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I use the cairolatex terminal to generate plots with gnuplot for my latex documents. When I generate 3D plots with help of the command splot, the PDF generated by cairolatex exhibits fine structed grid lines which cause Moiré effects in the final document. This grid is not present when using the wxt terminal.

Here is my minimal example:

# set terminal wxt 1 size 700,700
set terminal cairolatex pdf size 7cm,7cm
set output 'test.tex'

set samples 100
set isosamples 100

set pm3d
set palette

f(x,y) = sin(sqrt(x**2+y**2)) / sqrt(x**2+y**2)

splot f(x,y) with pm3d

This is the output: The arrow marks the fine lines I want to avoid.

Difference between wxt and cairolatex terminal output

The fine grid also occurs when using pngcairo. I already tried several cairolatex options I found on this website with no success, e.g. using linewidth 0. I further tried to suppress the grid with help of the command

set style fill noborder

without success.

Does anyone know how to get rid of the fine structured grid?

I run gnuplot 5 with patchlevel 1 (64-bit version) on a Windows 7 machine.

Nex
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  • what platform, Gnuplot version are you using? I can't reproduce the issue... – ewcz May 23 '17 at 21:52
  • I added the platform and gnuplot version to the question. Meanwhile I tried different gnuplot versions: 5.0.1, 5.0.6, and 4.6.6. I also switched between 64-bit and 32-bit with no success. What platform and gnuplot version are you using ewcz? – Nex May 24 '17 at 08:37
  • I tried `cairolatex`/`pngcairo` with Gnuplot 5.0.6 on OSX, I can test it with Windows later... – ewcz May 24 '17 at 09:27
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    That's a main problem and not much you can do about this, see e.g. https://stackoverflow.com/q/18927493/2604213 – Christoph May 25 '17 at 17:52

1 Answers1

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  1. Grid lines surrounding the pm3d rectangles are controlled by set pm3d border. To turn them off, use set pm3d noborder.

  2. However, the lines you see are not generated by gnuplot, but instead are the background color that is sometimes visible at the "seam" between two neighboring polygons. You can see that, for example, by setting the terminal to set pdfcairo background rgb "green", and then the lines have the green background color. Whether not those seams are visible may depend on your pdf renderer.

  3. There is not much you can do about having visible seams between polygons in a vector output format. One possibility is to fill the seam by an actual line drawn in the color of your choice. For example, using your code snippet but changing the plot command to

    splot f(x,y) notitle with lines palette, f(x,y) with pm3d

    gives this result (cairolatex terminal, pdf file rendered by Preview on OS X): enter image description here

  4. If I use the pngcairo terminal I do not see the gaps between neighboring polygons:

enter image description here

user8153
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  • Thank you! The third suggestion works like a charm :). I already tried to plot with lines but I didn't think of plotting them with the palette attribute. – Nex May 25 '17 at 19:15