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);

Descrizione

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

Esempi

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;

Si veda anche

ST_DumpPoints