code: def check_init(yval, yl):
      Check initialization by comparing t=0 and t=end values"""
      suspect = []
      for var, label in zip(yval, yl):
          if abs(var[0] - var[-1]) >= 1e-6:
              suspect.append(label)
      if suspect:
          print('Initialization failure:')
          print(', '.join(suspect))
      else:
          print('Initialization is correct.')
docs: Check initialization by comparing t=0 and t=end values