H2GIS

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ST_MinimumDiameter

Signature

LINESTRING ST_MinimumDiameter(GEOMETRY geom);

Description

Returns the minimum diameter of geom, defined to be the width of the smallest band that contains the geometry, where a band is a strip of the plane defined by two parallel lines. This can be thought of as the smallest hole that the geometry can be moved through, with a single rotation.

Examples

SELECT ST_MinimumDiameter('POINT(395 278)');
-- Answer: LINESTRING(395 278, 395 278)

SELECT ST_MinimumDiameter('LINESTRING(0 0, 1 1, 3 9, 7 1)');
-- Answer: LINESTRING(1 3, 7 1)

SELECT ST_MinimumDiameter(
            'POLYGON((360 380, 230 150, 370 100, 510 100,
                      517 110, 650 390, 430 220, 360 380))');
-- Answer: LINESTRING(282.35 242.62, 517 110)

SELECT ST_MinimumDiameter(
            'GEOMETRYCOLLECTION(
                POLYGON((1 2, 4 2, 4 6, 1 6, 1 2)),
                LINESTRING(2 6, 6 2),
                MULTIPOINT((4 4), (1 1), (1 0), (0 3)))');
-- Answer: LINESTRING(5.8 2.4, 1 0)

See also