def test_jac_matrix():
f1 = lambda x, y: Var.log(x)**Var.sin(y)
f2 = lambda x, y: Var.sqrt(x) / y
ad = AD(np.array([4.12, 5.13]), np.array([1, 1]))
assert np.array_equal(
ad.jac_matrix([f1, f2]),
np.array([[pytest.approx(-0.11403015),
pytest.approx(0.10263124)],
[pytest.approx(0.048018),
pytest.approx(-0.07712832)]]))
def test_sqrt():
x = Var(3, np.array([1]))
y = 2
assert Var.sqrt(x) == Var(pytest.approx(1.7320508075688772),
np.array([pytest.approx(0.28867513)]))
assert Var.sqrt(y) == np.sqrt(y)
