docs: def parse_square_param(line):
      """
      Parse the line from the .eff file that contains the efficiency function
      parameters for a 'square' function
      line : the line containt the parameters, must start with 'square_param'
      """
      if not line.startswith("square_param="):
          raise ValueError("Not a valid square_param line")
      values = line.split()
      params = {'sigma': float(values.pop()),
                'm0': float(values.pop()),
                'c': float(values.pop()),
                'eff_max': float(values.pop())
                }
      return params