Re: [Gnuplot-info] something like plot filename using VarOne:($VarTwo*1.1) possible?

[Xiao-Yong J. <xj...@co...>]

On Thu, 27 May 2010 19:07:06 +0200, Jan Nowack wrote:

> Hi all,
> i have to plot a lot of datafiles in which the position of the columns
> could change. A change of the datafiles is not possible. So VarOne
> could be e.g on Pos 1 in one file, then on Pos. 17. So i wrote a
> script that writes the Variable Positions in a file like
> VarOne=17
> VarTwo=12
> and load the file at the beginnning. That works fine, but now i have
> to change some values by a factor. Something like

> plot filename using 1:($2*1.1)

> of course works. But it does not work with the User Variables, e.g.

> plot filename using VarOne:($VarTwo*1.1)

> Does anyone knows a solution?

Hi,

I don't know what is the best way to achieve this, but I
found myself sometimes using a combination of 'sprintf' and
'eval'.

In your case, I believe 'eval' would be suffice

  eval 'plot filename using '.VarOne.':($'.VarTow.'*1.1)'

Best,
Xiao-Yong

> With best regards

> Jan
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