I have some odometry data in CARMEN format, so it's like this:

ODOM x y theta tv rv accel

I already understand how to convert x, y and theta to values in a nav_msgs/Odometry ros message. However, I don't understand where do I put tv (translational velocity), rv (rotational velocity), accel (acceleration, I suppose). I see that a nav_msgs/Odometry message has a field called twist, from which I can get to a Twist message with fields linear and angular, and I would suppose this is what I need... if those fields weren't of type Vector3 and I didn't have just one value for each. So how do I store this data?

I have checked answers or other code sources such as this (and here nothing is done with tv and rv) and this (where I don't understand why are tv, rv and accel values put in a quaternion along with theta), but I did not understand much from those.