@classmethod
def from_mat_file(cls, file_name, cont_time=True, state_id='STATE',
    solver_options=None, estimator=None, visualizer=None, cache_region=
    'memory', name=None):
    """Create |LTIModel| from matrices stored in a .mat file.

        Parameters
        ----------
        file_name
            The name of the .mat file (extension .mat does not need to be included) containing A, B,
            C, and optionally D and E.
        cont_time
            `True` if the system is continuous-time, otherwise `False`.
        state_id
            Id of the state space.
        solver_options
            The solver options to use to solve the Lyapunov equations.
        estimator
            An error estimator for the problem. This can be any object with an
            `estimate(U, mu, model)` method. If `estimator` is not `None`, an `estimate(U, mu)`
            method is added to the model which will call `estimator.estimate(U, mu, self)`.
        visualizer
            A visualizer for the problem. This can be any object with a `visualize(U, model, ...)`
            method. If `visualizer` is not `None`, a `visualize(U, *args, **kwargs)` method is added
            to the model which forwards its arguments to the visualizer's `visualize` method.
        cache_region
            `None` or name of the cache region to use. See :mod:`pymor.core.cache`.
        name
            Name of the system.

        Returns
        -------
        lti
            The |LTIModel| with operators A, B, C, D, and E.
        """
    import scipy.io as spio
    mat_dict = spio.loadmat(file_name)
    assert 'A' in mat_dict and 'B' in mat_dict and 'C' in mat_dict
    A = mat_dict['A']
    B = mat_dict['B']
    C = mat_dict['C']
    D = mat_dict['D'] if 'D' in mat_dict else None
    E = mat_dict['E'] if 'E' in mat_dict else None
    return cls.from_matrices(A, B, C, D, E, cont_time=cont_time, state_id=
        state_id, solver_options=solver_options, estimator=estimator,
        visualizer=visualizer, cache_region=cache_region, name=name)
