title: LatLong falls within a given polygon in D3 + Leaflet
body: <p>I am trying to learn how to use the Javascript library <a href="http://leafletjs.com/" rel="nofollow">leaflet</a> along with <a href="http://d3js.org/" rel="nofollow">d3</a> to create various map visualisations.</p>
  
  <p>I have been following <a href="http://leafletjs.com/examples/choropleth.html" rel="nofollow">this tutorial</a> which creates a choropleth map of the United States with some interactivity. This provides some of what I need, but the main functionality I want is to have a list of lat/long coordinates classified according to which region they belong to.</p>
  
  <p>This would mean, in the tutorial map for example, if I had a lat long value (55, -3) which fell within the state of Arizona's polygon, the program could classify this point as belonging to Arizona.</p>
  
  <p>Is there a function in the leaflet (or d3) library which will allow me to enter a lat long coordinate as a parameter and return the name of the feature it belongs to? The tutorial above allows you to attach a function to every feature via the onEveryFeature property and can fire mouseover events when each feature is hovered over. Surely there is a way to extend this functionality to numerically entered data instead of mouse points?</p>