Negative scalings

[alackofcolor]

Using your decompose44 function, it correctly picks out the scaling factors, but doesn't seem to handle negative scalings. That is, reflections. Any way it could be modified to account for negative scalings? For example, the following matrix

A = np.array([[-2, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]])

should give

sx = -2
sy = 1
sz = 1

Thanks.

[LoiseauNicolas]

I got the same problem, what is the right way to have a positiv scale ?

[matthew-brett]

Sorry to be so slow. Just in case you're still interested, this is what I get:

[ins] In [6]: transforms3d.affines.decompose(A)                                                                        
Out[6]: 
(array([0, 0, 0]),
 array([[1., 0., 0.],
        [0., 1., 0.],
        [0., 0., 1.]]),
 array([-2.,  1.,  1.]),
 array([0., 0., 0.]))

Not so for you?

[matthew-brett]

@alackofcolor @LoiseauNicolas - checking back here - what do you get for my code above?