docs: def calc_exp_uncertainty(n, std, combined_unc, sys_unc, rel_unc=0.25,
                           confidence=0.95, mean=True):
      """Calculate expanded uncertainty.
  
      Parameters
      ----------
      n : Number of independent samples
      std : Sample standard deviation
      sys_unc : Systematic uncertainty (b in Coleman and Steele)
      rel_unc : Relative uncertainty of each systematic error source (guess 0.25)
      confidence : Confidence interval (0, 1)
      mean : bool whether or not the quantity is a mean value
  
      Returns
      -------
      exp_unc : Expanded uncertainty
      nu_x : Degrees of freedom
      """
      s_x = std
      if mean:
          s_x /= np.sqrt(n)
      nu_s_x = n - 1
      b = sys_unc
      nu_b = 0.5*rel_unc**(-2)
      nu_x = ((s_x**2 + b**2)**2)/(s_x**4/nu_s_x + b**4/nu_b)
      t = scipy.stats.t.interval(alpha=0.95, df=nu_x)[-1]
      exp_unc = t*combined_unc
      return exp_unc, nu_x