crankshaft/doc/09_voronoi.md

Voronoi

Function to construct the Voronoi Diagram from a dataset of scatter points, clipped to the significant area

PostGIS wil include this in future versions (doc for dev branch) and will perform faster for sure, but in the meantime...

CDB_Voronoi (geom geometry[], buffer numeric DEFAULT 0.5, tolerance numeric DEFAULT 1e-9)

Arguments

Name	Type	Description
geom	geometry[]	Array of points's geometries
buffer	numeric	enlargment ratio for the envelope area used for the restraints
tolerance	numeric	Delaunay tolerance, optional

Returns

Column Name	Type	Description
geom	geometry collection	Collection of polygons of the Voronoi cells

Example Usage

WITH a AS (
    SELECT
        ARRAY[
            ST_GeomFromText('POINT(2.1744 41.403)', 4326),
            ST_GeomFromText('POINT(2.1228 41.380)', 4326),
            ST_GeomFromText('POINT(2.1511 41.374)', 4326),
            ST_GeomFromText('POINT(2.1528 41.413)', 4326),
            ST_GeomFromText('POINT(2.165 41.391)', 4326),
            ST_GeomFromText('POINT(2.1498 41.371)', 4326),
            ST_GeomFromText('POINT(2.1533 41.368)', 4326),
            ST_GeomFromText('POINT(2.131386 41.41399)', 4326)
        ] AS geomin
)
SELECT
    ST_TRANSFORM(
        (ST_Dump(cdb_crankshaft.CDB_Voronoi(geomin, 0.2, 1e-9))).geom,
        3857) as the_geom_webmercator
FROM a;