Convex Hull of Geometry — gConvexHull • rgeos

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

See also

gBoundary gCentroid gEnvelope gPointOnSurface

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)