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

This commit is contained in:
Zhenwen Dai 2014-02-28 18:11:05 +00:00
commit c96d9ffc4c
20 changed files with 612 additions and 405 deletions

View file

@ -60,20 +60,6 @@ class Model(Parameterized):
self.priors = state.pop()
Parameterized._setstate(self, state)
def randomize(self):
"""
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))
# x = self._get_params_transformed()
x = np.random.randn(self.size_transformed)
x = self._untransform_params(x)
# now draw from prior where possible
[np.put(x, ind, p.rvs(ind.size)) for p, ind in self.priors.iteritems() 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...)
def optimize_restarts(self, num_restarts=10, robust=False, verbose=True, parallel=False, num_processes=None, **kwargs):
"""
Perform random restarts of the model, and set the model to the best
@ -240,6 +226,11 @@ class Model(Parameterized):
TODO: valid args
"""
if self.is_fixed:
raise RuntimeError, "Cannot optimize, when everything is fixed"
if self.size == 0:
raise RuntimeError, "Model without parameters cannot be minimized"
if optimizer is None:
optimizer = self.preferred_optimizer
@ -279,7 +270,7 @@ class Model(Parameterized):
and numerical gradients is within <tolerance> of unity.
"""
x = self._get_params_transformed().copy()
x = self._get_params_transformed()
if not verbose:
# make sure only to test the selected parameters
@ -297,7 +288,7 @@ class Model(Parameterized):
return
# just check the global ratio
dx = np.zeros_like(x)
dx = np.zeros(x.shape)
dx[transformed_index] = step * np.sign(np.random.uniform(-1, 1, transformed_index.size))
# evaulate around the point x
@ -308,9 +299,8 @@ class Model(Parameterized):
dx = dx[transformed_index]
gradient = gradient[transformed_index]
numerical_gradient = (f1 - f2) / (2 * dx)
global_ratio = (f1 - f2) / (2 * np.dot(dx, np.where(gradient == 0, 1e-32, gradient)))
return (np.abs(1. - global_ratio) < tolerance) or (np.abs(gradient - numerical_gradient).mean() < tolerance)
return (np.abs(1. - global_ratio) < tolerance)
else:
# check the gradient of each parameter individually, and do some pretty printing
try:

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@ -6,19 +6,6 @@ __updated__ = '2013-12-16'
import numpy as np
from parameter_core import Observable
class ParamList(list):
"""
List to store ndarray-likes in.
It will look for 'is' instead of calling __eq__ on each element.
"""
def __contains__(self, other):
for el in self:
if el is other:
return True
return False
pass
class ObservableArray(np.ndarray, Observable):
"""
An ndarray which reports changes to its observers.
@ -62,10 +49,11 @@ class ObservableArray(np.ndarray, Observable):
def __setitem__(self, s, val):
if self._s_not_empty(s):
super(ObservableArray, self).__setitem__(s, val)
self._notify_observers()
self._notify_observers(self[s])
def __getslice__(self, start, stop):
return self.__getitem__(slice(start, stop))
def __setslice__(self, start, stop, val):
return self.__setitem__(slice(start, stop), val)

View file

@ -5,47 +5,7 @@ Created on Oct 2, 2013
'''
import numpy
from numpy.lib.function_base import vectorize
from param import Param
from collections import defaultdict
class ParamDict(defaultdict):
def __init__(self):
"""
Default will be self._default, if not set otherwise
"""
defaultdict.__init__(self, self.default_factory)
def __getitem__(self, key):
try:
return defaultdict.__getitem__(self, key)
except KeyError:
for a in self.iterkeys():
if numpy.all(a==key) and a._parent_index_==key._parent_index_:
return defaultdict.__getitem__(self, a)
raise
def __contains__(self, key):
if defaultdict.__contains__(self, key):
return True
for a in self.iterkeys():
if numpy.all(a==key) and a._parent_index_==key._parent_index_:
return True
return False
def __setitem__(self, key, value):
if isinstance(key, Param):
for a in self.iterkeys():
if numpy.all(a==key) and a._parent_index_==key._parent_index_:
return super(ParamDict, self).__setitem__(a, value)
defaultdict.__setitem__(self, key, value)
class SetDict(ParamDict):
def default_factory(self):
return set()
class IntArrayDict(ParamDict):
def default_factory(self):
return numpy.int_([])
from lists_and_dicts import IntArrayDict
class ParameterIndexOperations(object):
'''
@ -194,9 +154,13 @@ class ParameterIndexOperationsView(object):
def shift_right(self, start, size):
raise NotImplementedError, 'Shifting only supported in original ParamIndexOperations'
self._param_index_ops.shift_right(start+self._offset, size)
def shift_left(self, start, size):
self._param_index_ops.shift_left(start+self._offset, size)
self._offset -= size
self._size -= size
def clear(self):
for i, ind in self.items():
self._param_index_ops.remove(i, ind+self._offset)
@ -232,9 +196,7 @@ class ParameterIndexOperationsView(object):
def __getitem__(self, prop):
ind = self._filter_index(self._param_index_ops[prop])
if ind.size > 0:
return ind
raise KeyError, prop
return ind
def __str__(self, *args, **kwargs):
import pprint

View file

@ -0,0 +1,35 @@
'''
Created on 27 Feb 2014
@author: maxz
'''
from collections import defaultdict
class DefaultArrayDict(defaultdict):
def __init__(self):
"""
Default will be self._default, if not set otherwise
"""
defaultdict.__init__(self, self.default_factory)
class SetDict(DefaultArrayDict):
def default_factory(self):
return set()
class IntArrayDict(DefaultArrayDict):
def default_factory(self):
import numpy as np
return np.int_([])
class ArrayList(list):
"""
List to store ndarray-likes in.
It will look for 'is' instead of calling __eq__ on each element.
"""
def __contains__(self, other):
for el in self:
if el is other:
return True
return False
pass

View file

@ -3,8 +3,8 @@
import itertools
import numpy
from parameter_core import Constrainable, Gradcheckable, Indexable, Parentable, adjust_name_for_printing
from array_core import ObservableArray, ParamList
from parameter_core import OptimizationHandlable, Gradcheckable, adjust_name_for_printing
from array_core import ObservableArray
###### printing
__constraints_name__ = "Constraint"
@ -15,7 +15,7 @@ __precision__ = numpy.get_printoptions()['precision'] # numpy printing precision
__print_threshold__ = 5
######
class Param(Constrainable, ObservableArray, Gradcheckable):
class Param(OptimizationHandlable, ObservableArray, Gradcheckable):
"""
Parameter object for GPy models.
@ -50,7 +50,7 @@ class Param(Constrainable, ObservableArray, Gradcheckable):
obj._realsize_ = obj.size
obj._realndim_ = obj.ndim
obj._updated_ = False
from index_operations import SetDict
from lists_and_dicts import SetDict
obj._tied_to_me_ = SetDict()
obj._tied_to_ = []
obj._original_ = True
@ -148,8 +148,11 @@ class Param(Constrainable, ObservableArray, Gradcheckable):
#===========================================================================
# get/set parameters
#===========================================================================
def _set_params(self, param, update=True):
def _set_params(self, param, trigger_parent=True):
self.flat = param
if trigger_parent: min_priority = None
else: min_priority = -numpy.inf
self._notify_observers(None, min_priority)
def _get_params(self):
return self.flat
@ -172,11 +175,9 @@ class Param(Constrainable, ObservableArray, Gradcheckable):
try: new_arr._current_slice_ = s; new_arr._original_ = self.base is new_arr.base
except AttributeError: pass # returning 0d array or float, double etc
return new_arr
def __setitem__(self, s, val):
super(Param, self).__setitem__(s, val)
if self.has_parent():
self._direct_parent_._notify_parameters_changed()
#self._notify_observers()
#===========================================================================
# Index Operations:
@ -204,6 +205,7 @@ class Param(Constrainable, ObservableArray, Gradcheckable):
ind = self._indices(slice_index)
if ind.ndim < 2: ind = ind[:, None]
return numpy.asarray(numpy.apply_along_axis(lambda x: numpy.sum(extended_realshape * x), 1, ind), dtype=int)
def _expand_index(self, slice_index=None):
# this calculates the full indexing arrays from the slicing objects given by get_item for _real..._ attributes
# it basically translates slices to their respective index arrays and turns negative indices around
@ -230,7 +232,8 @@ class Param(Constrainable, ObservableArray, Gradcheckable):
#===========================================================================
@property
def is_fixed(self):
return self._highest_parent_._is_fixed(self)
from transformations import __fixed__
return self.constraints[__fixed__].size == self.size
#def round(self, decimals=0, out=None):
# view = super(Param, self).round(decimals, out).view(Param)
# view.__array_finalize__(self)
@ -267,7 +270,7 @@ class Param(Constrainable, ObservableArray, Gradcheckable):
return [t._short() for t in self._tied_to_] or ['']
def __repr__(self, *args, **kwargs):
name = "\033[1m{x:s}\033[0;0m:\n".format(
x=self.hirarchy_name())
x=self.hierarchy_name())
return name + super(Param, self).__repr__(*args, **kwargs)
def _ties_for(self, rav_index):
# size = sum(p.size for p in self._tied_to_)
@ -301,12 +304,12 @@ class Param(Constrainable, ObservableArray, Gradcheckable):
gen = map(lambda x: " ".join(map(str, x)), gen)
return reduce(lambda a, b:max(a, len(b)), gen, len(header))
def _max_len_values(self):
return reduce(lambda a, b:max(a, len("{x:=.{0}g}".format(__precision__, x=b))), self.flat, len(self.hirarchy_name()))
return reduce(lambda a, b:max(a, len("{x:=.{0}g}".format(__precision__, x=b))), self.flat, len(self.hierarchy_name()))
def _max_len_index(self, ind):
return reduce(lambda a, b:max(a, len(str(b))), ind, len(__index_name__))
def _short(self):
# short string to print
name = self.hirarchy_name()
name = self.hierarchy_name()
if self._realsize_ < 2:
return name
ind = self._indices()
@ -329,8 +332,8 @@ class Param(Constrainable, ObservableArray, Gradcheckable):
if lp is None: lp = self._max_len_names(prirs, __tie_name__)
sep = '-'
header_format = " {i:{5}^{2}s} | \033[1m{x:{5}^{1}s}\033[0;0m | {c:{5}^{0}s} | {p:{5}^{4}s} | {t:{5}^{3}s}"
if only_name: header = header_format.format(lc, lx, li, lt, lp, ' ', x=self.hirarchy_name(), c=sep*lc, i=sep*li, t=sep*lt, p=sep*lp) # nice header for printing
else: header = header_format.format(lc, lx, li, lt, lp, ' ', x=self.hirarchy_name(), c=__constraints_name__, i=__index_name__, t=__tie_name__, p=__priors_name__) # nice header for printing
if only_name: header = header_format.format(lc, lx, li, lt, lp, ' ', x=self.hierarchy_name(), c=sep*lc, i=sep*li, t=sep*lt, p=sep*lp) # nice header for printing
else: header = header_format.format(lc, lx, li, lt, lp, ' ', x=self.hierarchy_name(), c=__constraints_name__, i=__index_name__, t=__tie_name__, p=__priors_name__) # nice header for printing
if not ties: ties = itertools.cycle([''])
return "\n".join([header] + [" {i!s:^{3}s} | {x: >{1}.{2}g} | {c:^{0}s} | {p:^{5}s} | {t:^{4}s} ".format(lc, lx, __precision__, li, lt, lp, x=x, c=" ".join(map(str, c)), p=" ".join(map(str, p)), t=(t or ''), i=i) for i, x, c, t, p in itertools.izip(indices, vals, constr_matrix, ties, prirs)]) # return all the constraints with right indices
# except: return super(Param, self).__str__()
@ -345,7 +348,8 @@ class ParamConcatenation(object):
See :py:class:`GPy.core.parameter.Param` for more details on constraining.
"""
# self.params = params
self.params = ParamList([])
from lists_and_dicts import ArrayList
self.params = ArrayList([])
for p in params:
for p in p.flattened_parameters:
if p not in self.params:
@ -353,6 +357,21 @@ class ParamConcatenation(object):
self._param_sizes = [p.size for p in self.params]
startstops = numpy.cumsum([0] + self._param_sizes)
self._param_slices_ = [slice(start, stop) for start,stop in zip(startstops, startstops[1:])]
parents = dict()
for p in self.params:
if p.has_parent():
parent = p._direct_parent_
level = 0
while parent is not None:
if parent in parents:
parents[parent] = max(level, parents[parent])
else:
parents[parent] = level
level += 1
parent = parent._direct_parent_
import operator
self.parents = map(lambda x: x[0], sorted(parents.iteritems(), key=operator.itemgetter(1)))
#===========================================================================
# Get/set items, enable broadcasting
#===========================================================================
@ -366,24 +385,26 @@ class ParamConcatenation(object):
val = val._vals()
ind = numpy.zeros(sum(self._param_sizes), dtype=bool); ind[s] = True;
vals = self._vals(); vals[s] = val; del val
[numpy.place(p, ind[ps], vals[ps]) and update and p._notify_observers()
[numpy.place(p, ind[ps], vals[ps])
for p, ps in zip(self.params, self._param_slices_)]
if update:
self.update_all_params()
def _vals(self):
return numpy.hstack([p._get_params() for p in self.params])
#===========================================================================
# parameter operations:
#===========================================================================
def update_all_params(self):
for p in self.params:
p._notify_observers()
for par in self.parents:
par._notify_observers(-numpy.inf)
def constrain(self, constraint, warning=True):
[param.constrain(constraint, update=False) for param in self.params]
[param.constrain(constraint, trigger_parent=False) for param in self.params]
self.update_all_params()
constrain.__doc__ = Param.constrain.__doc__
def constrain_positive(self, warning=True):
[param.constrain_positive(warning, update=False) for param in self.params]
[param.constrain_positive(warning, trigger_parent=False) for param in self.params]
self.update_all_params()
constrain_positive.__doc__ = Param.constrain_positive.__doc__
@ -393,12 +414,12 @@ class ParamConcatenation(object):
fix = constrain_fixed
def constrain_negative(self, warning=True):
[param.constrain_negative(warning, update=False) for param in self.params]
[param.constrain_negative(warning, trigger_parent=False) for param in self.params]
self.update_all_params()
constrain_negative.__doc__ = Param.constrain_negative.__doc__
def constrain_bounded(self, lower, upper, warning=True):
[param.constrain_bounded(lower, upper, warning, update=False) for param in self.params]
[param.constrain_bounded(lower, upper, warning, trigger_parent=False) for param in self.params]
self.update_all_params()
constrain_bounded.__doc__ = Param.constrain_bounded.__doc__

View file

@ -2,34 +2,58 @@
# Licensed under the BSD 3-clause license (see LICENSE.txt)
from transformations import Transformation, Logexp, NegativeLogexp, Logistic, __fixed__, FIXED, UNFIXED
import heapq
__updated__ = '2013-12-16'
class HierarchyError(Exception):
"""
Gets thrown when something is wrong with the parameter hierarchy
"""
def adjust_name_for_printing(name):
if name is not None:
return name.replace(" ", "_").replace(".", "_").replace("-", "").replace("+", "").replace("!", "").replace("*", "").replace("/", "")
return ''
class Observable(object):
_updated = True
def __init__(self, *args, **kwargs):
from collections import defaultdict
self._observer_callables_ = defaultdict(list)
def add_observer(self, observer, callble):
self._observer_callables_[observer].append(callble)
self._observer_callables_ = []
def add_observer(self, observer, callble, priority=0):
heapq.heappush(self._observer_callables_, (priority, observer, callble))
def remove_observer(self, observer, callble=None):
if observer in self._observer_callables_:
if callble is None:
del self._observer_callables_[observer]
elif callble in self._observer_callables_[observer]:
self._observer_callables_[observer].remove(callble)
if len(self._observer_callables_[observer]) == 0:
self.remove_observer(observer)
def _notify_observers(self):
[[callble(self) for callble in callables]
for callables in self._observer_callables_.itervalues()]
to_remove = []
for p, obs, clble in self._observer_callables_:
if callble is not None:
if (obs == observer) and (callble == clble):
to_remove.append((p, obs, clble))
else:
if obs is observer:
to_remove.append((p, obs, clble))
for r in to_remove:
self._observer_callables_.remove(r)
def _notify_observers(self, which=None, min_priority=None):
"""
Notifies all observers. Which is the element, which kicked off this
notification loop.
NOTE: notifies only observers with priority p > min_priority!
^^^^^^^^^^^^^^^^
:param which: object, which started this notification loop
:param min_priority: only notify observers with priority > min_priority
if min_priority is None, notify all observers in order
"""
if which is None:
which = self
if min_priority is None:
[callble(which) for _, _, callble in heapq.nlargest(len(self._observer_callables_), self._observer_callables_)]
else:
[callble(which) for p, _, callble in heapq.nlargest(len(self._observer_callables_), self._observer_callables_) if p > min_priority]
class Pickleable(object):
def _getstate(self):
@ -95,11 +119,11 @@ class Nameable(Parentable):
self._name = name
if self.has_parent():
self._direct_parent_._name_changed(self, from_name)
def hirarchy_name(self, adjust_for_printing=True):
def hierarchy_name(self, adjust_for_printing=True):
if adjust_for_printing: adjust = lambda x: adjust_name_for_printing(x)
else: adjust = lambda x: x
if self.has_parent():
return self._direct_parent_.hirarchy_name() + "." + adjust(self.name)
return self._direct_parent_.hierarchy_name() + "." + adjust(self.name)
return adjust(self.name)
@ -156,7 +180,7 @@ class Constrainable(Nameable, Indexable):
#===========================================================================
# Fixing Parameters:
#===========================================================================
def constrain_fixed(self, value=None, warning=True):
def constrain_fixed(self, value=None, warning=True, trigger_parent=True):
"""
Constrain this paramter to be fixed to the current value it carries.
@ -164,7 +188,7 @@ class Constrainable(Nameable, Indexable):
"""
if value is not None:
self[:] = value
self.constrain(__fixed__, warning=warning)
self.constrain(__fixed__, warning=warning, trigger_parent=trigger_parent)
rav_i = self._highest_parent_._raveled_index_for(self)
self._highest_parent_._set_fixed(rav_i)
fix = constrain_fixed
@ -205,9 +229,9 @@ class Constrainable(Nameable, Indexable):
#===========================================================================
# Prior Operations
#===========================================================================
def set_prior(self, prior, warning=True, update=True):
def set_prior(self, prior, warning=True, trigger_parent=True):
repriorized = self.unset_priors()
self._add_to_index_operations(self.priors, repriorized, prior, warning, update)
self._add_to_index_operations(self.priors, repriorized, prior, warning)
def unset_priors(self, *priors):
return self._remove_from_index_operations(self.priors, priors)
@ -233,7 +257,7 @@ class Constrainable(Nameable, Indexable):
# Constrain operations -> done
#===========================================================================
def constrain(self, transform, warning=True, update=True):
def constrain(self, transform, warning=True, trigger_parent=True):
"""
:param transform: the :py:class:`GPy.core.transformations.Transformation`
to constrain the this parameter to.
@ -243,9 +267,9 @@ class Constrainable(Nameable, Indexable):
:py:class:`GPy.core.transformations.Transformation`.
"""
if isinstance(transform, Transformation):
self._set_params(transform.initialize(self._get_params()), update=False)
self._set_params(transform.initialize(self._get_params()), trigger_parent=trigger_parent)
reconstrained = self.unconstrain()
self._add_to_index_operations(self.constraints, reconstrained, transform, warning, update)
self._add_to_index_operations(self.constraints, reconstrained, transform, warning)
def unconstrain(self, *transforms):
"""
@ -256,30 +280,30 @@ class Constrainable(Nameable, Indexable):
"""
return self._remove_from_index_operations(self.constraints, transforms)
def constrain_positive(self, warning=True, update=True):
def constrain_positive(self, warning=True, trigger_parent=True):
"""
:param warning: print a warning if re-constraining parameters.
Constrain this parameter to the default positive constraint.
"""
self.constrain(Logexp(), warning=warning, update=update)
self.constrain(Logexp(), warning=warning, trigger_parent=trigger_parent)
def constrain_negative(self, warning=True, update=True):
def constrain_negative(self, warning=True, trigger_parent=True):
"""
:param warning: print a warning if re-constraining parameters.
Constrain this parameter to the default negative constraint.
"""
self.constrain(NegativeLogexp(), warning=warning, update=update)
self.constrain(NegativeLogexp(), warning=warning, trigger_parent=trigger_parent)
def constrain_bounded(self, lower, upper, warning=True, update=True):
def constrain_bounded(self, lower, upper, warning=True, trigger_parent=True):
"""
:param lower, upper: the limits to bound this parameter to
:param warning: print a warning if re-constraining parameters.
Constrain this parameter to lie within the given range.
"""
self.constrain(Logistic(lower, upper), warning=warning, update=update)
self.constrain(Logistic(lower, upper), warning=warning, trigger_parent=trigger_parent)
def unconstrain_positive(self):
"""
@ -309,12 +333,11 @@ class Constrainable(Nameable, Indexable):
for p in self._parameters_:
p._parent_changed(parent)
def _add_to_index_operations(self, which, reconstrained, transform, warning, update):
def _add_to_index_operations(self, which, reconstrained, transform, warning):
if warning and reconstrained.size > 0:
# TODO: figure out which parameters have changed and only print those
print "WARNING: reconstraining parameters {}".format(self.parameter_names() or self.name)
which.add(transform, self._raveled_index())
if update:
self._notify_observers()
def _remove_from_index_operations(self, which, transforms):
if len(transforms) == 0:
@ -329,12 +352,76 @@ class Constrainable(Nameable, Indexable):
return removed
class OptimizationHandlable(Constrainable, Observable):
def _get_params_transformed(self):
# transformed parameters (apply transformation rules)
p = self._get_params()
[np.put(p, ind, c.finv(p[ind])) for c, ind in self.constraints.iteritems() if c != __fixed__]
if self._has_fixes():
return p[self._fixes_]
return p
def _set_params_transformed(self, p):
# inverse apply transformations for parameters and set the resulting parameters
self._set_params(self._untransform_params(p))
def _size_transformed(self):
return self.size - self.constraints[__fixed__].size
def _untransform_params(self, p):
p = p.copy()
if self._has_fixes(): tmp = self._get_params(); tmp[self._fixes_] = p; p = tmp; del tmp
[np.put(p, ind, c.f(p[ind])) for c, ind in self.constraints.iteritems() if c != __fixed__]
return p
def _get_params(self):
# don't overwrite this anymore!
if not self.size:
return np.empty(shape=(0,), dtype=np.float64)
return np.hstack([x._get_params() for x in self._parameters_ if x.size > 0])
class Parameterizable(Constrainable, Observable):
def _set_params(self, params, trigger_parent=True):
# don't overwrite this anymore!
raise NotImplementedError, "This needs to be implemented in Param and Parametrizable"
#===========================================================================
# Optimization handles:
#===========================================================================
def _get_param_names(self):
n = np.array([p.hierarchy_name() + '[' + str(i) + ']' for p in self.flattened_parameters for i in p._indices()])
return n
def _get_param_names_transformed(self):
n = self._get_param_names()
if self._has_fixes():
return n[self._fixes_]
return n
#===========================================================================
# Randomizeable
#===========================================================================
def randomize(self):
"""
Randomize the model.
Make this draw from the prior if one exists, else draw from N(0,1)
"""
import numpy as np
# first take care of all parameters (from N(0,1))
# x = self._get_params_transformed()
x = np.random.randn(self._size_transformed())
x = self._untransform_params(x)
# now draw from prior where possible
[np.put(x, ind, p.rvs(ind.size)) for p, ind in self.priors.iteritems() 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...)
import numpy as np
class Parameterizable(OptimizationHandlable):
def __init__(self, *args, **kwargs):
super(Parameterizable, self).__init__(*args, **kwargs)
from GPy.core.parameterization.array_core import ParamList
_parameters_ = ParamList()
from GPy.core.parameterization.lists_and_dicts import ArrayList
_parameters_ = ArrayList()
self._added_names_ = set()
def parameter_names(self, add_self=False, adjust_for_printing=False, recursive=True):
@ -357,7 +444,7 @@ class Parameterizable(Constrainable, Observable):
if pname in self._added_names_:
del self.__dict__[pname]
self._add_parameter_name(param)
else:
elif pname not in dir(self):
self.__dict__[pname] = param
self._added_names_.add(pname)
@ -377,28 +464,26 @@ class Parameterizable(Constrainable, Observable):
import itertools
[p._collect_gradient(target[s]) for p, s in itertools.izip(self._parameters_, self._param_slices_)]
def _set_params(self, params, trigger_parent=True):
import itertools
[p._set_params(params[s], trigger_parent=False) for p, s in itertools.izip(self._parameters_, self._param_slices_)]
if trigger_parent: min_priority = None
else: min_priority = -np.inf
self._notify_observers(None, min_priority)
def _set_gradient(self, g):
import itertools
[p._set_gradient(g[s]) for p, s in itertools.izip(self._parameters_, self._param_slices_)]
def _get_params(self):
import numpy as np
# don't overwrite this anymore!
if not self.size:
return np.empty(shape=(0,), dtype=np.float64)
return np.hstack([x._get_params() for x in self._parameters_ if x.size > 0])
def _set_params(self, params, update=True):
# don't overwrite this anymore!
import itertools
[p._set_params(params[s]) for p, s in itertools.izip(self._parameters_, self._param_slices_)]
self._notify_parameters_changed()
#===========================================================================
# TODO: not working yet
#===========================================================================
def copy(self):
"""Returns a (deep) copy of the current model"""
import copy
from .index_operations import ParameterIndexOperations, ParameterIndexOperationsView
from .array_core import ParamList
from .lists_and_dicts import ArrayList
dc = dict()
for k, v in self.__dict__.iteritems():
@ -412,7 +497,7 @@ class Parameterizable(Constrainable, Observable):
dc['_direct_parent_'] = None
dc['_parent_index_'] = None
dc['_parameters_'] = ParamList()
dc['_parameters_'] = ArrayList()
dc['constraints'].clear()
dc['priors'].clear()
dc['size'] = 0
@ -424,12 +509,6 @@ class Parameterizable(Constrainable, Observable):
s.add_parameter(p)
return s
def _notify_parameters_changed(self):
self.parameters_changed()
self._notify_observers()
if self.has_parent():
self._direct_parent_._notify_parameters_changed()
def parameters_changed(self):
"""

View file

@ -7,9 +7,9 @@ import cPickle
import itertools
from re import compile, _pattern_type
from param import ParamConcatenation
from parameter_core import Constrainable, Pickleable, Parentable, Observable, Parameterizable, adjust_name_for_printing, Gradcheckable
from parameter_core import Pickleable, Parameterizable, adjust_name_for_printing, Gradcheckable
from transformations import __fixed__
from array_core import ParamList
from lists_and_dicts import ArrayList
class Parameterized(Parameterizable, Pickleable, Gradcheckable):
"""
@ -56,8 +56,9 @@ class Parameterized(Parameterizable, Pickleable, Gradcheckable):
def __init__(self, name=None, *a, **kw):
super(Parameterized, self).__init__(name=name, parent=None, parent_index=None, *a, **kw)
self._in_init_ = True
self._parameters_ = ParamList()
self._parameters_ = ArrayList()
self.size = sum(p.size for p in self._parameters_)
self.add_observer(self, self._parameters_changed_notification, -100)
if not self._has_fixes():
self._fixes_ = None
self._param_slices_ = []
@ -65,7 +66,7 @@ class Parameterized(Parameterizable, Pickleable, Gradcheckable):
del self._in_init_
def build_pydot(self, G=None):
import pydot
import pydot # @UnresolvedImport
iamroot = False
if G is None:
G = pydot.Dot(graph_type='digraph')
@ -104,6 +105,14 @@ class Parameterized(Parameterizable, Pickleable, Gradcheckable):
self.remove_parameter(param)
self.add_parameter(param, index)
elif param not in self._parameters_:
if param.has_parent():
parent = param._direct_parent_
while parent is not None:
if parent is self:
from GPy.core.parameterization.parameter_core import HierarchyError
raise HierarchyError, "You cannot add a parameter twice into the hirarchy"
parent = parent._direct_parent_
param._direct_parent_.remove_parameter(param)
# make sure the size is set
if index is None:
self.constraints.update(param.constraints, self.size)
@ -116,12 +125,16 @@ class Parameterized(Parameterizable, Pickleable, Gradcheckable):
self.constraints.update(param.constraints, start)
self.priors.update(param.priors, start)
self._parameters_.insert(index, param)
param.add_observer(self, self._pass_through_notify_observers, -np.inf)
self.size += param.size
self._connect_parameters()
self._notify_parent_change()
self._connect_fixes()
else:
raise RuntimeError, """Parameter exists already added and no copy made"""
self._connect_parameters()
self._notify_parent_change()
self._connect_fixes()
def add_parameters(self, *parameters):
@ -144,12 +157,19 @@ class Parameterized(Parameterizable, Pickleable, Gradcheckable):
del self._parameters_[param._parent_index_]
param._disconnect_parent()
param.remove_observer(self, self._notify_parameters_changed)
param.remove_observer(self, self._pass_through_notify_observers)
self.constraints.shift_left(start, param.size)
self._connect_fixes()
self._connect_parameters()
self._notify_parent_change()
parent = self._direct_parent_
while parent is not None:
parent._connect_fixes()
parent._connect_parameters()
parent._notify_parent_change()
parent = parent._direct_parent_
def _connect_parameters(self):
# connect parameterlist to this parameterized object
@ -170,6 +190,13 @@ class Parameterized(Parameterizable, Pickleable, Gradcheckable):
self._add_parameter_name(p)
#===========================================================================
# notification system
#===========================================================================
def _parameters_changed_notification(self, which):
self.parameters_changed()
def _pass_through_notify_observers(self, which):
self._notify_observers(which)
#===========================================================================
# Pickling operations
#===========================================================================
def pickle(self, f, protocol=-1):
@ -237,42 +264,7 @@ class Parameterized(Parameterizable, Pickleable, Gradcheckable):
g[self._offset_for(p) + numpy.array(list(i))] += g[self._raveled_index_for(t)]
if self._has_fixes(): return g[self._fixes_]
return g
#===========================================================================
# Optimization handles:
#===========================================================================
def _get_param_names(self):
n = numpy.array([p.hirarchy_name() + '[' + str(i) + ']' for p in self.flattened_parameters for i in p._indices()])
return n
def _get_param_names_transformed(self):
n = self._get_param_names()
if self._has_fixes():
return n[self._fixes_]
return n
def _get_params_transformed(self):
# transformed parameters (apply transformation rules)
p = self._get_params()
[numpy.put(p, ind, c.finv(p[ind])) for c, ind in self.constraints.iteritems() if c != __fixed__]
if self._has_fixes():
return p[self._fixes_]
return p
def _set_params_transformed(self, p):
# inverse apply transformations for parameters and set the resulting parameters
self._set_params(self._untransform_params(p))
def _untransform_params(self, p):
p = p.copy()
if self._has_fixes(): tmp = self._get_params(); tmp[self._fixes_] = p; p = tmp; del tmp
[numpy.put(p, ind, c.f(p[ind])) for c, ind in self.constraints.iteritems() if c != __fixed__]
return p
#===========================================================================
# Indexable Handling
#===========================================================================
def _backtranslate_index(self, param, ind):
# translate an index in parameterized indexing into the index of param
ind = ind - self._offset_for(param)
ind = ind[ind >= 0]
internal_offset = param._internal_offset()
ind = ind[ind < param.size + internal_offset]
return ind
def _offset_for(self, param):
# get the offset in the parameterized index array for param
if param.has_parent():
@ -297,34 +289,22 @@ class Parameterized(Parameterizable, Pickleable, Gradcheckable):
this is not in the global view of things!
"""
return numpy.r_[:self.size]
#===========================================================================
# Fixing parameters:
#===========================================================================
def _fixes_for(self, param):
if self._has_fixes():
return self._fixes_[self._raveled_index_for(param)]
return numpy.ones(self.size, dtype=bool)[self._raveled_index_for(param)]
#===========================================================================
# Convenience for fixed, tied checking of param:
#===========================================================================
def fixed_indices(self):
return np.array([x.is_fixed for x in self._parameters_])
def _is_fixed(self, param):
# returns if the whole param is fixed
if not self._has_fixes():
return False
return not self._fixes_[self._raveled_index_for(param)].any()
# return not self._fixes_[self._offset_for(param): self._offset_for(param)+param._realsize_].any()
@property
def is_fixed(self):
for p in self._parameters_:
if not p.is_fixed: return False
return True
def _get_original(self, param):
# if advanced indexing is activated it happens that the array is a copy
# you can retrieve the original param through this method, by passing
# the copy here
return self._parameters_[param._parent_index_]
#===========================================================================
# Get/set parameters:
#===========================================================================
@ -365,7 +345,7 @@ class Parameterized(Parameterizable, Pickleable, Gradcheckable):
# Printing:
#===========================================================================
def _short(self):
return self.hirarchy_name()
return self.hierarchy_name()
@property
def flattened_parameters(self):
return [xi for x in self._parameters_ for xi in x.flattened_parameters]
@ -373,11 +353,6 @@ class Parameterized(Parameterizable, Pickleable, Gradcheckable):
def _parameter_sizes_(self):
return [x.size for x in self._parameters_]
@property
def size_transformed(self):
if self._has_fixes():
return sum(self._fixes_)
return self.size
@property
def parameter_shapes(self):
return [xi for x in self._parameters_ for xi in x.parameter_shapes]
@property

View file

@ -64,6 +64,36 @@ class Gaussian(Prior):
return np.random.randn(n) * self.sigma + self.mu
class Uniform(Prior):
domain = _REAL
_instances = []
def __new__(cls, lower, upper): # Singleton:
if cls._instances:
cls._instances[:] = [instance for instance in cls._instances if instance()]
for instance in cls._instances:
if instance().lower == lower and instance().upper == upper:
return instance()
o = super(Prior, cls).__new__(cls, lower, upper)
cls._instances.append(weakref.ref(o))
return cls._instances[-1]()
def __init__(self, lower, upper):
self.lower = float(lower)
self.upper = float(upper)
def __str__(self):
return "[" + str(np.round(self.lower)) + ', ' + str(np.round(self.upper)) + ']'
def lnpdf(self, x):
region = (x>=self.lower) * (x<=self.upper)
return region
def lnpdf_grad(self, x):
return np.zeros(x.shape)
def rvs(self, n):
return np.random.uniform(self.lower, self.upper, size=n)
class LogGaussian(Prior):
"""
Implementation of the univariate *log*-Gaussian probability function, coupled with random variables.

View file

@ -6,8 +6,11 @@ import numpy as np
from domains import _POSITIVE,_NEGATIVE, _BOUNDED
import weakref
import sys
#_lim_val = -np.log(sys.float_info.epsilon)
_exp_lim_val = np.finfo(np.float64).max
_lim_val = np.log(_exp_lim_val)#-np.log(sys.float_info.epsilon)
_lim_val = np.log(_exp_lim_val)#
#===============================================================================
# Fixing constants
@ -35,7 +38,6 @@ class Transformation(object):
""" produce a sensible initial value for f(x)"""
raise NotImplementedError
def plot(self, xlabel=r'transformed $\theta$', ylabel=r'$\theta$', axes=None, *args,**kw):
import sys
assert "matplotlib" in sys.modules, "matplotlib package has not been imported."
import matplotlib.pyplot as plt
from ...plotting.matplot_dep import base_plots
@ -52,7 +54,7 @@ class Transformation(object):
class Logexp(Transformation):
domain = _POSITIVE
def f(self, x):
return np.where(x>_lim_val, x, np.log(1. + np.exp(np.clip(x, -np.inf, _lim_val))))
return np.where(x>_lim_val, x, np.log(1. + np.exp(np.clip(x, -_lim_val, _lim_val))))
#raises overflow warning: return np.where(x>_lim_val, x, np.log(1. + np.exp(x)))
def finv(self, f):
return np.where(f>_lim_val, f, np.log(np.exp(f) - 1.))

View file

@ -85,11 +85,11 @@ class SparseGP(GP):
self.Z.gradient = self.kern.gradients_X(self.grad_dict['dL_dKmm'], self.Z)
self.Z.gradient += self.kern.gradients_X(self.grad_dict['dL_dKnm'].T, self.Z, self.X)
def _raw_predict(self, Xnew, X_variance_new=None, full_cov=False):
def _raw_predict(self, Xnew, full_cov=False):
"""
Make a prediction for the latent function values
"""
if X_variance_new is None:
if not isinstance(Xnew, VariationalPosterior):
Kx = self.kern.K(self.Z, Xnew)
mu = np.dot(Kx.T, self.posterior.woodbury_vector)
if full_cov:
@ -100,13 +100,13 @@ class SparseGP(GP):
Kxx = self.kern.Kdiag(Xnew)
var = (Kxx - np.sum(np.dot(np.atleast_3d(self.posterior.woodbury_inv).T, Kx) * Kx[None,:,:], 1)).T
else:
Kx = self.kern.psi1(self.Z, Xnew, X_variance_new)
mu = np.dot(Kx, self.Cpsi1V)
Kx = self.kern.psi1(self.Z, Xnew)
mu = np.dot(Kx, self.posterior.woodbury_vector)
if full_cov:
raise NotImplementedError, "TODO"
else:
Kxx = self.kern.psi0(self.Z, Xnew, X_variance_new)
psi2 = self.kern.psi2(self.Z, Xnew, X_variance_new)
Kxx = self.kern.psi0(self.Z, Xnew)
psi2 = self.kern.psi2(self.Z, Xnew)
var = Kxx - np.sum(np.sum(psi2 * Kmmi_LmiBLmi[None, :, :], 1), 1)
return mu, var

View file

@ -187,10 +187,10 @@ def _simulate_sincos(D1, D2, D3, N, num_inducing, Q, plot_sim=False):
_np.random.seed(1234)
x = _np.linspace(0, 4 * _np.pi, N)[:, None]
s1 = _np.vectorize(lambda x: -_np.sin(_np.exp(x)))
s1 = _np.vectorize(lambda x: _np.sin(x))
s2 = _np.vectorize(lambda x: _np.cos(x)**2)
s3 = _np.vectorize(lambda x:-_np.exp(-_np.cos(2 * x)))
sS = _np.vectorize(lambda x: x*_np.sin(x))
sS = _np.vectorize(lambda x: _np.cos(x))
s1 = s1(x)
s2 = s2(x)
@ -202,7 +202,7 @@ def _simulate_sincos(D1, D2, D3, N, num_inducing, Q, plot_sim=False):
s3 -= s3.mean(); s3 /= s3.std(0)
sS -= sS.mean(); sS /= sS.std(0)
S1 = _np.hstack([s1, s2, sS])
S1 = _np.hstack([s1, sS])
S2 = _np.hstack([s2, s3, sS])
S3 = _np.hstack([s3, sS])
@ -270,7 +270,7 @@ def bgplvm_simulation(optimize=True, verbose=1,
from GPy import kern
from GPy.models import BayesianGPLVM
D1, D2, D3, N, num_inducing, Q = 13, 5, 8, 45, 5, 9
D1, D2, D3, N, num_inducing, Q = 13, 5, 8, 45, 3, 9
_, _, Ylist = _simulate_sincos(D1, D2, D3, N, num_inducing, Q, plot_sim)
Y = Ylist[0]
k = kern.Linear(Q, ARD=True)# + kern.white(Q, _np.exp(-2)) # + kern.bias(Q)
@ -294,7 +294,7 @@ def bgplvm_simulation_missing_data(optimize=True, verbose=1,
from GPy.models import BayesianGPLVM
from GPy.inference.latent_function_inference.var_dtc import VarDTCMissingData
D1, D2, D3, N, num_inducing, Q = 13, 5, 8, 45, 5, 9
D1, D2, D3, N, num_inducing, Q = 13, 5, 8, 45, 7, 9
_, _, Ylist = _simulate_sincos(D1, D2, D3, N, num_inducing, Q, plot_sim)
Y = Ylist[0]
k = kern.Linear(Q, ARD=True)# + kern.white(Q, _np.exp(-2)) # + kern.bias(Q)

View file

@ -60,8 +60,7 @@ class VarDTC(object):
_, output_dim = Y.shape
#see whether we've got a different noise variance for each datum
beta = 1./np.squeeze(likelihood.variance)
beta = 1./np.fmax(likelihood.variance, 1e-6)
# VVT_factor is a matrix such that tdot(VVT_factor) = VVT...this is for efficiency!
#self.YYTfactor = self.get_YYTfactor(Y)
#VVT_factor = self.get_VVTfactor(self.YYTfactor, beta)
@ -214,7 +213,7 @@ class VarDTCMissingData(object):
psi2_all = None
Ys, traces = self._Y(Y)
beta_all = 1./likelihood.variance
beta_all = 1./np.fmax(likelihood.variance, 1e-6)
het_noise = beta_all.size != 1
import itertools

View file

@ -112,10 +112,12 @@ class Kern(Parameterized):
"""
assert isinstance(other, Kern), "only kernels can be added to kernels..."
from add import Add
return Add([self, other], tensor)
def __call__(self, X, X2=None):
return self.K(X, X2)
kernels = []
if not tensor and isinstance(self, Add): kernels.extend(self._parameters_)
else: kernels.append(self)
if not tensor and isinstance(other, Add): kernels.extend(other._parameters_)
else: kernels.append(other)
return Add(kernels, tensor)
def __mul__(self, other):
""" Here we overload the '*' operator. See self.prod for more information"""

View file

@ -20,7 +20,7 @@ class RBF(Stationary):
"""
def __init__(self, input_dim, variance=1., lengthscale=None, ARD=False, name='RBF'):
def __init__(self, input_dim, variance=1., lengthscale=None, ARD=False, name='rbf'):
super(RBF, self).__init__(input_dim, variance, lengthscale, ARD, name)
self.weave_options = {}
@ -48,7 +48,7 @@ class RBF(Stationary):
if isinstance(variational_posterior, variational.SpikeAndSlabPosterior):
psi2, _, _, _, _, _, _ = ssrbf_psi_comp._psi2computations(self.variance, self.lengthscale, Z, variational_posterior.mean, variational_posterior.variance, variational_posterior.binary_prob)
else:
_, _, _, _, _, psi2 = self._psi2computations(Z, variational_posterior)
_, _, _, _, psi2 = self._psi2computations(Z, variational_posterior)
return psi2
def update_gradients_expectations(self, dL_dpsi0, dL_dpsi1, dL_dpsi2, Z, variational_posterior):
@ -70,37 +70,39 @@ class RBF(Stationary):
self.lengthscale.gradient += (dL_dpsi2[:,:,:,None] * _dpsi2_dlengthscale).reshape(-1,self.input_dim).sum(axis=0)
return
l2 = self.lengthscale **2
elif isinstance(variational_posterior, variational.NormalPosterior):
l2 = self.lengthscale **2
#contributions from psi0:
self.variance.gradient = np.sum(dL_dpsi0)
self.lengthscale.gradient = 0.
#contributions from psi0:
self.variance.gradient = np.sum(dL_dpsi0)
self.lengthscale.gradient = 0.
#from psi1
denom, _, dist_sq, psi1 = self._psi1computations(Z, variational_posterior)
d_length = psi1[:,:,None] * ((dist_sq - 1.)/(self.lengthscale*denom) +1./self.lengthscale)
dpsi1_dlength = d_length * dL_dpsi1[:, :, None]
if self.ARD:
self.lengthscale.gradient += dpsi1_dlength.sum(0).sum(0)
else:
self.lengthscale.gradient += dpsi1_dlength.sum()
self.variance.gradient += np.sum(dL_dpsi1 * psi1) / self.variance
#from psi2
S = variational_posterior.variance
_, Zdist_sq, _, mudist_sq, psi2 = self._psi2computations(Z, variational_posterior)
d_length = 2.*psi2[:, :, :, None] * (Zdist_sq * (2.*S[:,None,None,:]/l2 + 1.) + mudist_sq + S[:, None, None, :] / l2) / (2.*S[:,None,None,:] + l2)*self.lengthscale
dpsi2_dlength = d_length * dL_dpsi2[:, :, :, None]
if not self.ARD:
self.lengthscale.gradient += dpsi2_dlength.sum()
else:
self.lengthscale.gradient += dpsi2_dlength.sum(0).sum(0).sum(0)
self.variance.gradient += 2.*np.sum(dL_dpsi2 * psi2)/self.variance
#from psi1
denom, _, dist_sq, psi1 = self._psi1computations(Z, variational_posterior)
d_length = psi1[:,:,None] * ((dist_sq - 1.)/(self.lengthscale*denom) +1./self.lengthscale)
dpsi1_dlength = d_length * dL_dpsi1[:, :, None]
if not self.ARD:
self.lengthscale.gradient += dpsi1_dlength.sum()
else:
self.lengthscale.gradient += dpsi1_dlength.sum(0).sum(0)
self.variance.gradient += np.sum(dL_dpsi1 * psi1) / self.variance
#from psi2
S = variational_posterior.variance
denom, _, Zdist_sq, _, mudist_sq, psi2 = self._psi2computations(Z, variational_posterior)
d_length = 2.*psi2[:, :, :, None] * (Zdist_sq * denom + mudist_sq + S[:, None, None, :] / l2) / (self.lengthscale * denom)
#TODO: combine denom and l2 as denom_l2??
#TODO: tidy the above!
#TODO: tensordot below?
dpsi2_dlength = d_length * dL_dpsi2[:, :, :, None]
if not self.ARD:
self.lengthscale.gradient += dpsi2_dlength.sum()
else:
self.lengthscale.gradient += dpsi2_dlength.sum(0).sum(0).sum(0)
self.variance.gradient += 2.*np.sum(dL_dpsi2 * psi2)/self.variance
raise ValueError, "unknown distriubtion received for psi-statistics"
def gradients_Z_expectations(self, dL_dpsi1, dL_dpsi2, Z, variational_posterior):
# Spike-and-Slab GPLVM
@ -115,23 +117,26 @@ class RBF(Stationary):
grad += (dL_dpsi2[:, :, :, None] * _dpsi2_dZ).sum(axis=0).sum(axis=1)
return grad
l2 = self.lengthscale **2
#psi1
denom, dist, dist_sq, psi1 = self._psi1computations(Z, variational_posterior)
denominator = l2 * denom
dpsi1_dZ = -psi1[:, :, None] * (dist / denominator)
grad = np.sum(dL_dpsi1[:, :, None] * dpsi1_dZ, 0)
elif isinstance(variational_posterior, variational.NormalPosterior):
l2 = self.lengthscale **2
#psi2
denom, Zdist, Zdist_sq, mudist, mudist_sq, psi2 = self._psi2computations(Z, variational_posterior)
term1 = Zdist / l2 # M, M, Q
term2 = mudist / denom / l2 # N, M, M, Q
dZ = psi2[:, :, :, None] * (term1[None, :, :, :] + term2) #N,M,M,Q
grad += 2*(dL_dpsi2[:, :, :, None] * dZ).sum(0).sum(0)
#psi1
denom, dist, dist_sq, psi1 = self._psi1computations(Z, variational_posterior)
grad = np.einsum('ij,ij,ijk,ijk->jk', dL_dpsi1, psi1, dist, -1./(denom*l2))
return grad
#psi2
Zdist, Zdist_sq, mudist, mudist_sq, psi2 = self._psi2computations(Z, variational_posterior)
term1 = Zdist / l2 # M, M, Q
S = variational_posterior.variance
term2 = mudist / (2.*S[:,None,None,:] + l2) # N, M, M, Q
grad += 2.*np.einsum('ijk,ijk,ijkl->kl', dL_dpsi2, psi2, term1[None,:,:,:] + term2)
return grad
else:
raise ValueError, "unknown distriubtion received for psi-statistics"
def gradients_qX_expectations(self, dL_dpsi0, dL_dpsi1, dL_dpsi2, Z, variational_posterior):
# Spike-and-Slab GPLVM
@ -151,18 +156,24 @@ class RBF(Stationary):
grad_gamma += (dL_dpsi2[:,:,:, None] * _dpsi2_dgamma).reshape(ndata,-1,self.input_dim).sum(axis=1)
return grad_mu, grad_S, grad_gamma
elif isinstance(variational_posterior, variational.NormalPosterior):
l2 = self.lengthscale **2
#psi1
denom, dist, dist_sq, psi1 = self._psi1computations(Z, variational_posterior)
tmp = psi1[:, :, None] / l2 / denom
grad_mu = np.sum(dL_dpsi1[:, :, None] * tmp * dist, 1)
grad_S = np.sum(dL_dpsi1[:, :, None] * 0.5 * tmp * (dist_sq - 1), 1)
#psi2
denom, Zdist, Zdist_sq, mudist, mudist_sq, psi2 = self._psi2computations(Z, variational_posterior)
tmp = psi2[:, :, :, None] / l2 / denom
grad_mu += -2.*(dL_dpsi2[:, :, :, None] * tmp * mudist).sum(1).sum(1)
grad_S += (dL_dpsi2[:, :, :, None] * tmp * (2.*mudist_sq - 1)).sum(1).sum(1)
l2 = self.lengthscale **2
#psi1
denom, dist, dist_sq, psi1 = self._psi1computations(Z, variational_posterior)
tmp = psi1[:, :, None] / l2 / denom
grad_mu = np.sum(dL_dpsi1[:, :, None] * tmp * dist, 1)
grad_S = np.sum(dL_dpsi1[:, :, None] * 0.5 * tmp * (dist_sq - 1), 1)
#psi2
_, _, mudist, mudist_sq, psi2 = self._psi2computations(Z, variational_posterior)
S = variational_posterior.variance
tmp = psi2[:, :, :, None] / (2.*S[:,None,None,:] + l2)
grad_mu += -2.*np.einsum('ijk,ijkl,ijkl->il', dL_dpsi2, tmp , mudist)
grad_S += np.einsum('ijk,ijkl,ijkl->il', dL_dpsi2 , tmp , (2.*mudist_sq - 1))
else:
raise ValueError, "unknown distriubtion received for psi-statistics"
return grad_mu, grad_S
@ -170,61 +181,6 @@ class RBF(Stationary):
# Precomputations #
#---------------------------------------#
#TODO: this function is unused, but it will be useful in the stationary class
def _dL_dlengthscales_via_K(self, dL_dK, X, X2):
"""
A helper function for update_gradients_* methods
Computes the derivative of the objective L wrt the lengthscales via
dL_dl = sum_{i,j}(dL_dK_{ij} dK_dl)
assumes self._K_computations has just been called.
This is only valid if self.ARD=True
"""
target = np.zeros(self.input_dim)
dvardLdK = self._K_dvar * dL_dK
var_len3 = self.variance / np.power(self.lengthscale, 3)
if X2 is None:
# save computation for the symmetrical case
dvardLdK = dvardLdK + dvardLdK.T
code = """
int q,i,j;
double tmp;
for(q=0; q<input_dim; q++){
tmp = 0;
for(i=0; i<num_data; i++){
for(j=0; j<i; j++){
tmp += (X(i,q)-X(j,q))*(X(i,q)-X(j,q))*dvardLdK(i,j);
}
}
target(q) += var_len3(q)*tmp;
}
"""
num_data, num_inducing, input_dim = X.shape[0], X.shape[0], self.input_dim
X, dvardLdK, var_len3 = param_to_array(X, dvardLdK, var_len3)
weave.inline(code, arg_names=['num_data', 'num_inducing', 'input_dim', 'X', 'target', 'dvardLdK', 'var_len3'], type_converters=weave.converters.blitz, **self.weave_options)
else:
code = """
int q,i,j;
double tmp;
for(q=0; q<input_dim; q++){
tmp = 0;
for(i=0; i<num_data; i++){
for(j=0; j<num_inducing; j++){
tmp += (X(i,q)-X2(j,q))*(X(i,q)-X2(j,q))*dvardLdK(i,j);
}
}
target(q) += var_len3(q)*tmp;
}
"""
num_data, num_inducing, input_dim = X.shape[0], X2.shape[0], self.input_dim
X, X2, dvardLdK, var_len3 = param_to_array(X, X2, dvardLdK, var_len3)
weave.inline(code, arg_names=['num_data', 'num_inducing', 'input_dim', 'X', 'X2', 'target', 'dvardLdK', 'var_len3'], type_converters=weave.converters.blitz, **self.weave_options)
return target
@Cache_this(limit=1)
def _psi1computations(self, Z, vp):
mu, S = vp.mean, vp.variance
@ -237,7 +193,7 @@ class RBF(Stationary):
return denom, dist, dist_sq, psi1
#@cache_this(ignore_args=(1,))
@Cache_this(limit=1, ignore_args=(0,))
def _Z_distances(self, Z):
Zhat = 0.5 * (Z[:, None, :] + Z[None, :, :]) # M,M,Q
Zdist = 0.5 * (Z[:, None, :] - Z[None, :, :]) # M,M,Q
@ -309,8 +265,4 @@ class RBF(Stationary):
arg_names=['N', 'M', 'Q', 'mu', 'Zhat', 'mudist_sq', 'mudist', 'denom_l2', 'Zdist_sq', 'half_log_denom', 'psi2', 'variance_sq'],
type_converters=weave.converters.blitz, **self.weave_options)
return denom, Zdist, Zdist_sq, mudist, mudist_sq, psi2
def input_sensitivity(self):
if self.ARD: return 1./self.lengthscale
else: return (1./self.lengthscale).repeat(self.input_dim)
return Zdist, Zdist_sq, mudist, mudist_sq, psi2

View file

@ -12,6 +12,35 @@ from scipy import integrate
from ...util.caching import Cache_this
class Stationary(Kern):
"""
Stationary kernels (covariance functions).
Stationary covariance fucntion depend only on r, where r is defined as
r = \sqrt{ \sum_{q=1}^Q (x_q - x'_q)^2 }
The covariance function k(x, x' can then be written k(r).
In this implementation, r is scaled by the lengthscales parameter(s):
r = \sqrt{ \sum_{q=1}^Q \frac{(x_q - x'_q)^2}{\ell_q^2} }.
By default, there's only one lengthscale: seaprate lengthscales for each
dimension can be enables by setting ARD=True.
To implement a stationary covariance function using this class, one need
only define the covariance function k(r), and it derivative.
...
def K_of_r(self, r):
return foo
def dK_dr(self, r):
return bar
The lengthscale(s) and variance parameters are added to the structure automatically.
"""
def __init__(self, input_dim, variance, lengthscale, ARD, name):
super(Stationary, self).__init__(input_dim, name)
self.ARD = ARD
@ -20,11 +49,11 @@ class Stationary(Kern):
lengthscale = np.ones(1)
else:
lengthscale = np.asarray(lengthscale)
assert lengthscale.size == 1, "Only lengthscale needed for non-ARD kernel"
assert lengthscale.size == 1, "Only 1 lengthscale needed for non-ARD kernel"
else:
if lengthscale is not None:
lengthscale = np.asarray(lengthscale)
assert lengthscale.size in [1, input_dim], "Bad lengthscales"
assert lengthscale.size in [1, input_dim], "Bad number of lengthscales"
if lengthscale.size != input_dim:
lengthscale = np.ones(input_dim)*lengthscale
else:
@ -35,26 +64,25 @@ class Stationary(Kern):
self.add_parameters(self.variance, self.lengthscale)
def K_of_r(self, r):
raise NotImplementedError, "implement the covaraiance function as a fn of r to use this class"
raise NotImplementedError, "implement the covariance function as a fn of r to use this class"
def dK_dr(self, r):
raise NotImplementedError, "implement the covaraiance function as a fn of r to use this class"
raise NotImplementedError, "implement derivative of the covariance function wrt r to use this class"
#@Cache_this(limit=5, ignore_args=())
@Cache_this(limit=5, ignore_args=())
def K(self, X, X2=None):
r = self._scaled_dist(X, X2)
return self.K_of_r(r)
#@Cache_this(limit=5, ignore_args=(0,))
def _dist(self, X, X2):
if X2 is None:
X2 = X
return X[:, None, :] - X2[None, :, :]
@Cache_this(limit=3, ignore_args=())
def dK_dr_via_X(self, X, X2):
#a convenience function, so we can cache dK_dr
return self.dK_dr(self._scaled_dist(X, X2))
#@Cache_this(limit=5, ignore_args=(0,))
@Cache_this(limit=5, ignore_args=(0,))
def _unscaled_dist(self, X, X2=None):
"""
Compute the square distance between each row of X and X2, or between
Compute the Euclidean distance between each row of X and X2, or between
each pair of rows of X if X2 is None.
"""
if X2 is None:
@ -65,12 +93,12 @@ class Stationary(Kern):
X2sq = np.sum(np.square(X2),1)
return np.sqrt(-2.*np.dot(X, X2.T) + (X1sq[:,None] + X2sq[None,:]))
#@Cache_this(limit=5, ignore_args=())
@Cache_this(limit=5, ignore_args=())
def _scaled_dist(self, X, X2=None):
"""
Efficiently compute the scaled distance, r.
r = \sum_{q=1}^Q (x_q - x'q)^2/l_q^2
r = \sqrt( \sum_{q=1}^Q (x_q - x'q)^2/l_q^2 )
Note that if thre is only one lengthscale, l comes outside the sum. In
this case we compute the unscaled distance first (in a separate
@ -84,7 +112,6 @@ class Stationary(Kern):
else:
return self._unscaled_dist(X, X2)/self.lengthscale
def Kdiag(self, X):
ret = np.empty(X.shape[0])
ret[:] = self.variance
@ -95,20 +122,23 @@ class Stationary(Kern):
self.lengthscale.gradient = 0.
def update_gradients_full(self, dL_dK, X, X2=None):
r = self._scaled_dist(X, X2)
K = self.K_of_r(r)
rinv = self._inv_dist(X, X2)
dL_dr = self.dK_dr(r) * dL_dK
self.variance.gradient = np.einsum('ij,ij,i', self.K(X, X2), dL_dK, 1./self.variance)
#now the lengthscale gradient(s)
dL_dr = self.dK_dr_via_X(X, X2) * dL_dK
if self.ARD:
x_xl3 = np.square(self._dist(X, X2)) / self.lengthscale**3
self.lengthscale.gradient = -((dL_dr*rinv)[:,:,None]*x_xl3).sum(0).sum(0)
#rinv = self._inv_dis# this is rather high memory? Should we loop instead?t(X, X2)
#d = X[:, None, :] - X2[None, :, :]
#x_xl3 = np.square(d)
#self.lengthscale.gradient = -((dL_dr*rinv)[:,:,None]*x_xl3).sum(0).sum(0)/self.lengthscale**3
tmp = dL_dr*self._inv_dist(X, X2)
if X2 is None: X2 = X
self.lengthscale.gradient = np.array([np.einsum('ij,ij,...', tmp, np.square(X[:,q:q+1] - X2[:,q:q+1].T), -1./self.lengthscale[q]**3) for q in xrange(self.input_dim)])
else:
x_xl3 = np.square(self._dist(X, X2)) / self.lengthscale**3
self.lengthscale.gradient = -((dL_dr*rinv)[:,:,None]*x_xl3).sum()
r = self._scaled_dist(X, X2)
self.lengthscale.gradient = -np.sum(dL_dr*r)/self.lengthscale
self.variance.gradient = np.sum(K * dL_dK)/self.variance
def _inv_dist(self, X, X2=None):
"""
@ -116,7 +146,7 @@ class Stationary(Kern):
diagonal, where we return zero (the distance on the diagonal is zero).
This term appears in derviatives.
"""
dist = self._scaled_dist(X, X2)
dist = self._scaled_dist(X, X2).copy()
if X2 is None:
nondiag = util.diag.offdiag_view(dist)
nondiag[:] = 1./nondiag
@ -128,10 +158,11 @@ class Stationary(Kern):
"""
Given the derivative of the objective wrt K (dL_dK), compute the derivative wrt X
"""
r = self._scaled_dist(X, X2)
invdist = self._inv_dist(X, X2)
dL_dr = self.dK_dr(r) * dL_dK
#The high-memory numpy way: ret = np.sum((invdist*dL_dr)[:,:,None]*self._dist(X, X2),1)/self.lengthscale**2
dL_dr = self.dK_dr_via_X(X, X2) * dL_dK
#The high-memory numpy way:
#d = X[:, None, :] - X2[None, :, :]
#ret = np.sum((invdist*dL_dr)[:,:,None]*d,1)/self.lengthscale**2
#if X2 is None:
#ret *= 2.
@ -141,7 +172,7 @@ class Stationary(Kern):
tmp *= 2.
X2 = X
ret = np.empty(X.shape, dtype=np.float64)
[np.copyto(ret[:,q], np.sum(tmp*(X[:,q][:,None]-X2[:,q][None,:]), 1)) for q in xrange(self.input_dim)]
[np.einsum('ij,ij->i', tmp, X[:,q][:,None]-X2[:,q][None,:], out=ret[:,q]) for q in xrange(self.input_dim)]
ret /= self.lengthscale**2
return ret
@ -214,7 +245,7 @@ class Matern52(Stationary):
.. math::
k(r) = \sigma^2 (1 + \sqrt{5} r + \\frac53 r^2) \exp(- \sqrt{5} r) \ \ \ \ \ \\text{ where } r = \sqrt{\sum_{i=1}^input_dim \\frac{(x_i-y_i)^2}{\ell_i^2} }
k(r) = \sigma^2 (1 + \sqrt{5} r + \\frac53 r^2) \exp(- \sqrt{5} r)
"""
def __init__(self, input_dim, variance=1., lengthscale=None, ARD=False, name='Mat52'):
super(Matern52, self).__init__(input_dim, variance, lengthscale, ARD, name)
@ -225,7 +256,7 @@ class Matern52(Stationary):
def dK_dr(self, r):
return self.variance*(10./3*r -5.*r -5.*np.sqrt(5.)/3*r**2)*np.exp(-np.sqrt(5.)*r)
def Gram_matrix(self,F,F1,F2,F3,lower,upper):
def Gram_matrix(self, F, F1, F2, F3, lower, upper):
"""
Return the Gram matrix of the vector of functions F with respect to the RKHS norm. The use of this function is limited to input_dim=1.

View file

@ -8,7 +8,7 @@ from .. import likelihoods
from .. import kern
from ..inference.latent_function_inference import VarDTC
from ..util.misc import param_to_array
from ..core.parameterization.variational import VariationalPosterior
from ..core.parameterization.variational import NormalPosterior
class SparseGPRegression(SparseGP):
"""
@ -47,7 +47,7 @@ class SparseGPRegression(SparseGP):
likelihood = likelihoods.Gaussian()
if not (X_variance is None):
X = VariationalPosterior(X,X_variance)
X = NormalPosterior(X,X_variance)
SparseGP.__init__(self, X, Y, Z, kernel, likelihood, inference_method=VarDTC())

View file

@ -56,10 +56,13 @@ def plot_fit(model, plot_limits=None, which_data_rows='all',
if ax is None:
fig = pb.figure(num=fignum)
ax = fig.add_subplot(111)
X, Y = param_to_array(model.X, model.Y)
if hasattr(model, 'has_uncertain_inputs') and model.has_uncertain_inputs(): X_variance = model.X_variance
if hasattr(model, 'has_uncertain_inputs') and model.has_uncertain_inputs():
X = model.X.mean
X_variance = param_to_array(model.X.variance)
else:
X = model.X
X, Y = param_to_array(X, model.Y)
if hasattr(model, 'Z'): Z = param_to_array(model.Z)
#work out what the inputs are for plotting (1D or 2D)
@ -98,10 +101,10 @@ def plot_fit(model, plot_limits=None, which_data_rows='all',
#add error bars for uncertain (if input uncertainty is being modelled)
#if hasattr(model,"has_uncertain_inputs") and model.has_uncertain_inputs():
# ax.errorbar(X[which_data_rows, free_dims].flatten(), Y[which_data_rows, which_data_ycols].flatten(),
# xerr=2 * np.sqrt(X_variance[which_data_rows, free_dims].flatten()),
# ecolor='k', fmt=None, elinewidth=.5, alpha=.5)
if hasattr(model,"has_uncertain_inputs") and model.has_uncertain_inputs():
ax.errorbar(X[which_data_rows, free_dims].flatten(), Y[which_data_rows, which_data_ycols].flatten(),
xerr=2 * np.sqrt(X_variance[which_data_rows, free_dims].flatten()),
ecolor='k', fmt=None, elinewidth=.5, alpha=.5)
#set the limits of the plot to some sensible values

View file

@ -0,0 +1,133 @@
'''
Created on 27 Feb 2014
@author: maxz
'''
import unittest
from GPy.core.parameterization.parameterized import Parameterized
from GPy.core.parameterization.param import Param
import numpy
class ParamTestParent(Parameterized):
parent_changed_count = 0
def parameters_changed(self):
self.parent_changed_count += 1
class ParameterizedTest(Parameterized):
params_changed_count = 0
def parameters_changed(self):
self.params_changed_count += 1
def _set_params(self, params, trigger_parent=True):
Parameterized._set_params(self, params, trigger_parent=trigger_parent)
class Test(unittest.TestCase):
def setUp(self):
self.parent = ParamTestParent('test parent')
self.par = ParameterizedTest('test model')
self.par2 = ParameterizedTest('test model 2')
self.p = Param('test parameter', numpy.random.normal(1,2,(10,3)))
self.par.add_parameter(self.p)
self.par.add_parameter(Param('test1', numpy.random.normal(0,1,(1,))))
self.par.add_parameter(Param('test2', numpy.random.normal(0,1,(1,))))
self.par2.add_parameter(Param('par2 test1', numpy.random.normal(0,1,(1,))))
self.par2.add_parameter(Param('par2 test2', numpy.random.normal(0,1,(1,))))
self.parent.add_parameter(self.par)
self.parent.add_parameter(self.par2)
self._observer_triggered = None
self._trigger_count = 0
self._first = None
self._second = None
def _trigger(self, which):
self._observer_triggered = float(which)
self._trigger_count += 1
if self._first is not None:
self._second = self._trigger
else:
self._first = self._trigger
def _trigger_priority(self, which):
if self._first is not None:
self._second = self._trigger_priority
else:
self._first = self._trigger_priority
def test_observable(self):
self.par.add_observer(self, self._trigger, -1)
self.assertEqual(self.par.params_changed_count, 0, 'no params changed yet')
self.assertEqual(self.par.params_changed_count, self.parent.parent_changed_count, 'parent should be triggered as often as param')
self.p[0,1] = 3 # trigger observers
self.assertEqual(self._observer_triggered, 3, 'observer should have triggered')
self.assertEqual(self._trigger_count, 1, 'observer should have triggered once')
self.assertEqual(self.par.params_changed_count, 1, 'params changed once')
self.assertEqual(self.par.params_changed_count, self.parent.parent_changed_count, 'parent should be triggered as often as param')
self.par.remove_observer(self)
self.p[2,1] = 4
self.assertEqual(self._observer_triggered, 3, 'observer should not have triggered')
self.assertEqual(self._trigger_count, 1, 'observer should have triggered once')
self.assertEqual(self.par.params_changed_count, 2, 'params changed second')
self.assertEqual(self.par.params_changed_count, self.parent.parent_changed_count, 'parent should be triggered as often as param')
self.par.add_observer(self, self._trigger, -1)
self.p[2,1] = 4
self.assertEqual(self._observer_triggered, 4, 'observer should have triggered')
self.assertEqual(self._trigger_count, 2, 'observer should have triggered once')
self.assertEqual(self.par.params_changed_count, 3, 'params changed second')
self.assertEqual(self.par.params_changed_count, self.parent.parent_changed_count, 'parent should be triggered as often as param')
self.par.remove_observer(self, self._trigger)
self.p[0,1] = 3
self.assertEqual(self._observer_triggered, 4, 'observer should not have triggered')
self.assertEqual(self._trigger_count, 2, 'observer should have triggered once')
self.assertEqual(self.par.params_changed_count, 4, 'params changed second')
self.assertEqual(self.par.params_changed_count, self.parent.parent_changed_count, 'parent should be triggered as often as param')
def test_set_params(self):
self.assertEqual(self.par.params_changed_count, 0, 'no params changed yet')
self.par._set_params(numpy.ones(self.par.size))
self.assertEqual(self.par.params_changed_count, 1, 'now params changed')
self.assertEqual(self.parent.parent_changed_count, self.par.params_changed_count)
self.parent._set_params(numpy.ones(self.parent.size) * 2)
self.assertEqual(self.par.params_changed_count, 2, 'now params changed')
self.assertEqual(self.parent.parent_changed_count, self.par.params_changed_count)
def test_priority_notify(self):
self.assertEqual(self.par.params_changed_count, 0)
self.par._notify_observers(0, None)
self.assertEqual(self.par.params_changed_count, 1)
self.assertEqual(self.parent.parent_changed_count, self.par.params_changed_count)
self.par._notify_observers(0, -numpy.inf)
self.assertEqual(self.par.params_changed_count, 2)
self.assertEqual(self.parent.parent_changed_count, 1)
def test_priority(self):
self.par.add_observer(self, self._trigger, -1)
self.par.add_observer(self, self._trigger_priority, 0)
self.par._notify_observers(0)
self.assertEqual(self._first, self._trigger_priority, 'priority should be first')
self.assertEqual(self._second, self._trigger, 'priority should be first')
self.par.remove_observer(self)
self._first = self._second = None
self.par.add_observer(self, self._trigger, 1)
self.par.add_observer(self, self._trigger_priority, 0)
self.par._notify_observers(0)
self.assertEqual(self._first, self._trigger, 'priority should be second')
self.assertEqual(self._second, self._trigger_priority, 'priority should be second')
if __name__ == "__main__":
#import sys;sys.argv = ['', 'Test.testName']
unittest.main()

View file

@ -6,6 +6,7 @@ Created on Feb 13, 2014
import unittest
import GPy
import numpy as np
from GPy.core.parameterization.parameter_core import HierarchyError
class Test(unittest.TestCase):
@ -65,7 +66,7 @@ class Test(unittest.TestCase):
self.assertListEqual(self.test1.constraints[Logexp()].tolist(), [0,1])
def test_add_parameter_already_in_hirarchy(self):
self.test1.add_parameter(self.white._parameters_[0])
self.assertRaises(HierarchyError, self.test1.add_parameter, self.white._parameters_[0])
def test_default_constraints(self):
self.assertIs(self.rbf.variance.constraints._param_index_ops, self.rbf.constraints._param_index_ops)

View file

@ -1,4 +1,5 @@
from ..core.parameterization.parameter_core import Observable
import itertools
class Cacher(object):
"""
@ -38,8 +39,11 @@ class Cacher(object):
if not all([isinstance(arg, Observable) for arg in observable_args]):
return self.operation(*args)
# TODO: WARNING !!! Cache OFFSWITCH !!! WARNING
# return self.operation(*args)
#if the result is cached, return the cached computation
state = [all(a is b for a, b in zip(args, cached_i)) for cached_i in self.cached_inputs]
state = [all(a is b for a, b in itertools.izip_longest(args, cached_i)) for cached_i in self.cached_inputs]
if any(state):
i = state.index(True)
if self.inputs_changed[i]: