On Tuesday, 16 June 2015 23:54:14 UTC+1, Ben P wrote: > > I am tracking rotation of an object using quaternions by accumulating each > successive rotation using quaternion composition. > I notice that probably due to rounding errors, the norm of each successive > quaternion is drifting from being 1, which means I need to normalize the > quaternion. > Is there an in-build function that would let me do this? > Otherwise, I can divide the quaternion by its norm. Is there a method I > can call on the quaternion to extract its norm? >
for r an element of your quaternion algebra Q, you can do something like vector(r.coefficient_tuple())*Q.inner_product_matrix()* vector(r.coefficient_tuple()) to get some kind of norm (probably you'd need to scale it) > I looked at the Quaternion documentation page but did not find anything > there Here is the page I am referring to: > http://doc.sagemath.org/html/en/reference/quat_algebras/sage/algebras/quatalg/quaternion_algebra.html > > > Thanks > Ben > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
