def to_lon deg, format = :dms, dp = 0
      deg = deg.normalize_lng
      lon = Dms.to_dms deg, format, dp
      lon == '' ? '' : lon + (deg<0 ? 'W' : 'E')
    end
def to_lon deg, format = :dms, dp = 0
      deg = deg.normalize_lng
      lon = Dms.to_dms deg, format, dp
      lon == '' ? '' : lon + (deg<0 ? 'W' : 'E')
    end
Convert numeric degrees to deg/min/sec longitude (suffixed with E/W)

 @param   {Number} deg: Degrees
 @param   {String} [format=dms]: Return value as 'd', 'dm', 'dms'
 @param   {Number} [dp=0|2|4]: No of decimal places to use - default 0 for dms, 2 for dm, 4 for d
 @returns {String} Deg/min/seconds