Say you have multiple quaternions (of the form q = w, x, y, z) that represent absolute rotations. How can you get a discrete direction from there such that if we see quaternion 0 for example we can deduce if the associated direction is :up, diagonal left or some kind of classification. Ideally, it would be nice to avoid the use of euler angles if that's even possible.
The goal here being to classify the quaternions absolute rotations and use them as labels in a classification task for a neural net.