[Gretl-users] detail in the movavg() doc

Hi, looking at the reference for the movavg() function, it says (for the simple p>1 case): '...from period t to t−p+1. If a non-zero value is supplied for the optional control parameter the MA is centered, otherwise it is “trailing”.' Do I understand correctly that the part "period t to t-p+1" only refers to the trailing case, strictly speaking -- because that is the concrete trailing specification already? Or to put it differently, for non-zero 'control' and thus for a centered MA the given time indices are not meant to apply, right? thanks sven