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fix the problem of multiple ties on the same param array object

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This commit is contained in:
Zhenwen Dai 2014-06-24 12:49:04 +01:00
parent 567612b3a9
commit 3f36a245d1
5 changed files with 18 additions and 24 deletions
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7
GPy/core/parameterization/parameter_core.py
View file

@ -500,8 +500,9 @@ class Indexable(Nameable, Observable):
#===========================================================================
def tie(self, name):
from ties_and_remappings import Tie
#remove any constraints
old_const = self.constraints.properties()[:]
old_const = [c for c in self.constraints.properties() if not isinstance(c,Tie)]
self.unconstrain()
#see if a tie exists with that name
@ -510,14 +511,14 @@ class Indexable(Nameable, Observable):
else:
#create a tie object
value = np.atleast_1d(self.param_array)[0]*1
from ties_and_remappings import Tie
t = Tie(value=value, name=name)
#add the new tie object to the global index
self._highest_parent_.ties[name] = t
self._highest_parent_.add_parameter(t)
#constrain the tie as we were constrained
if len(old_const)==1:
if len(old_const)>0:
t.constrain(old_const[0])
self.constraints.add(t, self._raveled_index())

8
GPy/core/parameterization/ties_and_remappings.py
View file

@ -46,7 +46,7 @@ class Tie(Remapping):
def callback(self, param=None, which=None):
"""
This gets called whenever any of the tied parameters changes. we spend
considerable effort working out whhat has changed ant to what value.
considerable effort working out what has changed and to what value.
Then we store that value in self.value, and broadcast it everywhere
with parameters_changed.
"""
@ -54,11 +54,13 @@ class Tie(Remapping):
index = self._highest_parent_.constraints[self]
if len(index)==0:
return # nothing to tie together, this tie exists without any tied parameters
self.value.gradient[:] = self._highest_parent_.gradient[index].sum()
self.collate_gradient()
vals = self._highest_parent_.param_array[index]
uvals = np.unique(vals)
if len(uvals)==1:
#all of the tied things are at the same value
if (self.value==uvals[0]).all():
return # DO NOT DO ANY CHANGES IF THE TIED PART IS NOT CHANGED!
self.value[...] = uvals[0]
elif len(uvals)==2:
#only *one* of the tied things has changed. it must be different to self.value
@ -69,7 +71,7 @@ class Tie(Remapping):
raise ValueError, "something is wrong with the tieing"
def parameters_changed(self):
super(Tie,self).parameters_changed()
self.value.gradient[:] = self._highest_parent_.gradient[self._highest_parent_.constraints[self]].sum()
self.collate_gradient()
def mapping(self):
return self.value

7
GPy/core/parameterization/variational.py
View file

@ -40,7 +40,6 @@ class SpikeAndSlabPrior(VariationalPrior):
self.pi = Param('pi', pi, Logistic(1e-10,1.-1e-10))
self.variance = Param('variance',variance)
self.add_parameters(self.pi)
self.group_spike_prob = False
def KL_divergence(self, variational_posterior):
mu = variational_posterior.mean
@ -56,11 +55,7 @@ class SpikeAndSlabPrior(VariationalPrior):
S = variational_posterior.variance
gamma = variational_posterior.binary_prob
if self.group_spike_prob:
gamma_grad = np.log((1-self.pi)/self.pi*gamma/(1.-gamma))+(np.square(mu)+S-np.log(S)-1.)/2.
gamma.gradient -= gamma_grad.mean(axis=0)
else:
gamma.gradient -= np.log((1-self.pi)/self.pi*gamma/(1.-gamma))+(np.square(mu)+S-np.log(S)-1.)/2.
gamma.gradient -= np.log((1-self.pi)/self.pi*gamma/(1.-gamma))+(np.square(mu)+S-np.log(S)-1.)/2.
mu.gradient -= gamma*mu
S.gradient -= (1. - (1. / (S))) * gamma /2.
self.pi.gradient = (gamma/self.pi - (1.-gamma)/(1.-self.pi)).sum(axis=0)