def testBijectorIdentity(self):
with self.cached_session():
chain = Chain()
self.assertEqual("identity", chain.name)
x = np.asarray([[[1., 2.],
[2., 3.]]])
self.assertAllClose(x, chain.forward(x).eval())
self.assertAllClose(x, chain.inverse(x).eval())
self.assertAllClose(
0., chain.inverse_log_det_jacobian(x, event_ndims=1).eval())
self.assertAllClose(
0., chain.forward_log_det_jacobian(x, event_ndims=1).eval())
def testBijector(self):
with self.cached_session():
chain = Chain((Exp(), Softplus()))
self.assertEqual("chain_of_exp_of_softplus", chain.name)
x = np.asarray([[[1., 2.],
[2., 3.]]])
self.assertAllClose(1. + np.exp(x), chain.forward(x).eval())
self.assertAllClose(np.log(x - 1.), chain.inverse(x).eval())
self.assertAllClose(
-np.sum(np.log(x - 1.), axis=2),
chain.inverse_log_det_jacobian(x, event_ndims=1).eval())
self.assertAllClose(
np.sum(x, axis=2),
chain.forward_log_det_jacobian(x, event_ndims=1).eval())
def testChainAffineExp(self):
scale_diag = np.array([1., 2., 3.], dtype=np.float32)
chain = Chain([Affine(scale_diag=scale_diag), Exp()])
x = [0., np.log(2., dtype=np.float32), np.log(3., dtype=np.float32)]
y = [1., 4., 9.]
self.assertAllClose(y, self.evaluate(chain.forward(x)))
self.assertAllClose(x, self.evaluate(chain.inverse(y)))
self.assertAllClose(
np.log(6, dtype=np.float32) + np.sum(x),
self.evaluate(chain.forward_log_det_jacobian(x, event_ndims=1)))
self.assertAllClose(
-np.log(6, dtype=np.float32) - np.sum(x),
self.evaluate(chain.inverse_log_det_jacobian(y, event_ndims=1)))