Data.Geometry.Geos.Topology

Documentation

envelope :: Geometry a -> Some Geometry

Returns a Polygon that represents the bounding envelope of this geometry. Note that it can also return a Point if the input geometry is a point.

intersection :: Geometry a -> Geometry b -> Some Geometry

Returns a Geometry representing the points shared by both geometries.

convexHull :: Geometry a -> Geometry Polygon

Returns the smallest Polygon that contains all the points in the geometry.

difference :: Geometry a -> Geometry b -> Some Geometry

Returns a Geometry representing the points making up this geometry that do not make up other.

symmetricDifference :: Geometry a -> Geometry b -> Some Geometry

Returns a Geometry combining the points in this geometry not in other, and the points in other not in this geometry.

boundary :: Geometry a -> Some Geometry

union :: Geometry a -> Geometry b -> Some Geometry

Returns a Geometry representing all the points in both geometries.

Computes the union of all the elements of this geometry. Heterogeneous GeometryCollections are fully supported.

The result obeys the following contract:

Unioning a set of LineStrings has the effect of fully noding and dissolving the linework. Unioning a set of Polygons will always return a Polygonal geometry (unlike {link #union(Geometry)}, which may return geometrys of lower dimension if a topology collapse occurred.

unaryUnion :: Geometry a -> Some Geometry

pointOnSurface :: Geometry a -> Geometry Point

Computes and returns a Point guaranteed to be on the interior of this geometry.

centroid :: Geometry a -> Geometry Point

Returns a Point object representing the geometric center of the geometry. The point is not guaranteed to be on the interior of the geometry.

node :: Geometry a -> Some Geometry

delaunayTriangulation :: Geometry a -> Double -> Geometry MultiLineString

Return a Delaunay triangulation of the vertex of the given geometry g, where tol is the snapping tolerance to use.