newton.math.quat_velocity

newton.math.quat_velocity(q_now, q_prev, dt)

Approximate angular velocity from successive world quaternions (world frame).

Uses right-trivialized mapping via \(\Delta q = q_{\text{now}} q_{\text{prev}}^{-1}\).

\[\Delta q = q_{now} q_{prev}^{-1},\quad \omega \approx \hat{u}(\Delta q)\,\frac{\theta(\Delta q)}{\Delta t}\]

Parameters:

• q_now (quatf) – Current orientation in world frame.

• q_prev (quatf) – Previous orientation in world frame.

• dt (float) – Time step [s].

Returns:

Angular velocity \(\omega\) in world frame [rad/s].

Return type:

vec3f