Talk:Quaternions and spatial rotation: Difference between revisions

Revision as of 23:41, 20 February 2006

Revision as of 23:47, 20 February 2006

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== In Summary ==

The section"Quaternion on rotationsrotation" has a summary where it gives the cookbook formula for making a quaternion given an angle and a unit vector.

Could someone add the converse - the formula for getting the vector and the angle from an arbitrary quaternion? Yes, I suppose the reader can work it out from what's given but it would be nice and encyclopedic to include it.

Actually - why not make this summary a separate section? Name it "this is how you actually do it", or something.

Oh - and why use <''u'', ''v''> (rather than the dot operator) for the dot product when the cross operator is used for the cross product?

As an afterthought: please don't remove thisthese sectionequations. There's an annoying trend on the math pages for hard-core math guys to remove the cookbook ("analytic") stuff. I imagine they feel that people should make the effort to understand the deeper beauties and derive the equations themselves, thatbecause the actual resulting equations are uninteresting: but it really imposes a learning curve and makes it difficult for people like me who just want to write code. One would imagine, anyway, that this entry should be nuts-and-bolts friendly.