PostGIS
Description
Returns a version of the given geometry with duplicate consecutive points removed. The function processes only (Multi)LineStrings, (Multi)Polygons and MultiPoints but it can be called with any kind of geometry. Elements of GeometryCollections are processed individually. The endpoints of LineStrings are preserved.
If the `tolerance` parameter is provided, vertices within the tolerance distance of one another are considered to be duplicates.
Enhanced: 3.2.0
Availability: 2.2.0
This function
supports Polyhedral surfaces.
This function
supports 3d and will not drop the z-index.
Examples
SELECT ST_AsText( ST_RemoveRepeatedPoints( 'MULTIPOINT ((1 1), (2 2), (3 3), (2 2))'));
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MULTIPOINT(1 1,2 2,3 3)SELECT ST_AsText( ST_RemoveRepeatedPoints( 'LINESTRING (0 0, 0 0, 1 1, 0 0, 1 1, 2 2)'));
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LINESTRING(0 0,1 1,0 0,1 1,2 2)Example: Collection elements are processed individually.
SELECT ST_AsText( ST_RemoveRepeatedPoints( 'GEOMETRYCOLLECTION (LINESTRING (1 1, 2 2, 2 2, 3 3), POINT (4 4), POINT (4 4), POINT (5 5))'));
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GEOMETRYCOLLECTION(LINESTRING(1 1,2 2,3 3),POINT(4 4),POINT(4 4),POINT(5 5))Example: Repeated point removal with a distance tolerance.
SELECT ST_AsText( ST_RemoveRepeatedPoints( 'LINESTRING (0 0, 0 0, 1 1, 5 5, 1 1, 2 2)', 2));
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LINESTRING(0 0,5 5,2 2)