def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types):
        """
        See :meth:`superclass method
        <.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
        for spec of input and result values.
        """
        assert all(stddev_type in self.DEFINED_FOR_STANDARD_DEVIATION_TYPES
                   for stddev_type in stddev_types)

        C = self.COEFFS[imt]
        mean = self._compute_mean(C, rup.mag, dists.rrup)
        if isinstance(imt, SA) or isinstance(imt, PGA):
            # Convert from m/s**2 to g
            mean = mean - np.log(g)
        elif isinstance(imt, PGV):  # Convert from m/s to cm/s
            mean = mean + np.log(100.0)
        stddevs = self._get_stddevs(C, stddev_types, rup.mag,
                                    dists.rrup.shape[0])

        return mean, stddevs
See :meth:`superclass method
        <.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
        for spec of input and result values.