Joe Reid wrote:
> The usual practice is to use the right-hand rule to determine the
> direction
> of the vector representing the rotation. Consider the z-axis to be the
> axis of rotation and the rotation to be such that the x-axis moves toward
> the y-axis. Then if the y-axis is considered to extend behind the x-z
> plane, the system is right-handed. If the y-axis is considered to extend
> in front of the x-z plane, the system is left-handed.
>
> I am sorry for this convoluted explanation. If I had you with me in the
> same room I could do better. In short, the direction of the vector
> representing the axis of rotation is determined by the direction of
> rotation according to the convention used by the mathematician.
>
As I've said to others in this thread, Joe, my problem isn't with
understanding the above. It's something I learned almost 50 years ago.
My problem was with your referring to the axis itself as a vector, when the
axis is only the directional component of the vector.
Bill Potts, CMS
San Jose, CA
http://metric1.org [SI Navigator]
