Dear Ed,
On 03/31/2014 08:55 PM, Edward A. Berry wrote:
[...]
>
> Looking at the math, it depends whether you multiply from right to left
> or left to right
>
>
> x' = Rz(a) Ry(b) Rz(g) x
> or
> x' = Rz(a) (Ry(b) (Rz(g) x))
>
[...]
Actually it does not depend - the rotation matrices are a representation
of the group SO(3) and hence the matrix multiplication is associative.
It does not matter whether you start left or right or in the middle -
that is not the same as not being commutative.
Cheers,
Tim
--
Dr Tim Gruene
Institut fuer anorganische Chemie
Tammannstr. 4
D-37077 Goettingen
GPG Key ID = A46BEE1A
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