ContourExport

Beautiful contour plots using Mathematica and TikZ

When you export a ContourPlot from Mathematica to a PDF file for inclusion in another document it will by default export it as a vector graphics. This results in good print quality at the cost of a huge file. Additionally, the font of text elements in the plot might not match the font in your document. An alternative is to export a rasterized version of your plot. This gives a lower file size but you need a rather high resolution so lines, text and other vector elements do not appear blurred on print. The font matching problem is not solved by this either.

Wouldn't it be nice if you could simply export only parts of the plot (like axes and text) as a vector graphics and only rasterize the rest? This Mathematica package provides the command ContourExport that takes a ContourPlot and exports the background to a PNG file while writing the contour lines to a CSV. These files can then be combined using TikZ and plot elements like axes, ticks and labels matching your document's style can be added at will.

Installing

To install this package, download the latest tarball and extract it. Copy ContourExport.wl to the Mathematica Applications directory (~/.local/share/mathematica/Applications on Linux). You can then load the package in Mathematica using

<< ContourExport`

or

Needs["ContourExport`"]

Using ContourExport

Let's suppose you have stored the result of ContourPlot in a variable named plot. To export this plot you can use

ContourExport["myplot", plot]

and three files will be written to your current directory:

• myplot.csv contains points that describe the contour lines,
• myplot.png contains an image of the regions between the contour lines,
• myplot.tex contains a tikzpicture environment that draws the contour lines from myplot.csv on top of myplot.png and adds axes, labels (if your plot had ones) and a colorbar using PgfPlots.

You may pass the ImageSize as an option to ContourExport to set the resolution of the PNG file. For example,

ContourExport["myplot", plot, ImageSize -> 500]

will output a 500x500 image. Using AspectRatio as an option you can set the aspect ratio (height/width) of the PNG file, e.g.

ContourExport["myplot", plot, ImageSize -> 500, AspectRatio -> 2]

will output a 500x1000 image.

You can control the resolution of the contour lines using the SampleStep option. A bigger value will output less points.

Using the WriteTikz option you can control the output of the myplot.tex file:

• WriteTikz -> False will disable writing a TeX file,
• WriteTikz -> True outputs the TeX file with only a tikzpicture environment (default),
• WriteTikz -> Standalone outputs the TeX file as a complete TeX document with the standalone documentclass.

When you use PrintColorbar -> True the ContourExport function will print the part of the TeX file with the colorbar definition to your notebook. This might be useful when you have manually added other graphical elements to the TeX file and just want to tune the contour part. If the domain of the plot has not changed it should be enough to just replace the colorbar definitions with the output due to PrintColorbar -> True.

You can find a working example in example/randomsin.nb.

Contributing

If you find any bugs or want to propose some enhancement, feel free to send a pull request.

Licensing

The code in this project is licensed under the MIT license (see LICENSE).