Re: [Gretl-users] Dealing with NAs in Lists

Thanks for all replies. It seems there are several alternative ways of doing this. Here is the final look of the option I took to compute a cross sectional mean and a cross sectional standard deviation functions: <hansl> function series my_cross_sectional_mean (list L) set skip_missing off matrix m = {L} matrix result = {} loop i=1..rows(m) matrix mi = m[i,] result |= meanr(selifc(mi, ok(mi))) # and analogous with sdc(selifc(...)')' endloop series cross_sectional_mean = result return cross_sectional_mean end function function series my_cross_sectional_stdev (list L) set skip_missing off matrix m = {L} matrix result = {} loop i=1..rows(m) matrix mi = m[i,] result |= sdc(selifc(mi, ok(mi))',sum(ok(mi))-1)' # I'm using sum(ok(mi))-1 as degrees of freedom, to correct sdc for the # sample standard deviation endloop series cross_sectional_stdev = result return cross_sectional_stdev end function # load example data open data4-10 list L = ENROLL CATHOL INCOME INCOME[10] = NA series mL = my_cross_sectional_mean(L) series sL = my_cross_sectional_stdev(L) print L mL sL -o </hansl> I used a correction for degrees of freedom in the sdc formula. The above code works perfectly! Filipe