examples

x = readWKT(paste("POLYGON((0 40,10 50,0 60,40 60,40 100,50 90,60 100,60",
 "60,100 60,90 50,100 40,60 40,60 0,50 10,40 0,40 40,0 40))"))

ch = gConvexHull(x)

plot(x,col='blue',border='blue')
plot(ch,add=TRUE)