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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_sigma(imt):
 """ Return the value of the total sigma :param float imt: An :class:`openquake.hazardlib.imt.IMT` instance :returns: A float representing the total sigma value """

    if imt.period < 0.2:
        return np.log(10**0.23)
    elif imt.period > 1.0:
        return np.log(10**0.27)
    else:
        return np.log(10**(0.23 + (imt.period - 0.2)/0.8 * 0.04))