random

CORE
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.
warning
It never generates more than the requested number of points, but there is a small chance of generating less points.
geog: GEOGRAPHY a polygon; the random points generated will be inside this polygon.
npoints: INT number of points to generate.
Constraints
npoints must not exceed 100000.
Return type
ARRAY
Example
SELECT CARTO.CARTO.ST_GENERATEPOINTS(TO_GEOGRAPHY('POLYGON((0 0, 10 0, 10 10, 0 0))'), 100);
-- "{\"coordinates\":[6.781385759749447e+00,9.240795947965740e-01],\"type\":\"Point\"}"
-- "{\"coordinates\":[9.993805698147805e+00,5.083022246239731e+00],\"type\":\"Point\"}"
-- "{\"coordinates\":[3.228015360947772e+00,5.353450085600810e-01],\"type\":\"Point\"}"
-- ...
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Last modified 6mo ago