velocity and delta_theta

[LongfeiProjects]

https://github.com/chauby/V-REP-YouBot-Demo/blob/6faa738604f30092c802430400bdb4be59a02c6f/7_Demo_youBotPickAndPlace/code/NextState.py#L19

I went across the tutorial, and came across with this confusion: I suppose theta_dot is the derivative of theta with respect to time, namely wheel rotating(angular) velocity. If that stands, theta_dot is equal to speed[0,5:], instead of delta_theta, which is a step rotation(\omega * \delta t)