test_polysys.py 文件源码

def test_solve_poly_system():
    assert solve_poly_system([x - 1], x) == [(S.One,)]

    assert solve_poly_system([y - x, y - x - 1], x, y) is None

    assert solve_poly_system([y - x**2, y + x**2], x, y) == [(S.Zero, S.Zero)]

    assert solve_poly_system([2*x - 3, 3*y/2 - 2*x, z - 5*y], x, y, z) == \
        [(Rational(3, 2), Integer(2), Integer(10))]

    assert solve_poly_system([x*y - 2*y, 2*y**2 - x**2], x, y) == \
        [(0, 0), (2, -sqrt(2)), (2, sqrt(2))]

    assert solve_poly_system([y - x**2, y + x**2 + 1], x, y) == \
        [(-I*sqrt(S.Half), -S.Half), (I*sqrt(S.Half), -S.Half)]

    f_1 = x**2 + y + z - 1
    f_2 = x + y**2 + z - 1
    f_3 = x + y + z**2 - 1

    a, b = sqrt(2) - 1, -sqrt(2) - 1

    assert solve_poly_system([f_1, f_2, f_3], x, y, z) == \
        [(0, 0, 1), (0, 1, 0), (1, 0, 0), (a, a, a), (b, b, b)]

    solution = [(1, -1), (1, 1)]

    assert solve_poly_system([Poly(x**2 - y**2), Poly(x - 1)]) == solution
    assert solve_poly_system([x**2 - y**2, x - 1], x, y) == solution
    assert solve_poly_system([x**2 - y**2, x - 1]) == solution

    assert solve_poly_system(
        [x + x*y - 3, y + x*y - 4], x, y) == [(-3, -2), (1, 2)]

    raises(NotImplementedError, lambda: solve_poly_system([x**3 - y**3], x, y))
    raises(PolynomialError, lambda: solve_poly_system([1/x], x))