Return a ready-initialized seit-manager object from the CRTomo
        tools. This function only works if the crtomo_tools are installed.

def export_to_crtomo_seit_manager(self, grid):
        """Return a ready-initialized seit-manager object from the CRTomo
        tools. This function only works if the crtomo_tools are installed.
        """
        import crtomo
        g = self.data.groupby('frequency')
        seit_data = {}
        for name, item in g:
            print(name, item.shape, item.size)
            if item.shape[0] > 0:
                seit_data[name] = item[
                    ['a', 'b', 'm', 'n', 'r', 'rpha']
                ].values
        seit = crtomo.eitMan(grid=grid, seit_data=seit_data)
        return seit