On Mon, 28 Jan 2008, andreas.rosenblad(a)ltv.se wrote: Re. 1854919: Resampling rows of a matrix is something you can do easily with the existing gretl tools, there's no need for a special function. (We're systematizing the documentation for all gretl functions, so hopefully this sort of thing should become more apparent.) For example: nulldata 5 scalar T = 20 # rows of original matrix scalar R = 20 # resampled rows: you choose matrix A = mnormal(T,2) matrix rsel = int(muniform(R,1)*T+1) matrix B = A[rsel] print A B rsel One small thing: the line "matrix B = A[rsel]" works fine, but it might be more transparent if it read matrix B = A[rsel,] Unfortunately the latter variant doesn't work in the current release because of a stupid copy-n-paste bug in the code for parsing matrix sub-slices, but that's fixed in CVS. Allin.