Groups > comp.graphics.apps.gnuplot > #4181

Re: strange discrepancy between stats command result and fitting result

Path	csiph.com!weretis.net!feeder6.news.weretis.net!feeder5.news.weretis.net!news.solani.org!.POSTED!not-for-mail
From	Karl Ratzsch <mail.kfr@gmx.net>
Newsgroups	comp.graphics.apps.gnuplot
Subject	Re: strange discrepancy between stats command result and fitting result
Date	Sun, 14 Apr 2019 18:56:11 +0200
Organization	solani.org
Lines	22
Message-ID	<q8vone$p69$1@solani.org> (permalink)
References	<09207591-2b4d-4b5a-8460-cec754f3496d@googlegroups.com>
Mime-Version	1.0
Content-Type	text/plain; charset=utf-8
Content-Transfer-Encoding	7bit
X-Trace	solani.org 1555260974 25801 127.0.0.43 (14 Apr 2019 16:56:14 GMT)
X-Complaints-To	abuse@news.solani.org
NNTP-Posting-Date	Sun, 14 Apr 2019 16:56:14 +0000 (UTC)
User-Agent	Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1
Cancel-Lock	sha1:6SEbWORxF3dCpeCeaG0AZ66x2YI=
Content-Language	de-DE-1901
In-Reply-To	<09207591-2b4d-4b5a-8460-cec754f3496d@googlegroups.com>
X-User-ID	eJwVxsERACEIBLCWEGFXy0GQ/ks4b/KJTwwkDQ7zfgpxdt3YLUzlP5lDqqiaK00qurn6zaj4ADNeEZI=
Xref	csiph.com comp.graphics.apps.gnuplot:4181

Show key headers only | View raw

Am 14.04.2019 um 17:19 schrieb hugocoolens@gmail.com:
> I am puzzled by the following discrepancy between a stats command result and the result which I have from normal Gnuplot fitting:

> f(x)=a*log10(x)+b
> a=-1.06
> b=-4.78
> fit [3e-3:1] f(x) datafile using ($1):($2) via a,b
> stats [3e-3:1] datafile using (log10($1)):($2)
> 
> 
> The Gnuplot fitting gives me y=ax+b, with the correct a=-1.16816 and b=-4.78604
> But the stats-command gives:  y = -3.104 x - 4.194


Not problem with fit or stats, your range setting for stats was
wrong: you have to logarithmise it as well

  stats [log10(3e-3):log10(1)] $dat using (log10($1)):($2)

and the linear model that comes out is y = -1.168 x - 4.786

;-)

Back to comp.graphics.apps.gnuplot | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

strange discrepancy between stats command result and fitting result "hugocoolens@gmail.com" <hugocoolens@gmail.com> - 2019-04-14 08:19 -0700
  Re: strange discrepancy between stats command result and fitting result Karl Ratzsch <mail.kfr@gmx.net> - 2019-04-14 18:56 +0200
    Re: strange discrepancy between stats command result and fitting result "hugocoolens@gmail.com" <hugocoolens@gmail.com> - 2019-04-14 23:46 -0700

csiph-web