> I am a bit puzzled by the grelt syntax. Why can I not use (s is a > series) > > print s[1] > > but I can use > > scalar z = s[1] > > print z Although it may seem so, this doesn't really have to do with accessing series elements. The 'print' command is limited to work on one pre-specified object. The alternative for you is to use 'eval' to evaluate a general hansl expression: eval s[1] > ??? It cost me some time to get it that actually accessing single > elements works as it is written in hansl, simply because I did not > understand the error msg from using the print command I can confirm that the error message is strange: I get "invalid observation index 1", which is certainly misleading. > or leading ? to check my understanding of syntax...). Also, in hansl it > is said that one may use > > lagged_s =s[-1] > > to produce a lagged version of the series. But to no avail (at least > not, if there are some NA included). Wheras the (undocumented?) > > lagged_s = s(-1) works Where is it said that you should use square brackets instead of round ones? (honest question) In my memory it has always been s(-1). thanks, sven