def convert_tau_sigma(y_data, ztau_sample):
    '''Converts normalized tau samples back to original scale SD.

    :Arguments:
    y_data: original predicted data list.
    ztau_sample: normalized tau parameter samples.

    '''
    z_sigma = 1 / np.sqrt(ztau_sample)
    y_sd = np.sqrt(np.var(y_data))
    sigma = z_sigma * y_sd
    return sigma
dataset/ETHPy150Open erikson84/BayesDataAnalysisWithPyMC/BayesDataAnalysisWithPymc/normalize.py/convert_tau_sigma/original