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I have to create a video presenting the evolution of some quantities as functions of time. I am creating images with gnuplot and I assemble them to make a movie. I am getting trouble generating the two first images: the first image is supposed to have no point on it (it is supposed to show only the title of the graph, the x and y axes and the labels of the axes) and the second one is supposed to have one single point on it.

  • Is it possible to create a graph containing no data on it with gnuplot?

  • Is it possible to create a graph containing one single point with gnuplot using an input file? The input file contains:

    0 15

Thank you in advance for your answers,

Julien

Julien
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1 Answers1

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To plot an empty graph, just plot a completely undefined function like

plot NaN

The main issue here is, that the autoscaling fails since there are no valid points. You must give a fixed xrange and yrange to get a plot:

set xrange [0:1]
set yrange [0:1]
plot NaN notitle

Plotting a single point works fine using

plot 'file.dat' using 1:2 with points

You'll get warnings saying Warning: empty x range [0:0], adjusting to [-1:1] and Warning: empty y range [15:15], adjusting to [14.85:15.15], but you get a plot. To remove the warnings, you must again provide a fixed xrange and yrange.

Christoph
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