[warped stuff] plotting and normalizer in warped gps

This commit is contained in:
mzwiessele 2016-08-17 14:51:29 +01:00
parent f50b691ec6
commit d343ec8b41
8 changed files with 112 additions and 78 deletions

View file

@ -15,7 +15,7 @@ class WarpedGP(GP):
This defines a GP Regression model that applies a
warping function to the output.
"""
def __init__(self, X, Y, kernel=None, warping_function=None, warping_terms=3):
def __init__(self, X, Y, kernel=None, warping_function=None, warping_terms=3, normalizer=False):
if kernel is None:
kernel = kern.RBF(X.shape[1])
if warping_function == None:
@ -23,33 +23,23 @@ class WarpedGP(GP):
self.warping_params = (np.random.randn(self.warping_function.n_terms * 3 + 1) * 1)
else:
self.warping_function = warping_function
self.scale_data = False
if self.scale_data:
Y = self._scale_data(Y)
#self.has_uncertain_inputs = False
self.Y_untransformed = Y.copy()
self.predict_in_warped_space = True
likelihood = likelihoods.Gaussian()
GP.__init__(self, X, self.transform_data(), likelihood=likelihood, kernel=kernel)
super(WarpedGP, self).__init__(X, Y.copy(), likelihood=likelihood, kernel=kernel, normalizer=normalizer)
self.Y_normalized = self.Y_normalized.copy()
self.Y_untransformed = self.Y_normalized.copy()
self.predict_in_warped_space = True
self.link_parameter(self.warping_function)
def set_XY(self, X=None, Y=None):
self.Y_untransformed = Y.copy()
GP.set_XY(self, X, self.transform_data())
def _scale_data(self, Y):
self._Ymax = Y.max()
self._Ymin = Y.min()
return (Y - self._Ymin) / (self._Ymax - self._Ymin) - 0.5
def _unscale_data(self, Y):
return (Y + 0.5) * (self._Ymax - self._Ymin) + self._Ymin
super(WarpedGP, self).set_XY(X, Y)
self.Y_untransformed = self.Y_normalized.copy()
self.update_model(True)
def parameters_changed(self):
"""
Notice that we update the warping function gradients here.
"""
self.Y[:] = self.transform_data()
self.Y_normalized[:] = self.transform_data()
super(WarpedGP, self).parameters_changed()
Kiy = self.posterior.woodbury_vector.flatten()
self.warping_function.update_grads(self.Y_untransformed, Kiy)
@ -96,7 +86,7 @@ class WarpedGP(GP):
deg_gauss_hermite=deg_gauss_hermite)
return arg1 - (arg2 ** 2)
def predict(self, Xnew, which_parts='all', pred_init=None, full_cov=False, Y_metadata=None,
def predict(self, Xnew, kern=None, pred_init=None, Y_metadata=None,
median=False, deg_gauss_hermite=20, likelihood=None):
"""
Prediction results depend on:
@ -104,9 +94,12 @@ class WarpedGP(GP):
- The median flag passed as argument
The likelihood keyword is never used, it is just to follow the plotting API.
"""
mu, var = GP._raw_predict(self, Xnew)
#mu, var = GP._raw_predict(self, Xnew)
# now push through likelihood
mean, var = self.likelihood.predictive_values(mu, var)
#mean, var = self.likelihood.predictive_values(mu, var)
mean, var = super(WarpedGP, self).predict(Xnew, kern=kern, full_cov=False, likelihood=likelihood)
if self.predict_in_warped_space:
std = np.sqrt(var)
@ -120,11 +113,9 @@ class WarpedGP(GP):
else:
wmean = mean
wvar = var
if self.scale_data:
pred = self._unscale_data(pred)
return wmean, wvar
def predict_quantiles(self, X, quantiles=(2.5, 97.5), Y_metadata=None, likelihood=None, median=False):
def predict_quantiles(self, X, quantiles=(2.5, 97.5), Y_metadata=None, likelihood=None, kern=None):
"""
Get the predictive quantiles around the prediction at X
@ -135,15 +126,19 @@ class WarpedGP(GP):
:returns: list of quantiles for each X and predictive quantiles for interval combination
:rtype: [np.ndarray (Xnew x self.input_dim), np.ndarray (Xnew x self.input_dim)]
"""
m, v = self._raw_predict(X, full_cov=False)
if self.normalizer is not None:
m, v = self.normalizer.inverse_mean(m), self.normalizer.inverse_variance(v)
a, b = self.likelihood.predictive_quantiles(m, v, quantiles, Y_metadata)
if not self.predict_in_warped_space:
return [a, b]
new_a = self.warping_function.f_inv(a)
new_b = self.warping_function.f_inv(b)
return [new_a, new_b]
qs = super(WarpedGP, self).predict_quantiles(X, quantiles, Y_metadata=Y_metadata, likelihood=likelihood, kern=kern)
if self.predict_in_warped_space:
return [self.warping_function.f_inv(q) for q in qs]
return qs
#m, v = self._raw_predict(X, full_cov=False)
#if self.normalizer is not None:
# m, v = self.normalizer.inverse_mean(m), self.normalizer.inverse_variance(v)
#a, b = self.likelihood.predictive_quantiles(m, v, quantiles, Y_metadata)
#if not self.predict_in_warped_space:
# return [a, b]
#new_a = self.warping_function.f_inv(a)
#new_b = self.warping_function.f_inv(b)
#return [new_a, new_b]
def log_predictive_density(self, x_test, y_test, Y_metadata=None):
"""