Return ln(QMED) model errors for a list of catchments

        :param catchments: List of gauged catchments
        :type catchments: list of :class:`Catchment`
        :return: Model errors
        :rtype: list of float

def _vec_lnqmed_residuals(self, catchments):
        """
        Return ln(QMED) model errors for a list of catchments

        :param catchments: List of gauged catchments
        :type catchments: list of :class:`Catchment`
        :return: Model errors
        :rtype: list of float
        """
        result = np.empty(len(catchments))
        for index, donor in enumerate(catchments):
            result[index] = self._lnqmed_residual(donor)
        return result