def _iter_info(self, niter, level=logging.INFO):
        """
        Log iteration number and mismatch

        Parameters
        ----------
        level
            logging level
        Returns
        -------
        None
        """
        max_mis = self.iter_mis[niter - 1]
        msg = ' Iter {:<d}.  max mismatch = {:8.7f}'.format(niter, max_mis)
        logger.info(msg)