Creating uniform random quaternion and multiplication of two quaternions

Question

I have a python (NumPy) function which creates a uniform random quaternion. I would like to get two quaternion multiplication as 2-dimensional returned array from the same or an

Answer 1

A 2-Dimensional Array is an array like this: foo[0][1]

You don't need to do that. Multiplying two quaternions yields one single quaternion. I don't see why you would need a two-dimensional array, or how you would even use one.

Just have a function that takes two arrays as arguments:

def multQuat(q1, q2):

then return the relevant array.

return array([-q2[1] * q1[1], ...])

Answer 2

A simple rendition of your request would be:

In [70]: def multQ(Q1,Q2):
    ...:     w0,x0,y0,z0 = Q1   # unpack
    ...:     w1,x1,y1,z1 = Q2
    ...:     return([-x1*x0 - y1*y0 - z1*z0 + w1*w0, x1*w0 + y1*z0 - z1*y0 +
    ...:     w1*x0, -x1*z0 + y1*w0 + z1*x0 + w1*y0, x1*y0 - y1*x0 + z1*w0 +
    ...:     w1*z0])
    ...:     

In [72]: multQ(randQ(1),randQ(2))
Out[72]: 
[array([-0.37695449,  0.79178506]),
 array([-0.38447116,  0.22030199]),
 array([ 0.44019022,  0.56496059]),
 array([ 0.71855397,  0.07323243])]

The result is a list of 4 arrays. Just wrap it in np.array() to get a 2d array:

In [73]: M=np.array(_)

In [74]: M
Out[74]: 
array([[-0.37695449,  0.79178506],
       [-0.38447116,  0.22030199],
       [ 0.44019022,  0.56496059],
       [ 0.71855397,  0.07323243]])

I haven't tried to understand or clean up your description - just rendering it as working code.