Constructing Voronoi diagram in PostGIS

Constructing Voronoi Diagrams in PostGIS: Making Spatial Analysis a Breeze

Ever wondered how to divide up a map based on what’s closest to a bunch of different points? That’s where Voronoi diagrams come in handy. Also known as Voronoi tessellations (try saying that three times fast!), these diagrams are super useful for all sorts of things, from figuring out the best spot for a new school to understanding how materials are structured. And the best part? PostGIS, the spatial extension for PostgreSQL, lets you create them with a nifty function called ST_VoronoiPolygons. Let’s dive in and see how it works!

Voronoi Diagrams: The Lowdown

So, what exactly is a Voronoi diagram? Imagine you have a bunch of dots scattered on a piece of paper. A Voronoi diagram basically draws boundaries around each dot, creating “cells.” Each cell contains all the spots on the paper that are closer to that dot than to any other. Think of it like dividing up territory based on who’s closest! The lines between the cells? Those are just the perpendicular bisectors of the lines connecting the dots. Simple, right?

Getting Your Hands Dirty: Creating Diagrams in PostGIS

PostGIS makes creating these diagrams surprisingly easy. The magic happens with the ST_VoronoiPolygons function. This function takes your points and spits out a collection of polygons, each representing a Voronoi cell.

The Syntax:

Here’s the basic rundown:

sql