I have a grid of points, each with a value to it as shown in the image below. The data was retrieved from PostGIS and rendered in Quantum GIS. The final result should be a polygons of a choropleth map that will be used to render on the browser.
Question: How can PostGIS use the grid of weighted points to create the choropleth polygons?
Polygons to be created in PostGIS, rendered in Leaflet. Classes group according to some rule like:
d > 1000 ? '#800026' : d > 500 ? '#BD0026' : d > 200 ? '#E31A1C' : d > 100 ? '#FC4E2A' : d > 50 ? '#FD8D3C' : d > 20 ? '#FEB24C' : d > 10 ? '#FED976' :