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ST_ConvexHull

Signatures

GEOMETRY ST_ConvexHull(GEOMETRY geom)

Description

Computes the smallest convex POLYGON that contains all the points of geom. geom can be a set of POINTs, LINESTRINGs, POLYGONs or a GEOMETRYCOLLECTION.

Implements the OpenGIS Simple Features Implementation Specification for SQL version 1.2.1.

Examples

SELECT ST_ConvexHull('GEOMETRYCOLLECTION(
                        POINT(1 2),
                        LINESTRING(1 4, 4 7),
                        POLYGON((3 1, 7 1, 7 6, 3 1)))');

-- Answer: POLYGON((3 1, 7 1, 7 6, 4 7, 1 4, 1 2, 3 1))

See also