def test_normal_prior_batch_log_prob(self, cuda=False):
device = torch.device("cuda") if cuda else torch.device("cpu")
mean = torch.tensor([0.0, 1.0], device=device)
variance = torch.tensor([1.0, 2.0], device=device)
prior = NormalPrior(mean, variance)
dist = Normal(mean, variance)
t = torch.zeros(2, device=device)
self.assertTrue(torch.equal(prior.log_prob(t), dist.log_prob(t)))
t = torch.zeros(2, 2, device=device)
self.assertTrue(torch.equal(prior.log_prob(t), dist.log_prob(t)))
with self.assertRaises(RuntimeError):
prior.log_prob(torch.zeros(3, device=device))
mean = torch.tensor([[0.0, 1.0], [-1.0, 2.0]], device=device)
variance = torch.tensor([[1.0, 2.0], [0.5, 1.0]], device=device)
prior = NormalPrior(mean, variance)
dist = Normal(mean, variance)
t = torch.zeros(2, device=device)
self.assertTrue(torch.equal(prior.log_prob(t), dist.log_prob(t)))
t = torch.zeros(2, 2, device=device)
self.assertTrue(torch.equal(prior.log_prob(t), dist.log_prob(t)))
with self.assertRaises(RuntimeError):
prior.log_prob(torch.zeros(3, device=device))
with self.assertRaises(RuntimeError):
prior.log_prob(torch.zeros(2, 3, device=device))
def test_normal_prior_log_prob_log_transform(self, cuda=False):
device = torch.device("cuda") if cuda else torch.device("cpu")
mean = torch.tensor(0.0, device=device)
variance = torch.tensor(1.0, device=device)
prior = NormalPrior(mean, variance, transform=torch.exp)
dist = Normal(mean, variance)
t = torch.tensor(0.0, device=device)
self.assertTrue(torch.equal(prior.log_prob(t), dist.log_prob(t.exp())))
t = torch.tensor([-1, 0.5], device=device)
self.assertTrue(torch.equal(prior.log_prob(t), dist.log_prob(t.exp())))
t = torch.tensor([[-1, 0.5], [0.1, -2.0]], device=device)
self.assertTrue(torch.equal(prior.log_prob(t), dist.log_prob(t.exp())))
def test_scalar_normal_prior_log_transform(self):
prior = NormalPrior(0, 1, log_transform=True)
self.assertTrue(prior.log_transform)
self.assertAlmostEqual(prior.log_prob(prior.loc.new([0.0])).item(),
math.log(1 / math.sqrt(2 * math.pi) *
math.exp(-0.5)),
places=5)
def test_scalar_normal_prior(self):
prior = NormalPrior(0, 1)
self.assertFalse(prior.log_transform)
self.assertTrue(prior.is_in_support(torch.rand(1)))
self.assertEqual(prior.shape, torch.Size([1]))
self.assertEqual(prior.loc.item(), 0.0)
self.assertEqual(prior.scale.item(), 1.0)
self.assertAlmostEqual(prior.log_prob(prior.loc.new([0.0])).item(),
math.log(1 / math.sqrt(2 * math.pi)),
places=5)
def test_vector_normal_prior_size(self):
prior = NormalPrior(0, 1, size=2)
self.assertFalse(prior.log_transform)
self.assertTrue(prior.is_in_support(torch.zeros(1)))
self.assertEqual(prior.shape, torch.Size([2]))
self.assertTrue(torch.equal(prior.loc, torch.tensor([0.0, 0.0])))
self.assertTrue(torch.equal(prior.scale, torch.tensor([1.0, 1.0])))
parameter = torch.tensor([1.0, 2.0])
self.assertAlmostEqual(
prior.log_prob(parameter).item(),
2 * math.log(1 / math.sqrt(2 * math.pi)) - 0.5 * (parameter ** 2).sum().item(),
places=5,
)
def test_vector_normal_prior(self):
prior = NormalPrior(torch.tensor([-0.5, 0.5]), torch.tensor([0.5,
1.0]))
self.assertFalse(prior.log_transform)
self.assertTrue(prior.is_in_support(torch.rand(1)))
self.assertEqual(prior.shape, torch.Size([2]))
self.assertTrue(torch.equal(prior.loc, prior.loc.new([-0.5, 0.5])))
self.assertTrue(torch.equal(prior.scale, prior.scale.new([0.5, 1.0])))
parameter = prior.loc.new([1.0, 2.0])
expected_log_prob = (
((1 / math.sqrt(2 * math.pi) / prior.scale).log() -
0.5 / prior.scale**2 *
(prior.loc.new_tensor(parameter) - prior.loc)**2).sum().item())
self.assertAlmostEqual(prior.log_prob(
prior.loc.new_tensor(parameter)).item(),
expected_log_prob,
places=5)
