[Gretl-users] issue

Dear gretl community, I am trying to program some dynamic multipliers on gretl. Unfortunately, I've got some problems. Consider the following part of the script: ----------------------------------- scalar h = 60 scalar k = 1 matrix mtheta = {0.035316 ; -0.021316 ; -0.012700} mtheta mpsi = zeros(h,k) mpsi[1,] = mtheta[1,] mpsi[1+1,] = vphi[1:1]*mpsi[1:1,] + mtheta[1+1,] mpsi[2+1,] = vphi[1:2]*mpsi[2:1,] + mtheta[2+1,] #Stops here: "Range 2 to 1 is non-positive!" mpsi[3+1,] = vphi[1:3]*mpsi[3:1,] + mtheta[3+1,] -------------------------------------------------------------- Unfortunately, the program stops (where it shoudn't) at the marked stage due to the reason that the computed number becomes non-positive. Is there any way to circumvent this behaviour? Thanks in advance! Artur