# Why convert Quaternion to Euler Angle

I've recently played with the IMU filter in MATLAB. When using their examples, they always plot the rotations by stating something alike this:

plot(t,eulerd(orientation,'ZYX','frame'))


( Note: orientation variable would be the collection of quaternion results )

As a result, I did the same, as I wanted to observe my roll, pitch, and yaw values. However, I ended up using the solution from this post. ( Which gave me the same results )

With that in mind, when I do a stack query for roll, yaw, and pitch from quaternions, I am almost always taken to a tait bryan angle representation. Does this mean that capturing these values is not possible through quaternions? Or is more difficult to visualize? Obviously my quaternion knowledge is small, as most of it is significantly over my head, but shouldn't I be able to calculate rotations and show them without relying on euler rotations?

• You don't need Euler angles at all. Check this material on "visualizing quaternions": eater.net/quaternions – Mauricio Cele Lopez Belon Mar 16 at 21:36
• I can't comment on why the programmers at MATLAB made the choices they did. All methods of representing orientation are equivalent. You get exactly the same information out of all of them. If a method wasn't equivalent, it wouldn't be a representation of orientation. Quaternions are commonly used because of the simplicity of their representation, and because the natural methods of calculating with them are more numerically stable than other representations. Probably you see Euler Angles because they are closer to how we think about rotations. – Paul Sinclair Mar 17 at 0:36