Geoff is a collection of JavaScript functions for working with GeoJSON objects. More generally, it's a library that eases the creation and manipulation of geographic geometries, and makes doing some things in Polymaps shockingly easy.


Show the extent of one Polymap on another

In this example we use geoff.extent() to draw the visible bounds of the map on the left onto the map on the right.


In these examples we use geoff.extent() to get the rectangular bounds of a GeoJSON Polygon feature loaded in this file, then use geoff.buffer() to add an outer ring to its geometry, which produces a "knock-out" drawing effect in SVG.