code: def latcyl(radius, lon, lat):
      
      radius = ctypes.c_double(radius)
      lon = ctypes.c_double(lon)
      lat = ctypes.c_double(lat)
      r = ctypes.c_double()
      lonc = ctypes.c_double()
      z = ctypes.c_double()
      libspice.latcyl_c(radius, lon, lat, ctypes.byref(r), ctypes.byref(lonc),
                        ctypes.byref(z))
      return r.value, lonc.value, z.value
docs: Convert from latitudinal coordinates to cylindrical coordinates.
  
      http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/latcyl_c.html
  
      :param radius: Distance of a point from the origin.
      :type radius:
      :param lon: Angle of the point from the XZ plane in radians.
      :param lat: Angle of the point from the XY plane in radians.
      :return: (r, lonc, z)
      :rtype: tuple