Dear R People: Is it possible to fit an AR model such as: y_t = fee_1 y_t-1 + fee_2 y_t-9 + a_t, please? I know that we can fit an AR(9) model, but I was wondering if we could do a partial as described. Thank you for your help. Sincerely, Laura Holt mailto: lauraholt_983 at hotmail.com _________________________________________________________________