;+ ;Function: q_angular_velocity ; av = q_angular_velocity(t,q) ;Purpose: Computer angular velocity of a rotation quaternion ; ;Reference: http://www.euclideanspace.com/physics/kinematics/angularvelocity/QuaternionDifferentiation2.pdf ; ; Author: Davin Larson ; $LastChangedBy: $ ; $LastChangedDate: $ ; $LastChangedRevision: $ ; $URL: $ ;- function q_angular_velocity, t,q,moving=moving dq_dt = qderiv(t,q) if keyword_set(moving) then omega = qmult(qconj(q),dq_dt) *2 $ ; moving else omega = qmult(dq_dt,qconj(q)) *2 ; unmoving return,omega end