How to define new units?

[milgner]

In a project I stumbled upon units like dpi (dots per inch) and lpi (lines per inch), which are frequently used in printing.

Now I wonder how to integrate this with this library? A dot, at least in this context, doesn't have any concrete physical concept attached to it but it still should be possible to combine with physical units like inch.

Do I have to implement something based on AbstractSystemOfUnits like PrintingUnits? What base classes can I derive from or do I need to implement all the interfaces?

[keilw]

Please check other system libraries like

• https://github.com/unitsofmeasurement/si-units
• https://github.com/unitsofmeasurement/uom-systems
• https://github.com/unitsofmeasurement/uom-domain (Domain-specific units including those for Imaging/Print like PIXEL or PIXEL_PER_INCH (PPI) @milgner if you would like to contribute others like LPI or DPI, and DOT, we'd be more than happy about your contribution. Or use it as an inspiration for your own libraries.