=================================== FAILURES ===================================
1967________________________ TestCanonical.test_modal_form _________________________
1968
1969self = <control.tests.canonical_test.TestCanonical testMethod=test_modal_form>
1970
1971    def test_modal_form(self):
1972        """Test the modal canonical form"""
1973    
1974        # Create a system in the modal canonical form
1975        A_true = np.diag([4.0, 3.0, 2.0, 1.0]) # order from the largest to the smallest
1976        B_true = np.matrix("1.1 2.2 3.3 4.4").T
1977        C_true = np.matrix("1.3 1.4 1.5 1.6")
1978        D_true = 42.0
...
2016>       sys_check, T_check = canonical_form(ss(A, B, C, D), 'modal')
2017
2018control/tests/canonical_test.py:107: 
2019_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
2020control/canonical.py:42: in canonical_form
2021    return modal_form(xsys)
2022control/canonical.py:211: in modal_form
2023    zsys.A = solve(Tzx, xsys.A).dot(Tzx)
2024<__array_function__ internals>:5: in solve
2025    ???
2026../../../miniconda/envs/test-environment/lib/python3.8/site-packages/numpy/linalg/linalg.py:385: in solve
2027    _assert_stacked_2d(a)
2028_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
2029
2030arrays = (array([-0.56303537, -0.3564182 ,  0.06171638, -0.22836009,  0.        ,
2031        0.17111809, -0.54651494, -0.41477707,  0.40688007, -0.8141637 ,
2032       -0.38002113,  0.16483334, -0.44769516,  0.15654653, -0.50060858,
2033        0.72419146]),)
2034a = array([-0.56303537, -0.3564182 ,  0.06171638, -0.22836009,  0.        ,
2035        0.17111809, -0.54651494, -0.41477707,  0.40688007, -0.8141637 ,
2036       -0.38002113,  0.16483334, -0.44769516,  0.15654653, -0.50060858,
2037        0.72419146])
2038
2039    def _assert_stacked_2d(*arrays):
2040        for a in arrays:
2041            if a.ndim < 2:
2042>               raise LinAlgError('%d-dimensional array given. Array must be '
2043                        'at least two-dimensional' % a.ndim)
2044E               numpy.linalg.LinAlgError: 1-dimensional array given. Array must be at least two-dimensional
2045
2046../../../miniconda/envs/test-environment/lib/python3.8/site-packages/numpy/linalg/linalg.py:206: LinAlgError

2047______________________ TestCanonical.test_observable_form ______________________
2048
2049self = <control.tests.canonical_test.TestCanonical testMethod=test_observable_form>
2050
2051    def test_observable_form(self):
2052        """Test the observable canonical form"""
2053    
...
2058        B_true = np.matrix("1.0 1.0 1.0 1.0").T
...
2071    
2072        # Create a state space system and convert it to the observable canonical form
2073        sys_check, T_check = canonical_form(ss(A, B, C, D), "observable")
2074    
2075        # Check against the true values
2076        np.testing.assert_array_almost_equal(sys_check.A, A_true)
2077>       np.testing.assert_array_almost_equal(sys_check.B, B_true)
2078E       AssertionError: 
2079E       Arrays are not almost equal to 6 decimals
2080E       
2081E       (shapes (4, 4), (4, 1) mismatch)
2082E        x: array([[ 0.508834,  0.748576, -1.417827, -0.827351],
2083E              [-0.134752, -0.070451, -0.032659, -0.090651],
2084E              [-0.18486 ,  0.369904,  0.172657, -0.07489 ],
2085E              [-0.222568,  0.077826, -0.248874,  0.360027]])
2086E        y: matrix([[1.],
2087E               [1.],
2088E               [1.],
2089E               [1.]])
2090
2091control/tests/canonical_test.py:190: AssertionError

2092________________________ TestCanonical.test_similarity _________________________
2093
2094self = <control.tests.canonical_test.TestCanonical testMethod=test_similarity>
2095
2096    def test_similarity(self):
2097        """Test similarty transform"""
2098    
2099        # Single input, single output systems
2100        siso_ini = tf2ss(tf([1, 1], [1, 1, 1]))
2101        for form in 'reachable', 'observable':
2102            # Convert the system to one of the canonical forms
2103            siso_can, T_can = canonical_form(siso_ini, form)
2104    
2105            # Use a similarity transformation to transform it back
2106>           siso_sim = similarity_transform(siso_can, np.linalg.inv(T_can))
2107
2108control/tests/canonical_test.py:231: 
2109_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
2110control/canonical.py:238: in similarity_transform
2111    zsys = StateSpace(xsys)
2112_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
2113
2114self = StateSpace(array([[-1.,  1.],
2115       [-1.,  0.]]), array([[ 1., -1.],
2116       [ 0., -0.]]), array([[1., 0.]]), array([[0.]]))
2117args = (StateSpace(array([[-1.,  1.],
2118       [-1.,  0.]]), array([[ 1., -1.],
2119       [ 0., -0.]]), array([[1., 0.]]), array([[0.]])),)
2120kw = {}, A = array([[-1.,  1.],
2121       [-1.,  0.]])
2122B = array([[ 1., -1.],
2123       [ 0., -0.]]), C = array([[1., 0.]])
2124D = array([[0.]]), dt = None, remove_useless = True
2125
2126    def __init__(self, *args, **kw):
2127        """
2128        StateSpace(A, B, C, D[, dt])
...
2206>           raise ValueError("B and D must have the same number of columns.")
2207E           ValueError: B and D must have the same number of columns.
2208
2209control/statesp.py:246: ValueError