code: def in_pixels(lon,lat,pixels,nside):
      
      pix = ang2pix(nside,lon,lat)
      return np.in1d(pix,pixels)
docs: Check if (lon,lat) in pixel list. Assumes RING formatting.
  
      Parameters:
      -----------
      lon    : longitude (deg)
      lat    : latitude (deg)
      pixels : pixel list [RING format] to check for inclusion
      nside  : nside of pixel list 
  
      Returns:
      --------
      inpix : boolean array for inclusion