Is this true north or magnetic north?

[johannesvollmer]

The magnetic north is rarely used in geography. Usually, true north is used, which depends on the observers location on the globe. What do you think about adding this to the library? Are you accepting contributions?

[Vittor-Javidan]

I'm about to test this library yet, but as a geologist I can guarantee you that making this library give the geographic north is a really bad idea.

IRL what we have what is called declination. We always know where the magnetic north is, but we never know what is the difference between the magnetic and geographic, because this changes a lot depending on what is your current position.

So, declination is basically the diference between the magnetic and geographic north in a specific region. You can access APIs to get the declination of the user, but this requires internet and gps access, and third party libraries, so is something that is better the developer do itself, instead getting directly from the lib.

Everyone that uses compass needs to find the declination of the region they are about to visit. And that info is displayed in actual physical maps. And the worst part, is that in 10 years, a same location can have its magnetic field changed, add or subtracting a few degrees to the geographic north