Why 4sg? - AndreasHeese/4sg GitHub Wiki

I didn't invest in commercial Sankey software, so I can't tell the difference. I made 4sg to fit my needs, so it might also fit yours. And it's free (under MIT license), not only free of charge but also free to change the source code at your convenience.

4sg is an XSLT script that converts the data stored in an XML file into a Sankey diagram generated as SVG file. SVG (Scalable Vector Graphics) is a W3C standard for vector graphics supported by all modern browsers. It can be edited with graphic design programs like Inkscape. Adobe Illustrator has difficulty doing this. This is not due to errors in the generated graphic. Illustrator does not correctly and completely master the SVG standard.

Another free tool for generating Sankey diagrams is D3.js (d3js.org), an excellent Javascript framework for data visualization.

Then why 4sg? D3.js also has disadvantages: it's not a ready-made solution, but a programming kit. The result is not a single graphic file for further processing, but a dynamic webpage. The exact placement of the elements can be interactively changed, but not be easily defined beforehand.

With 4sg, the graphic file to be generated can be defined in great detail without touching code. The script can be used as a „black box‟ without understanding or even reading the code. Settings in the data file are possible, but not necessary. When processing data without further specifications reasonable standard settings are used. These default settings can be permanently changed at a central point in the script.