Product of array elements
(Quaternion overloading of standard MATLAB® function)
Y = prod(X, dim)
prod(X, dim) computes the product of the elements of the quaternion array X along dimension dim.
The ordering within the product is important, because of the non-commutative quaternion product: the product is computed with the lowest index on the left and the highest index on the right (that is, left to right for a row vector, or downwards for a column vector).
>> prod([qi, qj, qk]) == -1 ans = 1