def test_solve_discrete_lyapunov_zero():
 A = (np.eye(4) * 0.95)
 B = np.zeros((4, 4))
 X = qme.solve_discrete_lyapunov(A, B)
 assert_allclose(X, np.zeros((4, 4)))

def test_solve_discrete_lyapunov_zero ( ) : A = ( np . eye ( 4 ) * 0.95 ) B = np . zeros ( ( 4 , 4 ) ) X = qme . solve_discrete_lyapunov ( A , B ) assert_allclose ( X , np . zeros ( ( 4 , 4 ) ) )
simple test where x is all zeros .