code: def _smooth_hpx_map(hpx_map, sigma):
          
          if hpx_map.hpx.ordering == "NESTED":
              ring_map = hpx_map.swap_scheme()
          else:
              ring_map = hpx_map
          ring_data = ring_map.data.copy()
          nebins = len(hpx_map.data)
          smoothed_data = np.zeros((hpx_map.data.shape))
          for i in range(nebins):
              smoothed_data[i] = healpy.sphtfunc.smoothing(
                  ring_data[i], sigma=np.radians(sigma), verbose=False)
  
          smoothed_data.clip(0., 1e99)
          smoothed_ring_map = HpxMap(smoothed_data, ring_map.hpx)
          if hpx_map.hpx.ordering == "NESTED":
              return smoothed_ring_map.swap_scheme()
          return smoothed_ring_map
docs: Smooth a healpix map using a Gaussian