code: def qd2apex(self, qlat, qlon, height):
          
  
          alat, alon = self._qd2apex(qlat, qlon, height)
  
          # if array is returned, the dtype is object, so convert to float
          return np.float64(alat), np.float64(alon)
docs: Converts quasi-dipole to modified apex coordinates.
  
          Parameters
          ==========
          qlat : array_like
              Quasi-dipole latitude
          qlon : array_like
              Quasi-dipole longitude
          height : array_like
              Altitude in km
  
          Returns
          =======
          alat : ndarray or float
              Modified apex latitude
          alon : ndarray or float
              Modified apex longitude
  
          Raises
          ======
          ApexHeightError
              if apex height < reference height