def test_string_overrides_work(self):
with pm.Model() as pmodel:
A = pm.Flat("A", initval=10)
B = pm.HalfFlat("B", initval=10)
C = pm.HalfFlat("C", initval=10)
fn = make_initial_point_fn(
model=pmodel,
jitter_rvs={},
return_transformed=True,
overrides={
"A": 1,
"B": 1,
"C_log__": 0,
},
)
iv = fn(0)
assert iv["A"] == 1
assert np.isclose(iv["B_log__"], 0)
assert iv["C_log__"] == 0
def test_untransformed_initial_point(self):
with pm.Model() as pmodel:
pm.Flat("A", initval="moment")
pm.HalfFlat("B", initval="moment")
fn = make_initial_point_fn(model=pmodel,
jitter_rvs={},
return_transformed=False)
iv = fn(0)
assert iv["A"] == 0
assert iv["B"] == 1
pass
def test_model_not_drawable_prior(self):
data = np.random.poisson(lam=10, size=200)
model = pm.Model()
with model:
mu = pm.HalfFlat("sigma")
pm.Poisson("foo", mu=mu, observed=data)
idata = pm.sample(tune=1000)
with model:
with pytest.raises(NotImplementedError) as excinfo:
pm.sample_prior_predictive(50)
assert "Cannot sample" in str(excinfo.value)
samples = pm.sample_posterior_predictive(idata, 40, return_inferencedata=False)
assert samples["foo"].shape == (40, 200)
def test_respects_overrides(self):
with pm.Model() as pmodel:
A = pm.Flat("A", initval="moment")
B = pm.HalfFlat("B", initval=4)
C = pm.Normal("C", mu=A + B, initval="moment")
fn = make_initial_point_fn(
model=pmodel,
jitter_rvs={},
return_transformed=True,
overrides={
A: at.as_tensor(2, dtype=int),
B: 3,
C: 5,
},
)
iv = fn(0)
assert iv["A"] == 2
assert np.isclose(iv["B_log__"], np.log(3))
assert iv["C"] == 5
def test_adds_jitter(self):
with pm.Model() as pmodel:
A = pm.Flat("A", initval="moment")
B = pm.HalfFlat("B", initval="moment")
C = pm.Normal("C", mu=A + B, initval="moment")
fn = make_initial_point_fn(model=pmodel,
jitter_rvs={B},
return_transformed=True)
iv = fn(0)
# Moment of the Flat is 0
assert iv["A"] == 0
# Moment of the HalfFlat is 1, but HalfFlat is log-transformed by default
# so the transformed initial value with jitter will be zero plus a jitter between [-1, 1].
b_transformed = iv["B_log__"]
b_untransformed = transform_back(B, b_transformed)
assert b_transformed != 0
assert -1 < b_transformed < 1
# C is centered on 0 + untransformed initval of B
assert np.isclose(
iv["C"], np.array(0 + b_untransformed, dtype=aesara.config.floatX))
# Test jitter respects seeding.
assert fn(0) == fn(0)
assert fn(0) != fn(1)
