Groups > comp.graphics.apps.gnuplot > #3657

Re: What's new in gnuplot 5.2

Path	csiph.com!weretis.net!feeder4.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: What's new in gnuplot 5.2
Date	Fri, 2 Jun 2017 10:18:37 +0200
Organization	solani.org
Lines	21
Message-ID	<ogr70t$1b2$1@solani.org> (permalink)
References	<ac6rb8.ur8.19.1@isomedia.com> <b30f5dfe-333f-4a47-b61e-ab6e6b0a96fc@googlegroups.com>
Mime-Version	1.0
Content-Type	text/plain; charset=utf-8
Content-Transfer-Encoding	7bit
X-Trace	solani.org 1496391517 1378 eJwFwYERADAEBLCV+PLOOGjtP0ITP1ROGJ3m6ztmuQIB7aK9iIzp60iN1wVhvbRXqDizrR8Q/xEg (2 Jun 2017 08:18:37 GMT)
X-Complaints-To	abuse@news.solani.org
NNTP-Posting-Date	Fri, 2 Jun 2017 08:18:37 +0000 (UTC)
User-Agent	Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1
X-NNTP-Posting-Host	eJwNyskBwCAIBMCWOFxky4kE+i9BX/MZeGjUXoFYGIxIqakRSZ5Hyf6/A7BHyPCk9ttDs450XvueD9Y=
In-Reply-To	<b30f5dfe-333f-4a47-b61e-ab6e6b0a96fc@googlegroups.com>
X-User-ID	eJwFwYEBwDAEBMCVCJ6Og/T3HyF3YVBsOgIeDHIqIWmdd4vQ+uh/coQtnW1l6mp9HIsTcx8fVhED
Cancel-Lock	sha1:sRGDhJVhdCEhkNJbVRCgJG5yd40=
Content-Language	de-DE-1901
Xref	csiph.com comp.graphics.apps.gnuplot:3657

Show key headers only | View raw

Am 01.06.2017 um 08:16 schrieb hugocoolens@gmail.com:
> Is it possible to put in an easy way constraints on the fitting parameters in this version of Gnuplot? I've always missed something like being able to put in "0<a<10" for a function fit with a as a parameter?

Unfortunately not, but for some good reason.

It's not a simple thing to add constraints to the Marquardt-Levenberg
algorithm, because it's not clear (and probably very problem-dependent)
what should happen when the parameter approaches that limit. You
probably know the feature from "OriginPro", and most people i know agree
that it messes up their fitting routines quite a bit.

Most often when one parameter wants to diverge, that is because the
given function does not really describe the data or the starting values
are bad. Trying to predetermine them by fitting only certain parts of
your data using simplified functions is usually helpful.

  Karl

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

Thread

What's new in gnuplot 5.2 Raoul Fleckman <raoul.fleckman@gmail.com> - 2017-05-26 21:13 +0000
  Re: What's new in gnuplot 5.2 "hugocoolens@gmail.com" <hugocoolens@gmail.com> - 2017-05-31 23:16 -0700
    Re: What's new in gnuplot 5.2 Karl Ratzsch <mail.kfr@gmx.net> - 2017-06-02 10:18 +0200
      Re: What's new in gnuplot 5.2 "hugocoolens@gmail.com" <hugocoolens@gmail.com> - 2017-06-02 02:32 -0700
        Re: What's new in gnuplot 5.2 Karl Ratzsch <mail.kfr@gmx.net> - 2017-06-02 12:11 +0200
          Re: What's new in gnuplot 5.2 "hugocoolens@gmail.com" <hugocoolens@gmail.com> - 2017-06-03 12:49 -0700
            Re: What's new in gnuplot 5.2 Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2017-06-03 22:45 +0200
              Re: What's new in gnuplot 5.2 "hugocoolens@gmail.com" <hugocoolens@gmail.com> - 2017-06-05 01:32 -0700
                Re: What's new in gnuplot 5.2 Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2017-06-05 14:47 +0200
                Re: What's new in gnuplot 5.2 "hugocoolens@gmail.com" <hugocoolens@gmail.com> - 2017-06-06 23:34 -0700
                Re: What's new in gnuplot 5.2 Dr Engelbert Buxbaum <engelbert_buxbaum@hotmail.com> - 2017-06-07 14:26 +0200

csiph-web