def test_dtype_wb_promotion():
wb = LowRank(B.ones(int, 5, 5)) + Diagonal(B.ones(int, 5))
assert B.dtype(wb) == np.int64
wb = LowRank(B.ones(float, 5, 5)) + Diagonal(B.ones(int, 5))
assert B.dtype(wb) == np.float64
wb = LowRank(B.ones(int, 5, 5)) + Diagonal(B.ones(float, 5))
assert B.dtype(wb) == np.float64
def test_kronecker_formatting():
left = Diagonal(B.ones(2))
right = Diagonal(B.ones(3))
assert (str(Kronecker(
left, right)) == "<Kronecker product: shape=6x6, dtype=float64>")
assert (repr(Kronecker(
left, right)) == "<Kronecker product: shape=6x6, dtype=float64\n"
" left=<diagonal matrix: shape=2x2, dtype=float64\n"
" diag=[1. 1.]>\n"
" right=<diagonal matrix: shape=3x3, dtype=float64\n"
" diag=[1. 1. 1.]>>")
def _compute(self, measure):
# Extract processes and inputs.
p_x, x = self.fdd.p, self.fdd.x
p_z, z = self.u.p, self.u.x
# Construct the necessary kernel matrices.
K_zx = measure.kernels[p_z, p_x](z, x)
K_z = convert(measure.kernels[p_z](z), AbstractMatrix)
self._K_z_store[id(measure)] = K_z
# Evaluating `e.kernel(x)` will yield incorrect results if `x` is a
# `MultiInput`, because `x` then still designates the particular components
# of `f`. Fix that by instead designating the elements of `e`.
if isinstance(x, MultiInput):
x_n = MultiInput(*(e(fdd.x)
for e, fdd in zip(self.e.kernel.ps, x.get())))
else:
x_n = x
# Construct the noise kernel matrix.
K_n = self.e.kernel(x_n)
# The approximation can only handle diagonal noise matrices.
if not isinstance(K_n, Diagonal):
raise RuntimeError("Kernel matrix of noise must be diagonal.")
# And construct the components for the inducing point approximation.
L_z = B.cholesky(K_z)
A = B.add(B.eye(K_z), B.iqf(K_n, B.transpose(B.solve(L_z, K_zx))))
self._A_store[id(measure)] = A
y_bar = uprank(self.y) - self.e.mean(x_n) - measure.means[p_x](x)
prod_y_bar = B.solve(L_z, B.iqf(K_n, B.transpose(K_zx), y_bar))
# Compute the optimal mean.
mu = B.add(
measure.means[p_z](z),
B.iqf(A, B.solve(L_z, K_z), prod_y_bar),
)
self._mu_store[id(measure)] = mu
# Compute the ELBO.
# NOTE: The calculation of `trace_part` asserts that `K_n` is diagonal.
# The rest, however, is completely generic.
trace_part = B.ratio(
Diagonal(measure.kernels[p_x].elwise(x)[:, 0]) -
Diagonal(B.iqf_diag(K_z, K_zx)),
K_n,
)
det_part = B.logdet(2 * B.pi * K_n) + B.logdet(A)
iqf_part = B.iqf(K_n, y_bar)[0, 0] - B.iqf(A, prod_y_bar)[0, 0]
self._elbo_store[id(measure)] = -0.5 * (trace_part + det_part +
iqf_part)
def __call__(self, x, y):
w_x, w_y = x.w, y.w
x, y = x.get(), y.get()
if x is y:
return Diagonal(1 / w_x)
else:
return Zero(B.dtype(x), num_elements(x), num_elements(y))
def diagonalise(self):
"""Diagonalise the normal distribution by setting the correlations to zero.
Returns:
:class:`.Normal`: Diagonal version of the distribution.
"""
return Normal(self.mean, Diagonal(self.var_diag))
def _noise_as_matrix(noise: B.Numeric, dtype: B.DType, n: int):
if B.isscalar(noise):
return B.fill_diag(noise, n)
elif B.rank(noise) == 1:
return Diagonal(noise)
else:
return Dense(noise)
def test_logpdf_missing_data():
# Setup model.
m = 3
noise = 1e-2
latent_noises = 2e-2 * B.ones(m)
kernels = [0.5 * EQ().stretch(0.75) for _ in range(m)]
x = B.linspace(0, 10, 20)
# Concatenate two orthogonal matrices, to make the missing data
# approximation exact.
u1 = B.svd(B.randn(m, m))[0]
u2 = B.svd(B.randn(m, m))[0]
u = Dense(B.concat(u1, u2, axis=0) / B.sqrt(2))
s_sqrt = Diagonal(B.rand(m))
# Construct a reference model.
oilmm_pp = ILMMPP(kernels, u @ s_sqrt, noise, latent_noises)
# Sample to generate test data.
y = oilmm_pp.sample(x, latent=False)
# Throw away data, but retain orthogonality.
y[5:10, 3:] = np.nan
y[10:, :3] = np.nan
# Construct OILMM to test.
oilmm = OILMM(kernels, u, s_sqrt, noise, latent_noises)
# Check that evidence is still exact.
approx(oilmm_pp.logpdf(x, y), oilmm.logpdf(x, y), atol=1e-7)
def __call__(self, x, y):
w_x, w_y = x.w, y.w
x, y = x.get(), y.get()
if x is y:
return Diagonal(1 / w_x)
else:
x, y = uprank(x), uprank(y)
return Zero(B.dtype(x), B.shape(x)[0], B.shape(y)[0])
def _compute(self):
# Extract processes.
p_x, x = type_parameter(self.x), self.x.get()
p_z, z = type_parameter(self.z), self.z.get()
# Construct the necessary kernel matrices.
K_zx = self.graph.kernels[p_z, p_x](z, x)
self._K_z = convert(self.graph.kernels[p_z](z), AbstractMatrix)
# Evaluating `e.kernel(x)` will yield incorrect results if `x` is a
# `MultiInput`, because `x` then still designates the particular
# components of `f`. Fix that by instead designating the elements of
# `e`.
if isinstance(x, MultiInput):
x_n = MultiInput(*(p(xi.get())
for p, xi in zip(self.e.kernel.ps, x.get())))
else:
x_n = x
# Construct the noise kernel matrix.
K_n = self.e.kernel(x_n)
# The approximation can only handle diagonal noise matrices.
if not isinstance(K_n, Diagonal):
raise RuntimeError('Kernel matrix of noise must be diagonal.')
# And construct the components for the inducing point approximation.
L_z = B.cholesky(self._K_z)
self._A = B.add(B.eye(self._K_z),
B.iqf(K_n, B.transpose(B.solve(L_z, K_zx))))
y_bar = uprank(self.y) - self.e.mean(x_n) - self.graph.means[p_x](x)
prod_y_bar = B.solve(L_z, B.iqf(K_n, B.transpose(K_zx), y_bar))
# Compute the optimal mean.
self._mu = B.add(self.graph.means[p_z](z),
B.iqf(self._A, B.solve(L_z, self._K_z), prod_y_bar))
# Compute the ELBO.
# NOTE: The calculation of `trace_part` asserts that `K_n` is diagonal.
# The rest, however, is completely generic.
trace_part = B.ratio(Diagonal(self.graph.kernels[p_x].elwise(x)[:, 0]) -
Diagonal(B.iqf_diag(self._K_z, K_zx)), K_n)
det_part = B.logdet(2 * B.pi * K_n) + B.logdet(self._A)
iqf_part = B.iqf(K_n, y_bar)[0, 0] - B.iqf(self._A, prod_y_bar)[0, 0]
self._elbo = -0.5 * (trace_part + det_part + iqf_part)
def _compute(self, measure):
# Extract processes and inputs.
p_x, x, noise_x = self.fdd.p, self.fdd.x, self.fdd.noise
p_z, z, noise_z = self.u.p, self.u.x, self.u.noise
# Construct the necessary kernel matrices.
K_zx = measure.kernels[p_z, p_x](z, x)
K_z = B.add(measure.kernels[p_z](z), noise_z)
self._K_z_store[id(measure)] = K_z
# Noise kernel matrix:
K_n = noise_x
# The approximation can only handle diagonal noise matrices.
if not isinstance(K_n, Diagonal):
raise RuntimeError(
f"Kernel matrix of observation noise must be diagonal, "
f'not "{type(K_n).__name__}".'
)
# And construct the components for the inducing point approximation.
L_z = B.cholesky(K_z)
A = B.add(B.eye(K_z), B.iqf(K_n, B.transpose(B.solve(L_z, K_zx))))
self._A_store[id(measure)] = A
y_bar = B.subtract(B.uprank(self.y), measure.means[p_x](x))
prod_y_bar = B.solve(L_z, B.iqf(K_n, B.transpose(K_zx), y_bar))
# Compute the optimal mean.
mu = B.add(
measure.means[p_z](z),
B.iqf(A, B.solve(L_z, K_z), prod_y_bar),
)
self._mu_store[id(measure)] = mu
# Compute the ELBO.
# NOTE: The calculation of `trace_part` asserts that `K_n` is diagonal.
# The rest, however, is completely generic.
trace_part = B.ratio(
Diagonal(measure.kernels[p_x].elwise(x)[:, 0])
- Diagonal(B.iqf_diag(K_z, K_zx)),
K_n,
)
det_part = B.logdet(2 * B.pi * K_n) + B.logdet(A)
iqf_part = B.iqf(K_n, y_bar)[0, 0] - B.iqf(A, prod_y_bar)[0, 0]
self._elbo_store[id(measure)] = -0.5 * (trace_part + det_part + iqf_part)
def construct_model(vs):
kernels = [
vs.pos(1, name=f"{i}/var") *
EQ().stretch(vs.pos(0.02, name=f"{i}/scale")) for i in range(m)
]
noise = vs.pos(1e-2, name="noise")
latent_noises = vs.pos(1e-2 * B.ones(m), name="latent_noises")
u = Dense(vs.orth(shape=(p, m), name="u"))
s_sqrt = Diagonal(vs.pos(shape=(m, ), name="s_sqrt"))
return OILMM(kernels, u, s_sqrt, noise, latent_noises)
def construct_oilmm():
# Setup model.
kernels = [EQ(), 2 * EQ().stretch(1.5)]
u, s_sqrt = B.svd(B.randn(3, 2))[:2]
u = Dense(u)
s_sqrt = Diagonal(s_sqrt)
def construct_iolmm(noise_amplification=1):
noise_obs = noise_amplification
noises_latent = np.array([0.1, 0.2]) * noise_amplification
return OILMM(kernels, u, s_sqrt, noise_obs, noises_latent)
return construct_iolmm
def construct_model(vs):
if args.separable:
# Copy same kernel `m` times.
kernel = [
Mat52().stretch(vs.bnd(6 * 30, lower=60, name="k_scale"))
]
kernels = kernel * m
else:
# Parametrise different kernels.
kernels = [
Mat52().stretch(vs.bnd(6 * 30, lower=60, name=f"{i}/k_scale"))
for i in range(m)
]
noise = vs.bnd(1e-2, name="noise")
latent_noises = vs.bnd(1e-2 * B.ones(m), name="latent_noises")
# Construct component of the mixing matrix over simulators.
u = vs.orth(init=u_s_init, shape=(p_s, m_s), name="sims/u")
s_sqrt = vs.bnd(init=s_sqrt_s_init, shape=(m_s, ), name="sims/s_sqrt")
u_s = Dense(u)
s_sqrt_s = Diagonal(s_sqrt)
# Construct components of the mixing matrix over space from a
# covariance.
scales = vs.bnd(init=scales_init, name="space/scales")
k = Mat52().stretch(scales)
u, s, _ = B.svd(B.dense(k(loc)))
u_r = Dense(u[:, :m_r])
s_sqrt_r = Diagonal(B.sqrt(s[:m_r]))
# Compose.
s_sqrt = Kronecker(s_sqrt_s, s_sqrt_r)
u = Kronecker(u_s, u_r)
return OILMM(kernels, u, s_sqrt, noise, latent_noises)
def test_woodbury_formatting():
diag = Diagonal(B.ones(3))
lr = LowRank(B.ones(3, 1), 2 * B.ones(3, 1))
assert str(Woodbury(diag,
lr)) == "<Woodbury matrix: shape=3x3, dtype=float64>"
assert (repr(Woodbury(
diag, lr)) == "<Woodbury matrix: shape=3x3, dtype=float64\n"
" diag=<diagonal matrix: shape=3x3, dtype=float64\n"
" diag=[1. 1. 1.]>\n"
" lr=<low-rank matrix: shape=3x3, dtype=float64, rank=1\n"
" left=[[1.]\n"
" [1.]\n"
" [1.]]\n"
" right=[[2.]\n"
" [2.]\n"
" [2.]]>>")
def construct_model(vs, m):
kernels = [
vs.pos(0.5, name=f"{i}/k_var") *
Matern52().stretch(vs.bnd(2 * 30, name=f"{i}/k_scale")) +
vs.pos(0.5, name=f"{i}/k_per_var") * (Matern52().stretch(
vs.bnd(1.0, name=f"{i}/k_per_scale")).periodic(365))
for i in range(m)
]
noise = vs.pos(1e-2, name="noise")
latent_noises = vs.pos(1e-2 * B.ones(m), name="latent_noises")
# Construct orthogonal matrix and time it.
time_h_start = time.time()
u = Dense(vs.orth(shape=(p, m), name="u"))
s_sqrt = Diagonal(vs.pos(shape=(m, ), name="s_sqrt"))
dur_h = time.time() - time_h_start
return OILMM(kernels, u, s_sqrt, noise, latent_noises), dur_h
def test_normaliser():
# Create test data.
mat = B.randn(3, 3)
dist = Normal(B.randn(3, 1), mat @ mat.T)
y = dist.sample(num=10).T
# Create normaliser.
norm = Normaliser(y)
y_norm = norm.normalise(y)
# Create distribution of normalised data.
scale = Diagonal(norm.scale[0])
dist_norm = Normal(
B.inv(scale) @ (dist.mean - norm.mean.T),
B.inv(scale) @ dist.var @ B.inv(scale))
approx(
B.sum(dist.logpdf(y.T)),
B.sum(dist_norm.logpdf(y_norm.T)) + norm.normalise_logdet(y),
)
def compute_K_z(model):
"""Covariance matrix :math:`K_z` of :math:`z_m` for :math:`m=0,\\ldots,2M`.
Args:
model (:class:`.gprv.GPRV`): Model.
Returns:
matrix: :math:`K_z`.
"""
# Compute harmonic frequencies.
m = model.ms - B.cast(model.dtype, model.ms > model.m_max) * model.m_max
omega = 2 * B.pi * m / (model.b - model.a)
# Compute the parameters of the kernel matrix.
lam_t = 1
alpha = 0.5 * (model.b - model.a) / psd_matern_12(omega, model.lam, lam_t)
alpha = alpha + alpha * B.cast(model.dtype, model.ms == 0)
beta = 1 / (lam_t**0.5) * B.cast(model.dtype, model.ms <= model.m_max)
return Diagonal(alpha) + LowRank(left=beta[:, None])
def construct_model(vs):
kernels = [
vs.pos(0.5, name=f"{i}/k_var") *
Matern52().stretch(vs.bnd(2 * 30, name=f"{i}/k_scale")) +
vs.pos(0.5, name=f"{i}/k_per_var") * (Matern52().stretch(
vs.bnd(1.0, name=f"{i}/k_per_scale")).periodic(365))
for i in range(m)
]
latent_noises = vs.pos(1e-2 * B.ones(m), name="latent_noises")
noise = vs.pos(1e-2, name="noise")
# Construct components of mixing matrix from a covariance over
# outputs.
variance = vs.pos(1, name="h/variance")
scales = vs.pos(init=scales_init, name="h/scales")
k = variance * Matern52().stretch(scales)
u, s, _ = B.svd(B.dense(B.reg(k(loc))))
u = Dense(u[:, :m])
s_sqrt = Diagonal(B.sqrt(s[:m]))
return OILMM(kernels, u, s_sqrt, noise, latent_noises)
def test_compare_ilmm():
# Setup models.
kernels = [EQ(), 2 * EQ().stretch(1.5)]
noise_obs = 0.1
noises_latent = np.array([0.1, 0.2])
u, s_sqrt = B.svd(B.randn(3, 2))[:2]
u = Dense(u)
s_sqrt = Diagonal(s_sqrt)
# Construct models.
ilmm = ILMMPP(kernels, u @ s_sqrt, noise_obs, noises_latent)
oilmm = OILMM(kernels, u, s_sqrt, noise_obs, noises_latent)
# Construct data.
x = B.linspace(0, 3, 5)
y = ilmm.sample(x, latent=False)
x2 = B.linspace(4, 7, 5)
y2 = ilmm.sample(x2, latent=False)
# Check LML before conditioning.
approx(ilmm.logpdf(x, y), oilmm.logpdf(x, y))
approx(ilmm.logpdf(x2, y2), oilmm.logpdf(x2, y2))
ilmm = ilmm.condition(x, y)
oilmm = oilmm.condition(x, y)
# Check LML after conditioning.
approx(ilmm.logpdf(x, y), oilmm.logpdf(x, y))
approx(ilmm.logpdf(x2, y2), oilmm.logpdf(x2, y2))
# Predict.
means_pp, lowers_pp, uppers_pp = ilmm.predict(x2)
means, lowers, uppers = oilmm.predict(x2)
# Check predictions.
approx(means_pp, means)
approx(lowers_pp, lowers)
approx(uppers_pp, uppers)
def test_woodbury_attributes():
diag = Diagonal(B.ones(3))
lr = LowRank(B.ones(3, 1), 2 * B.ones(3, 1))
wb = Woodbury(diag, lr)
assert wb.diag is diag
assert wb.lr is lr
def construct(diag, left, right, middle):
return Diagonal(diag) + LowRank(left, right, middle)
# Test giving a name to the constructor.
p3 = GP(EQ(), name="yet_another_name", measure=m)
assert m["yet_another_name"] is p3
assert p3.name == "yet_another_name"
assert m[p3] == "yet_another_name"
@pytest.mark.parametrize(
"generate_noise_tuple",
[
lambda x: (),
lambda x: (B.rand(), ),
lambda x: (B.rand(x), ),
lambda x: (B.diag(B.rand(x)), ),
lambda x: (Diagonal(B.rand(x)), ),
],
)
def test_conditioning(generate_noise_tuple):
m = Measure()
p1 = GP(EQ(), measure=m)
p2 = GP(Exp(), measure=m)
p_sum = p1 + p2
# Sample some data to condition on.
x1 = B.linspace(0, 2, 3)
n1 = generate_noise_tuple(x1)
y1 = p1(x1, *n1).sample()
tup1 = (p1(x1, *n1), y1)
x_sum = B.linspace(3, 5, 3)
n_sum = generate_noise_tuple(x_sum)
def test_structured():
assert structured(Diagonal(B.ones(3)))
assert not structured(Dense(B.ones(3, 3)))
assert not structured(B.ones(3, 3))
def objective(vs):
x_ind = vs.unbounded(x_ind_init, name="x_ind")
return -construct_model(vs).logpdf(x_data, y_data, x_ind=x_ind)
minimise_l_bfgs_b(objective, vs, trace=True, iters=args.i)
# Print variables.
vs.print()
def cov_to_corr(k):
std = B.sqrt(B.diag(k))
return k / std[:, None] / std[None, :]
# Compute correlations between simulators.
u = Dense(vs["sims/u"])
s_sqrt = Diagonal(vs["sims/s_sqrt"])
k = u @ s_sqrt @ s_sqrt @ u.T
std = B.sqrt(B.diag(k))
corr_learned = cov_to_corr(k)
# Compute empirical correlations.
all_obs = np.concatenate(
[sim.to_numpy()[:args.n].reshape(-1, 1) for sim in sims.values()],
axis=1)
corr_empirical = cov_to_corr(np.cov(all_obs.T))
# Compute predictions for latent processes.
model = construct_model(vs)
model = model.condition(x_data, y_data, x_ind=vs["x_ind"])
x_proj, y_proj, _, _ = model.project(x_data, y_data)
means, lowers, uppers = model.model.predict(x_proj)
def test_diagonal_formatting():
assert str(Diagonal(B.ones(3))) == "<diagonal matrix: shape=3x3, dtype=float64>"
assert (
repr(Diagonal(B.ones(3))) == "<diagonal matrix: shape=3x3, dtype=float64\n"
" diag=[1. 1. 1.]>"
)
def test_conversion_to_diagonal(dense1):
approx(Diagonal(dense1), B.diag(B.diag(dense1)))
def generate(code):
"""Generate a random tensor of a particular type, specified with a code.
Args:
code (str): Code of the matrix.
Returns:
tensor: Random tensor.
"""
mat_code, shape_code = code.split(":")
# Parse shape.
if shape_code == "":
shape = ()
else:
shape = tuple(int(d) for d in shape_code.split(","))
if mat_code == "randn":
return B.randn(*shape)
elif mat_code == "randn_pd":
mat = B.randn(*shape)
# If it is a scalar or vector, just pointwise square it.
if len(shape) in {0, 1}:
return mat**2 + 1
else:
return B.matmul(mat, mat, tr_b=True) + B.eye(shape[0])
elif mat_code == "zero":
return Zero(B.default_dtype, *shape)
elif mat_code == "const":
return Constant(B.randn(), *shape)
elif mat_code == "const_pd":
return Constant(B.randn()**2 + 1, *shape)
elif mat_code == "lt":
mat = B.vec_to_tril(B.randn(int(0.5 * shape[0] * (shape[0] + 1))))
return LowerTriangular(mat)
elif mat_code == "lt_pd":
mat = generate(f"randn_pd:{shape[0]},{shape[0]}")
return LowerTriangular(B.cholesky(B.reg(mat)))
elif mat_code == "ut":
mat = B.vec_to_tril(B.randn(int(0.5 * shape[0] * (shape[0] + 1))))
return UpperTriangular(B.transpose(mat))
elif mat_code == "ut_pd":
mat = generate(f"randn_pd:{shape[0]},{shape[0]}")
return UpperTriangular(B.transpose(B.cholesky(B.reg(mat))))
elif mat_code == "dense":
return Dense(generate(f"randn:{shape_code}"))
elif mat_code == "dense_pd":
return Dense(generate(f"randn_pd:{shape_code}"))
elif mat_code == "diag":
return Diagonal(generate(f"randn:{shape_code}"))
elif mat_code == "diag_pd":
return Diagonal(generate(f"randn_pd:{shape_code}"))
else:
raise RuntimeError(f'Cannot parse generation code "{code}".')
def test_kronecker_attributes():
left = Diagonal(B.ones(2))
right = Diagonal(B.ones(3))
kron = Kronecker(left, right)
assert kron.left is left
assert kron.right is right
def test_diagonal_attributes():
diag = Diagonal(B.ones(3))
approx(diag.diag, B.ones(3))
def __call__(self, x, y):
if x is y and B.shape(uprank(x))[0] == B.shape(self.noises)[0]:
return Diagonal(self.noises)
else:
x, y = uprank(x), uprank(y)
return Zero(B.dtype(x), B.shape(x)[0], B.shape(y)[0])
