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
