X caching is not yet done, parameter caching working fine. X cache must be adjusted to update at the right times

This commit is contained in:
Max Zwiessele 2013-10-27 17:04:46 +00:00
parent d3721b76a8
commit d8151eee61
12 changed files with 249 additions and 109 deletions

View file

@ -5,6 +5,7 @@ import pylab as pb
from model import Model
import warnings
from ..likelihoods import Gaussian, Gaussian_Mixed_Noise
from ..core.parameter import ObservableArray
class GPBase(Model):
"""
@ -14,7 +15,7 @@ class GPBase(Model):
def __init__(self, X, likelihood, kernel, normalize_X=False):
super(GPBase, self).__init__()
self.X = X
self.X = ObservableArray(X)
assert len(self.X.shape) == 2
self.num_data, self.input_dim = self.X.shape
assert isinstance(kernel, kern.kern)
@ -26,13 +27,14 @@ class GPBase(Model):
if normalize_X:
self._Xoffset = X.mean(0)[None, :]
self._Xscale = X.std(0)[None, :]
self.X = (X.copy() - self._Xoffset) / self._Xscale
self.X = ObservableArray((X.copy() - self._Xoffset) / self._Xscale)
else:
self._Xoffset = np.zeros((1, self.input_dim))
self._Xscale = np.ones((1, self.input_dim))
self.add_parameter(self.kern, gradient=self.dL_dtheta)
self.add_parameter(self.likelihood, gradient=self.dL_dlikelihood)
self.kern.connect_input(self.X)
# Model.__init__(self)
# All leaf nodes should call self._set_params(self._get_params()) at

View file

@ -6,7 +6,7 @@ Created on 4 Sep 2013
import itertools
import numpy
from transformations import Logexp, NegativeLogexp, Logistic
from parameterized import Parentable
from parameterized import Nameable, Pickleable
###### printing
__constraints_name__ = "Constraint"
@ -16,7 +16,48 @@ __precision__ = numpy.get_printoptions()['precision'] # numpy printing precision
__print_threshold__ = 5
######
class Param(numpy.ndarray, Parentable):
class ListArray(numpy.ndarray):
"""
ndarray which can be stored in lists and checked if it is in.
"""
def __new__(cls, input_array):
obj = numpy.asanyarray(input_array).view(cls)
return obj
def __eq__(self, other):
return other is self
class ObservableArray(ListArray):
"""
An ndarray which reports changed to it's observers.
The observers can add themselves with a callable, which
will be called every time this array changes. The callable
takes exactly one argument, which is this array itself.
"""
def __new__(cls, input_array):
obj = super(ObservableArray, cls).__new__(cls, input_array).view(cls)
obj._observers_ = {}
return obj
def __array_finalize__(self, obj):
# see InfoArray.__array_finalize__ for comments
if obj is None: return
self._observers_ = getattr(obj, '_observers_', None)
def add_observer(self, observer, callble):
self._observers_[observer] = callble
def remove_observer(self, observer):
del self._observers_[observer]
def _notify_observers(self):
[callble(self) for callble in self._observers_.itervalues()]
def __setitem__(self, s, val):
if not numpy.all(numpy.equal(self[s], val)):
numpy.put(self,s,val)
self._notify_observers()
def __getslice__(self, start, stop):
return self.__getitem__(slice(start, stop))
def __setslice__(self, start, stop, val):
return self.__setitem__(slice(start, stop), val)
class Param(ObservableArray, Nameable, Pickleable):
"""
Parameter object for GPy models.
@ -41,9 +82,9 @@ class Param(numpy.ndarray, Parentable):
"""
__array_priority__ = -numpy.inf # Never give back Param
def __new__(cls, name, input_array, *args, **kwargs):
obj = numpy.atleast_1d(numpy.array(input_array)).view(cls)
obj._name_ = name
obj = numpy.atleast_1d(super(Param, cls).__new__(cls, input_array=input_array))
obj._direct_parent_ = None
obj._name_ = name
obj._parent_index_ = None
obj._highest_parent_ = None
obj._current_slice_ = (slice(obj.shape[0]),)
@ -55,7 +96,10 @@ class Param(numpy.ndarray, Parentable):
obj._tied_to_me_ = ParamDict(set)
obj._tied_to_ = []
obj._original_ = True
return obj
return obj
def __init__(self, name, input_array):
super(Param, self).__init__(name=name)
def __array_finalize__(self, obj):
# see InfoArray.__array_finalize__ for comments
if obj is None: return
@ -71,11 +115,6 @@ class Param(numpy.ndarray, Parentable):
self._realndim_ = getattr(obj, '_realndim_', None)
self._updated_ = getattr(obj, '_updated_', None)
self._original_ = getattr(obj, '_original_', None)
def __eq__(self, other):
return other is self
if other is self:
return True
return super(Param, self).__eq__(other)
def __array_wrap__(self, out_arr, context=None):
return out_arr.view(numpy.ndarray)
@ -117,24 +156,24 @@ class Param(numpy.ndarray, Parentable):
#===========================================================================
def _set_params(self, param):
self.flat = param
self._fire_changed()
self._notify_tied_parameters()
def _get_params(self):
return self.flat
@property
def name(self):
"""
Name of this parameter.
This can be a callable without parameters. The callable will be called
every time the name property is accessed.
"""
if callable(self._name_):
return self._name_()
return self._name_
@name.setter
def name(self, new_name):
from_name = self.name
self._name_ = new_name
self._direct_parent_._name_changed(self, from_name)
# @property
# def name(self):
# """
# Name of this parameter.
# This can be a callable without parameters. The callable will be called
# every time the name property is accessed.
# """
# if callable(self._name_):
# return self._name_()
# return self._name_
# @name.setter
# def name(self, new_name):
# from_name = self.name
# self._name_ = new_name
# self._direct_parent_._name_changed(self, from_name)
@property
def _parameters_(self):
return []
@ -232,6 +271,11 @@ class Param(numpy.ndarray, Parentable):
Broadcasting is allowed, so you can tie a whole dimension to
one parameter: self[:,0].tie_to(other), where other is a one-value
parameter.
Note: this method will tie to the parameter which is the last in
the chain of ties. Thus, if you tie to a tied parameter,
this tie will be created to the parameter the param is tied
to.
"""
assert isinstance(param, Param), "Argument {1} not of type {0}".format(Param,param.__class__)
try:
@ -241,9 +285,17 @@ class Param(numpy.ndarray, Parentable):
self._direct_parent_._get_original(self)[self._current_slice_] = param
except ValueError:
raise ValueError("Trying to tie {} with shape {} to {} with shape {}".format(self.name, self.shape, param.name, param.shape))
if param is self:
raise RuntimeError, 'Cyclic tieing is not allowed'
if len(param._tied_to_) > 0:
self.tie_to(param._tied_to_[0])
return
self._direct_parent_._get_original(self)._tied_to_ += [param]
param._add_tie_listener(self)
self._highest_parent_._set_fixed(self)
for t in self._tied_to_me_.iterkeys():
t.untie()
t.tie_to(param)
# self._direct_parent_._add_tie(self, param)
def untie(self, *ties):
@ -254,9 +306,9 @@ class Param(numpy.ndarray, Parentable):
self._tied_to_ = [tied_to for tied_to in self._tied_to_ for t in tied_to._tied_to_me_ if self._parent_index_==t._direct_parent_._get_original(t)._parent_index_]
self._highest_parent_._set_unfixed(self)
# self._direct_parent_._remove_tie(self, *params)
def _fire_changed(self):
def _notify_tied_parameters(self):
for tied, ind in self._tied_to_me_.iteritems():
tied._on_change(self.base, list(ind))
tied._on_tied_parameter_changed(self.base, list(ind))
def _add_tie_listener(self, tied_to_me):
self._tied_to_me_[tied_to_me] |= set(self._raveled_index())
def _remove_tie_listener(self, to_remove):
@ -271,14 +323,14 @@ class Param(numpy.ndarray, Parentable):
del self._tied_to_me_[tmp]
else:
del self._tied_to_me_[t]
def _on_change(self, val, ind):
def _on_tied_parameter_changed(self, val, ind):
if not self._updated_: #not fast_array_equal(self, val[ind]):
self._updated_ = True
if self._original_:
self.__setitem__(slice(None), val[ind], update=False)
else: # this happens when indexing created a copy of the array
self._direct_parent_._get_original(self).__setitem__(self._current_slice_, val[ind], update=False)
self._fire_changed()
self._notify_tied_parameters()
self._updated_ = False
#===========================================================================
# Prior Operations
@ -307,17 +359,13 @@ class Param(numpy.ndarray, Parentable):
s = (s,)
if not reduce(lambda a,b: a or numpy.any(b is Ellipsis), s, False) and len(s) <= self.ndim:
s += (Ellipsis,)
new_arr = numpy.ndarray.__getitem__(self, s, *args, **kwargs)
new_arr = super(Param, self).__getitem__(s, *args, **kwargs)
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 __getslice__(self, start, stop):
return self.__getitem__(slice(start, stop))
def __setslice__(self, start, stop, val):
return self.__setitem__(slice(start, stop), val)
def __setitem__(self, s, val, update=True):
numpy.ndarray.__setitem__(self, s, val)
self._fire_changed()
super(Param, self).__setitem__(s, val)
self._notify_tied_parameters()
if update:
self._highest_parent_.parameters_changed()
#===========================================================================
@ -494,7 +542,7 @@ class ParamConcatenation(object):
def __setitem__(self, s, val, update=True):
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 p._fire_changed()
[numpy.place(p, ind[ps], vals[ps]) and p._notify_tied_parameters()
for p, ps in zip(self.params, self._param_slices_)]
if update:
self.params[0]._highest_parent_.parameters_changed()

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@ -32,6 +32,24 @@ class Nameable(Parentable):
if self.has_parent():
self._direct_parent_._name_changed(self, from_name)
class Pickleable(object):
def getstate(self):
"""
Returns the state of this class in a memento pattern.
The state must be a list-like structure of all the fields
this class need to run
"""
raise NotImplementedError, "To be able to use pickling you need to implement this method"
def setstate(self, state):
"""
Set the state (memento pattern) of this class to the given state.
Usually this is just the counterpart to getstate, such that
an object is a copy of another when calling
copy = <classname>.__new__(*args,**kw).setstate(<to_be_copied>.getstate())
"""
raise NotImplementedError, "To be able to use pickling you need to implement this method"
from parameter import ParamConcatenation
from index_operations import ParameterIndexOperations,\
index_empty
@ -47,7 +65,7 @@ FIXED = False
UNFIXED = True
#===============================================================================
class Parameterized(Nameable):
class Parameterized(Nameable, Pickleable):
"""
Parameterized class
@ -161,7 +179,7 @@ class Parameterized(Nameable):
def add_parameters(self, *parameters):
"""
convinience method for adding several
convenience method for adding several
parameters without gradient specification
"""
[self.add_parameter(p) for p in parameters]
@ -178,8 +196,15 @@ class Parameterized(Nameable):
# or p in names_params_indices)]
# self._connect_parameters()
def parameters_changed(self):
"""
This method gets called when parameters have changed.
Another way of listening to parameter changes is to
add self as a listener to the parameter, such that
updates get passed through. See :py:function:``GPy.core.parameter.Observable.add_observer``
"""
# will be called as soon as paramters have changed
pass
def _connect_parameters(self):
# connect parameterlist to this parameterized object
# This just sets up the right connection for the params objects

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@ -52,6 +52,9 @@ class kern(Parameterized):
def parameters_changed(self):
[p.parameters_changed() for p in self._parameters_]
def connect_input(self, Xparam):
[p.connect_input(Xparam) for p in self._parameters_]
def getstate(self):
"""
Get the current state of the class,

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@ -16,7 +16,7 @@ class Bias(Kernpart):
:type variance: float
"""
super(Bias, self).__init__(input_dim, 'bias')
self.variance = Param("variance", variance, None)
self.variance = Param("variance", variance)
self.add_parameter(self.variance)
#self._set_params(np.array([variance]).flatten())

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@ -21,7 +21,22 @@ class Kernpart(Parameterized):
# the name of the covariance function.
# link to parameterized objects
self._parameters_ = []
self._X = None
def connect_input(self, X):
X.add_observer(self, self.on_input_change)
self._X = X
def on_input_change(self, X):
"""
During optimization this function will be called when
the inputs X changed. Use this to update caches dependent
on the inputs X.
"""
# overwrite this to update kernel when inputs X change
pass
# def set_as_parameter_named(self, name, gradient, index=None, *args, **kwargs):
# """
# :param names: name of parameter to set as parameter

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@ -39,16 +39,23 @@ class Linear(Kernpart):
else:
if variances is not None:
variances = np.asarray(variances)
assert variances.size == self.input_dim, "bad number of lengthscales"
assert variances.size == self.input_dim, "bad number of variances, need one ARD variance per input_dim"
else:
variances = np.ones(self.input_dim)
self.variances = Param('variances', variances)
self.add_parameters(self.variances)
self.variances.add_observer(self, self.update_variance)
# initialize cache
self._Z, self._mu, self._S = np.empty(shape=(3, 1))
self._X, self._X2 = np.empty(shape=(2, 1))
def update_variance(self, v):
self.variances2 = np.square(self.variances)
def on_input_change(self, X):
self._K_computations(X, None)
# def _get_params(self):
# return self.variances
@ -56,8 +63,8 @@ class Linear(Kernpart):
# def _set_params(self, x):
# assert x.size == (self.num_params)
# self.variances = x
def parameters_changed(self):
self.variances2 = np.square(self.variances)
#def parameters_changed(self):
# self.variances2 = np.square(self.variances)
#
# def _get_param_names(self):
# if self.num_params == 1:
@ -74,7 +81,8 @@ class Linear(Kernpart):
XX2 = X2 * np.sqrt(self.variances)
target += np.dot(XX, XX2.T)
else:
self._K_computations(X, X2)
if X is not self._X or X2 is not None:
self._K_computations(X, X2)
target += self.variances * self._dot_product
def Kdiag(self, X, target):
@ -88,7 +96,8 @@ class Linear(Kernpart):
product = X[:, None, :] * X2[None, :, :]
target += (dL_dK[:, :, None] * product).sum(0).sum(0)
else:
self._K_computations(X, X2)
if X is not self._X or X2 is not None:
self._K_computations(X, X2)
target += np.sum(self._dot_product * dL_dK)
def dKdiag_dtheta(self, dL_dKdiag, X, target):

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@ -50,32 +50,34 @@ class RBF(Kernpart):
else:
lengthscale = np.ones(self.input_dim)
#self._set_params(np.hstack((variance, lengthscale.flatten())))
self.variance = Param('variance', variance, None)
self.lengthscale = Param('lengthscale', lengthscale, None)
self.variance = Param('variance', variance)
self.lengthscale = Param('lengthscale', lengthscale)
self.lengthscale.add_observer(self, self.update_lengthscale)
self.add_parameters(self.variance, self.lengthscale)
# self.set_as_parameter('variance', self.variance, None)
# self.set_as_parameter('lengthscale', self.lengthscale, None)
# initialize cache
self._Z, self._mu, self._S = np.empty(shape=(3, 1))
self._X, self._X2, self._params_save = np.empty(shape=(3, 1))
#self._Z, self._mu, self._S = np.empty(shape=(3, 1))
#self._X, self._X2, self._params_save = np.empty(shape=(3, 1))
# a set of optional args to pass to weave
self.weave_options = {'headers' : ['<omp.h>'],
'extra_compile_args': ['-fopenmp -O3'], # -march=native'],
'extra_link_args' : ['-lgomp']}
def on_input_change(self, X):
import pdb;pdb.set_trace()
self._K_computations(X, None)
def update_lengthscale(self, l):
self.lengthscale2 = np.square(self.lengthscale)
def parameters_changed(self):
self.lengthscale2 = np.square(self.lengthscale)
# reset cached results
#self._X, self._X2, self._params_save = np.empty(shape=(3, 1))
#self._Z, self._mu, self._S = np.empty(shape=(3, 1)) # cached versions of Z,mu,S
self._X, self._X2 = np.empty(shape=(2, 1))
self._Z, self._mu, self._S = np.empty(shape=(3, 1)) # cached versions of Z,mu,S
#self._X, self._X2 = np.empty(shape=(2, 1))
#self._Z, self._mu, self._S = np.empty(shape=(3, 1)) # cached versions of Z,mu,S
pass
# def _get_params(self):
# return np.hstack((self.variance, self.lengthscale))
# #
@ -97,14 +99,17 @@ class RBF(Kernpart):
# return ['variance'] + ['lengthscale_%i' % i for i in range(self.lengthscale.size)]
def K(self, X, X2, target):
self._K_computations(X, X2)
if self._X is None or X.base is not self._X.base or X2 is not None:
import pdb;pdb.set_trace()
self._K_computations(X, X2)
target += self.variance * self._K_dvar
def Kdiag(self, X, target):
np.add(target, self.variance, target)
def dK_dtheta(self, dL_dK, X, X2, target):
self._K_computations(X, X2)
if self._X is None or X.base is not self._X.base or X2 is not None:
self._K_computations(X, X2)
target[0] += np.sum(self._K_dvar * dL_dK)
if self.ARD:
dvardLdK = self._K_dvar * dL_dK
@ -152,7 +157,8 @@ class RBF(Kernpart):
target[0] += np.sum(dL_dKdiag)
def dK_dX(self, dL_dK, X, X2, target):
self._K_computations(X, X2)
if self._X is None or X.base is not self._X.base or X2 is not None:
self._K_computations(X, X2)
if X2 is None:
_K_dist = 2*(X[:, None, :] - X[None, :, :])
else:
@ -241,7 +247,7 @@ class RBF(Kernpart):
def _K_computations(self, X, X2):
#params = self._get_params()
if not (fast_array_equal(X, self._X) and fast_array_equal(X2, self._X2)):# and fast_array_equal(self._params_save , params)):
self._X = X.copy()
#self._X = X.copy()
#self._params_save = params.copy()
if X2 is None:
self._X2 = None

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@ -17,7 +17,7 @@ class White(Kernpart):
def __init__(self,input_dim,variance=1.):
super(White, self).__init__(input_dim, 'white')
self.input_dim = input_dim
self.variance = Param('variance', variance, None)
self.variance = Param('variance', variance)
self.add_parameters(self.variance)
# self._set_params(np.array([variance]).flatten())
self._psi1 = 0 # TODO: more elegance here

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@ -13,6 +13,7 @@ from ..core import GP
from ..likelihoods import Gaussian
from .. import util
from GPy.util import plot_latent
from GPy.core.parameter import Param
class GPLVM(GP):
@ -34,7 +35,9 @@ class GPLVM(GP):
kernel = kern.rbf(input_dim, ARD=input_dim > 1) + kern.bias(input_dim, np.exp(-2))
likelihood = Gaussian(Y, normalize=normalize_Y, variance=np.exp(-2.))
GP.__init__(self, X, likelihood, kernel, normalize_X=False)
self.set_prior('.*X', Gaussian_prior(0, 1))
self.X = Param('q_mean', self.X)
self.add_parameter(self.X, self.dL_dK, 0)
#self.set_prior('.*X', Gaussian_prior(0, 1))
self.ensure_default_constraints()
def initialise_latent(self, init, input_dim, Y):
@ -50,33 +53,35 @@ class GPLVM(GP):
def setstate(self, state):
GP.setstate(self, state)
def _get_param_names(self):
return sum([['X_%i_%i' % (n, q) for q in range(self.input_dim)] for n in range(self.num_data)], []) + GP._get_param_names(self)
# def _get_param_names(self):
# return sum([['X_%i_%i' % (n, q) for q in range(self.input_dim)] for n in range(self.num_data)], []) + GP._get_param_names(self)
#
# def _get_params(self):
# return np.hstack((self.X.flatten(), GP._get_params(self)))
#
# def _set_params(self, x):
# self.X = x[:self.num_data * self.input_dim].reshape(self.num_data, self.input_dim).copy()
# GP._set_params(self, x[self.X.size:])
def _get_params(self):
return np.hstack((self.X.flatten(), GP._get_params(self)))
def _set_params(self, x):
self.X = x[:self.num_data * self.input_dim].reshape(self.num_data, self.input_dim).copy()
GP._set_params(self, x[self.X.size:])
def _log_likelihood_gradients(self):
dL_dX = self.kern.dK_dX(self.dL_dK, self.X)
return np.hstack((dL_dX.flatten(), GP._log_likelihood_gradients(self)))
def dK_dX(self):
return self.kern.dK_dX(self.dL_dK, self.X)
# def _log_likelihood_gradients(self):
# dL_dX = self.kern.dK_dX(self.dL_dK, self.X)
#
# return np.hstack((dL_dX.flatten(), GP._log_likelihood_gradients(self)))
def jacobian(self,X):
target = np.zeros((X.shape[0],X.shape[1],self.output_dim))
for i in range(self.output_dim):
target[:,:,i]=self.kern.dK_dX(np.dot(self.Ki,self.likelihood.Y[:,i])[None, :],X,self.X)
target[:,:,i]=self.kern.dK_dX(np.dot(self.Ki,self.likelihood.Y[:,i])[None, :],X,self.X)
return target
def magnification(self,X):
target=np.zeros(X.shape[0])
J = np.zeros((X.shape[0],X.shape[1],self.output_dim))
J=self.jacobian(X)
#J = np.zeros((X.shape[0],X.shape[1],self.output_dim))
J = self.jacobian(X)
for i in range(X.shape[0]):
target[i]=np.sqrt(pb.det(np.dot(J[i,:,:],np.transpose(J[i,:,:]))))
target[i]=np.sqrt(pb.det(np.dot(J[i,:,:],np.transpose(J[i,:,:]))))
return target
def plot(self):

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@ -4,7 +4,7 @@ import GPy
import numpy as np
import matplotlib as mpl
import time
import Image
from PIL import Image
try:
import visual
visual_available = True

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@ -35,45 +35,72 @@ The implementation of this function in mandatory.
For all kernparts the first parameter ``input_dim`` corresponds to the dimension of the input space, and the following parameters stand for the parameterization of the kernel.
The following attributes are compulsory: ``self.input_dim`` (the dimension, integer), ``self.name`` (name of the kernel, string), ``self.num_params`` (number of parameters, integer). ::
You have to call ``super(<class_name>, self).__init__(input_dim,
name)`` to make sure the input dimension and name of the kernel are
stored in the right place. These attributes are available as
``self.input_dim`` and ``self.name`` at runtime.
.. The following attributes are compulsory: ``self.input_dim`` (the dimension, integer), ``self.name`` (name of the kernel, string), ``self.num_params`` (number of parameters, integer). ::
Parameterization is done by adding
:py:class:``GPy.core.parameter.Param`` objects to ``self`` and use
them as normal numpy ``array-like``s in yout code. The parameters have
to be added by calling
:py:function:``GPy.core.parameterized:Parameterized.add_parameters``
with the :py:class:``GPy.core.parameter.Param`` objects as arguments.
def __init__(self,input_dim,variance=1.,lengthscale=1.,power=1.):
assert input_dim == 1, "For this kernel we assume input_dim=1"
self.input_dim = input_dim
self.num_params = 3
self.name = 'rat_quad'
self.variance = variance
self.lengthscale = lengthscale
self.power = power
super(RationalQuadratic, self).__init__(input_dim, 'rat_quad')
assert input_dim == 1, "For this kernel we assume input_dim=1"
self.variance = Param('variance', variance)
self.lengthscale = Param('lengtscale', lengthscale)
self.power = Param('power', power)
self.add_parameters(self.variance, self.lengthscale, self.power)
**_get_params(self)**
From now on you can use the parameters ``self.variance,
self.lengthscale, self.power`` as normal numpy ``array-like``s in your
code. Updates from the optimization routine will be done
automatically.
The implementation of this function in mandatory.
**parameters_changed(self)**
This function returns a one dimensional array of length ``self.num_params`` containing the value of the parameters. ::
The implementation of this function is optional.
def _get_params(self):
return np.hstack((self.variance,self.lengthscale,self.power))
This functions deals as a callback for each optimization iteration. If
one optimization step was successfull and the parameters (added by
:py:function:``GPy.core.parameterized:Parameterized.add_parameters``)
this callback function will be called to be able to update any
precomputations for the kernel.
**_set_params(self,x)**
def parameters_changed(self):
# nothing todo here
The implementation of this function in mandatory.
.. **_get_params(self)**
The input is a one dimensional array of length ``self.num_params`` containing the value of the parameters. The function has no output but it updates the values of the attribute associated to the parameters (such as ``self.variance``, ``self.lengthscale``, ...). ::
.. The implementation of this function in mandatory.
def _set_params(self,x):
self.variance = x[0]
self.lengthscale = x[1]
self.power = x[2]
.. This function returns a one dimensional array of length ``self.num_params`` containing the value of the parameters. ::
**_get_param_names(self)**
.. def _get_params(self):
.. return np.hstack((self.variance,self.lengthscale,self.power))
The implementation of this function in mandatory.
.. **_set_params(self,x)**
It returns a list of strings of length ``self.num_params`` corresponding to the parameter names. ::
.. The implementation of this function in mandatory.
def _get_param_names(self):
return ['variance','lengthscale','power']
.. The input is a one dimensional array of length ``self.num_params`` containing the value of the parameters. The function has no output but it updates the values of the attribute associated to the parameters (such as ``self.variance``, ``self.lengthscale``, ...). ::
.. def _set_params(self,x):
.. self.variance = x[0]
.. self.lengthscale = x[1]
.. self.power = x[2]
.. **_get_param_names(self)**
.. The implementation of this function in mandatory.
.. It returns a list of strings of length ``self.num_params`` corresponding to the parameter names. ::
.. def _get_param_names(self):
.. return ['variance','lengthscale','power']
**K(self,X,X2,target)**