X-Received: by 2002:a6b:3bd3:: with SMTP id i202mr2425366ioa.166.1553180558060; Thu, 21 Mar 2019 08:02:38 -0700 (PDT)
X-Received: by 2002:a9d:5d0d:: with SMTP id b13mr2888583oti.53.1553180557340; Thu, 21 Mar 2019 08:02:37 -0700 (PDT)
Path: csiph.com!xmission!news.snarked.org!border2.nntp.dca1.giganews.com!nntp.giganews.com!78no136196itl.0!news-out.google.com!l81ni154itl.0!nntp.google.com!w126no136437ita.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail
Newsgroups: comp.graphics.apps.gnuplot
Date: Thu, 21 Mar 2019 08:02:37 -0700 (PDT)
Complaints-To: groups-abuse@google.com
Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=193.190.225.245; posting-account=6f4zEAoAAABcPGvJdTxtF_Mhoal-gK1d
NNTP-Posting-Host: 193.190.225.245
User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <e19bcee9-4a4b-42cf-b403-0ee850efd01c@googlegroups.com>
Subject: different behaviour gnuplot4 and 5 concerning  "Implied independent variable y not found in fit function"
From: "hugocoolens@gmail.com" <hugocoolens@gmail.com>
Injection-Date: Thu, 21 Mar 2019 15:02:38 +0000
Content-Type: text/plain; charset="UTF-8"
Lines: 19
Xref: csiph.com comp.graphics.apps.gnuplot:4168

In a batch-file which worked fine for Gnuplot 4, I had the following lines:
f(x) = a*10e-8*(exp(x/b)-1)
err1(y)=0.01*0.033*y+2e-9
err2(y)=0.01*0.0031*y+20e-9
err3(y)=0.01*0.0034*y+200e-9
err4(y)=0.01*0.0045*y+2e-6
error(y)=(y<10e-6)? err1(y):(y<100e-6)? err2(y):(y<1e-3)? err3(y):err4(y)
a=30e-3
b=50e-3
fit f(x) '1n4148_linstep_1na_10ma.dat' using ($1):($2):(error($2)) via a,b

This worked fine in Gnuplot 4, however when I try this in Gnuplot 5, I get the following error message:
	> Implied independent variable y not found in fit function.
	> Assuming version 4 syntax with zerror in column 3 but no zerror keyword.


Does anyone here how to make the batch-file work again?

kind regards,
Hugo Coolens