Multiplication with scalar depend on order

[hovren]

Order of multiplication of scalar and quaternion matters. It works fine from right:

>>> q = np.quaternion(1,2,3,4)
>>> q * 5
quaternion(5, 10, 15, 20)

But not from left:

>>> 5 * q
TypeError: Input object is not a quaternion.

Even worse is that if you do this with an array of quaternions, there is no warning, but the result seems to be more or less random.

>>> q * np.arange(5)  # OK!
array([quaternion(0, 0, 0, 0), quaternion(1, 2, 3, 4),
   quaternion(2, 4, 6, 8), quaternion(3, 6, 9, 12),
   quaternion(4, 8, 12, 16)], dtype=quaternion)

>>> np.arange(5) * q  # Woops!
array([quaternion(4, 8, 12, 16), quaternion(0, 0, 0, 0),
   quaternion(0, 0, 0, 0), quaternion(0, 0, 0, 0),
   quaternion(0, 0, 0, 0)], dtype=quaternion)

[moble]

Thanks for opening this issue. I've figured out why 5*q wasn't working and found a bunch of less common bugs caused by the same line of code. I've added tests for this and the various other problems I turned up, and made sure they all pass. Will push that momentarily.

I'll have to dig a little more to figure out the array problem, but I'm working on it.

[moble]

I've added lots of tests to check all the (binary) ufuncs. So I'm satisfied that the second problem you pointed out is now also solved.

Thanks again for pointing this out, and please let me know if you find any more problems.

[hovren]

I can confirm that it works now. Thanks!