code: def build_delta_t_table(delta_t_recent):
      
      ancient = load_bundled_npy('morrison_stephenson_deltat.npy')
      historic = load_bundled_npy('historic_deltat.npy')
  
      # Prefer USNO over Morrison and Stephenson where they overlap.
      historic_start_time = historic[0,0]
      i = searchsorted(ancient[0], historic_start_time)
      bundled = concatenate([ancient[:,:i], historic], axis=1)
  
      # Let recent data replace everything else.
      recent_start_time = delta_t_recent[0,0]
      i = searchsorted(bundled[0], recent_start_time)
      row = ((0,),(0,))
      table = concatenate([row, bundled[:,:i], delta_t_recent, row], axis=1)
  
      # Create initial and final point to provide continuity with formula.
      century = 36524.0
      start = table[0,1] - century
      table[:,0] = start, delta_t_formula_morrison_and_stephenson_2004(start)
      end = table[0,-2] + century
      table[:,-1] = end, delta_t_formula_morrison_and_stephenson_2004(end)
      return table
docs: Build a table for interpolating Delta T.
  
      Given a 2xN array of recent Delta T values, whose element 0 is a
      sorted array of TT Julian dates and element 1 is Delta T values,
      this routine returns a more complete table by prepending two
      built-in data sources that ship with Skyfield as pre-built arrays:
  
      * The historical values from Morrison and Stephenson (2004) which
        the http://eclipse.gsfc.nasa.gov/SEcat5/deltat.html NASA web page
        presents in an HTML table.
  
      * The United States Naval Observatory ``historic_deltat.data``
        values for Delta T over the years 1657 through 1984.