Vector or cross product of two quaternions, or two or three octonions
Y = vector_product(A, B)
vector_product(A, B) returns the vector (or cross) product of the two arguments, elementwise on the two arrays, which must be pure.
The octonion version of the function accepts two or three parameters. The three-fold vector product is defined for full octonions. Its result is invariant to cyclic permutation of the parameters, but changes sign if two are interchanged.
>> vector_product(qi, qj) == qk ans = 1