Merge branch 'devel' of github.com:SheffieldML/GPy into devel

This commit is contained in:
James Hensman 2013-04-25 12:52:13 +01:00
commit 5dd343e89d
8 changed files with 617 additions and 264 deletions

View file

@ -7,7 +7,7 @@ from scipy import optimize
import sys, pdb
import multiprocessing as mp
from GPy.util.misc import opt_wrapper
#import numdifftools as ndt
# import numdifftools as ndt
from parameterised import parameterised, truncate_pad
import priors
from ..util.linalg import jitchol
@ -25,14 +25,14 @@ class model(parameterised):
self.preferred_optimizer = 'tnc'
def _get_params(self):
raise NotImplementedError, "this needs to be implemented to use the model class"
def _set_params(self,x):
def _set_params(self, x):
raise NotImplementedError, "this needs to be implemented to use the model class"
def log_likelihood(self):
raise NotImplementedError, "this needs to be implemented to use the model class"
def _log_likelihood_gradients(self):
raise NotImplementedError, "this needs to be implemented to use the model class"
def set_prior(self,which,what):
def set_prior(self, which, what):
"""
Sets priors on the model parameters.
@ -53,84 +53,59 @@ class model(parameterised):
which = self.grep_param_names(which)
#check tied situation
tie_partial_matches = [tie for tie in self.tied_indices if (not set(tie).isdisjoint(set(which))) & (not set(tie)==set(which))]
# check tied situation
tie_partial_matches = [tie for tie in self.tied_indices if (not set(tie).isdisjoint(set(which))) & (not set(tie) == set(which))]
if len(tie_partial_matches):
raise ValueError, "cannot place prior across partial ties"
tie_matches = [tie for tie in self.tied_indices if set(which)==set(tie) ]
if len(tie_matches)>1:
tie_matches = [tie for tie in self.tied_indices if set(which) == set(tie) ]
if len(tie_matches) > 1:
raise ValueError, "cannot place prior across multiple ties"
elif len(tie_matches)==1:
which = which[:1]# just place a prior object on the first parameter
elif len(tie_matches) == 1:
which = which[:1] # just place a prior object on the first parameter
#check constraints are okay
# check constraints are okay
if isinstance(what, (priors.gamma, priors.log_Gaussian)):
assert not np.any(which[:,None]==self.constrained_negative_indices), "constraint and prior incompatible"
assert not np.any(which[:,None]==self.constrained_bounded_indices), "constraint and prior incompatible"
assert not np.any(which[:, None] == self.constrained_negative_indices), "constraint and prior incompatible"
assert not np.any(which[:, None] == self.constrained_bounded_indices), "constraint and prior incompatible"
unconst = np.setdiff1d(which, self.constrained_positive_indices)
if len(unconst):
print "Warning: constraining parameters to be positive:"
print '\n'.join([n for i,n in enumerate(self._get_param_names()) if i in unconst])
print '\n'.join([n for i, n in enumerate(self._get_param_names()) if i in unconst])
print '\n'
self.constrain_positive(unconst)
elif isinstance(what,priors.Gaussian):
assert not np.any(which[:,None]==self.all_constrained_indices()), "constraint and prior incompatible"
elif isinstance(what, priors.Gaussian):
assert not np.any(which[:, None] == self.all_constrained_indices()), "constraint and prior incompatible"
else:
raise ValueError, "prior not recognised"
#store the prior in a local list
# store the prior in a local list
for w in which:
self.priors[w] = what
def get(self,name, return_names=False):
"""
Get a model parameter by name. The name is applied as a regular expression and all parameters that match that regular expression are returned.
"""
matches = self.grep_param_names(name)
if len(matches):
if return_names:
return self._get_params()[matches], np.asarray(self._get_param_names())[matches].tolist()
else:
return self._get_params()[matches]
else:
raise AttributeError, "no parameter matches %s"%name
def set(self,name,val):
"""
Set model parameter(s) by name. The name is provided as a regular expression. All parameters matching that regular expression are set to ghe given value.
"""
matches = self.grep_param_names(name)
if len(matches):
x = self._get_params()
x[matches] = val
self._set_params(x)
else:
raise AttributeError, "no parameter matches %s"%name
def get_gradient(self,name, return_names=False):
def get_gradient(self, name, return_names=False):
"""
Get model gradient(s) by name. The name is applied as a regular expression and all parameters that match that regular expression are returned.
"""
matches = self.grep_param_names(name)
if len(matches):
if return_names:
return self._log_likelihood_gradients()[matches], np.asarray(self._get_param_names())[matches].tolist()
return self._log_likelihood_gradients()[matches], np.asarray(self._get_param_names())[matches].tolist()
else:
return self._log_likelihood_gradients()[matches]
else:
raise AttributeError, "no parameter matches %s"%name
raise AttributeError, "no parameter matches %s" % name
def log_prior(self):
"""evaluate the prior"""
return np.sum([p.lnpdf(x) for p, x in zip(self.priors,self._get_params()) if p is not None])
return np.sum([p.lnpdf(x) for p, x in zip(self.priors, self._get_params()) if p is not None])
def _log_prior_gradients(self):
"""evaluate the gradients of the priors"""
x = self._get_params()
ret = np.zeros(x.size)
[np.put(ret,i,p.lnpdf_grad(xx)) for i,(p,xx) in enumerate(zip(self.priors,x)) if not p is None]
[np.put(ret, i, p.lnpdf_grad(xx)) for i, (p, xx) in enumerate(zip(self.priors, x)) if not p is None]
return ret
def _transform_gradients(self, g):
@ -139,13 +114,13 @@ class model(parameterised):
"""
x = self._get_params()
g[self.constrained_positive_indices] = g[self.constrained_positive_indices]*x[self.constrained_positive_indices]
g[self.constrained_negative_indices] = g[self.constrained_negative_indices]*x[self.constrained_negative_indices]
[np.put(g,i,g[i]*(x[i]-l)*(h-x[i])/(h-l)) for i,l,h in zip(self.constrained_bounded_indices, self.constrained_bounded_lowers, self.constrained_bounded_uppers)]
[np.put(g,i,v) for i,v in [(t[0],np.sum(g[t])) for t in self.tied_indices]]
g[self.constrained_positive_indices] = g[self.constrained_positive_indices] * x[self.constrained_positive_indices]
g[self.constrained_negative_indices] = g[self.constrained_negative_indices] * x[self.constrained_negative_indices]
[np.put(g, i, g[i] * (x[i] - l) * (h - x[i]) / (h - l)) for i, l, h in zip(self.constrained_bounded_indices, self.constrained_bounded_lowers, self.constrained_bounded_uppers)]
[np.put(g, i, v) for i, v in [(t[0], np.sum(g[t])) for t in self.tied_indices]]
if len(self.tied_indices) or len(self.constrained_fixed_indices):
to_remove = np.hstack((self.constrained_fixed_indices+[t[1:] for t in self.tied_indices]))
return np.delete(g,to_remove)
to_remove = np.hstack((self.constrained_fixed_indices + [t[1:] for t in self.tied_indices]))
return np.delete(g, to_remove)
else:
return g
@ -155,15 +130,15 @@ class model(parameterised):
Randomize the model.
Make this draw from the prior if one exists, else draw from N(0,1)
"""
#first take care of all parameters (from N(0,1))
# first take care of all parameters (from N(0,1))
x = self._get_params_transformed()
x = np.random.randn(x.size)
self._set_params_transformed(x)
#now draw from prior where possible
# now draw from prior where possible
x = self._get_params()
[np.put(x,i,p.rvs(1)) for i,p in enumerate(self.priors) if not p is None]
[np.put(x, i, p.rvs(1)) for i, p in enumerate(self.priors) if not p is None]
self._set_params(x)
self._set_params_transformed(self._get_params_transformed())#makes sure all of the tied parameters get the same init (since there's only one prior object...)
self._set_params_transformed(self._get_params_transformed()) # makes sure all of the tied parameters get the same init (since there's only one prior object...)
def optimize_restarts(self, Nrestarts=10, robust=False, verbose=True, parallel=False, num_processes=None, **kwargs):
@ -197,10 +172,10 @@ class model(parameterised):
pool = mp.Pool(processes=num_processes)
for i in range(Nrestarts):
self.randomize()
job = pool.apply_async(opt_wrapper, args = (self,), kwds = kwargs)
job = pool.apply_async(opt_wrapper, args=(self,), kwds=kwargs)
jobs.append(job)
pool.close() # signal that no more data coming in
pool.close() # signal that no more data coming in
pool.join() # wait for all the tasks to complete
except KeyboardInterrupt:
print "Ctrl+c received, terminating and joining pool."
@ -216,10 +191,10 @@ class model(parameterised):
self.optimization_runs.append(jobs[i].get())
if verbose:
print("Optimization restart {0}/{1}, f = {2}".format(i+1, Nrestarts, self.optimization_runs[-1].f_opt))
print("Optimization restart {0}/{1}, f = {2}".format(i + 1, Nrestarts, self.optimization_runs[-1].f_opt))
except Exception as e:
if robust:
print("Warning - optimization restart {0}/{1} failed".format(i+1, Nrestarts))
print("Warning - optimization restart {0}/{1} failed".format(i + 1, Nrestarts))
else:
raise e
@ -229,11 +204,11 @@ class model(parameterised):
else:
self._set_params_transformed(initial_parameters)
def ensure_default_constraints(self,warn=False):
def ensure_default_constraints(self, warn=False):
"""
Ensure that any variables which should clearly be positive have been constrained somehow.
"""
positive_strings = ['variance','lengthscale', 'precision']
positive_strings = ['variance', 'lengthscale', 'precision']
param_names = self._get_param_names()
currently_constrained = self.all_constrained_indices()
to_make_positive = []
@ -242,9 +217,9 @@ class model(parameterised):
if not (i in currently_constrained):
to_make_positive.append(re.escape(param_names[i]))
if warn:
print "Warning! constraining %s postive"%name
print "Warning! constraining %s postive" % name
if len(to_make_positive):
self.constrain_positive('('+'|'.join(to_make_positive)+')')
self.constrain_positive('(' + '|'.join(to_make_positive) + ')')
@ -262,14 +237,14 @@ class model(parameterised):
self._set_params_transformed(x)
LL_gradients = self._transform_gradients(self._log_likelihood_gradients())
prior_gradients = self._transform_gradients(self._log_prior_gradients())
return - LL_gradients - prior_gradients
return -LL_gradients - prior_gradients
def objective_and_gradients(self, x):
self._set_params_transformed(x)
obj_f = -self.log_likelihood() - self.log_prior()
obj_f = -self.log_likelihood() - self.log_prior()
LL_gradients = self._transform_gradients(self._log_likelihood_gradients())
prior_gradients = self._transform_gradients(self._log_prior_gradients())
obj_grads = - LL_gradients - prior_gradients
obj_grads = -LL_gradients - prior_gradients
return obj_f, obj_grads
def optimize(self, optimizer=None, start=None, **kwargs):
@ -289,13 +264,13 @@ class model(parameterised):
start = self._get_params_transformed()
optimizer = optimization.get_optimizer(optimizer)
opt = optimizer(start, model = self, **kwargs)
opt = optimizer(start, model=self, **kwargs)
opt.run(f_fp=self.objective_and_gradients, f=self.objective_function, fp=self.objective_function_gradients)
self.optimization_runs.append(opt)
self._set_params_transformed(opt.x_opt)
def optimize_SGD(self, momentum = 0.1, learning_rate = 0.01, iterations = 20, **kwargs):
def optimize_SGD(self, momentum=0.1, learning_rate=0.01, iterations=20, **kwargs):
# assert self.Y.shape[1] > 1, "SGD only works with D > 1"
sgd = SGD.StochasticGD(self, iterations, learning_rate, momentum, **kwargs)
sgd.run()
@ -303,8 +278,8 @@ class model(parameterised):
def Laplace_covariance(self):
"""return the covariance matric of a Laplace approximatino at the current (stationary) point"""
#TODO add in the prior contributions for MAP estimation
#TODO fix the hessian for tied, constrained and fixed components
# TODO add in the prior contributions for MAP estimation
# TODO fix the hessian for tied, constrained and fixed components
if hasattr(self, 'log_likelihood_hessian'):
A = -self.log_likelihood_hessian()
@ -318,8 +293,8 @@ class model(parameterised):
A = -h(x)
self._set_params(x)
# check for almost zero components on the diagonal which screw up the cholesky
aa = np.nonzero((np.diag(A)<1e-6) & (np.diag(A)>0.))[0]
A[aa,aa] = 0.
aa = np.nonzero((np.diag(A) < 1e-6) & (np.diag(A) > 0.))[0]
A[aa, aa] = 0.
return A
def Laplace_evidence(self):
@ -330,11 +305,11 @@ class model(parameterised):
hld = np.sum(np.log(np.diag(jitchol(A)[0])))
except:
return np.nan
return 0.5*self._get_params().size*np.log(2*np.pi) + self.log_likelihood() - hld
return 0.5 * self._get_params().size * np.log(2 * np.pi) + self.log_likelihood() - hld
def __str__(self):
s = parameterised.__str__(self).split('\n')
#add priors to the string
# add priors to the string
strs = [str(p) if p is not None else '' for p in self.priors]
width = np.array(max([len(p) for p in strs] + [5])) + 4
@ -345,16 +320,16 @@ class model(parameterised):
obj_funct += ', Log prior: {0:.3e}, LL+prior = {0:.3e}'.format(log_prior, log_like + log_prior)
obj_funct += '\n\n'
s[0] = obj_funct + s[0]
s[0] += "|{h:^{col}}".format(h = 'Prior', col = width)
s[1] += '-'*(width + 1)
s[0] += "|{h:^{col}}".format(h='Prior', col=width)
s[1] += '-' * (width + 1)
for p in range(2, len(strs)+2):
s[p] += '|{prior:^{width}}'.format(prior = strs[p-2], width = width)
for p in range(2, len(strs) + 2):
s[p] += '|{prior:^{width}}'.format(prior=strs[p - 2], width=width)
return '\n'.join(s)
def checkgrad(self, target_param = None, verbose=False, step=1e-6, tolerance = 1e-3):
def checkgrad(self, target_param=None, verbose=False, step=1e-6, tolerance=1e-3):
"""
Check the gradient of the model by comparing to a numerical estimate.
If the verbose flag is passed, invividual components are tested (and printed)
@ -374,27 +349,27 @@ class model(parameterised):
x = self._get_params_transformed().copy()
if not verbose:
#just check the global ratio
dx = step*np.sign(np.random.uniform(-1,1,x.size))
# just check the global ratio
dx = step * np.sign(np.random.uniform(-1, 1, x.size))
#evaulate around the point x
f1, g1 = self.objective_and_gradients(x+dx)
f2, g2 = self.objective_and_gradients(x-dx)
# evaulate around the point x
f1, g1 = self.objective_and_gradients(x + dx)
f2, g2 = self.objective_and_gradients(x - dx)
gradient = self.objective_function_gradients(x)
numerical_gradient = (f1-f2)/(2*dx)
global_ratio = (f1-f2)/(2*np.dot(dx,gradient))
numerical_gradient = (f1 - f2) / (2 * dx)
global_ratio = (f1 - f2) / (2 * np.dot(dx, gradient))
if (np.abs(1.-global_ratio)<tolerance) and not np.isnan(global_ratio):
if (np.abs(1. - global_ratio) < tolerance) and not np.isnan(global_ratio):
return True
else:
return False
else:
#check the gradient of each parameter individually, and do some pretty printing
# check the gradient of each parameter individually, and do some pretty printing
try:
names = self._get_param_names_transformed()
except NotImplementedError:
names = ['Variable %i'%i for i in range(len(x))]
names = ['Variable %i' % i for i in range(len(x))]
# Prepare for pretty-printing
header = ['Name', 'Ratio', 'Difference', 'Analytical', 'Numerical']
@ -403,9 +378,9 @@ class model(parameterised):
cols = [max_names]
cols.extend([max(float_len, len(header[i])) for i in range(1, len(header))])
cols = np.array(cols) + 5
header_string = ["{h:^{col}}".format(h = header[i], col = cols[i]) for i in range(len(cols))]
header_string = ["{h:^{col}}".format(h=header[i], col=cols[i]) for i in range(len(cols))]
header_string = map(lambda x: '|'.join(x), [header_string])
separator = '-'*len(header_string[0])
separator = '-' * len(header_string[0])
print '\n'.join([header_string[0], separator])
if target_param is None:
@ -421,11 +396,11 @@ class model(parameterised):
f2, g2 = self.objective_and_gradients(xx)
gradient = self.objective_function_gradients(x)[i]
numerical_gradient = (f1-f2)/(2*step)
ratio = (f1-f2)/(2*step*gradient)
difference = np.abs((f1-f2)/2/step - gradient)
numerical_gradient = (f1 - f2) / (2 * step)
ratio = (f1 - f2) / (2 * step * gradient)
difference = np.abs((f1 - f2) / 2 / step - gradient)
if (np.abs(ratio-1)<tolerance):
if (np.abs(ratio - 1) < tolerance):
formatted_name = "\033[92m {0} \033[0m".format(names[i])
else:
formatted_name = "\033[91m {0} \033[0m".format(names[i])
@ -433,7 +408,7 @@ class model(parameterised):
d = '%.6f' % float(difference)
g = '%.6f' % gradient
ng = '%.6f' % float(numerical_gradient)
grad_string = "{0:^{c0}}|{1:^{c1}}|{2:^{c2}}|{3:^{c3}}|{4:^{c4}}".format(formatted_name,r,d,g, ng, c0 = cols[0]+9, c1 = cols[1], c2 = cols[2], c3 = cols[3], c4 = cols[4])
grad_string = "{0:^{c0}}|{1:^{c1}}|{2:^{c2}}|{3:^{c3}}|{4:^{c4}}".format(formatted_name, r, d, g, ng, c0=cols[0] + 9, c1=cols[1], c2=cols[2], c3=cols[3], c4=cols[4])
print grad_string
def input_sensitivity(self):
@ -444,21 +419,21 @@ class model(parameterised):
TODO: proper sensitivity analysis
"""
if not hasattr(self,'kern'):
if not hasattr(self, 'kern'):
raise ValueError, "this model has no kernel"
k = [p for p in self.kern.parts if p.name in ['rbf','linear']]
if (not len(k)==1) or (not k[0].ARD):
k = [p for p in self.kern.parts if p.name in ['rbf', 'linear']]
if (not len(k) == 1) or (not k[0].ARD):
raise ValueError, "cannot determine sensitivity for this kernel"
k = k[0]
if k.name=='rbf':
if k.name == 'rbf':
return k.lengthscale
elif k.name=='linear':
return 1./k.variances
elif k.name == 'linear':
return 1. / k.variances
def pseudo_EM(self,epsilon=.1,**kwargs):
def pseudo_EM(self, epsilon=.1, **kwargs):
"""
TODO: Should this not bein the GP class?
EM - like algorithm for Expectation Propagation and Laplace approximation
@ -472,7 +447,7 @@ class model(parameterised):
:type optimzer: string TODO: valid strings?
"""
assert isinstance(self.likelihood,likelihoods.EP), "EPEM is only available for EP likelihoods"
assert isinstance(self.likelihood, likelihoods.EP), "EPEM is only available for EP likelihoods"
ll_change = epsilon + 1.
iteration = 0
last_ll = -np.exp(1000)
@ -492,9 +467,9 @@ class model(parameterised):
ll_change = new_ll - last_ll
if ll_change < 0:
self.likelihood = last_approximation #restore previous likelihood approximation
self._set_params(last_params) #restore model parameters
print "Log-likelihood decrement: %s \nLast likelihood update discarded." %ll_change
self.likelihood = last_approximation # restore previous likelihood approximation
self._set_params(last_params) # restore model parameters
print "Log-likelihood decrement: %s \nLast likelihood update discarded." % ll_change
stop = True
else:
self.optimize(**kwargs)
@ -503,5 +478,5 @@ class model(parameterised):
stop = True
iteration += 1
if stop:
print "%s iterations." %iteration
print "%s iterations." % iteration

View file

@ -8,24 +8,25 @@ import copy
import cPickle
import os
from ..util.squashers import sigmoid
import warnings
def truncate_pad(string,width,align='m'):
def truncate_pad(string, width, align='m'):
"""
A helper function to make aligned strings for parameterised.__str__
"""
width=max(width,4)
if len(string)>width:
return string[:width-3]+'...'
elif len(string)==width:
width = max(width, 4)
if len(string) > width:
return string[:width - 3] + '...'
elif len(string) == width:
return string
elif len(string)<width:
diff = width-len(string)
if align=='m':
return ' '*np.floor(diff/2.) + string + ' '*np.ceil(diff/2.)
elif align=='l':
return string + ' '*diff
elif align=='r':
return ' '*diff + string
elif len(string) < width:
diff = width - len(string)
if align == 'm':
return ' ' * np.floor(diff / 2.) + string + ' ' * np.ceil(diff / 2.)
elif align == 'l':
return string + ' ' * diff
elif align == 'r':
return ' ' * diff + string
else:
raise ValueError
@ -37,15 +38,15 @@ class parameterised(object):
self.tied_indices = []
self.constrained_fixed_indices = []
self.constrained_fixed_values = []
self.constrained_positive_indices = np.empty(shape=(0,),dtype=np.int64)
self.constrained_negative_indices = np.empty(shape=(0,),dtype=np.int64)
self.constrained_positive_indices = np.empty(shape=(0,), dtype=np.int64)
self.constrained_negative_indices = np.empty(shape=(0,), dtype=np.int64)
self.constrained_bounded_indices = []
self.constrained_bounded_uppers = []
self.constrained_bounded_lowers = []
def pickle(self,filename,protocol=-1):
f = file(filename,'w')
cPickle.dump(self,f,protocol)
def pickle(self, filename, protocol= -1):
f = file(filename, 'w')
cPickle.dump(self, f, protocol)
f.close()
def copy(self):
@ -55,18 +56,85 @@ class parameterised(object):
return copy.deepcopy(self)
@property
def params(self):
"""
Returns a **copy** of parameters in non transformed space
:see_also: :py:func:`GPy.core.parameterised.params_transformed`
"""
return self._get_params()
@params.setter
def params(self, params):
self._set_params(params)
@property
def params_transformed(self):
"""
Returns a **copy** of parameters in transformed space
:see_also: :py:func:`GPy.core.parameterised.params`
"""
return self._get_params_transformed()
@params_transformed.setter
def params_transformed(self, params):
self._set_params_transformed(params)
_get_set_deprecation = """get and set methods wont be available at next minor release
in the next releases you will get and set with following syntax:
Assume m is a model class:
print m['var'] # > prints all parameters matching 'var'
m['var'] = 2. # > sets all parameters matching 'var' to 2.
m['var'] = <array-like> # > sets parameters matching 'var' to <array-like>
"""
def get(self, name):
warnings.warn(self._get_set_deprecation, FutureWarning, stacklevel=2)
return self[name]
def set(self, name, val):
warnings.warn(self._get_set_deprecation, FutureWarning, stacklevel=2)
self[name] = val
def __getitem__(self, name, return_names=False):
"""
Get a model parameter by name. The name is applied as a regular expression and all parameters that match that regular expression are returned.
"""
matches = self.grep_param_names(name)
if len(matches):
if return_names:
return self._get_params()[matches], np.asarray(self._get_param_names())[matches].tolist()
else:
return self._get_params()[matches]
else:
raise AttributeError, "no parameter matches %s" % name
def __setitem__(self, name, val):
"""
Set model parameter(s) by name. The name is provided as a regular expression. All parameters matching that regular expression are set to ghe given value.
"""
matches = self.grep_param_names(name)
if len(matches):
val = np.array(val)
assert (val.size == 1) or val.size == len(matches), "Shape mismatch: {}:({},)".format(val.size, len(matches))
x = self.params
x[matches] = val
self.params = x
# import ipdb;ipdb.set_trace()
# self.params[matches] = val
else:
raise AttributeError, "no parameter matches %s" % name
def tie_params(self, which):
matches = self.grep_param_names(which)
assert matches.size > 0, "need at least something to tie together"
if len(self.tied_indices):
assert not np.any(matches[:,None]==np.hstack(self.tied_indices)), "Some indices are already tied!"
assert not np.any(matches[:, None] == np.hstack(self.tied_indices)), "Some indices are already tied!"
self.tied_indices.append(matches)
#TODO only one of the priors will be evaluated. Give a warning message if the priors are not identical
if hasattr(self,'prior'):
# TODO only one of the priors will be evaluated. Give a warning message if the priors are not identical
if hasattr(self, 'prior'):
pass
self._set_params_transformed(self._get_params_transformed())# sets tied parameters to single value
self._set_params_transformed(self._get_params_transformed()) # sets tied parameters to single value
def untie_everything(self):
"""Unties all parameters by setting tied_indices to an empty list."""
@ -74,7 +142,7 @@ class parameterised(object):
def all_constrained_indices(self):
"""Return a np array of all the constrained indices"""
ret = [np.hstack(i) for i in [self.constrained_bounded_indices, self.constrained_positive_indices, self.constrained_negative_indices, self.constrained_fixed_indices] if len(i)]
ret = [np.hstack(i) for i in [self.constrained_bounded_indices, self.constrained_positive_indices, self.constrained_negative_indices, self.constrained_fixed_indices] if len(i)]
if len(ret):
return np.hstack(ret)
else:
@ -117,44 +185,44 @@ class parameterised(object):
which -- np.array(dtype=int), or regular expression object or string
"""
matches = self.grep_param_names(which)
assert not np.any(matches[:,None]==self.all_constrained_indices()), "Some indices are already constrained"
assert not np.any(matches[:, None] == self.all_constrained_indices()), "Some indices are already constrained"
self.constrained_positive_indices = np.hstack((self.constrained_positive_indices, matches))
#check to ensure constraint is in place
# check to ensure constraint is in place
x = self._get_params()
for i,xx in enumerate(x):
if (xx<0) & (i in matches):
for i, xx in enumerate(x):
if (xx < 0) & (i in matches):
x[i] = -xx
self._set_params(x)
def unconstrain(self,which):
def unconstrain(self, which):
"""Unconstrain matching parameters. does not untie parameters"""
matches = self.grep_param_names(which)
#positive/negative
self.constrained_positive_indices = np.delete(self.constrained_positive_indices,np.nonzero(np.sum(self.constrained_positive_indices[:,None]==matches[None,:],1))[0])
self.constrained_negative_indices = np.delete(self.constrained_negative_indices,np.nonzero(np.sum(self.constrained_negative_indices[:,None]==matches[None,:],1))[0])
#bounded
# positive/negative
self.constrained_positive_indices = np.delete(self.constrained_positive_indices, np.nonzero(np.sum(self.constrained_positive_indices[:, None] == matches[None, :], 1))[0])
self.constrained_negative_indices = np.delete(self.constrained_negative_indices, np.nonzero(np.sum(self.constrained_negative_indices[:, None] == matches[None, :], 1))[0])
# bounded
if len(self.constrained_bounded_indices):
self.constrained_bounded_indices = [np.delete(a,np.nonzero(np.sum(a[:,None]==matches[None,:],1))[0]) for a in self.constrained_bounded_indices]
self.constrained_bounded_indices = [np.delete(a, np.nonzero(np.sum(a[:, None] == matches[None, :], 1))[0]) for a in self.constrained_bounded_indices]
if np.hstack(self.constrained_bounded_indices).size:
self.constrained_bounded_uppers, self.constrained_bounded_lowers, self.constrained_bounded_indices = zip(*[(u,l,i) for u,l,i in zip(self.constrained_bounded_uppers, self.constrained_bounded_lowers, self.constrained_bounded_indices) if i.size])
self.constrained_bounded_uppers, self.constrained_bounded_lowers, self.constrained_bounded_indices = zip(*[(u, l, i) for u, l, i in zip(self.constrained_bounded_uppers, self.constrained_bounded_lowers, self.constrained_bounded_indices) if i.size])
self.constrained_bounded_uppers, self.constrained_bounded_lowers, self.constrained_bounded_indices = list(self.constrained_bounded_uppers), list(self.constrained_bounded_lowers), list(self.constrained_bounded_indices)
else:
self.constrained_bounded_uppers, self.constrained_bounded_lowers, self.constrained_bounded_indices = [],[],[]
#fixed:
for i,indices in enumerate(self.constrained_fixed_indices):
self.constrained_fixed_indices[i] = np.delete(indices,np.nonzero(np.sum(indices[:,None]==matches[None,:],1))[0])
#remove empty elements
tmp = [(i,v) for i,v in zip(self.constrained_fixed_indices, self.constrained_fixed_values) if len(i)]
self.constrained_bounded_uppers, self.constrained_bounded_lowers, self.constrained_bounded_indices = [], [], []
# fixed:
for i, indices in enumerate(self.constrained_fixed_indices):
self.constrained_fixed_indices[i] = np.delete(indices, np.nonzero(np.sum(indices[:, None] == matches[None, :], 1))[0])
# remove empty elements
tmp = [(i, v) for i, v in zip(self.constrained_fixed_indices, self.constrained_fixed_values) if len(i)]
if tmp:
self.constrained_fixed_indices, self.constrained_fixed_values = zip(*tmp)
self.constrained_fixed_indices, self.constrained_fixed_values = list(self.constrained_fixed_indices), list(self.constrained_fixed_values)
else:
self.constrained_fixed_indices, self.constrained_fixed_values = [],[]
self.constrained_fixed_indices, self.constrained_fixed_values = [], []
def constrain_negative(self,which):
def constrain_negative(self, which):
"""
Set negative constraints.
@ -163,12 +231,12 @@ class parameterised(object):
"""
matches = self.grep_param_names(which)
assert not np.any(matches[:,None]==self.all_constrained_indices()), "Some indices are already constrained"
assert not np.any(matches[:, None] == self.all_constrained_indices()), "Some indices are already constrained"
self.constrained_negative_indices = np.hstack((self.constrained_negative_indices, matches))
#check to ensure constraint is in place
# check to ensure constraint is in place
x = self._get_params()
for i,xx in enumerate(x):
if (xx>0.) and (i in matches):
for i, xx in enumerate(x):
if (xx > 0.) and (i in matches):
x[i] = -xx
self._set_params(x)
@ -184,20 +252,20 @@ class parameterised(object):
lower -- (float) the lower bound on the constraint
"""
matches = self.grep_param_names(which)
assert not np.any(matches[:,None]==self.all_constrained_indices()), "Some indices are already constrained"
assert not np.any(matches[:, None] == self.all_constrained_indices()), "Some indices are already constrained"
assert lower < upper, "lower bound must be smaller than upper bound!"
self.constrained_bounded_indices.append(matches)
self.constrained_bounded_uppers.append(upper)
self.constrained_bounded_lowers.append(lower)
#check to ensure constraint is in place
# check to ensure constraint is in place
x = self._get_params()
for i,xx in enumerate(x):
if ((xx<=lower)|(xx>=upper)) & (i in matches):
x[i] = sigmoid(xx)*(upper-lower) + lower
for i, xx in enumerate(x):
if ((xx <= lower) | (xx >= upper)) & (i in matches):
x[i] = sigmoid(xx) * (upper - lower) + lower
self._set_params(x)
def constrain_fixed(self, which, value = None):
def constrain_fixed(self, which, value=None):
"""
Arguments
---------
@ -211,14 +279,14 @@ class parameterised(object):
To fix multiple parameters to the same value, simply pass a regular expression which matches both parameter names, or pass both of the indexes
"""
matches = self.grep_param_names(which)
assert not np.any(matches[:,None]==self.all_constrained_indices()), "Some indices are already constrained"
assert not np.any(matches[:, None] == self.all_constrained_indices()), "Some indices are already constrained"
self.constrained_fixed_indices.append(matches)
if value != None:
self.constrained_fixed_values.append(value)
else:
self.constrained_fixed_values.append(self._get_params()[self.constrained_fixed_indices[-1]])
#self.constrained_fixed_values.append(value)
# self.constrained_fixed_values.append(value)
self._set_params_transformed(self._get_params_transformed())
def _get_params_transformed(self):
@ -226,40 +294,40 @@ class parameterised(object):
x = self._get_params()
x[self.constrained_positive_indices] = np.log(x[self.constrained_positive_indices])
x[self.constrained_negative_indices] = np.log(-x[self.constrained_negative_indices])
[np.put(x,i,np.log(np.clip(x[i]-l,1e-10,np.inf)/np.clip(h-x[i],1e-10,np.inf))) for i,l,h in zip(self.constrained_bounded_indices, self.constrained_bounded_lowers, self.constrained_bounded_uppers)]
[np.put(x, i, np.log(np.clip(x[i] - l, 1e-10, np.inf) / np.clip(h - x[i], 1e-10, np.inf))) for i, l, h in zip(self.constrained_bounded_indices, self.constrained_bounded_lowers, self.constrained_bounded_uppers)]
to_remove = self.constrained_fixed_indices+[t[1:] for t in self.tied_indices]
to_remove = self.constrained_fixed_indices + [t[1:] for t in self.tied_indices]
if len(to_remove):
return np.delete(x,np.hstack(to_remove))
return np.delete(x, np.hstack(to_remove))
else:
return x
def _set_params_transformed(self,x):
def _set_params_transformed(self, x):
""" takes the vector x, which is then modified (by untying, reparameterising or inserting fixed values), and then call self._set_params"""
#work out how many places are fixed, and where they are. tricky logic!
# work out how many places are fixed, and where they are. tricky logic!
Nfix_places = 0.
if len(self.tied_indices):
Nfix_places += np.hstack(self.tied_indices).size-len(self.tied_indices)
Nfix_places += np.hstack(self.tied_indices).size - len(self.tied_indices)
if len(self.constrained_fixed_indices):
Nfix_places += np.hstack(self.constrained_fixed_indices).size
if Nfix_places:
fix_places = np.hstack(self.constrained_fixed_indices+[t[1:] for t in self.tied_indices])
fix_places = np.hstack(self.constrained_fixed_indices + [t[1:] for t in self.tied_indices])
else:
fix_places = []
free_places = np.setdiff1d(np.arange(Nfix_places+x.size,dtype=np.int),fix_places)
free_places = np.setdiff1d(np.arange(Nfix_places + x.size, dtype=np.int), fix_places)
#put the models values in the vector xx
xx = np.zeros(Nfix_places+free_places.size,dtype=np.float64)
# put the models values in the vector xx
xx = np.zeros(Nfix_places + free_places.size, dtype=np.float64)
xx[free_places] = x
[np.put(xx,i,v) for i,v in zip(self.constrained_fixed_indices, self.constrained_fixed_values)]
[np.put(xx,i,v) for i,v in [(t[1:],xx[t[0]]) for t in self.tied_indices] ]
[np.put(xx, i, v) for i, v in zip(self.constrained_fixed_indices, self.constrained_fixed_values)]
[np.put(xx, i, v) for i, v in [(t[1:], xx[t[0]]) for t in self.tied_indices] ]
xx[self.constrained_positive_indices] = np.exp(xx[self.constrained_positive_indices])
xx[self.constrained_negative_indices] = -np.exp(xx[self.constrained_negative_indices])
[np.put(xx,i,low+sigmoid(xx[i])*(high-low)) for i,low,high in zip(self.constrained_bounded_indices, self.constrained_bounded_lowers, self.constrained_bounded_uppers)]
[np.put(xx, i, low + sigmoid(xx[i]) * (high - low)) for i, low, high in zip(self.constrained_bounded_indices, self.constrained_bounded_lowers, self.constrained_bounded_uppers)]
self._set_params(xx)
def _get_param_names_transformed(self):
@ -267,33 +335,33 @@ class parameterised(object):
Returns the parameter names as propagated after constraining,
tying or fixing, i.e. a list of the same length as _get_params_transformed()
"""
n = self._get_param_names()
n = self._get_param_names()
#remove/concatenate the tied parameter names
# remove/concatenate the tied parameter names
if len(self.tied_indices):
for t in self.tied_indices:
n[t[0]] = "<tie>".join([n[tt] for tt in t])
remove = np.hstack([t[1:] for t in self.tied_indices])
else:
remove=np.empty(shape=(0,),dtype=np.int)
remove = np.empty(shape=(0,), dtype=np.int)
#also remove the fixed params
# also remove the fixed params
if len(self.constrained_fixed_indices):
remove = np.hstack((remove, np.hstack(self.constrained_fixed_indices)))
#add markers to show that some variables are constrained
# add markers to show that some variables are constrained
for i in self.constrained_positive_indices:
n[i] = n[i]+'(+ve)'
n[i] = n[i] + '(+ve)'
for i in self.constrained_negative_indices:
n[i] = n[i]+'(-ve)'
for i,l,h in zip(self.constrained_bounded_indices, self.constrained_bounded_lowers, self.constrained_bounded_uppers):
n[i] = n[i] + '(-ve)'
for i, l, h in zip(self.constrained_bounded_indices, self.constrained_bounded_lowers, self.constrained_bounded_uppers):
for ii in i:
n[ii] = n[ii]+'(bounded)'
n[ii] = n[ii] + '(bounded)'
n = [nn for i,nn in enumerate(n) if not i in remove]
n = [nn for i, nn in enumerate(n) if not i in remove]
return n
def __str__(self,nw=30):
def __str__(self, nw=30):
"""
Return a string describing the parameter names and their ties and constraints
"""
@ -302,10 +370,10 @@ class parameterised(object):
if not N:
return "This object has no free parameters."
header = ['Name','Value','Constraints','Ties']
values = self._get_params() #map(str,self._get_params())
#sort out the constraints
constraints = ['']*len(names)
header = ['Name', 'Value', 'Constraints', 'Ties']
values = self._get_params() # map(str,self._get_params())
# sort out the constraints
constraints = [''] * len(names)
for i in self.constrained_positive_indices:
constraints[i] = '(+ve)'
for i in self.constrained_negative_indices:
@ -313,14 +381,14 @@ class parameterised(object):
for i in self.constrained_fixed_indices:
for ii in i:
constraints[ii] = 'Fixed'
for i,u,l in zip(self.constrained_bounded_indices, self.constrained_bounded_uppers, self.constrained_bounded_lowers):
for i, u, l in zip(self.constrained_bounded_indices, self.constrained_bounded_uppers, self.constrained_bounded_lowers):
for ii in i:
constraints[ii] = '('+str(l)+', '+str(u)+')'
#sort out the ties
ties = ['']*len(names)
for i,tie in enumerate(self.tied_indices):
constraints[ii] = '(' + str(l) + ', ' + str(u) + ')'
# sort out the ties
ties = [''] * len(names)
for i, tie in enumerate(self.tied_indices):
for j in tie:
ties[j] = '('+str(i)+')'
ties[j] = '(' + str(i) + ')'
values = ['%.4f' % float(v) for v in values]
max_names = max([len(names[i]) for i in range(len(names))] + [len(header[0])])
@ -330,10 +398,10 @@ class parameterised(object):
cols = np.array([max_names, max_values, max_constraint, max_ties]) + 4
columns = cols.sum()
header_string = ["{h:^{col}}".format(h = header[i], col = cols[i]) for i in range(len(cols))]
header_string = ["{h:^{col}}".format(h=header[i], col=cols[i]) for i in range(len(cols))]
header_string = map(lambda x: '|'.join(x), [header_string])
separator = '-'*len(header_string[0])
param_string = ["{n:^{c0}}|{v:^{c1}}|{c:^{c2}}|{t:^{c3}}".format(n = names[i], v = values[i], c = constraints[i], t = ties[i], c0 = cols[0], c1 = cols[1], c2 = cols[2], c3 = cols[3]) for i in range(len(values))]
separator = '-' * len(header_string[0])
param_string = ["{n:^{c0}}|{v:^{c1}}|{c:^{c2}}|{t:^{c3}}".format(n=names[i], v=values[i], c=constraints[i], t=ties[i], c0=cols[0], c1=cols[1], c2=cols[2], c3=cols[3]) for i in range(len(values))]
return ('\n'.join([header_string[0], separator]+param_string)) + '\n'
return ('\n'.join([header_string[0], separator] + param_string)) + '\n'

View file

@ -112,14 +112,14 @@ def _simulate_sincos(D1, D2, D3, N, M, Q, plot_sim=False):
s3 = s3(x)
sS = sS(x)
s1 -= s1.mean()
s2 -= s2.mean()
s3 -= s3.mean()
sS -= sS.mean()
s1 /= .5 * (np.abs(s1).max() - np.abs(s1).min())
s2 /= .5 * (np.abs(s2).max() - np.abs(s2).min())
s3 /= .5 * (np.abs(s3).max() - np.abs(s3).min())
sS /= .5 * (np.abs(sS).max() - np.abs(sS).min())
# s1 -= s1.mean()
# s2 -= s2.mean()
# s3 -= s3.mean()
# sS -= sS.mean()
# s1 /= .5 * (np.abs(s1).max() - np.abs(s1).min())
# s2 /= .5 * (np.abs(s2).max() - np.abs(s2).min())
# s3 /= .5 * (np.abs(s3).max() - np.abs(s3).min())
# sS /= .5 * (np.abs(sS).max() - np.abs(sS).min())
S1 = np.hstack([s1, sS])
S2 = np.hstack([s2, sS])
@ -129,9 +129,9 @@ def _simulate_sincos(D1, D2, D3, N, M, Q, plot_sim=False):
Y2 = S2.dot(np.random.randn(S2.shape[1], D2))
Y3 = S3.dot(np.random.randn(S3.shape[1], D3))
Y1 += .5 * np.random.randn(*Y1.shape)
Y2 += .5 * np.random.randn(*Y2.shape)
Y3 += .5 * np.random.randn(*Y3.shape)
Y1 += .3 * np.random.randn(*Y1.shape)
Y2 += .3 * np.random.randn(*Y2.shape)
Y3 += .3 * np.random.randn(*Y3.shape)
Y1 -= Y1.mean(0)
Y2 -= Y2.mean(0)
@ -162,8 +162,11 @@ def _simulate_sincos(D1, D2, D3, N, M, Q, plot_sim=False):
return slist, [S1, S2, S3], Ylist
def bgplvm_simulation(burnin='scg', plot_sim=False, max_f_eval=12):
D1, D2, D3, N, M, Q = 2000, 8, 8, 500, 2, 6
def bgplvm_simulation(burnin='scg', plot_sim=False,
max_burnin=100, true_X=False,
do_opt=True,
max_f_eval=1000):
D1, D2, D3, N, M, Q = 10, 8, 8, 50, 30, 5
slist, Slist, Ylist = _simulate_sincos(D1, D2, D3, N, M, Q, plot_sim)
from GPy.models import mrd
@ -171,53 +174,73 @@ def bgplvm_simulation(burnin='scg', plot_sim=False, max_f_eval=12):
reload(mrd); reload(kern)
Y = Ylist[1]
Y = Ylist[0]
k = kern.linear(Q, ARD=True) + kern.white(Q, .00001) # + kern.bias(Q)
m = Bayesian_GPLVM(Y, Q, init="PCA", M=M, kernel=k)
# k = kern.white(Q, .00001) + kern.bias(Q)
m = Bayesian_GPLVM(Y, Q, init="PCA", M=M, kernel=k, _debug=True)
# m.set('noise',)
m.ensure_default_constraints()
# m.auto_scale_factor = True
# m.scale_factor = 1.
m.ensure_default_constraints()
if burnin:
print "initializing beta"
cstr = "noise"
m.unconstrain(cstr); m.constrain_fixed(cstr, Y.var() / 100.)
m.optimize(burnin, messages=1, max_f_eval=max_f_eval)
m.unconstrain(cstr); m.constrain_fixed(cstr, Y.var() / 70.)
m.optimize(burnin, messages=1, max_f_eval=max_burnin)
print "releasing beta"
cstr = "noise"
m.unconstrain(cstr); m.constrain_positive(cstr)
true_X = np.hstack((slist[1], slist[3], 0. * np.ones((N, Q - 2))))
m.set('X_\d', true_X)
m.constrain_fixed("X_\d")
if true_X:
true_X = np.hstack((slist[0], slist[3], 0. * np.ones((N, Q - 2))))
m.set('X_\d', true_X)
m.constrain_fixed("X_\d")
# # cstr = 'variance'
# # m.unconstrain(cstr), m.constrain_bounded(cstr, 1e-10, 1.)
cstr = 'X_variance'
# m.unconstrain(cstr), m.constrain_fixed(cstr, .0001)
m.unconstrain(cstr), m.constrain_bounded(cstr, 1e-7, .1)
# cstr = 'X_variance'
# m.unconstrain(cstr), m.constrain_bounded(cstr, 1e-3, 1.)
m['X_var'] = np.ones(N * Q) * .5 + np.random.randn(N * Q) * .01
# cstr = "iip"
# m.unconstrain(cstr); m.constrain_fixed(cstr)
# cstr = 'variance'
# m.unconstrain(cstr), m.constrain_bounded(cstr, 1e-10, 1.)
# cstr = 'X_\d'
# m.unconstrain(cstr), m.constrain_bounded(cstr, -100., 100.)
# m.unconstrain(cstr), m.constrain_bounded(cstr, -10., 10.)
#
# cstr = 'noise'
# m.unconstrain(cstr), m.constrain_bounded(cstr, 1e-3, 1.)
# m.unconstrain(cstr), m.constrain_bounded(cstr, 1e-5, 1.)
#
# cstr = 'white'
# m.unconstrain(cstr), m.constrain_bounded(cstr, 1e-6, 1.)
#
# cstr = 'linear_variance'
# m.unconstrain(cstr), m.constrain_bounded(cstr, 1e-10, 10.) # m.constrain_positive(cstr)
#
# cstr = 'X_variance'
# m.unconstrain(cstr), m.constrain_bounded(cstr, 1e-10, 1.) # m.constrain_positive(cstr)
# m.unconstrain(cstr), m.constrain_bounded(cstr, 1e-10, 10.)
# cstr = 'variance'
# m.unconstrain(cstr), m.constrain_bounded(cstr, 1e-10, 10.)
# np.seterr(all='call')
# def ipdbonerr(errtype, flags):
# import ipdb; ipdb.set_trace()
# np.seterrcall(ipdbonerr)
if do_opt and burnin:
try:
m.optimize(burnin, messages=1, max_f_eval=max_f_eval)
except:
pass
finally:
return m
return m
def mrd_simulation(plot_sim=False):
@ -261,6 +284,7 @@ def mrd_simulation(plot_sim=False):
m.set('{}_noise'.format(i + 1), Y.var() / 100.)
m.ensure_default_constraints()
m.auto_scale_factor = True
# cstr = 'variance'
# m.unconstrain(cstr), m.constrain_bounded(cstr, 1e-12, 1.)

View file

@ -0,0 +1,146 @@
#Copyright I. Nabney, N.Lawrence and James Hensman (1996 - 2012)
#Scaled Conjuagte Gradients, originally in Matlab as part of the Netlab toolbox by I. Nabney, converted to python N. Lawrence and given a pythonic interface by James Hensman
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT
# HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
# NOT LIMITED TO, THE IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
# OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF
# LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
# OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
import numpy as np
import sys
def SCG(f, gradf, x, optargs=(), maxiters=500, max_f_eval=500, display=True, xtol=1e-6, ftol=1e-6):
"""
Optimisation through Scaled Conjugate Gradients (SCG)
f: the objective function
gradf : the gradient function (should return a 1D np.ndarray)
x : the initial condition
Returns
x the optimal value for x
flog : a list of all the objective values
"""
sigma0 = 1.0e-4
fold = f(x, *optargs) # Initial function value.
function_eval = 1
fnow = fold
gradnew = gradf(x, *optargs) # Initial gradient.
gradold = gradnew.copy()
d = -gradnew # Initial search direction.
success = True # Force calculation of directional derivs.
nsuccess = 0 # nsuccess counts number of successes.
beta = 1.0 # Initial scale parameter.
betamin = 1.0e-15 # Lower bound on scale.
betamax = 1.0e100 # Upper bound on scale.
status = "Not converged"
flog = [fold]
iteration = 0
# Main optimization loop.
while iteration < maxiters:
# Calculate first and second directional derivatives.
if success:
mu = np.dot(d, gradnew)
if mu >= 0:
d = -gradnew
mu = np.dot(d, gradnew)
kappa = np.dot(d, d)
sigma = sigma0/np.sqrt(kappa)
xplus = x + sigma*d
gplus = gradf(xplus, *optargs)
theta = np.dot(d, (gplus - gradnew))/sigma
# Increase effective curvature and evaluate step size alpha.
delta = theta + beta*kappa
if delta <= 0:
delta = beta*kappa
beta = beta - theta/kappa
alpha = - mu/delta
# Calculate the comparison ratio.
xnew = x + alpha*d
fnew = f(xnew, *optargs)
function_eval += 1
if function_eval >= max_f_eval:
status = "Maximum number of function evaluations exceeded"
return x, flog, function_eval, status
Delta = 2.*(fnew - fold)/(alpha*mu)
if Delta >= 0.:
success = True
nsuccess += 1
x = xnew
fnow = fnew
else:
success = False
fnow = fold
# Store relevant variables
flog.append(fnow) # Current function value
iteration += 1
if display:
print '\r',
print 'Iteration: {0:>5g} Objective:{1:> 12e} Scale:{2:> 12e}'.format(iteration, fnow, beta),
# print 'Iteration:', iteration, ' Objective:', fnow, ' Scale:', beta, '\r',
sys.stdout.flush()
if success:
# Test for termination
if (np.max(np.abs(alpha*d)) < xtol) or (np.abs(fnew-fold) < ftol):
status='converged'
return x, flog, function_eval, status
else:
# Update variables for new position
fold = fnew
gradold = gradnew
gradnew = gradf(x, *optargs)
# If the gradient is zero then we are done.
if np.dot(gradnew,gradnew) == 0:
return x, flog, function_eval, status
# Adjust beta according to comparison ratio.
if Delta < 0.25:
beta = min(4.0*beta, betamax)
if Delta > 0.75:
beta = max(0.5*beta, betamin)
# Update search direction using Polak-Ribiere formula, or re-start
# in direction of negative gradient after nparams steps.
if nsuccess == x.size:
d = -gradnew
nsuccess = 0
elif success:
gamma = np.dot(gradold - gradnew,gradnew)/(mu)
d = gamma*d - gradnew
# If we get here, then we haven't terminated in the given number of
# iterations.
status = "maxiter exceeded"
return x, flog, function_eval, status

View file

@ -70,8 +70,8 @@ class kern(parameterised):
ard_params = 1. / p.lengthscale
ax.bar(np.arange(len(ard_params)) - 0.4, ard_params)
ax.set_xticks(np.arange(len(ard_params)),
["${}$".format(i + 1) for i in range(len(ard_params))])
ax.set_xticks(np.arange(len(ard_params)))
ax.set_xticklabels([r"${}$".format(i + 1) for i in range(len(ard_params))])
return ax
def _transform_gradients(self, g):

View file

@ -10,6 +10,7 @@ from GPy.util.linalg import pdinv
from ..likelihoods import Gaussian
from .. import kern
from numpy.linalg.linalg import LinAlgError
import itertools
class Bayesian_GPLVM(sparse_GP, GPLVM):
"""
@ -23,7 +24,9 @@ class Bayesian_GPLVM(sparse_GP, GPLVM):
:type init: 'PCA'|'random'
"""
def __init__(self, Y, Q, X=None, X_variance=None, init='PCA', M=10, Z=None, kernel=None, oldpsave=5, **kwargs):
def __init__(self, Y, Q, X=None, X_variance=None, init='PCA', M=10,
Z=None, kernel=None, oldpsave=5, _debug=False,
**kwargs):
if X == None:
X = self.initialise_latent(init, Q, Y)
@ -39,6 +42,12 @@ class Bayesian_GPLVM(sparse_GP, GPLVM):
self.oldpsave = oldpsave
self._oldps = []
self._debug = _debug
if self._debug:
self._count = itertools.count()
self._savedklll = []
self._savedparams = []
sparse_GP.__init__(self, X, Gaussian(Y), kernel, Z=Z, X_variance=X_variance, **kwargs)
@ -70,16 +79,18 @@ class Bayesian_GPLVM(sparse_GP, GPLVM):
x = np.hstack((self.X.flatten(), self.X_variance.flatten(), sparse_GP._get_params(self)))
return x
def _set_params(self, x, save_old=True):
def _set_params(self, x, save_old=True, save_count=0):
try:
N, Q = self.N, self.Q
self.X = x[:self.X.size].reshape(N, Q).copy()
self.X_variance = x[(N * Q):(2 * N * Q)].reshape(N, Q).copy()
sparse_GP._set_params(self, x[(2 * N * Q):])
self.oldps = x
except (LinAlgError, FloatingPointError):
print "\rWARNING: Caught LinAlgError, reconstructing old state "
self._set_params(self.oldps[-1], save_old=False)
except (LinAlgError, FloatingPointError, ZeroDivisionError):
print "\rWARNING: Caught LinAlgError, continueing without setting "
# if save_count > 10:
# raise
# self._set_params(self.oldps[-1], save_old=False, save_count=save_count + 1)
def dKL_dmuS(self):
dKL_dS = (1. - (1. / (self.X_variance))) * 0.5
@ -103,15 +114,29 @@ class Bayesian_GPLVM(sparse_GP, GPLVM):
def log_likelihood(self):
ll = sparse_GP.log_likelihood(self)
kl = self.KL_divergence()
return ll + kl
# if ll < -2E4:
# ll = -2E4 + np.random.randn()
# if kl > 5E4:
# kl = 5E4 + np.random.randn()
if self._debug:
f_call = self._count.next()
self._savedklll.append([f_call, ll, kl])
if f_call % 1 == 0:
self._savedparams.append([f_call, self._get_params()])
# print "\nkl:", kl, "ll:", ll
return ll - kl
def _log_likelihood_gradients(self):
dKL_dmu, dKL_dS = self.dKL_dmuS()
dL_dmu, dL_dS = self.dL_dmuS()
# TODO: find way to make faster
d_dmu = (dL_dmu + dKL_dmu).flatten()
d_dS = (dL_dS + dKL_dS).flatten()
d_dmu = (dL_dmu - dKL_dmu).flatten()
d_dS = (dL_dS - dKL_dS).flatten()
# TEST KL: ====================
# d_dmu = (dKL_dmu).flatten()
# d_dS = (dKL_dS).flatten()
@ -135,3 +160,140 @@ class Bayesian_GPLVM(sparse_GP, GPLVM):
ax = GPLVM.plot_latent(self, which_indices=[input_1, input_2], *args, **kwargs)
ax.plot(self.Z[:, input_1], self.Z[:, input_2], '^w')
return ax
def plot_X_1d(self, fig_num="MRD X 1d", axes=None, colors=None):
import pylab
fig = pylab.figure(num=fig_num, figsize=(min(8, (3 * len(self.bgplvms))), min(12, (2 * self.X.shape[1]))))
if colors is None:
colors = pylab.gca()._get_lines.color_cycle
pylab.clf()
plots = []
for i in range(self.X.shape[1]):
if axes is None:
ax = fig.add_subplot(self.X.shape[1], 1, i + 1)
else:
ax = axes[i]
ax.plot(self.X, c='k', alpha=.3)
plots.extend(ax.plot(self.X.T[i], c=colors.next(), label=r"$\mathbf{{X_{}}}$".format(i)))
ax.fill_between(np.arange(self.X.shape[0]),
self.X.T[i] - 2 * np.sqrt(self.X_variance.T[i]),
self.X.T[i] + 2 * np.sqrt(self.X_variance.T[i]),
facecolor=plots[-1].get_color(),
alpha=.3)
ax.legend(borderaxespad=0.)
if i < self.X.shape[1] - 1:
ax.set_xticklabels('')
pylab.draw()
fig.tight_layout(h_pad=.01) # , rect=(0, 0, 1, .95))
return fig
def _debug_filter_params(self, x):
start, end = 0, self.X.size,
X = x[start:end].reshape(self.N, self.Q)
start, end = end, end + self.X_variance.size
X_v = x[start:end].reshape(self.N, self.Q)
start, end = end, end + (self.M * self.Q)
Z = x[start:end].reshape(self.M, self.Q)
start, end = end, end + self.Q
theta = x[start:]
return X, X_v, Z, theta
def _debug_plot(self):
assert self._debug, "must enable _debug, to debug-plot"
import pylab
from mpl_toolkits.mplot3d import Axes3D
fig = pylab.figure('BGPLVM DEBUG', figsize=(12, 10))
fig.clf()
# log like
splotshape = (6, 4)
ax1 = pylab.subplot2grid(splotshape, (0, 0), 1, 4)
ax1.text(.5, .5, "Optimization", alpha=.3, transform=ax1.transAxes,
ha='center', va='center')
kllls = np.array(self._savedklll)
LL, = ax1.plot(kllls[:, 0], kllls[:, 1] - kllls[:, 2], label=r'$\log p(\mathbf{Y})$', mew=1.5)
KL, = ax1.plot(kllls[:, 0], kllls[:, 2], label=r'$\mathcal{KL}(p||q)$', mew=1.5)
L, = ax1.plot(kllls[:, 0], kllls[:, 1], label=r'$L$', mew=1.5) # \mathds{E}_{q(\mathbf{X})}[p(\mathbf{Y|X})\frac{p(\mathbf{X})}{q(\mathbf{X})}]
drawn = dict(self._savedparams)
iters = np.array(drawn.keys())
self.showing = 0
ax2 = pylab.subplot2grid(splotshape, (1, 0), 2, 4)
ax2.text(.5, .5, r"$\mathbf{X}$", alpha=.5, transform=ax2.transAxes,
ha='center', va='center')
ax3 = pylab.subplot2grid(splotshape, (3, 0), 2, 4, sharex=ax2)
ax3.text(.5, .5, r"$\mathbf{S}$", alpha=.5, transform=ax3.transAxes,
ha='center', va='center')
ax4 = pylab.subplot2grid(splotshape, (5, 0), 2, 2)
ax4.text(.5, .5, r"$\mathbf{Z}$", alpha=.5, transform=ax4.transAxes,
ha='center', va='center')
ax5 = pylab.subplot2grid(splotshape, (5, 2), 2, 2)
ax5.text(.5, .5, r"${\theta}$", alpha=.5, transform=ax5.transAxes,
ha='center', va='center')
X, S, Z, theta = self._debug_filter_params(drawn[self.showing])
Xlatentplts = ax2.plot(X, ls="-", marker="x")
Slatentplts = ax3.plot(S, ls="-", marker="x")
Zplts = ax4.plot(Z, ls="-", marker="x")
thetaplts = ax5.bar(np.arange(len(theta)) - .4, theta)
ax5.set_xticks(np.arange(len(theta)))
ax5.set_xticklabels(self._get_param_names()[-len(theta):], rotation=17)
Qleg = ax1.legend(Xlatentplts, [r"$Q_{}$".format(i + 1) for i in range(self.Q)],
loc=3, ncol=self.Q, bbox_to_anchor=(0, 1.15, 1, 1.15),
borderaxespad=0, mode="expand")
Lleg = ax1.legend()
Lleg.draggable()
ax1.add_artist(Qleg)
indicatorKL, = ax1.plot(kllls[self.showing, 0], kllls[self.showing, 2], 'o', c=KL.get_color())
indicatorLL, = ax1.plot(kllls[self.showing, 0], kllls[self.showing, 1] - kllls[self.showing, 2], 'o', c=LL.get_color())
indicatorL, = ax1.plot(kllls[self.showing, 0], kllls[self.showing, 1], 'o', c=L.get_color())
try:
pylab.draw()
pylab.tight_layout(box=(0, .1, 1, .9))
except:
pass
# parameter changes
# ax2 = pylab.subplot2grid((4, 1), (1, 0), 3, 1, projection='3d')
def onclick(event):
if event.inaxes is ax1 and event.button == 1:
# event.button, event.x, event.y, event.xdata, event.ydata)
tmp = np.abs(iters - event.xdata)
closest_hit = iters[tmp == tmp.min()][0]
if closest_hit != self.showing:
self.showing = closest_hit
# print closest_hit, iters, event.xdata
indicatorLL.set_data(self.showing, kllls[self.showing, 1] - kllls[self.showing, 2])
indicatorKL.set_data(self.showing, kllls[self.showing, 2])
indicatorL.set_data(self.showing, kllls[self.showing, 1])
X, S, Z, theta = self._debug_filter_params(drawn[self.showing])
for i, Xlatent in enumerate(Xlatentplts):
Xlatent.set_ydata(X[:, i])
for i, Slatent in enumerate(Slatentplts):
Slatent.set_ydata(S[:, i])
for i, Zlatent in enumerate(Zplts):
Zlatent.set_ydata(Z[:, i])
for p, t in zip(thetaplts, theta):
p.set_height(t)
ax2.relim()
ax3.relim()
ax4.relim()
ax5.relim()
ax2.autoscale()
ax3.autoscale()
ax4.autoscale()
ax5.autoscale()
fig.canvas.draw()
cid = fig.canvas.mpl_connect('button_press_event', onclick)
return ax1, ax2, ax3, ax4, ax5

View file

@ -287,29 +287,6 @@ class MRD(model):
else:
return pylab.gcf()
def plot_X_1d(self, fig_num="MRD X 1d", axes=None, colors=None):
fig = pylab.figure(num=fig_num, figsize=(min(8, (3 * len(self.bgplvms))), min(12, (2 * self.X.shape[1]))))
if colors is None:
colors = pylab.gca()._get_lines.color_cycle
pylab.clf()
plots = []
for i in range(self.X.shape[1]):
if axes is None:
ax = fig.add_subplot(self.X.shape[1], 1, i + 1)
ax.plot(self.X, c='k', alpha=.3)
plots.extend(ax.plot(self.X.T[i], c=colors.next(), label=r"$\mathbf{{X_{}}}$".format(i)))
ax.fill_between(numpy.arange(self.X.shape[0]),
self.X.T[i] - 2 * numpy.sqrt(self.gref.X_variance.T[i]),
self.X.T[i] + 2 * numpy.sqrt(self.gref.X_variance.T[i]),
facecolor=plots[-1].get_color(),
alpha=.3)
ax.legend(borderaxespad=0.)
if i < self.X.shape[1] - 1:
ax.set_xticklabels('')
pylab.draw()
fig.tight_layout(h_pad=.01) # , rect=(0, 0, 1, .95))
return fig
def plot_X(self, fig_num="MRD Predictions", axes=None):
fig = self._handle_plotting(fig_num, axes, lambda i, g, ax: ax.imshow(g.X))
return fig

View file

@ -57,6 +57,7 @@ class Test(unittest.TestCase):
X_var = .5 * numpy.ones_like(X) + .4 * numpy.clip(numpy.random.randn(*X.shape), 0, 1)
Z = numpy.random.permutation(X)[:M]
Y = X.dot(numpy.random.randn(Q, D))
kernels = [GPy.kern.linear(Q), GPy.kern.rbf(Q), GPy.kern.bias(Q)]
kernels = [GPy.kern.linear(Q), GPy.kern.rbf(Q), GPy.kern.bias(Q),
GPy.kern.linear(Q) + GPy.kern.bias(Q),