def test_forward_methods_are_correct(self):
key = jax.random.PRNGKey(42)
x = jax.random.normal(key, (2, 3, 4, 5))
bij_no_scale = scalar_affine.ScalarAffine(shift=3.)
bij_with_scale = scalar_affine.ScalarAffine(shift=3., scale=1.)
bij_with_log_scale = scalar_affine.ScalarAffine(shift=3., log_scale=0.)
for bij in [bij_no_scale, bij_with_scale, bij_with_log_scale]:
y, logdet = self.variant(bij.forward_and_log_det)(x)
np.testing.assert_allclose(y, x + 3., atol=1e-8)
np.testing.assert_allclose(logdet, 0., atol=1e-8)
def test_inverse_methods_are_correct(self):
k1, k2, k3, k4 = jax.random.split(jax.random.PRNGKey(42), 4)
x = jax.random.normal(k1, (2, 3, 4, 5))
shift = jax.random.normal(k2, (4, 5))
scale = jax.random.uniform(k3, (3, 4, 5)) + 0.1
log_scale = jax.random.normal(k4, (3, 4, 5))
bij_no_scale = scalar_affine.ScalarAffine(shift)
bij_with_scale = scalar_affine.ScalarAffine(shift, scale=scale)
bij_with_log_scale = scalar_affine.ScalarAffine(shift,
log_scale=log_scale)
for bij in [bij_no_scale, bij_with_scale, bij_with_log_scale]:
y, logdet_fwd = self.variant(bij.forward_and_log_det)(x)
x_rec, logdet_inv = self.variant(bij.inverse_and_log_det)(y)
np.testing.assert_allclose(x_rec, x, atol=1e-5)
np.testing.assert_allclose(logdet_fwd, -logdet_inv, atol=3e-6)
def test_properties(self):
bij = scalar_affine.ScalarAffine(shift=0., scale=1.)
self.assertTrue(bij.is_constant_jacobian)
self.assertTrue(bij.is_constant_log_det)
np.testing.assert_allclose(bij.shift, 0.)
np.testing.assert_allclose(bij.scale, 1.)
np.testing.assert_allclose(bij.log_scale, 0.)
def test_jittable(self):
@jax.jit
def f(x, b):
return b.forward(x)
bijector = block_bijector.Block(scalar_affine.ScalarAffine(0), 1)
x = np.zeros((2, 3))
f(x, bijector)
def test_jittable(self):
@jax.jit
def f(x, b):
return b.forward(x)
bijector = scalar_affine.ScalarAffine(0, 1)
x = np.zeros(())
f(x, bijector)
def test_integer_inputs(self, inputs):
bijector = inverse.Inverse(scalar_affine.ScalarAffine(shift=1.0))
output, log_det = self.variant(bijector.forward_and_log_det)(inputs)
expected_out = jnp.array(inputs, dtype=jnp.float32) - 1.0
expected_log_det = jnp.zeros_like(inputs, dtype=jnp.float32)
np.testing.assert_array_equal(output, expected_out)
np.testing.assert_array_equal(log_det, expected_log_det)
def test_shapes_are_correct(self):
k1, k2, k3, k4 = jax.random.split(jax.random.PRNGKey(42), 4)
x = jax.random.normal(k1, (2, 3, 4, 5))
shift = jax.random.normal(k2, (4, 5))
scale = jax.random.uniform(k3, (3, 4, 5)) + 0.1
log_scale = jax.random.normal(k4, (3, 4, 5))
bij_no_scale = scalar_affine.ScalarAffine(shift)
bij_with_scale = scalar_affine.ScalarAffine(shift, scale=scale)
bij_with_log_scale = scalar_affine.ScalarAffine(shift,
log_scale=log_scale)
for bij in [bij_no_scale, bij_with_scale, bij_with_log_scale]:
# Forward methods.
y, logdet = self.variant(bij.forward_and_log_det)(x)
self.assertEqual(y.shape, (2, 3, 4, 5))
self.assertEqual(logdet.shape, (2, 3, 4, 5))
# Inverse methods.
x, logdet = self.variant(bij.inverse_and_log_det)(y)
self.assertEqual(x.shape, (2, 3, 4, 5))
self.assertEqual(logdet.shape, (2, 3, 4, 5))
def test_jittable(self):
@jax.jit
def f(x, d):
return d.log_prob(x)
base = normal.Normal(0, 1)
bijector = scalar_affine.ScalarAffine(0, 1)
dist = transformed.Transformed(base, bijector)
x = np.zeros(())
f(x, dist)
def test_batched_parameters(self, scale_batch_shape, shift_batch_shape,
input_batch_shape):
k1, k2, k3 = jax.random.split(jax.random.PRNGKey(42), 3)
log_scale = jax.random.normal(k1, scale_batch_shape)
shift = jax.random.normal(k2, shift_batch_shape)
bijector = scalar_affine.ScalarAffine(shift, log_scale=log_scale)
x = jax.random.normal(k3, input_batch_shape)
y, logdet_fwd = self.variant(bijector.forward_and_log_det)(x)
z, logdet_inv = self.variant(bijector.inverse_and_log_det)(x)
output_batch_shape = jnp.broadcast_arrays(log_scale, shift, x)[0].shape
self.assertEqual(y.shape, output_batch_shape)
self.assertEqual(z.shape, output_batch_shape)
self.assertEqual(logdet_fwd.shape, output_batch_shape)
self.assertEqual(logdet_inv.shape, output_batch_shape)
log_scale = jnp.broadcast_to(log_scale, output_batch_shape).flatten()
shift = jnp.broadcast_to(shift, output_batch_shape).flatten()
x = jnp.broadcast_to(x, output_batch_shape).flatten()
y = y.flatten()
z = z.flatten()
logdet_fwd = logdet_fwd.flatten()
logdet_inv = logdet_inv.flatten()
for i in range(np.prod(output_batch_shape)):
bijector = scalar_affine.ScalarAffine(shift[i],
jnp.exp(log_scale[i]))
this_y, this_logdet_fwd = self.variant(
bijector.forward_and_log_det)(x[i])
this_z, this_logdet_inv = self.variant(
bijector.inverse_and_log_det)(x[i])
np.testing.assert_allclose(this_y, y[i], atol=1e-7)
np.testing.assert_allclose(this_z, z[i], atol=1e-5)
np.testing.assert_allclose(this_logdet_fwd,
logdet_fwd[i],
atol=1e-4)
np.testing.assert_allclose(this_logdet_inv,
logdet_inv[i],
atol=1e-4)
def test_integer_inputs(self, inputs, base_dist):
base = base_dist(jnp.zeros_like(inputs, dtype=jnp.float32),
jnp.ones_like(inputs, dtype=jnp.float32))
bijector = scalar_affine.ScalarAffine(shift=0.0)
dist = transformed.Transformed(base, bijector)
log_prob = self.variant(dist.log_prob)(inputs)
standard_normal_log_prob_of_zero = -0.9189385
expected_log_prob = jnp.full_like(
inputs, standard_normal_log_prob_of_zero, dtype=jnp.float32)
np.testing.assert_array_equal(log_prob, expected_log_prob)
def test_composite_methods_are_consistent(self):
k1, k2, k3, k4 = jax.random.split(jax.random.PRNGKey(42), 4)
bij = scalar_affine.ScalarAffine(shift=jax.random.normal(k1, (4, 5)),
log_scale=jax.random.normal(
k2, (4, 5)))
# Forward methods.
x = jax.random.normal(k3, (2, 3, 4, 5))
y1 = self.variant(bij.forward)(x)
logdet1 = self.variant(bij.forward_log_det_jacobian)(x)
y2, logdet2 = self.variant(bij.forward_and_log_det)(x)
np.testing.assert_allclose(y1, y2, atol=1e-12)
np.testing.assert_allclose(logdet1, logdet2, atol=1e-12)
# Inverse methods.
y = jax.random.normal(k4, (2, 3, 4, 5))
x1 = self.variant(bij.inverse)(y)
logdet1 = self.variant(bij.inverse_log_det_jacobian)(y)
x2, logdet2 = self.variant(bij.inverse_and_log_det)(y)
np.testing.assert_allclose(x1, x2, atol=1e-12)
np.testing.assert_allclose(logdet1, logdet2, atol=1e-12)
def test_raises_if_both_scale_and_log_scale_are_specified(self):
with self.assertRaises(ValueError):
scalar_affine.ScalarAffine(shift=0., scale=1., log_scale=0.)
