Name
ST_ClusterWithinWin — Window function that returns a cluster id for each input geometry, clustering using separation distance.
Synopsis
integer ST_ClusterWithinWin(geometry winset geom, float8 distance);
Description
ST_ClusterWithinWin is a window function that returns an integer for each input geometry, where the integer the cluster number the geometry is a member of. Clusters represent a set of input geometries separated by no more than the specified distance. (Distances are Cartesian distances in the units of the SRID.)
ST_ClusterWithinWin is equivalent to running ST_ClusterDBSCAN with a `minpoints` of zero.
Availability: 3.4.0
This method supports Circular Strings and Curves
Examples
WITH testdata AS (
SELECT id, geom::geometry FROM (
VALUES (1, 'LINESTRING (0 0, 1 1)'),
(2, 'LINESTRING (5 5, 4 4)'),
(3, 'LINESTRING (6 6, 7 7)'),
(4, 'LINESTRING (0 0, -1 -1)'),
(5, 'POLYGON ((0 0, 4 0, 4 4, 0 4, 0 0))')) AS t(id, geom)
)
SELECT id,
ST_AsText(geom),
ST_ClusterWithinWin(geom, 1.4) OVER () AS cluster
FROM testdata;
id | st_astext | cluster
----+--------------------------------+---------
1 | LINESTRING(0 0,1 1) | 0
2 | LINESTRING(5 5,4 4) | 0
3 | LINESTRING(6 6,7 7) | 1
4 | LINESTRING(0 0,-1 -1) | 0
5 | POLYGON((0 0,4 0,4 4,0 4,0 0)) | 0