def local_meanfield(global_natparam, node_potentials):
# global_natparam = \eta_{\theta}^0
# node_potentials = r(\phi, y)
dirichlet_natparam, niw_natparams = global_natparam
node_potentials = gaussian.pack_dense(*node_potentials)
#### compute expected global parameters using current global factors
# label_global = E_{q(\pi)}[t(\pi)] here q(\pi) is posterior which is dirichlet with parameter dirichlet_natparam and t is [log\pi_1, log\pi_2....]
# gaussian_globals = E_{q(\mu, \Sigma)}[t(\mu, \Sigma)] here q(\mu, \Sigma) is posterior which is NIW
label_global = dirichlet.expectedstats(dirichlet_natparam)
gaussian_globals = niw.expectedstats(niw_natparams)
#### compute mean field fixed point using unboxed node_potentials
label_stats = meanfield_fixed_point(label_global, gaussian_globals, getval(node_potentials))
#### compute values that depend directly on boxed node_potentials at optimum
gaussian_natparam, gaussian_stats, gaussian_kl = \
gaussian_meanfield(gaussian_globals, node_potentials, label_stats)
label_natparam, label_stats, label_kl = \
label_meanfield(label_global, gaussian_globals, gaussian_stats)
#### collect sufficient statistics for gmm prior (sum across conditional iid)
dirichlet_stats = np.sum(label_stats, 0)
niw_stats = np.tensordot(label_stats, gaussian_stats, [0, 0])
local_stats = label_stats, gaussian_stats
prior_stats = dirichlet_stats, niw_stats
natparam = label_natparam, gaussian_natparam
kl = label_kl + gaussian_kl
return local_stats, prior_stats, natparam, kl
def local_meanfield(global_natparam, gaussian_suff_stats):
# global_natparam = \eta_{\theta}^0
dirichlet_natparam, niw_natparams = global_natparam
#node_potentials = gaussian.pack_dense(*node_potentials)
#### compute expected global parameters using current global factors
# label_global = E_{q(\pi)}[t(\pi)] here q(\pi) is posterior which is dirichlet with parameter dirichlet_natparam and t is [log\pi_1, log\pi_2....]
# gaussian_globals = E_{q(\mu, \Sigma)}[t(\mu, \Sigma)] here q(\mu, \Sigma) is posterior which is NIW
# label_stats = E_{q(z)}[t(z)] -> categorical expected statistics. Shape = (batch_size, K)
# gaussian_suff_stats Shape = (batch_size, 4, 4)
label_global = dirichlet.expectedstats(dirichlet_natparam)
gaussian_globals = niw.expectedstats(niw_natparams)
#### compute values that depend directly on boxed node_potentials at optimum
label_natparam, label_stats, label_kl = \
label_meanfield(label_global, gaussian_globals, gaussian_suff_stats)
#### collect sufficient statistics for gmm prior (sum across conditional iid)
dirichlet_stats = np.sum(label_stats, 0)
niw_stats = np.tensordot(label_stats, gaussian_suff_stats, [0, 0])
local_stats = label_stats, gaussian_suff_stats
prior_stats = dirichlet_stats, niw_stats
natparam = label_natparam
kl = label_kl
return prior_stats, natparam, kl
def local_meanfield(global_natparam, node_potentials):
dirichlet_natparam, niw_natparams = global_natparam
node_potentials = gaussian.pack_dense(*node_potentials)
# compute expected global parameters using current global factors
label_global = dirichlet.expectedstats(dirichlet_natparam)
gaussian_globals = niw.expectedstats(niw_natparams)
# compute mean field fixed point using unboxed node_potentials
label_stats = meanfield_fixed_point(label_global, gaussian_globals, getval(node_potentials))
# compute values that depend directly on boxed node_potentials at optimum
gaussian_natparam, gaussian_stats, gaussian_kl = \
gaussian_meanfield(gaussian_globals, node_potentials, label_stats)
label_natparam, label_stats, label_kl = \
label_meanfield(label_global, gaussian_globals, gaussian_stats)
# collect sufficient statistics for gmm prior (sum across conditional iid)
dirichlet_stats = np.sum(label_stats, 0)
niw_stats = np.tensordot(label_stats, gaussian_stats, [0, 0])
local_stats = label_stats, gaussian_stats
prior_stats = dirichlet_stats, niw_stats
natparam = label_natparam, gaussian_natparam
kl = label_kl + gaussian_kl
return local_stats, prior_stats, natparam, kl
def plot_components(ax, params):
pgm_params, loglike_params, recogn_params = params
dirichlet_natparams, niw_natparams = pgm_params
normalize = lambda arr: np.minimum(1., arr / np.sum(arr) * num_clusters)
weights = normalize(np.exp(dirichlet.expectedstats(dirichlet_natparams)))
components = map(get_component, niw.expectedstats(niw_natparams))
lines = repeat(None) if isinstance(ax, plt.Axes) else ax
for weight, (mu, Sigma), line in zip(weights, components, lines):
plot_ellipse(ax, weight, mu, Sigma, line)
def plot_components(ax, params):
pgm_params = params
dirichlet_natparams, niw_natparams = pgm_params
normalize = lambda arr: np.minimum(1., arr / np.sum(arr) * num_clusters
)
weights = normalize(
np.exp(dirichlet.expectedstats(dirichlet_natparams)))
components = map(get_component, niw.expectedstats(niw_natparams))
S, m, kappa, nu = niw.natural_to_standard(niw_natparams)
#print m
lines = repeat(None) if isinstance(ax, plt.Axes) else ax
for weight, (mu, Sigma), line in zip(weights, components, lines):
#print mu
plot_ellipse(ax, weight, mu, Sigma, line)
def plot_density(density_ax, params):
pgm_params, loglike_params, recogn_params = params
dirichlet_natparams, niw_natparams = pgm_params
normalize = lambda arr: np.minimum(1., arr / np.sum(arr) * num_clusters)
weights = normalize(np.exp(dirichlet.expectedstats(dirichlet_natparams)))
components = map(get_component, niw.expectedstats(niw_natparams))
num_samples = 1000
#lines = repeat(None) if isinstance(ax, plt.Axes) else ax
idx = 0
for weight, (mu, Sigma) in zip(weights, components):
samples = npr.RandomState(0).multivariate_normal(mu, Sigma, num_samples)
density = decode_density(samples, loglike_params, decode, 75. * weight)
density_axis.plot(data[:,0], data[:,1], color='k', marker='.', linestyle='')
xlim, ylim = density_axis.get_xlim(), density_axis.get_ylim()
plot_transparent_hexbin(density_axis, density, xlim, ylim, gridsize, colors[idx % len(colors)])
idx+=1
def check_expectedstats(natparam):
E_stats1 = expectedstats(natparam)
E_stats2 = grad(logZ)(natparam)
assert np.allclose(E_stats1, E_stats2)
def prior_expectedstats(gmm_natparam):
dirichlet_natparam, niw_natparams = gmm_natparam
dirichlet_expectedstats = dirichlet.expectedstats(dirichlet_natparam)
niw_expectedstats = niw.expectedstats(niw_natparams)
return dirichlet_expectedstats, niw_expectedstats
def prior_expectedstats(gmm_natparam):
dirichlet_natparam, niw_natparams = gmm_natparam
dirichlet_expectedstats = dirichlet.expectedstats(dirichlet_natparam)
niw_expectedstats = niw.expectedstats(niw_natparams)
return dirichlet_expectedstats, niw_expectedstats
def pgm_expectedstats(global_natparam):
dirichlet_natparam, niw_natparams = global_natparam
return dirichlet.expectedstats(dirichlet_natparam), niw.expectedstats(niw_natparams)
def check_expectedstats(natparam):
E_stats1 = expectedstats(natparam)
E_stats2 = grad(logZ)(natparam)
assert np.allclose(E_stats1, E_stats2)