From: Lars Ingebrigtsen <larsi@gnus.org>
To: Stefan Monnier <monnier@iro.umontreal.ca>
Cc: emacs-devel@gnu.org
Subject: Re: master 792ba71: Add a new function 'buffer-line-statistics'
Date: Tue, 12 Jan 2021 19:39:54 +0100 [thread overview]
Message-ID: <87pn2ahudh.fsf@gnus.org> (raw)
In-Reply-To: <jwveeiq2ffk.fsf-monnier+emacs@gnu.org> (Stefan Monnier's message of "Tue, 12 Jan 2021 13:15:25 -0500")
Stefan Monnier <monnier@iro.umontreal.ca> writes:
> I must admit to not being fully cognizant of Knuth, but doesn't this
> compute the average rather than the mean?
Arithmetic mean, which is the meanest of the mean.
> 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's the median, and that's what I also thought, but it turns out that
you can approximate the median to the desired accuracy with much less
than O(N) space:
https://www.stat.cmu.edu/~ryantibs/papers/median.pdf
Which we can consider if somebody wants it. :-)
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no
next prev parent reply other threads:[~2021-01-12 18:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210112174748.18372.29339@vcs0.savannah.gnu.org>
[not found] ` <20210112174750.5928220B2C@vcs0.savannah.gnu.org>
2021-01-12 18:15 ` master 792ba71: Add a new function 'buffer-line-statistics' Stefan Monnier
2021-01-12 18:29 ` Philipp Stephani
2021-01-12 19:06 ` Stefan Monnier
2021-01-12 18:37 ` Eli Zaretskii
2021-01-12 18:43 ` Eli Zaretskii
2021-01-12 18:39 ` Lars Ingebrigtsen [this message]
2021-01-12 19:18 ` Eli Zaretskii
2021-01-12 19:54 ` Stefan Monnier
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