test_prde.py 文件源码

def test_is_deriv_k():
    DE = DifferentialExtension(extension={'D': [Poly(1, x), Poly(1/x, t1), Poly(1/(x + 1), t2)],
        'L_K': [1, 2], 'E_K': [], 'L_args': [x, x + 1], 'E_args': []})
    assert is_deriv_k(Poly(2*x**2 + 2*x, t2), Poly(1, t2), DE) == \
        ([(t1, 1), (t2, 1)], t1 + t2, 2)

    DE = DifferentialExtension(extension={'D': [Poly(1, x), Poly(1/x, t1), Poly(t2, t2)],
        'L_K': [1], 'E_K': [2], 'L_args': [x], 'E_args': [x]})
    assert is_deriv_k(Poly(x**2*t2**3, t2), Poly(1, t2), DE) == \
        ([(x, 3), (t1, 2)], 2*t1 + 3*x, 1)
    # TODO: Add more tests, including ones with exponentials

    DE = DifferentialExtension(extension={'D': [Poly(1, x), Poly(2/x, t1)],
        'L_K': [1], 'E_K': [], 'L_args': [x**2], 'E_args': []})
    assert is_deriv_k(Poly(x, t1), Poly(1, t1), DE) == \
        ([(t1, S(1)/2)], t1/2, 1)

    DE = DifferentialExtension(extension={'D': [Poly(1, x), Poly(2/(1 + x), t0)],
        'L_K': [1], 'E_K': [], 'L_args': [x**2 + 2*x + 1], 'E_args': []})
    assert is_deriv_k(Poly(1 + x, t0), Poly(1, t0), DE) == \
        ([(t0, S(1)/2)], t0/2, 1)