def dir_names(dirrepo, panel_id):
    """Defines structure of subdirectories in calibration repository.
    """
    dir_panel  = '%s/%s' % (dirrepo, panel_id)
    dir_offset = '%s/offset'    % dir_panel
    dir_peds   = '%s/pedestals' % dir_panel
    dir_plots  = '%s/plots'     % dir_panel
    dir_work   = '%s/work'      % dir_panel
    dir_gain   = '%s/gain'      % dir_panel
    dir_rms    = '%s/rms'       % dir_panel
    dir_status = '%s/status'    % dir_panel
    return dir_panel, dir_offset, dir_peds, dir_plots, dir_work, dir_gain, dir_rms, dir_status