def test_moments(self):
"""
Test the moments of Poisson nodes.
"""
# Simple test
X = Poisson(12.8)
u = X._message_to_child()
self.assertEqual(len(u), 1)
self.assertAllClose(u[0], 12.8)
# Test plates in rate
X = Poisson(12.8 * np.ones((2, 3)))
u = X._message_to_child()
self.assertAllClose(u[0], 12.8 * np.ones((2, 3)))
# Test with gamma prior
alpha = Gamma(5, 2)
r = np.exp(alpha._message_to_child()[1])
X = Poisson(alpha)
u = X._message_to_child()
self.assertAllClose(u[0], r)
# Test with broadcasted plates in parents
X = Poisson(Gamma(5, 2, plates=(2, 3)))
u = X._message_to_child()
self.assertAllClose(u[0] * np.ones((2, 3)), r * np.ones((2, 3)))
pass
def test_init(self):
"""
Test the creation of Poisson nodes.
"""
# Some simple initializations
X = Poisson(12.8)
X = Poisson(Gamma(43, 24))
# Check that plates are correct
X = Poisson(np.ones((2, 3)))
self.assertEqual(X.plates, (2, 3))
X = Poisson(Gamma(1, 1, plates=(2, 3)))
self.assertEqual(X.plates, (2, 3))
# Invalid rate
self.assertRaises(ValueError, Poisson, -0.1)
# Inconsistent plates
self.assertRaises(ValueError, Poisson, np.ones(3), plates=(2, ))
# Explicit plates too small
self.assertRaises(ValueError, Poisson, np.ones(3), plates=(1, ))
pass
def test_moments(self):
"""
Test the moments of Poisson nodes.
"""
# Simple test
X = Poisson(12.8)
u = X._message_to_child()
self.assertEqual(len(u),
1)
self.assertAllClose(u[0],
12.8)
# Test plates in rate
X = Poisson(12.8*np.ones((2,3)))
u = X._message_to_child()
self.assertAllClose(u[0],
12.8*np.ones((2,3)))
# Test with gamma prior
alpha = Gamma(5, 2)
r = np.exp(alpha._message_to_child()[1])
X = Poisson(alpha)
u = X._message_to_child()
self.assertAllClose(u[0],
r)
# Test with broadcasted plates in parents
X = Poisson(Gamma(5, 2, plates=(2,3)))
u = X._message_to_child()
self.assertAllClose(u[0]*np.ones((2,3)),
r*np.ones((2,3)))
pass
def model(M=10, N=100, D=3):
"""
Construct linear state-space model.
See, for instance, the following publication:
"Fast variational Bayesian linear state-space model"
Luttinen (ECML 2013)
"""
# Dynamics matrix with ARD
alpha = Gamma(1e-5, 1e-5, plates=(D, ), name='alpha')
A = GaussianARD(0,
alpha,
shape=(D, ),
plates=(D, ),
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=1,
scale=0),
name='A')
A.initialize_from_value(np.identity(D))
# Latent states with dynamics
X = GaussianMarkovChain(
np.zeros(D), # mean of x0
1e-3 * np.identity(D), # prec of x0
A, # dynamics
np.ones(D), # innovation
n=N, # time instances
plotter=bpplt.GaussianMarkovChainPlotter(scale=2),
name='X')
X.initialize_from_value(np.random.randn(N, D))
# Mixing matrix from latent space to observation space using ARD
gamma = Gamma(1e-5, 1e-5, plates=(D, ), name='gamma')
gamma.initialize_from_value(1e-2 * np.ones(D))
C = GaussianARD(0,
gamma,
shape=(D, ),
plates=(M, 1),
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=2,
scale=0),
name='C')
C.initialize_from_value(np.random.randn(M, 1, D))
# Observation noise
tau = Gamma(1e-5, 1e-5, name='tau')
tau.initialize_from_value(1e2)
# Underlying noiseless function
F = SumMultiply('i,i', C, X, name='F')
# Noisy observations
Y = GaussianARD(F, tau, name='Y')
Q = VB(Y, F, C, gamma, X, A, alpha, tau, C)
return Q
def test_lower_bound_contribution(self):
a = 15
b = 21
y = 4
x = Gamma(a, b)
x.observe(y)
testing.assert_allclose(
x.lower_bound_contribution(),
(
a * np.log(b) +
(a - 1) * np.log(y) -
b * y -
special.gammaln(a)
)
)
# Just one latent node so we'll get exact marginal likelihood
#
# p(Y) = p(Y,X)/p(X|Y) = p(Y|X) * p(X) / p(X|Y)
a = 2.3
b = 4.1
x = 1.9
y = 4.8
tau = Gamma(a, b)
Y = GaussianARD(x, tau)
Y.observe(y)
mu = x
nu = 2 * a
s2 = b / a
a_post = a + 0.5
b_post = b + 0.5*(y - x)**2
tau.update()
testing.assert_allclose(
[-b_post, a_post],
tau.phi
)
testing.assert_allclose(
Y.lower_bound_contribution() + tau.lower_bound_contribution(), # + tau.g,
(
special.gammaln((nu+1)/2)
- special.gammaln(nu/2)
- 0.5 * np.log(nu)
- 0.5 * np.log(np.pi)
- 0.5 * np.log(s2)
- 0.5 * (nu + 1) * np.log(
1 + (y - mu)**2 / (nu * s2)
)
)
)
return
def test_message_to_child(self):
"""
Test the message to child of Mixture node.
"""
K = 3
#
# Estimate moments from parents only
#
# Simple case
mu = GaussianARD([0,2,4], 1,
ndim=0,
plates=(K,))
alpha = Gamma(1, 1,
plates=(K,))
z = Categorical(np.ones(K)/K)
X = Mixture(z, GaussianARD, mu, alpha)
self.assertEqual(X.plates, ())
self.assertEqual(X.dims, ( (), () ))
u = X._message_to_child()
self.assertAllClose(u[0],
2)
self.assertAllClose(u[1],
2**2+1)
# Broadcasting the moments on the cluster axis
mu = GaussianARD(2, 1,
ndim=0,
plates=(K,))
alpha = Gamma(1, 1,
plates=(K,))
z = Categorical(np.ones(K)/K)
X = Mixture(z, GaussianARD, mu, alpha)
self.assertEqual(X.plates, ())
self.assertEqual(X.dims, ( (), () ))
u = X._message_to_child()
self.assertAllClose(u[0],
2)
self.assertAllClose(u[1],
2**2+1)
#
# Estimate moments with observed children
#
pass
def test_mask_to_parent(self):
"""
Test the mask handling in Mixture node
"""
K = 3
Z = Categorical(np.ones(K)/K,
plates=(4,5,1))
Mu = GaussianARD(0, 1,
shape=(2,),
plates=(4,K,5))
Alpha = Gamma(1, 1,
plates=(4,K,5,2))
X = Mixture(Z, GaussianARD, Mu, Alpha, cluster_plate=-3)
Y = GaussianARD(X, 1, ndim=1)
mask = np.reshape((np.mod(np.arange(4*5), 2) == 0),
(4,5))
Y.observe(np.ones((4,5,2)),
mask=mask)
self.assertArrayEqual(Z.mask,
mask[:,:,None])
self.assertArrayEqual(Mu.mask,
mask[:,None,:])
self.assertArrayEqual(Alpha.mask,
mask[:,None,:,None])
pass
def _setup_linear_regression():
"""
Setup code for the pdf and contour tests.
This code is from http://www.bayespy.org/examples/regression.html
"""
np.random.seed(1)
k = 2 # slope
c = 5 # bias
s = 2 # noise standard deviation
x = np.arange(10)
y = k * x + c + s * np.random.randn(10)
X = np.vstack([x, np.ones(len(x))]).T
B = GaussianARD(0, 1e-6, shape=(2, ))
F = SumMultiply('i,i', B, X)
tau = Gamma(1e-3, 1e-3)
Y = GaussianARD(F, tau)
Y.observe(y)
Q = VB(Y, B, tau)
Q.update(repeat=1000)
xh = np.linspace(-5, 15, 100)
Xh = np.vstack([xh, np.ones(len(xh))]).T
Fh = SumMultiply('i,i', B, Xh)
return locals()
def fit(self, X, y):
self.weights = GaussianARD(0, 1e-6, shape=(X.shape[-1], ))
y_mean = SumMultiply('i,i', self.weights, X)
precision = Gamma(1, .1)
y_obs = GaussianARD(y_mean, precision)
y_obs.observe(y)
Q = VB(y_obs, self.weights, precision)
Q.update(repeat=self.n_iter, tol=self.tolerance, verbose=False)
def pca():
np.random.seed(41)
M = 10
N = 3000
D = 5
# Construct the PCA model
alpha = Gamma(1e-3, 1e-3, plates=(D, ), name='alpha')
W = GaussianARD(0, alpha, plates=(M, 1), shape=(D, ), name='W')
X = GaussianARD(0, 1, plates=(1, N), shape=(D, ), name='X')
tau = Gamma(1e-3, 1e-3, name='tau')
W.initialize_from_random()
F = SumMultiply('d,d->', W, X)
Y = GaussianARD(F, tau, name='Y')
# Observe data
data = np.sum(np.random.randn(M, 1, D - 1) * np.random.randn(1, N, D - 1),
axis=-1) + 1e-1 * np.random.randn(M, N)
Y.observe(data)
# Initialize VB engine
Q = VB(Y, X, W, alpha, tau)
# Take one update step (so phi is ok)
Q.update(repeat=1)
Q.save()
# Run VB-EM
Q.update(repeat=200)
bpplt.pyplot.plot(np.cumsum(Q.cputime), Q.L, 'k-')
# Restore the state
Q.load()
# Run Riemannian conjugate gradient
#Q.optimize(X, alpha, maxiter=100, collapsed=[W, tau])
Q.optimize(W, tau, maxiter=100, collapsed=[X, alpha])
bpplt.pyplot.plot(np.cumsum(Q.cputime), Q.L, 'r:')
bpplt.pyplot.show()
def test_init(self):
"""
Test the creation of Mixture node
"""
# Do not accept non-negative cluster plates
z = Categorical(np.random.dirichlet([1, 1]))
self.assertRaises(ValueError,
Mixture,
z,
GaussianARD,
GaussianARD(0, 1, plates=(2, )),
Gamma(1, 1, plates=(2, )),
cluster_plate=0)
# Try constructing a mixture without any of the parents having the
# cluster plate axis
z = Categorical(np.random.dirichlet([1, 1]))
self.assertRaises(ValueError, Mixture, z, GaussianARD,
GaussianARD(0, 1, plates=()), Gamma(1, 1, plates=()))
def test_message_to_parents(self):
""" Check gradient passed to inputs parent node """
D = 3
X = Gaussian(np.random.randn(D), random.covariance(D))
a = Gamma(np.random.rand(D), np.random.rand(D))
Y = GaussianARD(X, a)
Y.observe(np.random.randn(D))
self.assert_message_to_parent(Y, X)
self.assert_message_to_parent(Y, a)
pass
def fit(self, X, y):
self._init_weights()
# self.cost,
# self.myopic_voc(action, state),
# self.vpi_action(action, state),
# self.vpi(state),
# self.expected_term_reward(state)
self.tau = Gamma(self.prior_a, self.prior_b)
F = SumMultiply('i,i', self.weights, X)
y_obs = GaussianARD(F, self.tau)
y_obs.observe(y)
Q = VB(y_obs, self.weights)
Q.update(repeat=10, tol=1e-4, verbose=False)
def model(M, N, D, K):
"""
Construct the linear state-space model with time-varying dynamics
For reference, see the following publication:
(TODO)
"""
#
# The model block for the latent mixing weight process
#
# Dynamics matrix with ARD
# beta : (K) x ()
beta = Gamma(1e-5, 1e-5, plates=(K, ), name='beta')
# B : (K) x (K)
B = GaussianARD(np.identity(K),
beta,
shape=(K, ),
plates=(K, ),
name='B',
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=1,
scale=0),
initialize=False)
B.initialize_from_value(np.identity(K))
# Mixing weight process, that is, the weights in the linear combination of
# state dynamics matrices
# S : () x (N,K)
S = GaussianMarkovChain(np.ones(K),
1e-6 * np.identity(K),
B,
np.ones(K),
n=N,
name='S',
plotter=bpplt.GaussianMarkovChainPlotter(scale=2),
initialize=False)
s = 10 * np.random.randn(N, K)
s[:, 0] = 10
S.initialize_from_value(s)
#
# The model block for the latent states
#
# Projection matrix of the dynamics matrix
# alpha : (K) x ()
alpha = Gamma(1e-5, 1e-5, plates=(D, K), name='alpha')
alpha.initialize_from_value(1 * np.ones((D, K)))
# A : (D) x (D,K)
A = GaussianARD(0,
alpha,
shape=(D, K),
plates=(D, ),
name='A',
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=1,
scale=0),
initialize=False)
# Initialize S and A such that A*S is almost an identity matrix
a = np.zeros((D, D, K))
a[np.arange(D), np.arange(D), np.zeros(D, dtype=int)] = 1
a[:, :, 0] = np.identity(D) / s[0, 0]
a[:, :, 1:] = 0.1 / s[0, 0] * np.random.randn(D, D, K - 1)
A.initialize_from_value(a)
# Latent states with dynamics
# X : () x (N,D)
X = VaryingGaussianMarkovChain(
np.zeros(D), # mean of x0
1e-3 * np.identity(D), # prec of x0
A, # dynamics matrices
S._convert(GaussianMoments)[1:], # temporal weights
np.ones(D), # innovation
n=N, # time instances
name='X',
plotter=bpplt.GaussianMarkovChainPlotter(scale=2),
initialize=False)
X.initialize_from_value(np.random.randn(N, D))
#
# The model block for observations
#
# Mixing matrix from latent space to observation space using ARD
# gamma : (D) x ()
gamma = Gamma(1e-5, 1e-5, plates=(D, ), name='gamma')
gamma.initialize_from_value(1e-2 * np.ones(D))
# C : (M,1) x (D)
C = GaussianARD(0,
gamma,
shape=(D, ),
plates=(M, 1),
name='C',
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=2,
scale=0))
C.initialize_from_value(np.random.randn(M, 1, D))
# Noiseless process
# F : (M,N) x ()
F = SumMultiply('d,d', C, X, name='F')
# Observation noise
# tau : () x ()
tau = Gamma(1e-5, 1e-5, name='tau')
tau.initialize_from_value(1e2)
# Observations
# Y: (M,N) x ()
Y = GaussianARD(F, tau, name='Y')
# Construct inference machine
Q = VB(Y, F, C, gamma, X, A, alpha, tau, S, B, beta)
return Q
def test_message_to_child(self):
"""
Test the message to child of GaussianGammaISO node.
"""
# Simple test
mu = np.array([1, 2, 3])
Lambda = np.identity(3)
a = 2
b = 10
X_alpha = GaussianGammaISO(mu, Lambda, a, b)
u = X_alpha._message_to_child()
self.assertEqual(len(u), 4)
tau = np.array(a / b)
self.assertAllClose(u[0], tau[..., None] * mu)
self.assertAllClose(
u[1],
(linalg.inv(Lambda) + tau[..., None, None] * linalg.outer(mu, mu)))
self.assertAllClose(u[2], tau)
self.assertAllClose(u[3], -np.log(b) + special.psi(a))
# Test with unknown parents
mu = Gaussian(np.arange(3), 10 * np.identity(3))
Lambda = Wishart(10, np.identity(3))
a = 2
b = Gamma(3, 15)
X_alpha = GaussianGammaISO(mu, Lambda, a, b)
u = X_alpha._message_to_child()
(mu, mumu) = mu._message_to_child()
Cov_mu = mumu - linalg.outer(mu, mu)
(Lambda, _) = Lambda._message_to_child()
(b, _) = b._message_to_child()
(tau, logtau) = Gamma(
a, b + 0.5 * np.sum(Lambda * Cov_mu))._message_to_child()
self.assertAllClose(u[0], tau[..., None] * mu)
self.assertAllClose(
u[1],
(linalg.inv(Lambda) + tau[..., None, None] * linalg.outer(mu, mu)))
self.assertAllClose(u[2], tau)
self.assertAllClose(u[3], logtau)
# Test with plates
mu = Gaussian(np.reshape(np.arange(3 * 4), (4, 3)),
10 * np.identity(3),
plates=(4, ))
Lambda = Wishart(10, np.identity(3))
a = 2
b = Gamma(3, 15)
X_alpha = GaussianGammaISO(mu, Lambda, a, b, plates=(4, ))
u = X_alpha._message_to_child()
(mu, mumu) = mu._message_to_child()
Cov_mu = mumu - linalg.outer(mu, mu)
(Lambda, _) = Lambda._message_to_child()
(b, _) = b._message_to_child()
(tau, logtau) = Gamma(
a, b +
0.5 * np.sum(Lambda * Cov_mu, axis=(-1, -2)))._message_to_child()
self.assertAllClose(u[0] * np.ones((4, 1)),
np.ones((4, 1)) * tau[..., None] * mu)
self.assertAllClose(
u[1] * np.ones((4, 1, 1)),
np.ones((4, 1, 1)) *
(linalg.inv(Lambda) + tau[..., None, None] * linalg.outer(mu, mu)))
self.assertAllClose(u[2] * np.ones(4), np.ones(4) * tau)
self.assertAllClose(u[3] * np.ones(4), np.ones(4) * logtau)
pass
def test_init(self):
"""
Test the constructor of GaussianARD
"""
def check_init(true_plates, true_shape, mu, alpha, **kwargs):
X = GaussianARD(mu, alpha, **kwargs)
self.assertEqual(X.dims, (true_shape, true_shape + true_shape),
msg="Constructed incorrect dimensionality")
self.assertEqual(X.plates,
true_plates,
msg="Constructed incorrect plates")
#
# Create from constant parents
#
# Use ndim=0 for constant mu
check_init((), (), 0, 1)
check_init((3, 2), (), np.zeros((
3,
2,
)), np.ones((2, )))
check_init((4, 2, 2, 3), (), np.zeros((
2,
1,
3,
)), np.ones((4, 1, 2, 3)))
# Use ndim
check_init((4, 2), (2, 3),
np.zeros((
2,
1,
3,
)),
np.ones((4, 1, 2, 3)),
ndim=2)
# Use shape
check_init((4, 2), (2, 3),
np.zeros((
2,
1,
3,
)),
np.ones((4, 1, 2, 3)),
shape=(2, 3))
# Use ndim and shape
check_init((4, 2), (2, 3),
np.zeros((
2,
1,
3,
)),
np.ones((4, 1, 2, 3)),
ndim=2,
shape=(2, 3))
#
# Create from node parents
#
# Infer ndim from parent mu
check_init((3, ), (), GaussianARD(0, 1, plates=(3, )),
Gamma(1, 1, plates=(3, )))
# Infer ndim from mu, take broadcasted shape
check_init((4, ), (2, 2, 3),
GaussianARD(np.zeros((2, 1, 3)), np.ones((2, 1, 3)),
ndim=3),
Gamma(np.ones((4, 1, 2, 3)), np.ones((4, 1, 2, 3))))
# Use ndim
check_init((4, ), (2, 2, 3),
GaussianARD(np.zeros((4, 1, 2, 3)),
np.ones((4, 1, 2, 3)),
ndim=2),
Gamma(np.ones((4, 2, 1, 3)), np.ones((4, 2, 1, 3))),
ndim=3)
# Use shape
check_init((4, ), (2, 2, 3),
GaussianARD(np.zeros((4, 1, 2, 3)),
np.ones((4, 1, 2, 3)),
ndim=2),
Gamma(np.ones((4, 2, 1, 3)), np.ones((4, 2, 1, 3))),
shape=(2, 2, 3))
# Use ndim and shape
check_init((4, 2), (2, 3),
GaussianARD(np.zeros((2, 1, 3)), np.ones((2, 1, 3)),
ndim=2),
Gamma(np.ones((4, 1, 2, 3)), np.ones((4, 1, 2, 3))),
ndim=2,
shape=(2, 3))
# Test for a found bug
check_init((), (3, ), np.ones(3), 1, ndim=1)
# Add axes if necessary
check_init((), (1, 2, 3),
GaussianARD(np.zeros((2, 3)), np.ones((2, 3)), ndim=2),
1,
ndim=3)
#
# Errors
#
# Inconsistent shapes
self.assertRaises(ValueError,
GaussianARD,
GaussianARD(np.zeros((2, 3)),
np.ones((2, 3)),
ndim=1),
np.ones((4, 3)),
ndim=2)
# Inconsistent dims of mu and alpha
self.assertRaises(ValueError, GaussianARD, np.zeros((2, 3)),
np.ones((2, )))
# Inconsistent plates of mu and alpha
self.assertRaises(ValueError,
GaussianARD,
GaussianARD(np.zeros((3, 2, 3)),
np.ones((3, 2, 3)),
ndim=2),
np.ones((3, 4, 2, 3)),
ndim=3)
# Inconsistent ndim and shape
self.assertRaises(ValueError,
GaussianARD,
np.zeros((2, 3)),
np.ones((2, )),
shape=(2, 3),
ndim=1)
# Parent mu has more axes
self.assertRaises(ValueError,
GaussianARD,
GaussianARD(np.zeros((2, 3)),
np.ones((2, 3)),
ndim=2),
np.ones((2, 3)),
ndim=1)
# Incorrect shape
self.assertRaises(ValueError,
GaussianARD,
GaussianARD(np.zeros((2, 3)),
np.ones((2, 3)),
ndim=2),
np.ones((2, 3)),
shape=(2, 2))
pass
def test_message_to_parent(self):
"""
Test the message to parents of Mixture node.
"""
K = 3
# Broadcasting the moments on the cluster axis
Mu = GaussianARD(2, 1,
ndim=0,
plates=(K,))
(mu, mumu) = Mu._message_to_child()
Alpha = Gamma(3, 1,
plates=(K,))
(alpha, logalpha) = Alpha._message_to_child()
z = Categorical(np.ones(K)/K)
X = Mixture(z, GaussianARD, Mu, Alpha)
tau = 4
Y = GaussianARD(X, tau)
y = 5
Y.observe(y)
(x, xx) = X._message_to_child()
m = z._message_from_children()
self.assertAllClose(m[0] * np.ones(K),
random.gaussian_logpdf(xx*alpha,
x*alpha*mu,
mumu*alpha,
logalpha,
0)
* np.ones(K))
m = Mu._message_from_children()
self.assertAllClose(m[0],
1/K * (alpha*x) * np.ones(3))
self.assertAllClose(m[1],
-0.5 * 1/K * alpha * np.ones(3))
# Some parameters do not have cluster plate axis
Mu = GaussianARD(2, 1,
ndim=0,
plates=(K,))
(mu, mumu) = Mu._message_to_child()
Alpha = Gamma(3, 1) # Note: no cluster plate axis!
(alpha, logalpha) = Alpha._message_to_child()
z = Categorical(np.ones(K)/K)
X = Mixture(z, GaussianARD, Mu, Alpha)
tau = 4
Y = GaussianARD(X, tau)
y = 5
Y.observe(y)
(x, xx) = X._message_to_child()
m = z._message_from_children()
self.assertAllClose(m[0] * np.ones(K),
random.gaussian_logpdf(xx*alpha,
x*alpha*mu,
mumu*alpha,
logalpha,
0)
* np.ones(K))
m = Mu._message_from_children()
self.assertAllClose(m[0],
1/K * (alpha*x) * np.ones(3))
self.assertAllClose(m[1],
-0.5 * 1/K * alpha * np.ones(3))
# Cluster assignments do not have as many plate axes as parameters.
M = 2
Mu = GaussianARD(2, 1,
ndim=0,
plates=(K,M))
(mu, mumu) = Mu._message_to_child()
Alpha = Gamma(3, 1,
plates=(K,M))
(alpha, logalpha) = Alpha._message_to_child()
z = Categorical(np.ones(K)/K)
X = Mixture(z, GaussianARD, Mu, Alpha, cluster_plate=-2)
tau = 4
Y = GaussianARD(X, tau)
y = 5 * np.ones(M)
Y.observe(y)
(x, xx) = X._message_to_child()
m = z._message_from_children()
self.assertAllClose(m[0]*np.ones(K),
np.sum(random.gaussian_logpdf(xx*alpha,
x*alpha*mu,
mumu*alpha,
logalpha,
0) *
np.ones((K,M)),
axis=-1))
m = Mu._message_from_children()
self.assertAllClose(m[0] * np.ones((K,M)),
1/K * (alpha*x) * np.ones((K,M)))
self.assertAllClose(m[1] * np.ones((K,M)),
-0.5 * 1/K * alpha * np.ones((K,M)))
# Mixed distribution broadcasts g
# This tests for a found bug. The bug caused an error.
Z = Categorical([0.3, 0.5, 0.2])
X = Mixture(Z, Categorical, [[0.2,0.8], [0.1,0.9], [0.3,0.7]])
m = Z._message_from_children()
#
# Test nested mixtures
#
t1 = [1, 1, 0, 3, 3]
t2 = [2]
p = Dirichlet([1, 1], plates=(4, 3))
X = Mixture(t1, Mixture, t2, Categorical, p)
X.observe([1, 1, 0, 0, 0])
p.update()
self.assertAllClose(
p.phi[0],
[
[[1, 1], [1, 1], [2, 1]],
[[1, 1], [1, 1], [1, 3]],
[[1, 1], [1, 1], [1, 1]],
[[1, 1], [1, 1], [3, 1]],
]
)
# Test sample plates in nested mixtures
t1 = Categorical([0.3, 0.7], plates=(5,))
t2 = [[1], [1], [0], [3], [3]]
t3 = 2
p = Dirichlet([1, 1], plates=(2, 4, 3))
X = Mixture(t1, Mixture, t2, Mixture, t3, Categorical, p)
X.observe([1, 1, 0, 0, 0])
p.update()
self.assertAllClose(
p.phi[0],
[
[
[[1, 1], [1, 1], [1.3, 1]],
[[1, 1], [1, 1], [1, 1.6]],
[[1, 1], [1, 1], [1, 1]],
[[1, 1], [1, 1], [1.6, 1]],
],
[
[[1, 1], [1, 1], [1.7, 1]],
[[1, 1], [1, 1], [1, 2.4]],
[[1, 1], [1, 1], [1, 1]],
[[1, 1], [1, 1], [2.4, 1]],
]
]
)
# Check that Gate and nested Mixture are equal
t1 = Categorical([0.3, 0.7], plates=(5,))
t2 = Categorical([0.1, 0.3, 0.6], plates=(5, 1))
p = Dirichlet([1, 2, 3, 4], plates=(2, 3))
X = Mixture(t1, Mixture, t2, Categorical, p)
X.observe([3, 3, 1, 2, 2])
t1_msg = t1._message_from_children()
t2_msg = t2._message_from_children()
p_msg = p._message_from_children()
t1 = Categorical([0.3, 0.7], plates=(5,))
t2 = Categorical([0.1, 0.3, 0.6], plates=(5, 1))
p = Dirichlet([1, 2, 3, 4], plates=(2, 3))
X = Categorical(Gate(t1, Gate(t2, p)))
X.observe([3, 3, 1, 2, 2])
t1_msg2 = t1._message_from_children()
t2_msg2 = t2._message_from_children()
p_msg2 = p._message_from_children()
self.assertAllClose(t1_msg[0], t1_msg2[0])
self.assertAllClose(t2_msg[0], t2_msg2[0])
self.assertAllClose(p_msg[0], p_msg2[0])
pass
def test_init(self):
"""
Test the creation of GaussianGammaISO node
"""
# Simple construction
X_alpha = GaussianGammaISO([1, 2, 3], np.identity(3), 2, 10)
self.assertEqual(X_alpha.plates, ())
self.assertEqual(X_alpha.dims, ((3, ), (3, 3), (), ()))
# Plates
X_alpha = GaussianGammaISO([1, 2, 3],
np.identity(3),
2,
10,
plates=(4, ))
self.assertEqual(X_alpha.plates, (4, ))
self.assertEqual(X_alpha.dims, ((3, ), (3, 3), (), ()))
# Plates in mu
X_alpha = GaussianGammaISO(np.ones((4, 3)), np.identity(3), 2, 10)
self.assertEqual(X_alpha.plates, (4, ))
self.assertEqual(X_alpha.dims, ((3, ), (3, 3), (), ()))
# Plates in Lambda
X_alpha = GaussianGammaISO(np.ones(3),
np.ones((4, 3, 3)) * np.identity(3), 2, 10)
self.assertEqual(X_alpha.plates, (4, ))
self.assertEqual(X_alpha.dims, ((3, ), (3, 3), (), ()))
# Plates in a
X_alpha = GaussianGammaISO(np.ones(3), np.identity(3), np.ones(4), 10)
self.assertEqual(X_alpha.plates, (4, ))
self.assertEqual(X_alpha.dims, ((3, ), (3, 3), (), ()))
# Plates in Lambda
X_alpha = GaussianGammaISO(np.ones(3), np.identity(3), 2, np.ones(4))
self.assertEqual(X_alpha.plates, (4, ))
self.assertEqual(X_alpha.dims, ((3, ), (3, 3), (), ()))
# Inconsistent plates
self.assertRaises(ValueError,
GaussianGammaISO,
np.ones((4, 3)),
np.identity(3),
2,
10,
plates=())
# Inconsistent plates
self.assertRaises(ValueError,
GaussianGammaISO,
np.ones((4, 3)),
np.identity(3),
2,
10,
plates=(5, ))
# Unknown parameters
mu = Gaussian(np.zeros(3), np.identity(3))
Lambda = Wishart(10, np.identity(3))
b = Gamma(1, 1)
X_alpha = GaussianGammaISO(mu, Lambda, 2, b)
self.assertEqual(X_alpha.plates, ())
self.assertEqual(X_alpha.dims, ((3, ), (3, 3), (), ()))
# mu is Gaussian-gamma
mu_tau = GaussianGammaISO(np.ones(3), np.identity(3), 5, 5)
X_alpha = GaussianGammaISO(mu_tau, np.identity(3), 5, 5)
self.assertEqual(X_alpha.plates, ())
self.assertEqual(X_alpha.dims, ((3, ), (3, 3), (), ()))
pass
y = np.mean(xx)
firstline = False
continue
y = np.vstack([y, (k * np.mean(xx) + c + s * np.random.randn(1))])
y = y.reshape(y.shape[0], )
X = x2.reshape(x2.shape[0], 1)
from bayespy.nodes import GaussianARD
B = GaussianARD(0, 1e-6, shape=(X.shape[1], ))
from bayespy.nodes import SumMultiply
F = SumMultiply('i,i', B, X)
from bayespy.nodes import Gamma
tau = Gamma(1e-3, 1e-3)
Y = GaussianARD(F, tau)
Y.observe(y)
from bayespy.inference import VB
Q = VB(Y, B, tau)
#Q.update(repeat=100990)
distribution = []
result = []
distribution = F.get_moments()
for min_val, max_val in zip(distribution[0], distribution[1]):
#mean = []
mean = (min_val + max_val) / 2
result.append(mean)
#result = mean
#x3 = []
#x3 = pd.DataFrame({result:buffer_data})
def test_gradient(self):
"""Test standard gradient of a Gamma node."""
D = 3
np.random.seed(42)
#
# Without observations
#
# Construct model
a = np.random.rand(D)
b = np.random.rand(D)
tau = Gamma(a, b)
Q = VB(tau)
# Random initialization
tau.initialize_from_parameters(np.random.rand(D),
np.random.rand(D))
# Initial parameters
phi0 = tau.phi
# Gradient
rg = tau.get_riemannian_gradient()
g = tau.get_gradient(rg)
# Numerical gradient
eps = 1e-8
p0 = tau.get_parameters()
l0 = Q.compute_lowerbound(ignore_masked=False)
g_num = [np.zeros(D), np.zeros(D)]
for i in range(D):
e = np.zeros(D)
e[i] = eps
p1 = p0[0] + e
tau.set_parameters([p1, p0[1]])
l1 = Q.compute_lowerbound(ignore_masked=False)
g_num[0][i] = (l1 - l0) / eps
for i in range(D):
e = np.zeros(D)
e[i] = eps
p1 = p0[1] + e
tau.set_parameters([p0[0], p1])
l1 = Q.compute_lowerbound(ignore_masked=False)
g_num[1][i] = (l1 - l0) / eps
# Check
self.assertAllClose(g[0],
g_num[0])
self.assertAllClose(g[1],
g_num[1])
#
# With observations
#
# Construct model
a = np.random.rand(D)
b = np.random.rand(D)
tau = Gamma(a, b)
mu = np.random.randn(D)
Y = GaussianARD(mu, tau)
Y.observe(np.random.randn(D))
Q = VB(Y, tau)
# Random initialization
tau.initialize_from_parameters(np.random.rand(D),
np.random.rand(D))
# Initial parameters
phi0 = tau.phi
# Gradient
rg = tau.get_riemannian_gradient()
g = tau.get_gradient(rg)
# Numerical gradient
eps = 1e-8
p0 = tau.get_parameters()
l0 = Q.compute_lowerbound(ignore_masked=False)
g_num = [np.zeros(D), np.zeros(D)]
for i in range(D):
e = np.zeros(D)
e[i] = eps
p1 = p0[0] + e
tau.set_parameters([p1, p0[1]])
l1 = Q.compute_lowerbound(ignore_masked=False)
g_num[0][i] = (l1 - l0) / eps
for i in range(D):
e = np.zeros(D)
e[i] = eps
p1 = p0[1] + e
tau.set_parameters([p0[0], p1])
l1 = Q.compute_lowerbound(ignore_masked=False)
g_num[1][i] = (l1 - l0) / eps
# Check
self.assertAllClose(g[0],
g_num[0])
self.assertAllClose(g[1],
g_num[1])
pass
def test_message_to_parent_alpha(self):
"""
Test the message from GaussianARD the 2nd parent (alpha).
"""
# Check formula with uncertain parent mu
mu = GaussianARD(1,1)
tau = Gamma(0.5*1e10, 1e10)
X = GaussianARD(mu,
tau)
X.observe(3)
(m0, m1) = tau._message_from_children()
self.assertAllClose(m0,
-0.5*(3**2 - 2*3*1 + 1**2+1))
self.assertAllClose(m1,
0.5)
# Check formula with uncertain node
tau = Gamma(1e10, 1e10)
X = GaussianARD(2, tau)
Y = GaussianARD(X, 1)
Y.observe(5)
X.update()
(m0, m1) = tau._message_from_children()
self.assertAllClose(m0,
-0.5*(1/(1+1)+3.5**2 - 2*3.5*2 + 2**2))
self.assertAllClose(m1,
0.5)
# Check alpha larger than mu
alpha = Gamma(np.ones((3,2,3))*1e10, 1e10)
X = GaussianARD(np.ones((2,3)),
alpha,
ndim=3)
X.observe(2*np.ones((3,2,3)))
(m0, m1) = alpha._message_from_children()
self.assertAllClose(m0 * np.ones((3,2,3)),
-0.5*(2**2 - 2*2*1 + 1**2) * np.ones((3,2,3)))
self.assertAllClose(m1*np.ones((3,2,3)),
0.5*np.ones((3,2,3)))
# Check mu larger than alpha
tau = Gamma(np.ones((2,3))*1e10, 1e10)
X = GaussianARD(np.ones((3,2,3)),
tau,
ndim=3)
X.observe(2*np.ones((3,2,3)))
(m0, m1) = tau._message_from_children()
self.assertAllClose(m0,
-0.5*(2**2 - 2*2*1 + 1**2) * 3 * np.ones((2,3)))
self.assertAllClose(m1 * np.ones((2,3)),
0.5 * 3 * np.ones((2,3)))
# Check node larger than mu and alpha
tau = Gamma(np.ones((3,))*1e10, 1e10)
X = GaussianARD(np.ones((2,3)),
tau,
shape=(3,2,3))
X.observe(2*np.ones((3,2,3)))
(m0, m1) = tau._message_from_children()
self.assertAllClose(m0 * np.ones(3),
-0.5*(2**2 - 2*2*1 + 1**2) * 6 * np.ones((3,)))
self.assertAllClose(m1 * np.ones(3),
0.5 * 6 * np.ones(3))
# Check plates for smaller mu than node
tau = Gamma(np.ones((4,1,2,3))*1e10, 1e10)
X = GaussianARD(GaussianARD(1, 1,
shape=(3,),
plates=(4,1,1)),
tau,
shape=(2,3),
plates=(4,5))
X.observe(2*np.ones((4,5,2,3)))
(m0, m1) = tau._message_from_children()
self.assertAllClose(m0 * np.ones((4,1,2,3)),
(-0.5 * (2**2 - 2*2*1 + 1**2+1)
* 5*np.ones((4,1,2,3))))
self.assertAllClose(m1 * np.ones((4,1,2,3)),
5*0.5 * np.ones((4,1,2,3)))
# Check mask
tau = Gamma(np.ones((4,3))*1e10, 1e10)
X = GaussianARD(np.ones(3),
tau,
shape=(3,),
plates=(2,4,))
X.observe(2*np.ones((2,4,3)), mask=[[True, False, True, False],
[False, True, True, False]])
(m0, m1) = tau._message_from_children()
self.assertAllClose(m0 * np.ones((4,3)),
(-0.5 * (2**2 - 2*2*1 + 1**2)
* np.ones((4,3))
* np.array([[1], [1], [2], [0]])))
self.assertAllClose(m1 * np.ones((4,3)),
0.5 * np.array([[1], [1], [2], [0]]) * np.ones((4,3)))
# Check non-ARD Gaussian child
mu = np.array([1,2])
alpha = np.array([3,4])
Alpha = Gamma(alpha*1e10, 1e10)
Lambda = np.array([[1, 0.5],
[0.5, 1]])
X = GaussianARD(mu, Alpha, ndim=1)
Y = Gaussian(X, Lambda)
y = np.array([5,6])
Y.observe(y)
X.update()
(m0, m1) = Alpha._message_from_children()
Cov = np.linalg.inv(np.diag(alpha)+Lambda)
mean = np.dot(Cov, np.dot(np.diag(alpha), mu)
+ np.dot(Lambda, y))
self.assertAllClose(m0 * np.ones(2),
-0.5 * np.diag(
np.outer(mean, mean) + Cov
- np.outer(mean, mu)
- np.outer(mu, mean)
+ np.outer(mu, mu)))
self.assertAllClose(m1 * np.ones(2),
0.5 * np.ones(2))
pass
def test_message_to_parent(self):
"""
Test the message to parents of Mixture node.
"""
K = 3
# Broadcasting the moments on the cluster axis
Mu = GaussianARD(2, 1,
ndim=0,
plates=(K,))
(mu, mumu) = Mu._message_to_child()
Alpha = Gamma(3, 1,
plates=(K,))
(alpha, logalpha) = Alpha._message_to_child()
z = Categorical(np.ones(K)/K)
X = Mixture(z, GaussianARD, Mu, Alpha)
tau = 4
Y = GaussianARD(X, tau)
y = 5
Y.observe(y)
(x, xx) = X._message_to_child()
m = X._message_to_parent(0)
self.assertAllClose(m[0],
random.gaussian_logpdf(xx*alpha,
x*alpha*mu,
mumu*alpha,
logalpha,
0))
m = X._message_to_parent(1)
self.assertAllClose(m[0],
1/K * (alpha*x) * np.ones(3))
self.assertAllClose(m[1],
-0.5 * 1/K * alpha * np.ones(3))
# Some parameters do not have cluster plate axis
Mu = GaussianARD(2, 1,
ndim=0,
plates=(K,))
(mu, mumu) = Mu._message_to_child()
Alpha = Gamma(3, 1) # Note: no cluster plate axis!
(alpha, logalpha) = Alpha._message_to_child()
z = Categorical(np.ones(K)/K)
X = Mixture(z, GaussianARD, Mu, Alpha)
tau = 4
Y = GaussianARD(X, tau)
y = 5
Y.observe(y)
(x, xx) = X._message_to_child()
m = X._message_to_parent(0)
self.assertAllClose(m[0],
random.gaussian_logpdf(xx*alpha,
x*alpha*mu,
mumu*alpha,
logalpha,
0))
m = X._message_to_parent(1)
self.assertAllClose(m[0],
1/K * (alpha*x) * np.ones(3))
self.assertAllClose(m[1],
-0.5 * 1/K * alpha * np.ones(3))
# Cluster assignments do not have as many plate axes as parameters.
M = 2
Mu = GaussianARD(2, 1,
ndim=0,
plates=(K,M))
(mu, mumu) = Mu._message_to_child()
Alpha = Gamma(3, 1,
plates=(K,M))
(alpha, logalpha) = Alpha._message_to_child()
z = Categorical(np.ones(K)/K)
X = Mixture(z, GaussianARD, Mu, Alpha, cluster_plate=-2)
tau = 4
Y = GaussianARD(X, tau)
y = 5 * np.ones(M)
Y.observe(y)
(x, xx) = X._message_to_child()
m = X._message_to_parent(0)
self.assertAllClose(m[0]*np.ones(K),
np.sum(random.gaussian_logpdf(xx*alpha,
x*alpha*mu,
mumu*alpha,
logalpha,
0) *
np.ones((K,M)),
axis=-1))
m = X._message_to_parent(1)
self.assertAllClose(m[0] * np.ones((K,M)),
1/K * (alpha*x) * np.ones((K,M)))
self.assertAllClose(m[1] * np.ones((K,M)),
-0.5 * 1/K * alpha * np.ones((K,M)))
pass
def model(M=10, N=100, D=3):
"""
Construct linear state-space model.
See, for instance, the following publication:
"Fast variational Bayesian linear state-space model"
Luttinen (ECML 2013)
"""
# Dynamics matrix with ARD
alpha = Gamma(1e-5,
1e-5,
plates=(D,),
name='alpha')
A = GaussianARD(0,
alpha,
shape=(D,),
plates=(D,),
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=1,
scale=0),
name='A')
A.initialize_from_value(np.identity(D))
# Latent states with dynamics
X = GaussianMarkovChain(np.zeros(D), # mean of x0
1e-3*np.identity(D), # prec of x0
A, # dynamics
np.ones(D), # innovation
n=N, # time instances
plotter=bpplt.GaussianMarkovChainPlotter(scale=2),
name='X')
X.initialize_from_value(np.random.randn(N,D))
# Mixing matrix from latent space to observation space using ARD
gamma = Gamma(1e-5,
1e-5,
plates=(D,),
name='gamma')
gamma.initialize_from_value(1e-2*np.ones(D))
C = GaussianARD(0,
gamma,
shape=(D,),
plates=(M,1),
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=2,
scale=0),
name='C')
C.initialize_from_value(np.random.randn(M,1,D))
# Observation noise
tau = Gamma(1e-5,
1e-5,
name='tau')
tau.initialize_from_value(1e2)
# Underlying noiseless function
F = SumMultiply('i,i',
C,
X,
name='F')
# Noisy observations
Y = GaussianARD(F,
tau,
name='Y')
Q = VB(Y, F, C, gamma, X, A, alpha, tau, C)
return Q
def lssm(M, N, D, K=1, drift_C=False, drift_A=False):
if (drift_C or drift_A) and not K > 0:
raise ValueError("K must be positive integer when using drift")
# Drift weights
if drift_A or drift_C:
# Dynamics matrix with ARD
# beta : (K) x ()
beta = Gamma(1e-5,
1e-5,
plates=(K,),
name='beta')
# B : (K) x (K)
B = GaussianArrayARD(np.identity(K),
beta,
shape=(K,),
plates=(K,),
name='B',
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=1,
scale=0),
initialize=False)
B.initialize_from_value(np.identity(K))
#B.initialize_from_mean_and_covariance(np.identity(K),
# 0.1*np.identity(K))
# State of the drift, that is, temporal weights for dynamics matrices
# S : () x (N,K)
S = GaussianMarkovChain(np.ones(K),
1e-6*np.identity(K),
B,
np.ones(K),
n=N,
name='S',
plotter=bpplt.GaussianMarkovChainPlotter(scale=2),
initialize=False)
#s = np.cumsum(np.random.randn(N,K), axis=0)
s = np.random.randn(N,K)
s[:,0] = 10
S.initialize_from_value(s)
#S.initialize_from_value(np.ones((N,K))+0.01*np.random.randn(N,K))
if not drift_A:
# Dynamic matrix
# alpha: (D) x ()
alpha = Gamma(1e-5,
1e-5,
plates=(D,),
name='alpha')
# A : (D) x (D)
A = GaussianArrayARD(0,
alpha,
shape=(D,),
plates=(D,),
name='A',
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=1,
scale=0),
initialize=False)
A.initialize_from_value(np.identity(D))
# Latent states with dynamics
# X : () x (N,D)
X = GaussianMarkovChain(np.zeros(D), # mean of x0
1e-3*np.identity(D), # prec of x0
A, # dynamics
np.ones(D), # innovation
n=N, # time instances
name='X',
plotter=bpplt.GaussianMarkovChainPlotter(),
initialize=False)
X.initialize_from_value(np.random.randn(N,D))
else:
# Projection matrix of the dynamics matrix
# alpha : (K) x ()
alpha = Gamma(1e-5,
1e-5,
plates=(D,K),
name='alpha')
# A : (D) x (D,K)
A = GaussianArrayARD(0,
alpha,
shape=(D,K),
plates=(D,),
name='A',
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=1,
scale=0),
initialize=False)
# Initialize S and A such that A*S is almost an identity matrix
a = np.zeros((D,D,K))
a[np.arange(D),np.arange(D),np.zeros(D,dtype=int)] = 1
a[:,:,0] = np.identity(D) / s[0,0]
a[:,:,1:] = 0.1/s[0,0]*np.random.randn(D,D,K-1)
A.initialize_from_value(a)
#A.initialize_from_mean_and_covariance(a,
# 0.1/s[0,0]**2*utils.identity(D,K))
#A.initialize_from_value(a + 0.01*np.random.randn(D,D,K))
# Latent states with dynamics
# X : () x (N,D)
X = DriftingGaussianMarkovChain(np.zeros(D), # mean of x0
1e-3*np.identity(D), # prec of x0
A, # dynamics matrices
S.as_gaussian()[1:], # temporal weights
np.ones(D), # innovation
n=N, # time instances
name='X',
plotter=bpplt.GaussianMarkovChainPlotter(scale=2),
initialize=False)
X.initialize_from_value(np.random.randn(N,D))
if not drift_C:
# Mixing matrix from latent space to observation space using ARD
# gamma : (D) x ()
gamma = Gamma(1e-5,
1e-5,
plates=(D,),
name='gamma')
# C : (M,1) x (D)
C = GaussianArrayARD(0,
gamma,
shape=(D,),
plates=(M,1),
name='C',
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=2,
scale=0))
C.initialize_from_value(np.random.randn(M,1,D))
#C.initialize_from_random()
#C.initialize_from_mean_and_covariance(C.random(),
# 0.1*utils.identity(D))
# Noiseless process
# F : (M,N) x ()
F = SumMultiply('d,d',
C,
X.as_gaussian(),
name='F')
else:
# Mixing matrix from latent space to observation space using ARD
# gamma : (D,K) x ()
gamma = Gamma(1e-5,
1e-5,
plates=(D,K),
name='gamma')
# C : (M,1) x (D,K)
C = GaussianArrayARD(0,
gamma,
shape=(D,K),
plates=(M,1),
name='C',
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=2,
scale=0))
C.initialize_from_random()
#C.initialize_from_mean_and_covariance(C.random(),
# 0.1*utils.identity(D, K))
# Noiseless process
# F : (M,N) x ()
F = SumMultiply('dk,d,k',
C,
X.as_gaussian(),
S.as_gaussian(),
name='F')
# Observation noise
# tau : () x ()
tau = Gamma(1e-5,
1e-5,
name='tau')
tau.initialize_from_value(1e2)
# Observations
# Y: (M,N) x ()
Y = GaussianArrayARD(F,
tau,
name='Y')
# Construct inference machine
if drift_C or drift_A:
Q = VB(Y, F, C, gamma, X, A, alpha, tau, S, B, beta)
else:
Q = VB(Y, F, C, gamma, X, A, alpha, tau)
return Q
def test_riemannian_gradient(self):
"""Test Riemannian gradient of a Gamma node."""
#
# Without observations
#
# Construct model
a = np.random.rand()
b = np.random.rand()
tau = Gamma(a, b)
# Random initialization
tau.initialize_from_parameters(np.random.rand(),
np.random.rand())
# Initial parameters
phi0 = tau.phi
# Gradient
g = tau.get_riemannian_gradient()
# Parameters after VB-EM update
tau.update()
phi1 = tau.phi
# Check
self.assertAllClose(g[0],
phi1[0] - phi0[0])
self.assertAllClose(g[1],
phi1[1] - phi0[1])
#
# With observations
#
# Construct model
a = np.random.rand()
b = np.random.rand()
tau = Gamma(a, b)
mu = np.random.randn()
Y = GaussianARD(mu, tau)
Y.observe(np.random.randn())
# Random initialization
tau.initialize_from_parameters(np.random.rand(),
np.random.rand())
# Initial parameters
phi0 = tau.phi
# Gradient
g = tau.get_riemannian_gradient()
# Parameters after VB-EM update
tau.update()
phi1 = tau.phi
# Check
self.assertAllClose(g[0],
phi1[0] - phi0[0])
self.assertAllClose(g[1],
phi1[1] - phi0[1])
pass
import numpy as np np.random.seed(1) data = np.random.normal(5, 10, size=(10, )) from bayespy.nodes import GaussianARD, Gamma mu = GaussianARD(0, 1e-6) tau = Gamma(1e-6, 1e-6) y = GaussianARD(mu, tau, plates=(10, )) y.observe(data) from bayespy.inference import VB Q = VB(mu, tau, y) Q.update(repeat=20) import bayespy.plot as bpplt bpplt.pyplot.subplot(2, 1, 1) bpplt.pdf(mu, np.linspace(-10, 20, num=100), color='k', name=r'\mu') bpplt.pyplot.subplot(2, 1, 2) bpplt.pdf(tau, np.linspace(1e-6, 0.08, num=100), color='k', name=r'\tau') bpplt.pyplot.tight_layout() bpplt.pyplot.show()
def model(M, N, D, K):
"""
Construct the linear state-space model with time-varying dynamics
For reference, see the following publication:
(TODO)
"""
#
# The model block for the latent mixing weight process
#
# Dynamics matrix with ARD
# beta : (K) x ()
beta = Gamma(1e-5,
1e-5,
plates=(K,),
name='beta')
# B : (K) x (K)
B = GaussianARD(np.identity(K),
beta,
shape=(K,),
plates=(K,),
name='B',
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=1,
scale=0),
initialize=False)
B.initialize_from_value(np.identity(K))
# Mixing weight process, that is, the weights in the linear combination of
# state dynamics matrices
# S : () x (N,K)
S = GaussianMarkovChain(np.ones(K),
1e-6*np.identity(K),
B,
np.ones(K),
n=N,
name='S',
plotter=bpplt.GaussianMarkovChainPlotter(scale=2),
initialize=False)
s = 10*np.random.randn(N,K)
s[:,0] = 10
S.initialize_from_value(s)
#
# The model block for the latent states
#
# Projection matrix of the dynamics matrix
# alpha : (K) x ()
alpha = Gamma(1e-5,
1e-5,
plates=(D,K),
name='alpha')
alpha.initialize_from_value(1*np.ones((D,K)))
# A : (D) x (D,K)
A = GaussianARD(0,
alpha,
shape=(D,K),
plates=(D,),
name='A',
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=1,
scale=0),
initialize=False)
# Initialize S and A such that A*S is almost an identity matrix
a = np.zeros((D,D,K))
a[np.arange(D),np.arange(D),np.zeros(D,dtype=int)] = 1
a[:,:,0] = np.identity(D) / s[0,0]
a[:,:,1:] = 0.1/s[0,0]*np.random.randn(D,D,K-1)
A.initialize_from_value(a)
# Latent states with dynamics
# X : () x (N,D)
X = VaryingGaussianMarkovChain(np.zeros(D), # mean of x0
1e-3*np.identity(D), # prec of x0
A, # dynamics matrices
S._convert(GaussianMoments)[1:], # temporal weights
np.ones(D), # innovation
n=N, # time instances
name='X',
plotter=bpplt.GaussianMarkovChainPlotter(scale=2),
initialize=False)
X.initialize_from_value(np.random.randn(N,D))
#
# The model block for observations
#
# Mixing matrix from latent space to observation space using ARD
# gamma : (D) x ()
gamma = Gamma(1e-5,
1e-5,
plates=(D,),
name='gamma')
gamma.initialize_from_value(1e-2*np.ones(D))
# C : (M,1) x (D)
C = GaussianARD(0,
gamma,
shape=(D,),
plates=(M,1),
name='C',
plotter=bpplt.GaussianHintonPlotter(rows=0,
cols=2,
scale=0))
C.initialize_from_value(np.random.randn(M,1,D))
# Noiseless process
# F : (M,N) x ()
F = SumMultiply('d,d',
C,
X,
name='F')
# Observation noise
# tau : () x ()
tau = Gamma(1e-5,
1e-5,
name='tau')
tau.initialize_from_value(1e2)
# Observations
# Y: (M,N) x ()
Y = GaussianARD(F,
tau,
name='Y')
# Construct inference machine
Q = VB(Y, F, C, gamma, X, A, alpha, tau, S, B, beta)
return Q
def test_message_to_parent(self):
"""
Test the message to parents of Mixture node.
"""
K = 3
# Broadcasting the moments on the cluster axis
Mu = GaussianARD(2, 1, ndim=0, plates=(K, ))
(mu, mumu) = Mu._message_to_child()
Alpha = Gamma(3, 1, plates=(K, ))
(alpha, logalpha) = Alpha._message_to_child()
z = Categorical(np.ones(K) / K)
X = Mixture(z, GaussianARD, Mu, Alpha)
tau = 4
Y = GaussianARD(X, tau)
y = 5
Y.observe(y)
(x, xx) = X._message_to_child()
m = z._message_from_children()
self.assertAllClose(
m[0] * np.ones(K),
random.gaussian_logpdf(xx * alpha, x * alpha * mu, mumu * alpha,
logalpha, 0) * np.ones(K))
m = Mu._message_from_children()
self.assertAllClose(m[0], 1 / K * (alpha * x) * np.ones(3))
self.assertAllClose(m[1], -0.5 * 1 / K * alpha * np.ones(3))
# Some parameters do not have cluster plate axis
Mu = GaussianARD(2, 1, ndim=0, plates=(K, ))
(mu, mumu) = Mu._message_to_child()
Alpha = Gamma(3, 1) # Note: no cluster plate axis!
(alpha, logalpha) = Alpha._message_to_child()
z = Categorical(np.ones(K) / K)
X = Mixture(z, GaussianARD, Mu, Alpha)
tau = 4
Y = GaussianARD(X, tau)
y = 5
Y.observe(y)
(x, xx) = X._message_to_child()
m = z._message_from_children()
self.assertAllClose(
m[0] * np.ones(K),
random.gaussian_logpdf(xx * alpha, x * alpha * mu, mumu * alpha,
logalpha, 0) * np.ones(K))
m = Mu._message_from_children()
self.assertAllClose(m[0], 1 / K * (alpha * x) * np.ones(3))
self.assertAllClose(m[1], -0.5 * 1 / K * alpha * np.ones(3))
# Cluster assignments do not have as many plate axes as parameters.
M = 2
Mu = GaussianARD(2, 1, ndim=0, plates=(K, M))
(mu, mumu) = Mu._message_to_child()
Alpha = Gamma(3, 1, plates=(K, M))
(alpha, logalpha) = Alpha._message_to_child()
z = Categorical(np.ones(K) / K)
X = Mixture(z, GaussianARD, Mu, Alpha, cluster_plate=-2)
tau = 4
Y = GaussianARD(X, tau)
y = 5 * np.ones(M)
Y.observe(y)
(x, xx) = X._message_to_child()
m = z._message_from_children()
self.assertAllClose(
m[0] * np.ones(K),
np.sum(random.gaussian_logpdf(xx * alpha, x * alpha * mu,
mumu * alpha, logalpha, 0) * np.ones(
(K, M)),
axis=-1))
m = Mu._message_from_children()
self.assertAllClose(m[0] * np.ones((K, M)),
1 / K * (alpha * x) * np.ones((K, M)))
self.assertAllClose(m[1] * np.ones((K, M)),
-0.5 * 1 / K * alpha * np.ones((K, M)))
# Mixed distribution broadcasts g
# This tests for a found bug. The bug caused an error.
Z = Categorical([0.3, 0.5, 0.2])
X = Mixture(Z, Categorical, [[0.2, 0.8], [0.1, 0.9], [0.3, 0.7]])
m = Z._message_from_children()
pass
def test_message_to_child(self):
"""
Test the message to child of GaussianGamma node.
"""
# Simple test
mu = np.array([1,2,3])
Lambda = np.identity(3)
a = 2
b = 10
X_alpha = GaussianGamma(mu, Lambda, a, b)
u = X_alpha._message_to_child()
self.assertEqual(len(u), 4)
tau = np.array(a/b)
self.assertAllClose(u[0],
tau[...,None] * mu)
self.assertAllClose(u[1],
(linalg.inv(Lambda)
+ tau[...,None,None] * linalg.outer(mu, mu)))
self.assertAllClose(u[2],
tau)
self.assertAllClose(u[3],
-np.log(b) + special.psi(a))
# Test with unknown parents
mu = Gaussian(np.arange(3), 10*np.identity(3))
Lambda = Wishart(10, np.identity(3))
a = 2
b = Gamma(3, 15)
X_alpha = GaussianGamma(mu, Lambda, a, b)
u = X_alpha._message_to_child()
(mu, mumu) = mu._message_to_child()
Cov_mu = mumu - linalg.outer(mu, mu)
(Lambda, _) = Lambda._message_to_child()
(b, _) = b._message_to_child()
(tau, logtau) = Gamma(a, b + 0.5*np.sum(Lambda*Cov_mu))._message_to_child()
self.assertAllClose(u[0],
tau[...,None] * mu)
self.assertAllClose(u[1],
(linalg.inv(Lambda)
+ tau[...,None,None] * linalg.outer(mu, mu)))
self.assertAllClose(u[2],
tau)
self.assertAllClose(u[3],
logtau)
# Test with plates
mu = Gaussian(np.reshape(np.arange(3*4), (4,3)),
10*np.identity(3),
plates=(4,))
Lambda = Wishart(10, np.identity(3))
a = 2
b = Gamma(3, 15)
X_alpha = GaussianGamma(mu, Lambda, a, b, plates=(4,))
u = X_alpha._message_to_child()
(mu, mumu) = mu._message_to_child()
Cov_mu = mumu - linalg.outer(mu, mu)
(Lambda, _) = Lambda._message_to_child()
(b, _) = b._message_to_child()
(tau, logtau) = Gamma(a,
b + 0.5*np.sum(Lambda*Cov_mu,
axis=(-1,-2)))._message_to_child()
self.assertAllClose(u[0] * np.ones((4,1)),
np.ones((4,1)) * tau[...,None] * mu)
self.assertAllClose(u[1] * np.ones((4,1,1)),
np.ones((4,1,1)) * (linalg.inv(Lambda)
+ tau[...,None,None] * linalg.outer(mu, mu)))
self.assertAllClose(u[2] * np.ones(4),
np.ones(4) * tau)
self.assertAllClose(u[3] * np.ones(4),
np.ones(4) * logtau)
pass
def model(M=20, N=100, D=10, K=3):
"""
Construct the linear state-space model with switching dynamics.
"""
#
# Switching dynamics (HMM)
#
# Prior for initial state probabilities
rho = Dirichlet(1e-3 * np.ones(K), name='rho')
# Prior for state transition probabilities
V = Dirichlet(1e-3 * np.ones(K), plates=(K, ), name='V')
v = 10 * np.identity(K) + 1 * np.ones((K, K))
v /= np.sum(v, axis=-1, keepdims=True)
V.initialize_from_value(v)
# Hidden states (with unknown initial state probabilities and state
# transition probabilities)
Z = CategoricalMarkovChain(rho,
V,
states=N - 1,
name='Z',
plotter=bpplt.CategoricalMarkovChainPlotter(),
initialize=False)
Z.u[0] = np.random.dirichlet(np.ones(K))
Z.u[1] = np.reshape(
np.random.dirichlet(0.5 * np.ones(K * K), size=(N - 2)), (N - 2, K, K))
#
# Linear state-space models
#
# Dynamics matrix with ARD
# (K,D) x ()
alpha = Gamma(1e-5, 1e-5, plates=(K, 1, D), name='alpha')
# (K,1,1,D) x (D)
A = GaussianARD(0,
alpha,
shape=(D, ),
plates=(K, D),
name='A',
plotter=bpplt.GaussianHintonPlotter())
A.initialize_from_value(
np.identity(D) * np.ones((K, D, D)) + 0.1 * np.random.randn(K, D, D))
# Latent states with dynamics
# (K,1) x (N,D)
X = SwitchingGaussianMarkovChain(
np.zeros(D), # mean of x0
1e-3 * np.identity(D), # prec of x0
A, # dynamics
Z, # dynamics selection
np.ones(D), # innovation
n=N, # time instances
name='X',
plotter=bpplt.GaussianMarkovChainPlotter())
X.initialize_from_value(10 * np.random.randn(N, D))
# Mixing matrix from latent space to observation space using ARD
# (K,1,1,D) x ()
gamma = Gamma(1e-5, 1e-5, plates=(D, ), name='gamma')
# (K,M,1) x (D)
C = GaussianARD(0,
gamma,
shape=(D, ),
plates=(M, 1),
name='C',
plotter=bpplt.GaussianHintonPlotter(rows=-3, cols=-1))
C.initialize_from_value(np.random.randn(M, 1, D))
# Underlying noiseless function
# (K,M,N) x ()
F = SumMultiply('i,i', C, X, name='F')
#
# Mixing the models
#
# Observation noise
tau = Gamma(1e-5, 1e-5, name='tau')
tau.initialize_from_value(1e2)
# Emission/observation distribution
Y = GaussianARD(F, tau, name='Y')
Q = VB(Y, F, Z, rho, V, C, gamma, X, A, alpha, tau)
return Q
def test_message_to_parent_mu(self):
"""
Test that GaussianARD computes the message to the 1st parent correctly.
"""
# Check formula with uncertain parent alpha
mu = GaussianARD(0, 1)
alpha = Gamma(2, 1)
X = GaussianARD(mu, alpha)
X.observe(3)
(m0, m1) = mu._message_from_children()
#(m0, m1) = X._message_to_parent(0)
self.assertAllClose(m0, 2 * 3)
self.assertAllClose(m1, -0.5 * 2)
# Check formula with uncertain node
mu = GaussianARD(1, 1e10)
X = GaussianARD(mu, 2)
Y = GaussianARD(X, 1)
Y.observe(5)
X.update()
(m0, m1) = mu._message_from_children()
self.assertAllClose(m0, 2 * 1 / (2 + 1) * (2 * 1 + 1 * 5))
self.assertAllClose(m1, -0.5 * 2)
# Check alpha larger than mu
mu = GaussianARD(np.zeros((2, 3)), 1e10, shape=(2, 3))
X = GaussianARD(mu, 2 * np.ones((3, 2, 3)))
X.observe(3 * np.ones((3, 2, 3)))
(m0, m1) = mu._message_from_children()
self.assertAllClose(m0, 2 * 3 * 3 * np.ones((2, 3)))
self.assertAllClose(m1, -0.5 * 3 * 2 * misc.identity(2, 3))
# Check mu larger than alpha
mu = GaussianARD(np.zeros((3, 2, 3)), 1e10, shape=(3, 2, 3))
X = GaussianARD(mu, 2 * np.ones((2, 3)))
X.observe(3 * np.ones((3, 2, 3)))
(m0, m1) = mu._message_from_children()
self.assertAllClose(m0, 2 * 3 * np.ones((3, 2, 3)))
self.assertAllClose(m1, -0.5 * 2 * misc.identity(3, 2, 3))
# Check node larger than mu and alpha
mu = GaussianARD(np.zeros((2, 3)), 1e10, shape=(2, 3))
X = GaussianARD(mu, 2 * np.ones((3, )), shape=(3, 2, 3))
X.observe(3 * np.ones((3, 2, 3)))
(m0, m1) = mu._message_from_children()
self.assertAllClose(m0, 2 * 3 * 3 * np.ones((2, 3)))
self.assertAllClose(m1, -0.5 * 2 * 3 * misc.identity(2, 3))
# Check broadcasting of dimensions
mu = GaussianARD(np.zeros((2, 1)), 1e10, shape=(2, 1))
X = GaussianARD(mu, 2 * np.ones((2, 3)), shape=(2, 3))
X.observe(3 * np.ones((2, 3)))
(m0, m1) = mu._message_from_children()
self.assertAllClose(m0, 2 * 3 * 3 * np.ones((2, 1)))
self.assertAllClose(m1, -0.5 * 2 * 3 * misc.identity(2, 1))
# Check plates for smaller mu than node
mu = GaussianARD(0, 1, shape=(3, ), plates=(4, 1, 1))
X = GaussianARD(mu, 2 * np.ones((3, )), shape=(2, 3), plates=(4, 5))
X.observe(3 * np.ones((4, 5, 2, 3)))
(m0, m1) = mu._message_from_children()
self.assertAllClose(m0 * np.ones((4, 1, 1, 3)),
2 * 3 * 5 * 2 * np.ones((4, 1, 1, 3)))
self.assertAllClose(
m1 * np.ones((4, 1, 1, 3, 3)),
-0.5 * 2 * 5 * 2 * misc.identity(3) * np.ones((4, 1, 1, 3, 3)))
# Check mask
mu = GaussianARD(np.zeros((2, 1, 3)), 1e10, shape=(3, ))
X = GaussianARD(mu,
2 * np.ones((2, 4, 3)),
shape=(3, ),
plates=(
2,
4,
))
X.observe(3 * np.ones((2, 4, 3)),
mask=[[True, True, True, False], [False, True, False, True]])
(m0, m1) = mu._message_from_children()
self.assertAllClose(m0, (2 * 3 * np.ones(
(2, 1, 3)) * np.array([[[3]], [[2]]])))
self.assertAllClose(m1, (-0.5 * 2 * misc.identity(3) * np.ones(
(2, 1, 1, 1)) * np.array([[[[3]]], [[[2]]]])))
# Check mask with different shapes
mu = GaussianARD(np.zeros((2, 1, 3)), 1e10, shape=())
X = GaussianARD(mu,
2 * np.ones((2, 4, 3)),
shape=(3, ),
plates=(
2,
4,
))
mask = np.array([[True, True, True, False], [False, True, False,
True]])
X.observe(3 * np.ones((2, 4, 3)), mask=mask)
(m0, m1) = mu._message_from_children()
self.assertAllClose(
m0, 2 * 3 * np.sum(
np.ones((2, 4, 3)) * mask[..., None], axis=-2, keepdims=True))
self.assertAllClose(m1, (-0.5 * 2 * np.sum(
np.ones((2, 4, 3)) * mask[..., None], axis=-2, keepdims=True)))
# Check non-ARD Gaussian child
mu = np.array([1, 2])
Mu = GaussianARD(mu, 1e10, shape=(2, ))
alpha = np.array([3, 4])
Lambda = np.array([[1, 0.5], [0.5, 1]])
X = GaussianARD(Mu, alpha)
Y = Gaussian(X, Lambda)
y = np.array([5, 6])
Y.observe(y)
X.update()
(m0, m1) = Mu._message_from_children()
mean = np.dot(np.linalg.inv(np.diag(alpha) + Lambda),
np.dot(np.diag(alpha), mu) + np.dot(Lambda, y))
self.assertAllClose(m0, np.dot(np.diag(alpha), mean))
self.assertAllClose(m1, -0.5 * np.diag(alpha))
# Check broadcasted variable axes
mu = GaussianARD(np.zeros(1), 1e10, shape=(1, ))
X = GaussianARD(mu, 2, shape=(3, ))
X.observe(3 * np.ones(3))
(m0, m1) = mu._message_from_children()
self.assertAllClose(m0,
2 * 3 * np.sum(np.ones(3), axis=-1, keepdims=True))
self.assertAllClose(
m1,
-0.5 * 2 * np.sum(np.identity(3), axis=(-1, -2), keepdims=True))
pass
import numpy as np
np.random.seed(1)
from bayespy.nodes import GaussianARD, GaussianMarkovChain, Gamma, Dot
M = 30
N = 400
D = 10
alpha = Gamma(1e-5, 1e-5, plates=(D, ), name='alpha')
A = GaussianARD(0, alpha, shape=(D, ), plates=(D, ), name='A')
X = GaussianMarkovChain(np.zeros(D),
1e-3 * np.identity(D),
A,
np.ones(D),
n=N,
name='X')
gamma = Gamma(1e-5, 1e-5, plates=(D, ), name='gamma')
C = GaussianARD(0, gamma, shape=(D, ), plates=(M, 1), name='C')
F = Dot(C, X, name='F')
C.initialize_from_random()
tau = Gamma(1e-5, 1e-5, name='tau')
Y = GaussianARD(F, tau, name='Y')
from bayespy.inference import VB
Q = VB(X, C, gamma, A, alpha, tau, Y)
w = 0.3
a = np.array([[np.cos(w), -np.sin(w), 0, 0], [np.sin(w),
np.cos(w), 0, 0], [0, 0, 1, 0],
[0, 0, 0, 0]])
c = np.random.randn(M, 4)
x = np.empty((N, 4))
f = np.empty((M, N))
y = np.empty((M, N))
x[0] = 10 * np.random.randn(4)
def test_message_to_parent_alpha(self):
"""
Test the message from GaussianARD the 2nd parent (alpha).
"""
# Check formula with uncertain parent mu
mu = GaussianARD(1, 1)
tau = Gamma(0.5 * 1e10, 1e10)
X = GaussianARD(mu, tau)
X.observe(3)
(m0, m1) = tau._message_from_children()
self.assertAllClose(m0, -0.5 * (3**2 - 2 * 3 * 1 + 1**2 + 1))
self.assertAllClose(m1, 0.5)
# Check formula with uncertain node
tau = Gamma(1e10, 1e10)
X = GaussianARD(2, tau)
Y = GaussianARD(X, 1)
Y.observe(5)
X.update()
(m0, m1) = tau._message_from_children()
self.assertAllClose(m0,
-0.5 * (1 / (1 + 1) + 3.5**2 - 2 * 3.5 * 2 + 2**2))
self.assertAllClose(m1, 0.5)
# Check alpha larger than mu
alpha = Gamma(np.ones((3, 2, 3)) * 1e10, 1e10)
X = GaussianARD(np.ones((2, 3)), alpha, ndim=3)
X.observe(2 * np.ones((3, 2, 3)))
(m0, m1) = alpha._message_from_children()
self.assertAllClose(
m0 * np.ones((3, 2, 3)),
-0.5 * (2**2 - 2 * 2 * 1 + 1**2) * np.ones((3, 2, 3)))
self.assertAllClose(m1 * np.ones((3, 2, 3)), 0.5 * np.ones((3, 2, 3)))
# Check mu larger than alpha
tau = Gamma(np.ones((2, 3)) * 1e10, 1e10)
X = GaussianARD(np.ones((3, 2, 3)), tau, ndim=3)
X.observe(2 * np.ones((3, 2, 3)))
(m0, m1) = tau._message_from_children()
self.assertAllClose(
m0, -0.5 * (2**2 - 2 * 2 * 1 + 1**2) * 3 * np.ones((2, 3)))
self.assertAllClose(m1 * np.ones((2, 3)), 0.5 * 3 * np.ones((2, 3)))
# Check node larger than mu and alpha
tau = Gamma(np.ones((3, )) * 1e10, 1e10)
X = GaussianARD(np.ones((2, 3)), tau, shape=(3, 2, 3))
X.observe(2 * np.ones((3, 2, 3)))
(m0, m1) = tau._message_from_children()
self.assertAllClose(
m0 * np.ones(3), -0.5 * (2**2 - 2 * 2 * 1 + 1**2) * 6 * np.ones(
(3, )))
self.assertAllClose(m1 * np.ones(3), 0.5 * 6 * np.ones(3))
# Check plates for smaller mu than node
tau = Gamma(np.ones((4, 1, 2, 3)) * 1e10, 1e10)
X = GaussianARD(GaussianARD(1, 1, shape=(3, ), plates=(4, 1, 1)),
tau,
shape=(2, 3),
plates=(4, 5))
X.observe(2 * np.ones((4, 5, 2, 3)))
(m0, m1) = tau._message_from_children()
self.assertAllClose(m0 * np.ones(
(4, 1, 2, 3)), (-0.5 * (2**2 - 2 * 2 * 1 + 1**2 + 1) * 5 * np.ones(
(4, 1, 2, 3))))
self.assertAllClose(m1 * np.ones((4, 1, 2, 3)), 5 * 0.5 * np.ones(
(4, 1, 2, 3)))
# Check mask
tau = Gamma(np.ones((4, 3)) * 1e10, 1e10)
X = GaussianARD(np.ones(3), tau, shape=(3, ), plates=(
2,
4,
))
X.observe(2 * np.ones((2, 4, 3)),
mask=[[True, False, True, False], [False, True, True,
False]])
(m0, m1) = tau._message_from_children()
self.assertAllClose(m0 * np.ones((4, 3)),
(-0.5 * (2**2 - 2 * 2 * 1 + 1**2) * np.ones(
(4, 3)) * np.array([[1], [1], [2], [0]])))
self.assertAllClose(
m1 * np.ones((4, 3)),
0.5 * np.array([[1], [1], [2], [0]]) * np.ones((4, 3)))
# Check non-ARD Gaussian child
mu = np.array([1, 2])
alpha = np.array([3, 4])
Alpha = Gamma(alpha * 1e10, 1e10)
Lambda = np.array([[1, 0.5], [0.5, 1]])
X = GaussianARD(mu, Alpha, ndim=1)
Y = Gaussian(X, Lambda)
y = np.array([5, 6])
Y.observe(y)
X.update()
(m0, m1) = Alpha._message_from_children()
Cov = np.linalg.inv(np.diag(alpha) + Lambda)
mean = np.dot(Cov, np.dot(np.diag(alpha), mu) + np.dot(Lambda, y))
self.assertAllClose(
m0 * np.ones(2), -0.5 * np.diag(
np.outer(mean, mean) + Cov - np.outer(mean, mu) -
np.outer(mu, mean) + np.outer(mu, mu)))
self.assertAllClose(m1 * np.ones(2), 0.5 * np.ones(2))
pass
# BayesPyによるベイジアンネットワーク
# Example model: Principal component analysis（主成分分析）
import numpy as np
from bayespy.nodes import Gaussian, GaussianARD, Wishart, Gamma
from bayespy.nodes import Dot
import bayespy.plot as bpplt
# -----Creating nodes-----
# 潜在空間(latent space)の次元数
D = 3
# 各ノードを定義
X = GaussianARD(0, 1, shape=(D, ), plates=(1, 100), name='X')
alpha = Gamma(1e-3, 1e-3, plates=(D, ), name='alpha')
C = GaussianARD(0, alpha, shape=(D, ), plates=(10, 1), name='C')
F = Dot(C, X) #内積
tau = Gamma(1e-3, 1e-3, name='tau')
Y = GaussianARD(F, tau, name='Y')
# -----Performing inference------
# １： Observe some nodes
c = np.random.randn(10, 2)
x = np.random.randn(2, 100)
data = np.dot(c, x) + 0.1 * np.random.randn(10, 100)
# data:10×100
Y.observe(data)
#（ Missing values）
Y.observe(data,
mask=[[True], [False], [False], [True], [True], [False], [True],
[True], [True], [False]])
def model(M=20, N=100, D=10, K=3):
"""
Construct the linear state-space model with switching dynamics.
"""
#
# Switching dynamics (HMM)
#
# Prior for initial state probabilities
rho = Dirichlet(1e-3*np.ones(K),
name='rho')
# Prior for state transition probabilities
V = Dirichlet(1e-3*np.ones(K),
plates=(K,),
name='V')
v = 10*np.identity(K) + 1*np.ones((K,K))
v /= np.sum(v, axis=-1, keepdims=True)
V.initialize_from_value(v)
# Hidden states (with unknown initial state probabilities and state
# transition probabilities)
Z = CategoricalMarkovChain(rho, V,
states=N-1,
name='Z',
plotter=bpplt.CategoricalMarkovChainPlotter(),
initialize=False)
Z.u[0] = np.random.dirichlet(np.ones(K))
Z.u[1] = np.reshape(np.random.dirichlet(0.5*np.ones(K*K), size=(N-2)),
(N-2, K, K))
#
# Linear state-space models
#
# Dynamics matrix with ARD
# (K,D) x ()
alpha = Gamma(1e-5,
1e-5,
plates=(K,1,D),
name='alpha')
# (K,1,1,D) x (D)
A = GaussianARD(0,
alpha,
shape=(D,),
plates=(K,D),
name='A',
plotter=bpplt.GaussianHintonPlotter())
A.initialize_from_value(np.identity(D)*np.ones((K,D,D))
+ 0.1*np.random.randn(K,D,D))
# Latent states with dynamics
# (K,1) x (N,D)
X = SwitchingGaussianMarkovChain(np.zeros(D), # mean of x0
1e-3*np.identity(D), # prec of x0
A, # dynamics
Z, # dynamics selection
np.ones(D), # innovation
n=N, # time instances
name='X',
plotter=bpplt.GaussianMarkovChainPlotter())
X.initialize_from_value(10*np.random.randn(N,D))
# Mixing matrix from latent space to observation space using ARD
# (K,1,1,D) x ()
gamma = Gamma(1e-5,
1e-5,
plates=(D,),
name='gamma')
# (K,M,1) x (D)
C = GaussianARD(0,
gamma,
shape=(D,),
plates=(M,1),
name='C',
plotter=bpplt.GaussianHintonPlotter(rows=-3,cols=-1))
C.initialize_from_value(np.random.randn(M,1,D))
# Underlying noiseless function
# (K,M,N) x ()
F = SumMultiply('i,i',
C,
X,
name='F')
#
# Mixing the models
#
# Observation noise
tau = Gamma(1e-5,
1e-5,
name='tau')
tau.initialize_from_value(1e2)
# Emission/observation distribution
Y = GaussianARD(F, tau,
name='Y')
Q = VB(Y, F,
Z, rho, V,
C, gamma, X, A, alpha,
tau)
return Q
import numpy
numpy.random.seed(1)
M = 20
N = 100
import numpy as np
x = np.random.randn(N, 2)
w = np.random.randn(M, 2)
f = np.einsum('ik,jk->ij', w, x)
y = f + 0.1 * np.random.randn(M, N)
D = 10
from bayespy.nodes import GaussianARD, Gamma, SumMultiply
X = GaussianARD(0, 1, plates=(1, N), shape=(D, ))
alpha = Gamma(1e-5, 1e-5, plates=(D, ))
C = GaussianARD(0, alpha, plates=(M, 1), shape=(D, ))
F = SumMultiply('d,d->', X, C)
tau = Gamma(1e-5, 1e-5)
Y = GaussianARD(F, tau)
Y.observe(y)
from bayespy.inference import VB
Q = VB(Y, X, C, alpha, tau)
C.initialize_from_random()
from bayespy.inference.vmp.transformations import RotateGaussianARD
rot_X = RotateGaussianARD(X)
rot_C = RotateGaussianARD(C, alpha)
from bayespy.inference.vmp.transformations import RotationOptimizer
R = RotationOptimizer(rot_X, rot_C, D)
Q.set_callback(R.rotate)
Q.update(repeat=1000)
import bayespy.plot as bpplt
bpplt.plot(F)
bpplt.plot(f, color='r', marker='x', linestyle='None')
def test_message_to_parent(self):
"""
Test the message to parents of Mixture node.
"""
K = 3
# Broadcasting the moments on the cluster axis
Mu = GaussianARD(2, 1,
ndim=0,
plates=(K,))
(mu, mumu) = Mu._message_to_child()
Alpha = Gamma(3, 1,
plates=(K,))
(alpha, logalpha) = Alpha._message_to_child()
z = Categorical(np.ones(K)/K)
X = Mixture(z, GaussianARD, Mu, Alpha)
tau = 4
Y = GaussianARD(X, tau)
y = 5
Y.observe(y)
(x, xx) = X._message_to_child()
m = z._message_from_children()
self.assertAllClose(m[0] * np.ones(K),
random.gaussian_logpdf(xx*alpha,
x*alpha*mu,
mumu*alpha,
logalpha,
0)
* np.ones(K))
m = Mu._message_from_children()
self.assertAllClose(m[0],
1/K * (alpha*x) * np.ones(3))
self.assertAllClose(m[1],
-0.5 * 1/K * alpha * np.ones(3))
# Some parameters do not have cluster plate axis
Mu = GaussianARD(2, 1,
ndim=0,
plates=(K,))
(mu, mumu) = Mu._message_to_child()
Alpha = Gamma(3, 1) # Note: no cluster plate axis!
(alpha, logalpha) = Alpha._message_to_child()
z = Categorical(np.ones(K)/K)
X = Mixture(z, GaussianARD, Mu, Alpha)
tau = 4
Y = GaussianARD(X, tau)
y = 5
Y.observe(y)
(x, xx) = X._message_to_child()
m = z._message_from_children()
self.assertAllClose(m[0] * np.ones(K),
random.gaussian_logpdf(xx*alpha,
x*alpha*mu,
mumu*alpha,
logalpha,
0)
* np.ones(K))
m = Mu._message_from_children()
self.assertAllClose(m[0],
1/K * (alpha*x) * np.ones(3))
self.assertAllClose(m[1],
-0.5 * 1/K * alpha * np.ones(3))
# Cluster assignments do not have as many plate axes as parameters.
M = 2
Mu = GaussianARD(2, 1,
ndim=0,
plates=(K,M))
(mu, mumu) = Mu._message_to_child()
Alpha = Gamma(3, 1,
plates=(K,M))
(alpha, logalpha) = Alpha._message_to_child()
z = Categorical(np.ones(K)/K)
X = Mixture(z, GaussianARD, Mu, Alpha, cluster_plate=-2)
tau = 4
Y = GaussianARD(X, tau)
y = 5 * np.ones(M)
Y.observe(y)
(x, xx) = X._message_to_child()
m = z._message_from_children()
self.assertAllClose(m[0]*np.ones(K),
np.sum(random.gaussian_logpdf(xx*alpha,
x*alpha*mu,
mumu*alpha,
logalpha,
0) *
np.ones((K,M)),
axis=-1))
m = Mu._message_from_children()
self.assertAllClose(m[0] * np.ones((K,M)),
1/K * (alpha*x) * np.ones((K,M)))
self.assertAllClose(m[1] * np.ones((K,M)),
-0.5 * 1/K * alpha * np.ones((K,M)))
# Mixed distribution broadcasts g
# This tests for a found bug. The bug caused an error.
Z = Categorical([0.3, 0.5, 0.2])
X = Mixture(Z, Categorical, [[0.2,0.8], [0.1,0.9], [0.3,0.7]])
m = Z._message_from_children()
pass
def test_init(self):
"""
Test the creation of Concatenate node
"""
# One parent only
X = GaussianARD(0, 1, plates=(3, ), shape=())
Y = Concatenate(X)
self.assertEqual(Y.plates, (3, ))
self.assertEqual(Y.dims, ((), ()))
X = GaussianARD(0, 1, plates=(3, ), shape=(2, 4))
Y = Concatenate(X)
self.assertEqual(Y.plates, (3, ))
self.assertEqual(Y.dims, ((2, 4), (2, 4, 2, 4)))
# Two parents
X1 = GaussianARD(0, 1, plates=(2, ), shape=())
X2 = GaussianARD(0, 1, plates=(3, ), shape=())
Y = Concatenate(X1, X2)
self.assertEqual(Y.plates, (5, ))
self.assertEqual(Y.dims, ((), ()))
# Two parents with shapes
X1 = GaussianARD(0, 1, plates=(2, ), shape=(4, 6))
X2 = GaussianARD(0, 1, plates=(3, ), shape=(4, 6))
Y = Concatenate(X1, X2)
self.assertEqual(Y.plates, (5, ))
self.assertEqual(Y.dims, ((4, 6), (4, 6, 4, 6)))
# Two parents with non-default axis
X1 = GaussianARD(0, 1, plates=(2, 4), shape=())
X2 = GaussianARD(0, 1, plates=(3, 4), shape=())
Y = Concatenate(X1, X2, axis=-2)
self.assertEqual(Y.plates, (5, 4))
self.assertEqual(Y.dims, ((), ()))
# Three parents
X1 = GaussianARD(0, 1, plates=(2, ), shape=())
X2 = GaussianARD(0, 1, plates=(3, ), shape=())
X3 = GaussianARD(0, 1, plates=(4, ), shape=())
Y = Concatenate(X1, X2, X3)
self.assertEqual(Y.plates, (9, ))
self.assertEqual(Y.dims, ((), ()))
# Constant parent
X1 = [7.2, 3.5]
X2 = GaussianARD(0, 1, plates=(3, ), shape=())
Y = Concatenate(X1, X2)
self.assertEqual(Y.plates, (5, ))
self.assertEqual(Y.dims, ((), ()))
# Different moments
X1 = GaussianARD(0, 1, plates=(3, ))
X2 = Gamma(1, 1, plates=(4, ))
self.assertRaises(ValueError, Concatenate, X1, X2)
# Incompatible shapes
X1 = GaussianARD(0, 1, plates=(3, ), shape=(2, ))
X2 = GaussianARD(0, 1, plates=(2, ), shape=())
self.assertRaises(ValueError, Concatenate, X1, X2)
# Incompatible plates
X1 = GaussianARD(0, 1, plates=(4, 3), shape=())
X2 = GaussianARD(0, 1, plates=(
5,
2,
), shape=())
self.assertRaises(ValueError, Concatenate, X1, X2)
pass
def test_messages(self):
D = 2
M = 3
np.random.seed(42)
def check(mu, Lambda, alpha, beta, ndim):
X = GaussianGamma(
mu,
(
Lambda if isinstance(Lambda._moments, WishartMoments) else
Lambda.as_wishart(ndim=ndim)
),
alpha,
beta,
ndim=ndim
)
self.assert_moments(
X,
postprocess=lambda u: [
u[0],
u[1] + linalg.transpose(u[1], ndim=ndim),
u[2],
u[3]
],
rtol=1e-5,
atol=1e-6,
eps=1e-8
)
X.observe(
(
np.random.randn(*(X.plates + X.dims[0])),
np.random.rand(*X.plates)
)
)
self.assert_message_to_parent(X, mu)
self.assert_message_to_parent(
X,
Lambda,
postprocess=lambda m: [
m[0] + linalg.transpose(m[0], ndim=ndim),
m[1],
]
)
self.assert_message_to_parent(X, beta)
check(
Gaussian(np.random.randn(M, D), random.covariance(D), plates=(M,)),
Wishart(D + np.random.rand(M), random.covariance(D), plates=(M,)),
np.random.rand(M),
Gamma(np.random.rand(M), np.random.rand(M), plates=(M,)),
ndim=1
)
check(
GaussianARD(np.random.randn(M, D), np.random.rand(M, D), ndim=0),
Gamma(np.random.rand(M, D), np.random.rand(M, D)),
np.random.rand(M, D),
Gamma(np.random.rand(M, D), np.random.rand(M, D)),
ndim=0
)
pass
