Hi,
I'll admit right away that this question has no real practical problem
behind it, it's just out of internal consistency:
The mean() function accepts a list and then averages across the members
of the list (and returns a series of per-obs-averages).
In contrast, the pmean() function doesn't have this second use, it only
accepts one series (as does mean). Any particular reason why not?
The same goes for pmax(), pmin(), psd(), psum(), and perhaps also
pxsum(), I guess.
thanks,
sven