docs: def index_lonlat_in_pixels(lon,lat,pixels,nside,sort=False,outside=-1):
      """
      Find the indices of a set of angles into a set of pixels
  
      Parameters:
      -----------
      pix    : set of search pixels
      pixels : set of reference pixels
    
      Returns:
      --------
      index : index into the reference pixels
      """
  
      pix = ang2pix(nside,lon,lat)
      return index_pix_in_pixels(pix,pixels,sort,outside)