Hi, I'm getting a strange "lag order: second arg must be scalar" error message in the following script. Notice the (unintended) blank between the series name "RS" and the lag call "(-1)": <hansl> open hendry_jae series d_short = diff(RS) series d_long = diff(RL) c = 0.01 ladung = -1 longrun = 1 series test = RS (-1) # works with the blank nls d_short = c + ladung * ( RS (-1) - longrun * RL(-1))  # fails with the blank   params c ladung longrun end nls </hansl> No big deal, obviously, but doesn't help in debugging. This is Nov 23rd git code base. cheers, sven