Geospatial · Areas and surfaces

Voronoi

Draws one area per point covering everywhere closer to it than to any other point, such as the nearest-store territory for every shop.

Also known as: Thiessen polygons

How it works

Pick the Point geometry column and a Mode. Planar (projected / regional), the default, builds the diagram on the flat plane and clips every region to a box slightly larger than the extent of the points; on lon/lat data it warns that the result is distorted, so reproject upstream or switch mode. Spherical (global lon/lat) builds the regions on the sphere, needs geographic coordinates and the scipy package in the project venv. Each row keeps its columns and its geometry column now holds the region instead of the point. A row whose geometry is not a point stops the run.

Inputs and outputs

Settings

{
  geometryColumn: string
  mode: "planar"|"spherical"
}

Example

You want a nearest-store territory for every shop in a city, with the stores in a projected CRS. Set Point geometry column to geometry and Mode to Planar, then Spatial Join customers to the territories to see which store each one is closest to.

More in Areas and surfaces

• Trade Areas — Builds catchment areas around each location: distance rings, drive-time bands, areas traced from demand, or rings cut into sectors.
• Gravity Model — Splits each area's demand between the locations in range by their attractiveness and distance (the Huff model). Gives the demand each location captures, such as a new store's sales and what it takes from the others, the top location per area, or a probability for every area and location.
• Calibrate Gravity Model — Fits the Gravity Model's attractiveness and distance-decay settings to what customers actually did, such as loyalty-card visits per area and store, and reports how well the fit reproduces each store.
• H3 Aggregate — Puts features into hexagon cells of a chosen size and summarizes each cell, for an even grid on density maps.
• Spatial Interpolate — Estimates a smooth surface from measured sample points, on a hexagon or square grid. For example, a pollution surface from sensors.