STConvexHull (geography Data Type)
Returns an object that represents the convex hull of a geography instance.
A. Using STConvexHull() on an uninitialized geography instance
The following example uses STConvexHull() on an uninitialized geography instance.
DECLARE @g geography;
SELECT @g.STConvexHull();
B. Using STConvexHull on an empty geography instance
The following example uses STConvexHull() on an empty Polygon instance.
DECLARE @g geography = 'POLYGON EMPTY';
SELECT @g.STConvexHull().ToString();
C. Finding the convex hull of a non-convex Polygon instance
The following example uses STConvexHull() to find the convex hull of a non-convex Polygon instance.
DECLARE @g geography;
SET @g = geography::Parse('POLYGON((-120.533 46.566, -118.283 46.1, -122.3 47.45, -120.533 46.566))');
SELECT @g.STConvexHull().ToString();
D. Finding the convex hull on a geography instance with an envelope angle larger than 90 degrees
The following example uses STConvexHull() on a geography instance with an envelope angle larger than 90 degrees.
DECLARE @g geography = 'POLYGON((20.533 46.566, -18.283 46.1, -22.3 47.45, 20.533 46.566))';
SELECT @g.STConvexHull().ToString();
