vpype VS WebPlotDigitizer

I'm not sure but that sounds like something vpype could do: https://github.com/abey79/vpype

If your polygons are closed you can try using vpype with the occult plug in to automatically remove invisible paths. The catch is that they really need to be closed polygons and not lines. There may be another plug in that does handle lines though.

The basics: I generated this plot via a program I wrote. That program was written in Javascript, using the p5.js library for drawing lines and stuff, and canvas-sketch to generate the SVG for plotting. I passed the SVG through vpype to merge & sort the lines, and then connected to the AxiDraw using saxi. Not knowing where you're at, those are a good choice to get started—Javascript is an okay language, and p5.js is really good for just getting stuff appearing on the page. And you can just start with the first 2, and add vpype and saxi later.

Ah, very nice.

That should reduce the effort needed to something you might be able to make quick work of, yourself, with some thought.

this website [1] recommends a tool called vpype [2] which might have an option to do what you need or might be able to be tweaked to do what you need

[1] https://www.acrylicode.com/svg-to-gcode-walkthrough/

[2] https://github.com/abey79/vpype

vpype: https://github.com/abey79/vpype occult plugin for vpype: https://github.com/LoicGoulefert/occult

I think the lines are so small it makes dots. You can use vpipe tool to fix up stuff like this. Don't ask me for the command I just know it exists. https://github.com/abey79/vpype

VPype has good tools for post-processing SVG to optimize plot speed. Simplifying the geometry and optimizing the line drawing order are the two basic things. Axidraw's Inkscape extension does some of this automatically, too.

Something similar which is more recently-maintained: https://github.com/automeris-io/WebPlotDigitizer

Are you looking for a digitizer tool like https://automeris.io/WebPlotDigitizer/ ? With the new AI tools being developed, I could see a tool like this being more automated.

If you’re only doing the one graph it makes more sense to just use an existing graph-to-data tool like this one.

There are several, yes. Here is one, and here is anther, and here is a third. There is a detailed comparison here.

Theory of Wing Sections by Abbott and von Doenhoff. Use a plot digitizer to extract data from published graphs.

If you don’t require complete accuracy you can try this for an approximation. https://automeris.io/WebPlotDigitizer/

At least in the case of Linux Debian, the cross-link to the project's homepage appears no longer accessible. Is it because the developer reorganized his web site? An alternative to scan the phase diagram can be Ankit Rohatgi's webplotdigitizer (Windows/Linux/Mac, can be used from the web browser).