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

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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

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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

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