def _compute_A(system_size, theta):
    (u, v, cross_terms, same_terms) = _compute_vector_terms(system_size)
    return ((np.eye(system_size) + (np.sin(theta) * cross_terms)) + ((np.cos(theta) - 1) * same_terms))
def _compute_A(system_size, theta):
    (u, v, cross_terms, same_terms) = _compute_vector_terms(system_size)
    return ((np.eye(system_size) + (np.sin(theta) * cross_terms)) + ((np.cos(theta) - 1) * same_terms))