| aggr_rep_lag | Aggregate, repeat and lag | 
| apply_to_columns | Apply method to multivariate | 
| change_ref_year | Change reference year | 
| compute_gr | Compute the growth-rate series | 
| gdp_current | Spanish GDP (Current prices) | 
| gdp_volume | Spanish GDP (Chain-linked volume) | 
| get_chain_linked | Get chain-linked indices | 
| get_pyp | Get pyp indices | 
| get_q_index | Get quantity index | 
| get_v_index | Get value index |