code: def reccyl(rectan):
      
      rectan = stypes.toDoubleVector(rectan)
      radius = ctypes.c_double(0)
      lon = ctypes.c_double(0)
      z = ctypes.c_double(0)
      libspice.reccyl_c(rectan, ctypes.byref(radius), ctypes.byref(lon),
                        ctypes.byref(z))
      return radius.value, lon.value, z.value
docs: Convert from rectangular to cylindrical coordinates.
  
      http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/reccyl_c.html
  
      :param rectan: Rectangular coordinates of a point.
      :type rectan: 3-Element Array of floats
      :return:
              Distance from z axis,
              Angle (radians) from xZ plane,
              Height above xY plane.
      :rtype: tuple