Created by Christopher Manning
This is a map of the Chicago Wards that demonstrates how to use the JSTS Topology Suite and D3.js to find and display intersections between polygons.
Wards shaded grey are scanned since their bounding boxes intersect with the search envelope and wards shaded blue intersect with the search polygon.
A Sort-Tile-Recursive R-tree is used to spatially index the wards and efficently query the polygons for intersections.