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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