def bounding_box(point, radius, options = {})
      lat,lon = extract_coordinates(point)
      radius  = radius.to_f
      [
        lat - (radius / latitude_degree_distance(options[:units])),
        lon - (radius / longitude_degree_distance(lat, options[:units])),
        lat + (radius / latitude_degree_distance(options[:units])),
        lon + (radius / longitude_degree_distance(lat, options[:units]))
      ]
    end
def bounding_box(point, radius, options = {})
      lat,lon = extract_coordinates(point)
      radius  = radius.to_f
      [
        lat - (radius / latitude_degree_distance(options[:units])),
        lon - (radius / longitude_degree_distance(lat, options[:units])),
        lat + (radius / latitude_degree_distance(options[:units])),
        lon + (radius / longitude_degree_distance(lat, options[:units]))
      ]
    end
Returns coordinates of the southwest and northeast corners of a box
 with the given point at its center. The radius is the shortest distance
 from the center point to any side of the box (the length of each side
 is twice the radius).

 This is useful for finding corner points of a map viewport, or for
 roughly limiting the possible solutions in a geo-spatial search
 (ActiveRecord queries use it thusly).

 See Geocoder::Calculations.distance_between for
 ways of specifying the point. Also accepts an options hash:

 * <tt>:units</tt> - <tt>:mi</tt> or <tt>:km</tt>.
   Use Geocoder.configure(:units => ...) to configure default units.