CRTomo importer

def import_crtomo(self, directory, frequency_file='frequencies.dat',
                      data_prefix='volt_', **kwargs):
        """CRTomo importer"""

        # we get not electrode positions (dummy1) and no topography data
        # (dummy2)
        df, dummy1, dumm2 = reda_crtomo_exporter.load_seit_data(
            directory, frequency_file, data_prefix, **kwargs)
        self._add_to_container(df)

        print('Summary:')
        self._describe_data(df)