[Gretl-users] Accumulating series

Dear Gretl Community, How can I accumulate a series in 12 months inside a script? Now this is what I'm doing: series var112m = var1 + var1(-1) + var1(-2) + var1(-3) + var1(-4) + var1(-5) + var1(-6) + var1(-7) + var1(-8) + var1(-9) + var1(-10) + var1(-11) Could you please suggest a more elegant way? Best, -- Henrique C. de Andrade Doutorando em Economia Aplicada Universidade Federal do Rio Grande do Sul www.ufrgs.br/ppge