In need of a quaternion example

Hi,

I don't know how to multiply two quaternions. Let's say that I want
to multiply two quaternions:

(1,2,3,4)*(5,6,7,8)

How do I do that?

From reading help I only know that I should start with:

  load(atensor);
  init_atensor(quaternion);

But then it starts talking about matrices, but quaternions are not
matrices, just a real number and three imaginary numbers. So I cannot
make any sense out of this.

How do I define a quaternion variable, how do I multiply two of those?

How do I conjugate, invert, logarithm, etc... a quaternion?


please help
-- 
Janek Kozicki                               http://janek.kozicki.pl/