def test_samples():
"""Tests setting and getting the number of samples"""
# Default should be None
assert settings.get_samples() is None
# Should be able to change to an int > 0
settings.set_samples(1)
assert settings.get_samples() == 1
settings.set_samples(10)
assert settings.get_samples() == 10
settings.set_samples(None)
assert settings.get_samples() is None
# But not anything <1
with pytest.raises(ValueError):
settings.set_samples(0)
with pytest.raises(ValueError):
settings.set_samples(-1)
# And it has to be an int
with pytest.raises(TypeError):
settings.set_samples(3.14)
with pytest.raises(TypeError):
settings.set_samples("lalala")
def __call__(self, x):
"""Perform the forward pass"""
x = to_tensor(x)
# Using the Flipout estimator
if (get_flipout() and self.flipout and self.probabilistic
and get_samples() is not None and get_samples() == 1):
# Flipout-estimated weight samples
s = O.rand_rademacher(O.shape(x))
r = O.rand_rademacher([O.shape(x)[0], self.d_out])
norm_samples = O.randn([self.d_in, self.d_out])
w_samples = self.weights.variables["scale"] * norm_samples
w_noise = r * ((x * s) @ w_samples)
w_outputs = x @ self.weights.variables["loc"] + w_noise
# Flipout-estimated bias samples
r = O.rand_rademacher([O.shape(x)[0], self.d_out])
norm_samples = O.randn([self.d_out])
b_samples = self.bias.variables["scale"] * norm_samples
b_outputs = self.bias.variables["loc"] + r * b_samples
return w_outputs + b_outputs
# Without Flipout
else:
return x @ self.weights() + self.bias()
def test_sampling():
"""Tests the Sampling context manager"""
# Defaults before sampling
assert settings.get_backend() == "tensorflow"
assert settings.get_samples() is None
assert settings.get_flipout() is False
# Default should be samples=1 and flipout=False
with settings.Sampling():
assert settings.get_samples() == 1
assert settings.get_flipout() is False
# Should return to defaults after sampling
assert settings.get_backend() == "tensorflow"
assert settings.get_samples() is None
assert settings.get_flipout() is False
# Should be able to set samples and flipout via kwargs
with settings.Sampling(n=100, flipout=True):
assert settings.get_samples() == 100
assert settings.get_flipout() is True
# Again should return to defaults after __exit__
assert settings.get_backend() == "tensorflow"
assert settings.get_samples() is None
assert settings.get_flipout() is False
def __call__(self):
"""Return a sample from or the MAP estimate of this parameter.
Returns
-------
sample : Tensor
A sample from this Parameter's variational posterior distribution
"""
n_samples = get_samples()
if n_samples is None:
return self.transform(self.posterior.mean())
elif n_samples == 1:
return self.transform(self.posterior.sample())
else:
return self.transform(self.posterior.sample(n_samples))
def test_sampling():
"""Tests the Sampling context manager"""
# Defaults before sampling
assert settings.get_backend() == "tensorflow"
assert settings.get_samples() is None
assert settings.get_flipout() is False
assert settings.get_static_sampling_uuid() is None
# Default should be Not to change anything
with settings.Sampling():
assert settings.get_backend() == "tensorflow"
assert settings.get_samples() is None
assert settings.get_flipout() is False
assert settings.get_static_sampling_uuid() is None
# Should be able to set samples and flipout via kwargs
with settings.Sampling(n=100, flipout=True):
assert settings.get_backend() == "tensorflow"
assert settings.get_samples() == 100
assert settings.get_flipout() is True
assert settings.get_static_sampling_uuid() is None
# Should return to defaults after sampling
assert settings.get_backend() == "tensorflow"
assert settings.get_samples() is None
assert settings.get_flipout() is False
assert settings.get_static_sampling_uuid() is None
# Should be able to set static sampling uuid
with settings.Sampling(static=True):
assert settings.get_backend() == "tensorflow"
assert settings.get_samples() is None
assert settings.get_flipout() is False
assert settings.get_static_sampling_uuid() is not None
assert isinstance(settings.get_static_sampling_uuid(), uuid.UUID)
# Should return to defaults after sampling
assert settings.get_backend() == "tensorflow"
assert settings.get_samples() is None
assert settings.get_flipout() is False
assert settings.get_static_sampling_uuid() is None
# Should be able to nest sampling context managers
with settings.Sampling(static=True):
assert settings.get_backend() == "tensorflow"
assert settings.get_samples() is None
assert settings.get_flipout() is False
assert settings.get_static_sampling_uuid() is not None
assert isinstance(settings.get_static_sampling_uuid(), uuid.UUID)
with settings.Sampling(n=100, flipout=True):
assert settings.get_backend() == "tensorflow"
assert settings.get_samples() == 100
assert settings.get_flipout() is True
assert settings.get_static_sampling_uuid() is not None
assert isinstance(settings.get_static_sampling_uuid(), uuid.UUID)
# Should return to defaults after sampling
assert settings.get_backend() == "tensorflow"
assert settings.get_samples() is None
assert settings.get_flipout() is False
assert settings.get_static_sampling_uuid() is None