GPy/GPy/models/sparse_gp_classification.py

47 lines
1.8 KiB
Python

# Copyright (c) 2013, Ricardo Andrade
# Licensed under the BSD 3-clause license (see LICENSE.txt)
import numpy as np
from ..core import sparse_GP
from .. import likelihoods
from .. import kern
from ..likelihoods import likelihood
class sparse_GP_classification(sparse_GP):
"""
sparse Gaussian Process model for classification
This is a thin wrapper around the sparse_GP class, with a set of sensible defaults
:param X: input observations
:param Y: observed values
:param likelihood: a GPy likelihood, defaults to Binomial with probit link_function
:param kernel: a GPy kernel, defaults to rbf+white
:param normalize_X: whether to normalize the input data before computing (predictions will be in original scales)
:type normalize_X: False|True
:param normalize_Y: whether to normalize the input data before computing (predictions will be in original scales)
:type normalize_Y: False|True
:rtype: model object
"""
def __init__(self, X, Y=None, likelihood=None, kernel=None, normalize_X=False, normalize_Y=False, Z=None, M=10):
if kernel is None:
kernel = kern.rbf(X.shape[1]) + kern.white(X.shape[1],1e-3)
if likelihood is None:
distribution = likelihoods.likelihood_functions.Binomial()
likelihood = likelihoods.EP(Y, distribution)
elif Y is not None:
if not all(Y.flatten() == likelihood.data.flatten()):
raise Warning, 'likelihood.data and Y are different.'
if Z is None:
i = np.random.permutation(X.shape[0])[:M]
Z = X[i].copy()
else:
assert Z.shape[1]==X.shape[1]
sparse_GP.__init__(self, X, likelihood, kernel, Z=Z, normalize_X=normalize_X)
self._set_params(self._get_params())