What you are doing wrong is not to notice that if w is the exchange factor to move R across Q in one direction it is (w inverse} which you need to move it in the other direction, not w. It doesn't matter whenever w = (w inverse), e.g. quaternions with w = -1.

Ah! Thank you.

regards,

Harold V. McIntosh -- Mike Stay staym@clear.net.nz http://www.xaim.com/staym