def _compute_phi_from_parents(*u_parents):
# Compute weighted average of the parameters
# Cluster parameters
Phi = distribution._compute_phi_from_parents(*(u_parents[1:]))
# Contributions/weights/probabilities
P = u_parents[0][0]
phi = list()
for ind in range(len(Phi)):
# Compute element-wise product and then sum over K clusters.
# Note that the dimensions aren't perfectly aligned because
# the cluster dimension (K) may be arbitrary for phi, and phi
# also has dimensions (Dd,..,D0) of the parameters.
# Shape(phi) = [Nn,..,K,..,N0,Dd,..,D0]
# Shape(p) = [Nn,..,N0,K]
# Shape(result) = [Nn,..,N0,Dd,..,D0]
# General broadcasting rules apply for Nn,..,N0, that is,
# preceding dimensions may be missing or dimension may be
# equal to one. Probably, shape(phi) has lots of missing
# dimensions and/or dimensions that are one.
if cluster_plate < 0:
cluster_axis = cluster_plate - distribution.ndims[ind]
#else:
# cluster_axis = cluster_plate
# Move cluster axis to the last:
# Shape(phi) = [Nn,..,N0,Dd,..,D0,K]
phi.append(utils.moveaxis(Phi[ind], cluster_axis, -1))
# Add axes to p:
# Shape(p) = [Nn,..,N0,K,1,..,1]
p = utils.add_trailing_axes(P, distribution.ndims[ind])
# Move cluster axis to the last:
# Shape(p) = [Nn,..,N0,1,..,1,K]
p = utils.moveaxis(p, -(distribution.ndims[ind]+1), -1)
#print('Mixture.compute_phi, p:', np.sum(p, axis=-1))
#print('mixture.compute_phi shapes:')
#print(np.shape(p))
#print(np.shape(phi[ind]))
# Now the shapes broadcast perfectly and we can sum
# p*phi over the last axis:
# Shape(result) = [Nn,..,N0,Dd,..,D0]
phi[ind] = utils.sum_product(p, phi[ind], axes_to_sum=-1)
return phi
def _compute_phi_from_parents(*u_parents):
# Compute weighted average of the parameters
# Cluster parameters
Phi = distribution._compute_phi_from_parents(*(u_parents[1:]))
# Contributions/weights/probabilities
P = u_parents[0][0]
phi = list()
for ind in range(len(Phi)):
# Compute element-wise product and then sum over K clusters.
# Note that the dimensions aren't perfectly aligned because
# the cluster dimension (K) may be arbitrary for phi, and phi
# also has dimensions (Dd,..,D0) of the parameters.
# Shape(phi) = [Nn,..,K,..,N0,Dd,..,D0]
# Shape(p) = [Nn,..,N0,K]
# Shape(result) = [Nn,..,N0,Dd,..,D0]
# General broadcasting rules apply for Nn,..,N0, that is,
# preceding dimensions may be missing or dimension may be
# equal to one. Probably, shape(phi) has lots of missing
# dimensions and/or dimensions that are one.
if cluster_plate < 0:
cluster_axis = cluster_plate - distribution.ndims[ind]
#else:
# cluster_axis = cluster_plate
# Move cluster axis to the last:
# Shape(phi) = [Nn,..,N0,Dd,..,D0,K]
phi.append(utils.moveaxis(Phi[ind], cluster_axis, -1))
# Add axes to p:
# Shape(p) = [Nn,..,N0,K,1,..,1]
p = utils.add_trailing_axes(P, distribution.ndims[ind])
# Move cluster axis to the last:
# Shape(p) = [Nn,..,N0,1,..,1,K]
p = utils.moveaxis(p, -(distribution.ndims[ind] + 1), -1)
#print('Mixture.compute_phi, p:', np.sum(p, axis=-1))
#print('mixture.compute_phi shapes:')
#print(np.shape(p))
#print(np.shape(phi[ind]))
# Now the shapes broadcast perfectly and we can sum
# p*phi over the last axis:
# Shape(result) = [Nn,..,N0,Dd,..,D0]
phi[ind] = utils.sum_product(p, phi[ind], axes_to_sum=-1)
return phi
def compute_phi_from_parents(self, *u_parents, mask=True):
# Compute weighted average of the parameters
# Cluster parameters
Phi = self.distribution.compute_phi_from_parents(*(u_parents[1:]))
# Contributions/weights/probabilities
P = u_parents[0][0]
phi = list()
for ind in range(len(Phi)):
# Compute element-wise product and then sum over K clusters.
# Note that the dimensions aren't perfectly aligned because
# the cluster dimension (K) may be arbitrary for phi, and phi
# also has dimensions (Dd,..,D0) of the parameters.
# Shape(phi) = [Nn,..,K,..,N0,Dd,..,D0]
# Shape(p) = [Nn,..,N0,K]
# Shape(result) = [Nn,..,N0,Dd,..,D0]
# General broadcasting rules apply for Nn,..,N0, that is,
# preceding dimensions may be missing or dimension may be
# equal to one. Probably, shape(phi) has lots of missing
# dimensions and/or dimensions that are one.
if self.cluster_plate < 0:
cluster_axis = self.cluster_plate - self.distribution.ndims[ind]
else:
raise RuntimeError("Cluster plate should be negative")
# Move cluster axis to the last:
# Shape(phi) = [Nn,..,N0,Dd,..,D0,K]
if np.ndim(Phi[ind]) >= abs(cluster_axis):
phi.append(utils.moveaxis(Phi[ind], cluster_axis, -1))
else:
phi.append(Phi[ind][...,None])
# Add axes to p:
# Shape(p) = [Nn,..,N0,K,1,..,1]
p = utils.add_trailing_axes(P, self.distribution.ndims[ind])
# Move cluster axis to the last:
# Shape(p) = [Nn,..,N0,1,..,1,K]
p = utils.moveaxis(p, -(self.distribution.ndims[ind]+1), -1)
# Now the shapes broadcast perfectly and we can sum
# p*phi over the last axis:
# Shape(result) = [Nn,..,N0,Dd,..,D0]
phi[ind] = utils.sum_product(p, phi[ind], axes_to_sum=-1)
return phi
def _compute_cgf_from_parents(*u_parents):
# Compute weighted average of g over the clusters.
# Shape(g) = [Nn,..,K,..,N0]
# Shape(p) = [Nn,..,N0,K]
# Shape(result) = [Nn,..,N0]
# Compute g for clusters:
# Shape(g) = [Nn,..,K,..,N0]
g = distribution._compute_cgf_from_parents(*(u_parents[1:]))
# Move cluster axis to last:
# Shape(g) = [Nn,..,N0,K]
g = utils.moveaxis(g, cluster_plate, -1)
# Cluster assignments/contributions/probabilities/weights:
# Shape(p) = [Nn,..,N0,K]
p = u_parents[0][0]
# Weighted average of g over the clusters. As p and g are
# properly aligned, you can just sum p*g over the last
# axis and utilize broadcasting:
# Shape(result) = [Nn,..,N0]
#print('mixture.compute_g_from_parents p and g:', np.shape(p), np.shape(g))
g = utils.sum_product(p, g, axes_to_sum=-1)
#print('mixture.compute_g_from_parents g:', np.sum(g), np.shape(g))
return g
def compute_cgf_from_parents(self, *u_parents):
# Compute weighted average of g over the clusters.
# Shape(g) = [Nn,..,K,..,N0]
# Shape(p) = [Nn,..,N0,K]
# Shape(result) = [Nn,..,N0]
# Compute g for clusters:
# Shape(g) = [Nn,..,K,..,N0]
g = self.distribution.compute_cgf_from_parents(*(u_parents[1:]))
# Move cluster axis to last:
# Shape(g) = [Nn,..,N0,K]
g = utils.moveaxis(g, self.cluster_plate, -1)
# Cluster assignments/contributions/probabilities/weights:
# Shape(p) = [Nn,..,N0,K]
p = u_parents[0][0]
# Weighted average of g over the clusters. As p and g are
# properly aligned, you can just sum p*g over the last
# axis and utilize broadcasting:
# Shape(result) = [Nn,..,N0]
g = utils.sum_product(p, g, axes_to_sum=-1)
return g
def integrated_logpdf_from_parents(self, x, index):
""" Approximates the posterior predictive pdf \int
p(x|parents) q(parents) dparents in log-scale as \int
q(parents_i) exp( \int q(parents_\i) \log p(x|parents)
dparents_\i ) dparents_i."""
if index == 0:
# Integrate out the cluster assignments
# First, integrate the cluster parameters in log-scale
# compute_logpdf(cls, u, phi, g, f):
# Shape(x) = [M1,..,Mm,N1,..,Nn,D1,..,Dd]
# Add the cluster axis to x:
# Shape(x) = [M1,..,Mm,N1,..,1,..,Nn,D1,..,Dd]
cluster_axis = self.cluster_plate - \
self._moments.ndim_observations
x = np.expand_dims(x, axis=cluster_axis)
u_parents = self._message_from_parents()
# Shape(u) = [M1,..,Mm,N1,..,1,..,Nn,D1,..,Dd]
# Shape(f) = [M1,..,Mm,N1,..,1,..,Nn]
(u, f) = self._distribution.distribution.compute_fixed_moments_and_f(x)
# Shape(phi) = [N1,..,K,..,Nn,D1,..,Dd]
phi = self._distribution.distribution.compute_phi_from_parents(*(u_parents[1:]))
# Shape(g) = [N1,..,K,..,Nn]
g = self._distribution.distribution.compute_cgf_from_parents(*(u_parents[1:]))
# Shape(lpdf) = [M1,..,Mm,N1,..,K,..,Nn]
lpdf = self._distribution.distribution.compute_logpdf(u, phi, g, f)
# From logpdf to pdf, but avoid over/underflow
lpdf_max = np.max(lpdf, axis=self.cluster_plate, keepdims=True)
pdf = np.exp(lpdf-lpdf_max)
# Move cluster axis to be the last:
# Shape(pdf) = [M1,..,Mm,N1,..,Nn,K]
pdf = utils.moveaxis(pdf, self.cluster_plate, -1)
# Cluster assignments/probabilities/weights
# Shape(p) = [N1,..,Nn,K]
p = u_parents[0][0]
# Weighted average. TODO/FIXME: Use einsum!
# Shape(pdf) = [M1,..,Mm,N1,..,Nn]
pdf = np.sum(pdf * p, axis=self.cluster_plate)
# Back to log-scale (add the overflow fix!)
lpdf_max = np.squeeze(lpdf_max, axis=self.cluster_plate)
lpdf = np.log(pdf) + lpdf_max
return lpdf
raise NotImplementedError()
def _compute_message_to_parent(parent, index, u, *u_parents):
""" . """
#print('Mixture.compute_message:')
if index == 0:
# Shape(phi) = [Nn,..,K,..,N0,Dd,..,D0]
# Shape(L) = [Nn,..,K,..,N0]
# Shape(u) = [Nn,..,N0,Dd,..,D0]
# Shape(result) = [Nn,..,N0,K]
# Compute g:
# Shape(g) = [Nn,..,K,..,N0]
g = distribution._compute_cgf_from_parents(*(u_parents[1:]))
# Reshape(g):
# Shape(g) = [Nn,..,N0,K]
g = utils.moveaxis(g, cluster_plate, -1)
# Compute phi:
# Shape(phi) = [Nn,..,K,..,N0,Dd,..,D0]
phi = distribution._compute_phi_from_parents(*(u_parents[1:]))
# Reshape phi:
# Shape(phi) = [Nn,..,N0,K,Dd,..,D0]
for ind in range(len(phi)):
phi[ind] = utils.moveaxis(
phi[ind], cluster_plate - distribution.ndims[ind],
-1 - distribution.ndims[ind])
# Reshape u:
# Shape(u) = [Nn,..,N0,1,Dd,..,D0]
u_self = list()
for ind in range(len(u)):
u_self.append(
np.expand_dims(u[ind],
axis=(-1 - distribution.ndims[ind])))
# Compute logpdf:
# Shape(L) = [Nn,..,N0,K]
L = distribution._compute_logpdf(u_self, phi, g, 0)
# Sum over other than the cluster dimensions? No!
# Hmm.. I think the message passing method will do
# that automatically
## print(np.shape(phi[0]))
## print(np.shape(u_self[0]))
## print(np.shape(g))
## print(np.shape(L))
return [L]
elif index >= 1:
# Parent index for the distribution used for the
# mixture.
index = index - 1
# Reshape u:
# Shape(u) = [Nn,..1,..,N0,Dd,..,D0]
u_self = list()
for ind in range(len(u)):
if cluster_plate < 0:
cluster_axis = cluster_plate - distribution.ndims[ind]
else:
cluster_axis = cluster_plate
u_self.append(np.expand_dims(u[ind], axis=cluster_axis))
# Message from the mixed distribution
m = distribution._compute_message_to_parent(
index, u_self, *(u_parents[1:]))
# Weigh the messages with the responsibilities
for i in range(len(m)):
# Shape(m) = [Nn,..,K,..,N0,Dd,..,D0]
# Shape(p) = [Nn,..,N0,K]
# Shape(result) = [Nn,..,K,..,N0,Dd,..,D0]
# Number of axes for the variable dimensions for
# the parent message.
D = distribution.ndims_parents[index][i]
# Responsibilities for clusters are the first
# parent's first moment:
# Shape(p) = [Nn,..,N0,K]
p = u_parents[0][0]
# Move the cluster axis to the proper place:
# Shape(p) = [Nn,..,K,..,N0]
p = utils.moveaxis(p, -1, cluster_plate)
# Add axes for variable dimensions to the contributions
# Shape(p) = [Nn,..,K,..,N0,1,..,1]
p = utils.add_trailing_axes(p, D)
if cluster_plate < 0:
# Add the variable dimensions
cluster_axis = cluster_plate - D
# Add axis for clusters:
# Shape(m) = [Nn,..,1,..,N0,Dd,..,D0]
#m[i] = np.expand_dims(m[i], axis=cluster_axis)
#
# TODO: You could do summing here already so that
# you wouldn't compute huge matrices as
# intermediate result. Use einsum.
## print(np.shape(m[i]))
## print(np.shape(p))
# Compute the message contributions for each
# cluster:
# Shape(result) = [Nn,..,K,..,N0,Dd,..,D0]
m[i] = m[i] * p
#print(np.shape(m[i]))
return m
def compute_message_to_parent(self, parent, index, u, *u_parents):
if index == 0:
# Shape(phi) = [Nn,..,K,..,N0,Dd,..,D0]
# Shape(L) = [Nn,..,K,..,N0]
# Shape(u) = [Nn,..,N0,Dd,..,D0]
# Shape(result) = [Nn,..,N0,K]
# Compute g:
# Shape(g) = [Nn,..,K,..,N0]
g = self.distribution.compute_cgf_from_parents(*(u_parents[1:]))
# Reshape(g):
# Shape(g) = [Nn,..,N0,K]
g = utils.moveaxis(g, self.cluster_plate, -1)
# Compute phi:
# Shape(phi) = [Nn,..,K,..,N0,Dd,..,D0]
phi = self.distribution.compute_phi_from_parents(*(u_parents[1:]))
# Move phi axis:
# Shape(phi) = [Nn,..,N0,K,Dd,..,D0]
for ind in range(len(phi)):
if self.cluster_plate < 0:
axis_from = self.cluster_plate - self.ndims[ind]
else:
raise RuntimeError("Cluster plate axis must be negative")
axis_to = -1 - self.ndims[ind]
if np.ndim(phi[ind]) >= abs(axis_from):
# Cluster plate axis exists, move it to the correct position
phi[ind] = utils.moveaxis(phi[ind], axis_from, axis_to)
else:
# No cluster plate axis, just add a new axis to the correct
# position, if phi has something on that axis
if np.ndim(phi[ind]) >= abs(axis_to):
phi[ind] = np.expand_dims(phi[ind], axis=axis_to)
# Reshape u:
# Shape(u) = [Nn,..,N0,1,Dd,..,D0]
u_self = list()
for ind in range(len(u)):
u_self.append(np.expand_dims(u[ind], axis=(-1 - self.ndims[ind])))
# Compute logpdf:
# Shape(L) = [Nn,..,N0,K]
L = self.distribution.compute_logpdf(u_self, phi, g, 0, self.ndims)
# Sum over other than the cluster dimensions? No!
# Hmm.. I think the message passing method will do
# that automatically
m = [L]
return m
elif index >= 1:
# Parent index for the distribution used for the
# mixture.
index = index - 1
# Reshape u:
# Shape(u) = [Nn,..1,..,N0,Dd,..,D0]
u_self = list()
for ind in range(len(u)):
if self.cluster_plate < 0:
cluster_axis = self.cluster_plate - self.ndims[ind]
else:
cluster_axis = self.cluster_plate
u_self.append(np.expand_dims(u[ind], axis=cluster_axis))
# Message from the mixed distribution
m = self.distribution.compute_message_to_parent(parent, index, u_self, *(u_parents[1:]))
# Weigh the messages with the responsibilities
for i in range(len(m)):
# Shape(m) = [Nn,..,K,..,N0,Dd,..,D0]
# Shape(p) = [Nn,..,N0,K]
# Shape(result) = [Nn,..,K,..,N0,Dd,..,D0]
# Number of axes for the variable dimensions for
# the parent message.
D = self.ndims_parents[index][i]
# Responsibilities for clusters are the first
# parent's first moment:
# Shape(p) = [Nn,..,N0,K]
p = u_parents[0][0]
# Move the cluster axis to the proper place:
# Shape(p) = [Nn,..,K,..,N0]
p = utils.atleast_nd(p, abs(self.cluster_plate))
p = utils.moveaxis(p, -1, self.cluster_plate)
# Add axes for variable dimensions to the contributions
# Shape(p) = [Nn,..,K,..,N0,1,..,1]
p = utils.add_trailing_axes(p, D)
if self.cluster_plate < 0:
# Add the variable dimensions
cluster_axis = self.cluster_plate - D
# Add axis for clusters:
# Shape(m) = [Nn,..,1,..,N0,Dd,..,D0]
# m[i] = np.expand_dims(m[i], axis=cluster_axis)
#
# TODO: You could do summing here already so that
# you wouldn't compute huge matrices as
# intermediate result. Use einsum.
# Compute the message contributions for each
# cluster:
# Shape(result) = [Nn,..,K,..,N0,Dd,..,D0]
m[i] = m[i] * p
return m
def compute_phi_from_parents(self, *u_parents, mask=True):
# Compute weighted average of the parameters
# Cluster parameters
Phi = self.distribution.compute_phi_from_parents(*(u_parents[1:]))
# Contributions/weights/probabilities
P = u_parents[0][0]
phi = list()
nans = False
for ind in range(len(Phi)):
# Compute element-wise product and then sum over K clusters.
# Note that the dimensions aren't perfectly aligned because
# the cluster dimension (K) may be arbitrary for phi, and phi
# also has dimensions (Dd,..,D0) of the parameters.
# Shape(phi) = [Nn,..,K,..,N0,Dd,..,D0]
# Shape(p) = [Nn,..,N0,K]
# Shape(result) = [Nn,..,N0,Dd,..,D0]
# General broadcasting rules apply for Nn,..,N0, that is,
# preceding dimensions may be missing or dimension may be
# equal to one. Probably, shape(phi) has lots of missing
# dimensions and/or dimensions that are one.
if self.cluster_plate < 0:
cluster_axis = self.cluster_plate - self.ndims[ind]
else:
raise RuntimeError("Cluster plate should be negative")
# Move cluster axis to the last:
# Shape(phi) = [Nn,..,N0,Dd,..,D0,K]
if np.ndim(Phi[ind]) >= abs(cluster_axis):
phi.append(utils.moveaxis(Phi[ind], cluster_axis, -1))
else:
phi.append(Phi[ind][..., None])
# Add axes to p:
# Shape(p) = [Nn,..,N0,K,1,..,1]
p = utils.add_trailing_axes(P, self.ndims[ind])
# Move cluster axis to the last:
# Shape(p) = [Nn,..,N0,1,..,1,K]
p = utils.moveaxis(p, -(self.ndims[ind] + 1), -1)
# Now the shapes broadcast perfectly and we can sum
# p*phi over the last axis:
# Shape(result) = [Nn,..,N0,Dd,..,D0]
phi[ind] = utils.sum_product(p, phi[ind], axes_to_sum=-1)
if np.any(np.isnan(phi[ind])):
nans = True
if nans:
warnings.warn(
"The natural parameters of mixture distribution "
"contain nans. This may happen if you use fixed "
"parameters in your model. Technically, one possible "
"reason is that the cluster assignment probability "
"for some element is zero (p=0) and the natural "
"parameter of that cluster is -inf, thus "
"0*(-inf)=nan. Solution: Use parameters that assign "
"non-zero probabilities for the whole domain."
)
return phi
def compute_message_to_parent(self, parent, index, u, *u_parents):
if index == 0:
# Shape(phi) = [Nn,..,K,..,N0,Dd,..,D0]
# Shape(L) = [Nn,..,K,..,N0]
# Shape(u) = [Nn,..,N0,Dd,..,D0]
# Shape(result) = [Nn,..,N0,K]
# Compute g:
# Shape(g) = [Nn,..,K,..,N0]
g = self.distribution.compute_cgf_from_parents(*(u_parents[1:]))
# Reshape(g):
# Shape(g) = [Nn,..,N0,K]
g = utils.moveaxis(g, self.cluster_plate, -1)
# Compute phi:
# Shape(phi) = [Nn,..,K,..,N0,Dd,..,D0]
phi = self.distribution.compute_phi_from_parents(*(u_parents[1:]))
# Move phi axis:
# Shape(phi) = [Nn,..,N0,K,Dd,..,D0]
for ind in range(len(phi)):
if self.cluster_plate < 0:
axis_from = self.cluster_plate-self.distribution.ndims[ind]
else:
raise RuntimeError("Cluster plate axis must be negative")
axis_to = -1-self.distribution.ndims[ind]
if np.ndim(phi[ind]) >= abs(axis_from):
# Cluster plate axis exists, move it to the correct position
phi[ind] = utils.moveaxis(phi[ind], axis_from, axis_to)
else:
# No cluster plate axis, just add a new axis to the correct
# position, if phi has something on that axis
if np.ndim(phi[ind]) >= abs(axis_to):
phi[ind] = np.expand_dims(phi[ind], axis=axis_to)
# Reshape u:
# Shape(u) = [Nn,..,N0,1,Dd,..,D0]
u_self = list()
for ind in range(len(u)):
u_self.append(np.expand_dims(u[ind],
axis=(-1-self.distribution.ndims[ind])))
# Compute logpdf:
# Shape(L) = [Nn,..,N0,K]
L = self.distribution.compute_logpdf(u_self, phi, g, 0)
# Sum over other than the cluster dimensions? No!
# Hmm.. I think the message passing method will do
# that automatically
m = [L]
return m
elif index >= 1:
# Parent index for the distribution used for the
# mixture.
index = index - 1
# Reshape u:
# Shape(u) = [Nn,..1,..,N0,Dd,..,D0]
u_self = list()
for ind in range(len(u)):
if self.cluster_plate < 0:
cluster_axis = self.cluster_plate - self.distribution.ndims[ind]
else:
cluster_axis = self.cluster_plate
u_self.append(np.expand_dims(u[ind], axis=cluster_axis))
# Message from the mixed distribution
m = self.distribution.compute_message_to_parent(parent,
index,
u_self,
*(u_parents[1:]))
# Weigh the messages with the responsibilities
for i in range(len(m)):
# Shape(m) = [Nn,..,K,..,N0,Dd,..,D0]
# Shape(p) = [Nn,..,N0,K]
# Shape(result) = [Nn,..,K,..,N0,Dd,..,D0]
# Number of axes for the variable dimensions for
# the parent message.
D = self.distribution.ndims_parents[index][i]
# Responsibilities for clusters are the first
# parent's first moment:
# Shape(p) = [Nn,..,N0,K]
p = u_parents[0][0]
# Move the cluster axis to the proper place:
# Shape(p) = [Nn,..,K,..,N0]
p = utils.atleast_nd(p, abs(self.cluster_plate))
p = utils.moveaxis(p, -1, self.cluster_plate)
# Add axes for variable dimensions to the contributions
# Shape(p) = [Nn,..,K,..,N0,1,..,1]
p = utils.add_trailing_axes(p, D)
if self.cluster_plate < 0:
# Add the variable dimensions
cluster_axis = self.cluster_plate - D
# Add axis for clusters:
# Shape(m) = [Nn,..,1,..,N0,Dd,..,D0]
#m[i] = np.expand_dims(m[i], axis=cluster_axis)
#
# TODO: You could do summing here already so that
# you wouldn't compute huge matrices as
# intermediate result. Use einsum.
# Compute the message contributions for each
# cluster:
# Shape(result) = [Nn,..,K,..,N0,Dd,..,D0]
m[i] = m[i] * p
return m
def _compute_message_to_parent(parent, index, u, *u_parents):
""" . """
#print('Mixture.compute_message:')
if index == 0:
# Shape(phi) = [Nn,..,K,..,N0,Dd,..,D0]
# Shape(L) = [Nn,..,K,..,N0]
# Shape(u) = [Nn,..,N0,Dd,..,D0]
# Shape(result) = [Nn,..,N0,K]
# Compute g:
# Shape(g) = [Nn,..,K,..,N0]
g = distribution._compute_cgf_from_parents(*(u_parents[1:]))
# Reshape(g):
# Shape(g) = [Nn,..,N0,K]
g = utils.moveaxis(g, cluster_plate, -1)
# Compute phi:
# Shape(phi) = [Nn,..,K,..,N0,Dd,..,D0]
phi = distribution._compute_phi_from_parents(*(u_parents[1:]))
# Reshape phi:
# Shape(phi) = [Nn,..,N0,K,Dd,..,D0]
for ind in range(len(phi)):
phi[ind] = utils.moveaxis(phi[ind],
cluster_plate-distribution.ndims[ind],
-1-distribution.ndims[ind])
# Reshape u:
# Shape(u) = [Nn,..,N0,1,Dd,..,D0]
u_self = list()
for ind in range(len(u)):
u_self.append(np.expand_dims(u[ind],
axis=(-1-distribution.ndims[ind])))
# Compute logpdf:
# Shape(L) = [Nn,..,N0,K]
L = distribution._compute_logpdf(u_self, phi, g, 0)
# Sum over other than the cluster dimensions? No!
# Hmm.. I think the message passing method will do
# that automatically
## print(np.shape(phi[0]))
## print(np.shape(u_self[0]))
## print(np.shape(g))
## print(np.shape(L))
return [L]
elif index >= 1:
# Parent index for the distribution used for the
# mixture.
index = index - 1
# Reshape u:
# Shape(u) = [Nn,..1,..,N0,Dd,..,D0]
u_self = list()
for ind in range(len(u)):
if cluster_plate < 0:
cluster_axis = cluster_plate - distribution.ndims[ind]
else:
cluster_axis = cluster_plate
u_self.append(np.expand_dims(u[ind], axis=cluster_axis))
# Message from the mixed distribution
m = distribution._compute_message_to_parent(index,
u_self,
*(u_parents[1:]))
# Weigh the messages with the responsibilities
for i in range(len(m)):
# Shape(m) = [Nn,..,K,..,N0,Dd,..,D0]
# Shape(p) = [Nn,..,N0,K]
# Shape(result) = [Nn,..,K,..,N0,Dd,..,D0]
# Number of axes for the variable dimensions for
# the parent message.
D = distribution.ndims_parents[index][i]
# Responsibilities for clusters are the first
# parent's first moment:
# Shape(p) = [Nn,..,N0,K]
p = u_parents[0][0]
# Move the cluster axis to the proper place:
# Shape(p) = [Nn,..,K,..,N0]
p = utils.moveaxis(p, -1, cluster_plate)
# Add axes for variable dimensions to the contributions
# Shape(p) = [Nn,..,K,..,N0,1,..,1]
p = utils.add_trailing_axes(p, D)
if cluster_plate < 0:
# Add the variable dimensions
cluster_axis = cluster_plate - D
# Add axis for clusters:
# Shape(m) = [Nn,..,1,..,N0,Dd,..,D0]
#m[i] = np.expand_dims(m[i], axis=cluster_axis)
#
# TODO: You could do summing here already so that
# you wouldn't compute huge matrices as
# intermediate result. Use einsum.
## print(np.shape(m[i]))
## print(np.shape(p))
# Compute the message contributions for each
# cluster:
# Shape(result) = [Nn,..,K,..,N0,Dd,..,D0]
m[i] = m[i] * p
#print(np.shape(m[i]))
return m
