Name
ST_GeneratePoints — Generates a multipoint of random points contained in a Polygon or MultiPolygon.
Synopsis
geometry
ST_GeneratePoints
(
geometry
g
, integer
npoints
, integer
seed = 0
)
;
Description
ST_GeneratePoints generates a multipoint consisting of a given number of pseudo-random points
which lie within the input area.
The optional
seed
is used to regenerate a deterministic sequence of points,
and must be greater than zero.
Availability: 2.3.0
Enhanced: 3.0.0, added seed parameter
Examples
Generated a multipoint consisting of 12 Points overlaid on top of original polygon using a random seed value 1996
SELECT ST_GeneratePoints(geom, 12, 1996)
FROM (
SELECT ST_Buffer(
ST_GeomFromText(
'LINESTRING(50 50,150 150,150 50)'),
10, 'endcap=round join=round') AS geom
) AS s;
Given a table of polygons s, return 12 individual points per polygon. Results will be different each time you run.
SELECT s.id, dp.path[1] AS pt_id, dp.geom FROM s, ST_DumpPoints(ST_GeneratePoints(s.geom,12)) AS dp;