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Newsgroups: comp.graphics.apps.gnuplot
Date: Sun, 27 Nov 2016 07:31:07 -0800 (PST)
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Subject: linear fit of looped (and cutted) data set
From: =?UTF-8?Q?Markus_Gr=C3=BCnwald?= <m_grueni@web.de>
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Xref: csiph.com comp.graphics.apps.gnuplot:3485

I've done measurements of cycling loads and saved into a text-file. Now i n=
eed to make a linear fit to these data points by only take care of a specif=
ic part of data points (limited y-range). - Hard to descirbe - therefore i =
tried to make a sketch of it: see http://ovh.to/2u45XF4

If i'll do this by setting a set of range during fit-command by using:
[code]
f(x) =3D k*x + d
fit [x_min:x_max] [y_min:y_max] f(x) "DATA.txt" using 2:3 via k,d
[/code]
i'll get a wrong fitting curve, because gnuplot seams to connect the dead e=
nds of the cutted Data-set (seen in (1) of my sketch).

I think i will need a function that fits the linear function best to existi=
ng points ignoring the cutted dead ends (seen in (2) of my sketch).

Does anyone know a solution to get this behaviour?