def distance_from(lat, long)
      dLat = self.degrees_to_radians(lat - self.latitude)
      dLon = self.degrees_to_radians(long - self.longitude)

      lat1 = self.degrees_to_radians(lat)
      lat2 = self.degrees_to_radians(self.latitude)

      a = Math.sin(dLat / 2) * Math.sin(dLat / 2) +
          Math.sin(dLon / 2) * Math.sin(dLon / 2) *
          Math.cos(lat1) * Math.cos(lat2)

      c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a))

      EARTH_RADIUS * c
    end
def distance_from(lat, long)
      dLat = self.degrees_to_radians(lat - self.latitude)
      dLon = self.degrees_to_radians(long - self.longitude)

      lat1 = self.degrees_to_radians(lat)
      lat2 = self.degrees_to_radians(self.latitude)

      a = Math.sin(dLat / 2) * Math.sin(dLat / 2) +
          Math.sin(dLon / 2) * Math.sin(dLon / 2) *
          Math.cos(lat1) * Math.cos(lat2)

      c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a))

      EARTH_RADIUS * c
    end
Returns the distance this object is from the given
 latitude and longitude.  Distance is as the crow flies.

 @param  lat [Float] [A latitude position]
 @param  long [Float] [A longitude position]

 @return [Float] [Distance from the input postion in miles]