random

This module contains functions to generate random geographies.

ST_GENERATEPOINTS

ST_GENERATEPOINTS(geog, npoints)

Description

Generates randomly placed points inside a polygon and returns them in an array of geographies.

The distribution of the generated points is spherically uniform (i.e. if the coordinates are interpreted as longitude and latitude on a sphere); this means that WGS84 coordinates will be only approximately uniformly distributed, since WGS84 is based on an ellipsoidal model.

Input parameters

• geog: GEOMETRY a polygon; the random points generated will be inside this polygon.

• npoints: INT number of points to generate.

Constraints

npoints must not exceed 1000.

Return type

VARCHAR(MAX)

Example

SELECT carto.ST_GENERATEPOINTS(ST_GEOMFROMTEXT('POLYGON((0 0, 10 0, 10 10, 0 0))'), 100);
-- {"type": "MultiPoint", "coordinates": [[8.383157939015296, 1.062699131285872], ...