[time-nuts] Discarding outliers in two dimensions
Poul-Henning Kamp
phk at phk.freebsd.dk
Wed Dec 9 14:02:20 UTC 2009
In message <20091209105308.17C67BCFE at ip-64-139-1-69.sjc.megapath.net>, Hal Murr
ay writes:
>For one dimension, you sort, compute the average, then compute the distance
>of the first and last samples from the average. Discard the one that is
>farther from the average.
You want to use the median rather than the average, even if it involves
sorting your samples.
>The problem with two dimensions is I don't know how to sort.
If the two noise-sources are orthogonal, you just do it on each
axis independently and alternately.
If they are not, things get more complicated.
In general I can highly recommend www.nr.com for stuff like this.
Poul-Henning
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
More information about the time-nuts
mailing list