[Offtopic] Line fitting [was Re: Numpy outlier removal]

[Chris Angelico]

On Tue, Jan 8, 2013 at 1:06 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
>> given that weather patterns have been known to follow cycles at least
>> that long.
>
> That is not a given. "Weather patterns" don't last for thirty years.
> Perhaps you are talking about climate patterns?

Yes, that's what I meant. In any case, debate about global warming is
quite tangential to the point about statistical validity; it looks
quite significant to show a line going from the bottom of the graph to
the top, but sounds a lot less noteworthy when you see it as a
half-degree increase on about (I think?) 30 degrees, and even less
when you measure temperatures in absolute scale (Kelvin) and it's half
a degree in three hundred. Those are principles worth considering,
regardless of the subject matter. If your railway tracks have widened
by a full eight millimeters due to increased pounding from heavier
vehicles travelling over it, that's significant and dangerous on
HO-scale model trains, but utterly insignificant on 5'3" gauge.

ChrisA