def test_trivial_noninvertible(self):
def f(x):
del x
return 1.
with self.assertRaises(ValueError):
inverse(f)(1.)
def test_simple_inverse(self):
def f(x):
return np.exp(x)
f_inv = inverse(f, 0.1)
onp.testing.assert_allclose(f_inv(1.0), 0.)
def f2(x):
return np.exp(x)
f2_inv = inverse(f2, np.zeros(2))
onp.testing.assert_allclose(f2_inv(np.ones(2)), np.zeros(2))
def test_div_inverse(self):
def f(x):
return x / 2.
f_inv = inverse(f)
onp.testing.assert_allclose(f_inv(1.0), 2.)
def f2(x):
return 2. / x
f2_inv = inverse(f2)
onp.testing.assert_allclose(f2_inv(1.0), 2.)
def test_mul_inverse(self):
def f(x):
return x * 2.
f_inv = inverse(f)
onp.testing.assert_allclose(f_inv(1.0), 0.5)
def f2(x):
return 2. * x
f2_inv = inverse(f2)
onp.testing.assert_allclose(f2_inv(1.0), 0.5)
def test_trivial_inverse(self):
def f(x):
return x
f_inv = inverse(f)
onp.testing.assert_allclose(f_inv(1.0), 1.0)
def f2(x, y):
return x, y
f2_inv = inverse(f2)
onp.testing.assert_allclose(f2_inv(1.0, 2.0), (1.0, 2.0))
def test_advanced_inverse_two(self):
def f(x, y):
return np.exp(x), x**2 + y
f_inv = inverse(f, 0.1, 0.2)
onp.testing.assert_allclose(f_inv(2.0, 2.0),
(np.log(2.), 2 - np.log(2.)**2))
def test_advanced_inverse_three(self):
def f(x, y, z):
return np.exp(x), x**2 + y, np.exp(z + y)
f_inv = inverse(f, 0., 0., 0.)
onp.testing.assert_allclose(
f_inv(2.0, 2.0, 2.0),
(np.log(2.), 2 - np.log(2.)**2, np.log(2.0) - (2 - np.log(2.)**2)))
def test_conditional_inverse(self):
def f(x, y):
return x + 1., np.exp(x + 1.) + y
f_inv = inverse(f, 0., 2.)
onp.testing.assert_allclose(f_inv(0., 2.), (-1., 1.))
def test_noninvertible(self):
def f(x, y):
return x + y, x + y
with self.assertRaises(ValueError):
inverse(f)(1., 2.)