Groups > comp.graphics.apps.gnuplot > #935

Re: How to plot data relative to a specific data point

Path	csiph.com!x330-a1.tempe.blueboxinc.net!newsfeed.hal-mli.net!feeder3.hal-mli.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!border3.nntp.dca.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!postnews.google.com!gi10g2000vbb.googlegroups.com!not-for-mail
From	Péter Juhász <peter.juhasz83@gmail.com>
Newsgroups	comp.graphics.apps.gnuplot
Subject	Re: How to plot data relative to a specific data point
Date	Fri, 10 Feb 2012 10:12:55 -0800 (PST)
Organization	http://groups.google.com
Lines	28
Message-ID	<22c2db05-16c6-472e-a450-99c66ad884ae@gi10g2000vbb.googlegroups.com> (permalink)
References	<43950b82-c09e-4e85-8863-a175abfdf84f@uc9g2000pbc.googlegroups.com>
NNTP-Posting-Host	78.92.1.86
Mime-Version	1.0
Content-Type	text/plain; charset=ISO-8859-1
Content-Transfer-Encoding	quoted-printable
X-Trace	posting.google.com 1328897575 26493 127.0.0.1 (10 Feb 2012 18:12:55 GMT)
X-Complaints-To	groups-abuse@google.com
NNTP-Posting-Date	Fri, 10 Feb 2012 18:12:55 +0000 (UTC)
Complaints-To	groups-abuse@google.com
Injection-Info	gi10g2000vbb.googlegroups.com; posting-host=78.92.1.86; posting-account=zDLjuQoAAAC_blU_eX_4MHabi0k_sknv
User-Agent	G2/1.0
X-Google-Web-Client	true
X-Google-Header-Order	HUALENKRC
X-HTTP-UserAgent	Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:10.0) Gecko/20100101 Firefox/10.0,gzip(gfe)
Xref	x330-a1.tempe.blueboxinc.net comp.graphics.apps.gnuplot:935

Show key headers only | View raw

On Feb 10, 6:42 pm, Tom Gederberg <tgederb...@gmail.com> wrote:
> I know this is probably a stupid question but I have not been able to
> find the answer anywhere.
>
> Suppose I have a data file that looks like:
>
> Time    Value1   Value2   Value3
>
> 568744.0    -3.2    5.4    8.8
> 568744.2     9.1    8.1   -3.5
>     .               .        .       .
>     .               .        .       .
>     .               .        .       .
> 568423.0    5.7     6.1   7.7
>
> I want to plot the data against time, but want time starting at 0, not
> 568744.0.
>
> I know I can say
> plot "data.txt" u ($1 - 568774.0):2 w lines
>
> but is there a way to tell gnuplot to refer to the first time value
> (something like $1(0)).  Does this question make sense?

first=0
plot 'data.txt' u (first=($0==1?$1:first),$1-first):2

Péter Juhász

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

Thread

How to plot data relative to a specific data point Tom Gederberg <tgederberg@gmail.com> - 2012-02-10 09:42 -0800
  Re: How to plot data relative to a specific data point Péter Juhász <peter.juhasz83@gmail.com> - 2012-02-10 10:12 -0800

csiph-web