@classmethod
def create_from_file(cls, filename):
    """Read initdata and spectral data from file, and use those to create a new SpectrumData object.

        Parameters
        ----------
        filename: str

        Returns
        -------
        SpectrumData
            new SpectrumData object, initialized with data read from file
        """
    import scqubits.io_utils.fileio as io
    return io.read(filename)
