test_cubic_spline_test_general.txt

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============================= test session starts ==============================
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collecting ... collected 1 item

scipy/interpolate/tests/test_polyint.py::TestCubicSpline::test_general FAILED [100%]

=================================== FAILURES ===================================
_________________________ TestCubicSpline.test_general _________________________

self = <scipy.interpolate.tests.test_polyint.TestCubicSpline object at 0xf4b04e8c>

    def test_general(self):
        x = np.array([-1, 0, 0.5, 2, 4, 4.5, 5.5, 9])
        y = np.array([0, -0.5, 2, 3, 2.5, 1, 1, 0.5])
        for n in [2, 3, x.size]:
            self.check_all_bc(x[:n], y[:n], 0)
    
            Y = np.empty((2, n, 2))
            Y[0, :, 0] = y[:n]
            Y[0, :, 1] = y[:n] - 1
            Y[1, :, 0] = y[:n] + 2
            Y[1, :, 1] = y[:n] + 3
>           self.check_all_bc(x[:n], Y, 1)

Y          = array([[[ 0. , -1. ],
        [-0.5, -1.5],
        [ 2. ,  1. ]],

       [[ 2. ,  3. ],
        [ 1.5,  2.5],
        [ 4. ,  5. ]]])
n          = 3
self       = <scipy.interpolate.tests.test_polyint.TestCubicSpline object at 0xf4b04e8c>
x          = array([-1. ,  0. ,  0.5,  2. ,  4. ,  4.5,  5.5,  9. ])
y          = array([ 0. , -0.5,  2. ,  3. ,  2.5,  1. ,  1. ,  0.5])

scipy/interpolate/tests/test_polyint.py:576: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
scipy/interpolate/tests/test_polyint.py:558: in check_all_bc
    self.check_correctness(S, bc, bc)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

S = <scipy.interpolate._cubic.CubicSpline object at 0xf4b1114c>
bc_start = 'natural', bc_end = 'natural', tol = 1e-14

    @staticmethod
    def check_correctness(S, bc_start='not-a-knot', bc_end='not-a-knot',
                          tol=1e-14):
        """Check that spline coefficients satisfy the continuity and boundary
            conditions."""
        x = S.x
        c = S.c
        dx = np.diff(x)
        dx = dx.reshape([dx.shape[0]] + [1] * (c.ndim - 2))
        dxi = dx[:-1]
    
        # Check C2 continuity.
        assert_allclose(c[3, 1:], c[0, :-1] * dxi**3 + c[1, :-1] * dxi**2 +
                        c[2, :-1] * dxi + c[3, :-1], rtol=tol, atol=tol)
        assert_allclose(c[2, 1:], 3 * c[0, :-1] * dxi**2 +
                        2 * c[1, :-1] * dxi + c[2, :-1], rtol=tol, atol=tol)
        assert_allclose(c[1, 1:], 3 * c[0, :-1] * dxi + c[1, :-1],
                        rtol=tol, atol=tol)
    
        # Check that we found a parabola, the third derivative is 0.
        if x.size == 3 and bc_start == 'not-a-knot' and bc_end == 'not-a-knot':
            assert_allclose(c[0], 0, rtol=tol, atol=tol)
            return
    
        # Check periodic boundary conditions.
        if bc_start == 'periodic':
            assert_allclose(S(x[0], 0), S(x[-1], 0), rtol=tol, atol=tol)
            assert_allclose(S(x[0], 1), S(x[-1], 1), rtol=tol, atol=tol)
            assert_allclose(S(x[0], 2), S(x[-1], 2), rtol=tol, atol=tol)
            return
    
        # Check other boundary conditions.
        if bc_start == 'not-a-knot':
            if x.size == 2:
                slope = (S(x[1]) - S(x[0])) / dx[0]
                assert_allclose(S(x[0], 1), slope, rtol=tol, atol=tol)
            else:
                assert_allclose(c[0, 0], c[0, 1], rtol=tol, atol=tol)
        elif bc_start == 'clamped':
            assert_allclose(S(x[0], 1), 0, rtol=tol, atol=tol)
        elif bc_start == 'natural':
            assert_allclose(S(x[0], 2), 0, rtol=tol, atol=tol)
        else:
            order, value = bc_start
            assert_allclose(S(x[0], order), value, rtol=tol, atol=tol)
    
        if bc_end == 'not-a-knot':
            if x.size == 2:
                slope = (S(x[1]) - S(x[0])) / dx[0]
                assert_allclose(S(x[1], 1), slope, rtol=tol, atol=tol)
            else:
                assert_allclose(c[0, -1], c[0, -2], rtol=tol, atol=tol)
        elif bc_end == 'clamped':
            assert_allclose(S(x[-1], 1), 0, rtol=tol, atol=tol)
        elif bc_end == 'natural':
>           assert_allclose(S(x[-1], 2), 0, rtol=tol, atol=tol)
E           AssertionError: 
E           Not equal to tolerance rtol=1e-14, atol=1e-14
E           
E           (mismatch 100.0%)
E            x: array([[-1.065814e-14, -1.065814e-14],
E                  [-1.065814e-14, -1.065814e-14]])
E            y: array(0)

S          = <scipy.interpolate._cubic.CubicSpline object at 0xf4b1114c>
bc_end     = 'natural'
bc_start   = 'natural'
c          = array([[[[ 1.83333333,  1.83333333],
         [ 1.83333333,  1.83333333]],

        [[-3.66666667, -3.66666667],
     ... ],
         [ 2.        ,  3.        ]],

        [[-0.5       , -1.5       ],
         [ 1.5       ,  2.5       ]]]])
dx         = array([[[1. ]],

       [[0.5]]])
dxi        = array([[[1.]]])
tol        = 1e-14
x          = array([-1. ,  0. ,  0.5])

scipy/interpolate/tests/test_polyint.py:537: AssertionError
=========================== 1 failed in 0.32 seconds ===========================