Re: master 792ba71: Add a new function 'buffer-line-statistics'

[Eli Zaretskii]

> Date: Tue, 12 Jan 2021 20:37:25 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: larsi@gnus.org, emacs-devel@gnu.org
> 
> > From: Stefan Monnier <monnier@iro.umontreal.ca>
> > Date: Tue, 12 Jan 2021 13:15:25 -0500
> > Cc: Lars Ingebrigtsen <larsi@gnus.org>
> > 
> > I thought computing the mean was necessarily O(N) in space (like
> > keeping the full sequence of line lengths so you can sort it and then
> > pick the middle point).
> 
> That the median, not the mean.  "Mean" and "average" are identical.

Btw, there are algorithms for true sequential estimation of the
median, without keeping all the samples in memory.  But they are
somewhat complex, and I'm not sure this case justifies such
complexity, as we shouldn't care in this case about the lack of
robustness of the average as a statistic.