code: def apex2qd(self, alat, alon, height):
          
  
          qlat, qlon = self._apex2qd(alat, alon, height)
  
          # if array is returned, the dtype is object, so convert to float
          return np.float64(qlat), np.float64(qlon)
docs: Converts modified apex to quasi-dipole coordinates.
  
          Parameters
          ==========
          alat : array_like
              Modified apex latitude
          alon : array_like
              Modified apex longitude
          height : array_like
              Altitude in km
  
          Returns
          =======
          qlat : ndarray or float
              Quasi-dipole latitude
          qlon : ndarray or float
              Quasi-dipole longitude
  
          Raises
          ======
          ApexHeightError
              if `height` > apex height