test_prde.py 文件源码

def test_prde_special_denom():
    a = Poly(t + 1, t)
    ba = Poly(t**2, t)
    bd = Poly(1, t)
    G = [(Poly(t, t), Poly(1, t)), (Poly(t**2, t), Poly(1, t)), (Poly(t**3, t), Poly(1, t))]
    DE = DifferentialExtension(extension={'D': [Poly(1, x), Poly(t, t)]})
    assert prde_special_denom(a, ba, bd, G, DE) == \
        (Poly(t + 1, t), Poly(t**2, t), [(Poly(t, t), Poly(1, t)),
        (Poly(t**2, t), Poly(1, t)), (Poly(t**3, t), Poly(1, t))], Poly(1, t))
    G = [(Poly(t, t), Poly(1, t)), (Poly(1, t), Poly(t, t))]
    assert prde_special_denom(Poly(1, t), Poly(t**2, t), Poly(1, t), G, DE) == \
        (Poly(1, t), Poly(t**2 - 1, t), [(Poly(t**2, t), Poly(1, t)),
        (Poly(1, t), Poly(1, t))], Poly(t, t))
    DE = DifferentialExtension(extension={'D': [Poly(1, x), Poly(-2*x*t0, t0)]})
    DE.decrement_level()
    G = [(Poly(t, t), Poly(t**2, t)), (Poly(2*t, t), Poly(t, t))]
    assert prde_special_denom(Poly(5*x*t + 1, t), Poly(t**2 + 2*x**3*t, t), Poly(t**3 + 2, t), G, DE) == \
        (Poly(5*x*t + 1, t), Poly(0, t), [(Poly(t, t), Poly(t**2, t)),
        (Poly(2*t, t), Poly(t, t))], Poly(1, x))
    DE = DifferentialExtension(extension={'D': [Poly(1, x), Poly((t**2 + 1)*2*x, t)]})
    G = [(Poly(t + x, t), Poly(t*x, t)), (Poly(2*t, t), Poly(x**2, x))]
    assert prde_special_denom(Poly(5*x*t + 1, t), Poly(t**2 + 2*x**3*t, t), Poly(t**3, t), G, DE) == \
        (Poly(5*x*t + 1, t), Poly(0, t), [(Poly(t + x, t), Poly(x*t, t)),
        (Poly(2*t, t, x), Poly(x**2, t, x))], Poly(1, t))
    assert prde_special_denom(Poly(t + 1, t), Poly(t**2, t), Poly(t**3, t), G, DE) == \
        (Poly(t + 1, t), Poly(0, t), [(Poly(t + x, t), Poly(x*t, t)), (Poly(2*t, t, x),
        Poly(x**2, t, x))], Poly(1, t))