H2GIS

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ST_ShortestLine

Signatures

GEOMETRY ST_ShortestLine(GEOMETRY geomA, GEOMETRY geomB);

Description

Returns the 2-dimensional shortest LINESTRING between two geometries (geomA and geomB).

The function will only return the first shortest LINESTRING if more than one, that the function finds.

Examples

Cases with one solution

SELECT ST_ShortestLine('POINT(1 2)',
                       'LINESTRING(0 0, 4 2)') as THE_GEOM;
-- Answer: LINESTRING (1 2, 1.6 0.8)

SELECT ST_ShortestLine('POINT(1 2)',
                       'MULTILINESTRING ((0 0, 4 2), (1 4, 2 2))') as THE_GEOM;
-- Answer: LINESTRING (1 2, 1.8 2.4) 

SELECT ST_ShortestLine('POINT(4 3)',
                       'LINESTRING(0 0, 4 2)') as THE_GEOM;
-- Answer: LINESTRING (4 3, 4 2)  

SELECT ST_ShortestLine('POINT(4 3)',
                       'POLYGON ((2 4, 0 2, 3 0, 2 4))') as THE_GEOM;
-- Answer: LINESTRING (4 3, 2.353 2.5882)

Case with two possible solutions

SELECT ST_ShortestLine('POINT(2 2)',
                       'MULTILINESTRING ((1 1, 4 1), (1 3, 4 3))') as THE_GEOM;
-- Answer: LINESTRING (2 2, 2 1)

See also