GPy/GPy/models/sparse_GP_regression.py

44 lines
1.6 KiB
Python

# Copyright (c) 2012, James Hensman
# Licensed under the BSD 3-clause license (see LICENSE.txt)
import numpy as np
from sparse_GP import sparse_GP
from .. import likelihoods
from .. import kern
class sparse_GP_regression(sparse_GP):
"""
Gaussian Process model for regression
This is a thin wrapper around the GP class, with a set of sensible defalts
:param X: input observations
:param Y: observed values
: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
:param Xslices: how the X,Y data co-vary in the kernel (i.e. which "outputs" they correspond to). See (link:slicing)
:rtype: model object
.. Note:: Multiple independent outputs are allowed using columns of Y
"""
def __init__(self,X,Y,kernel=None,normalize_X=False,normalize_Y=False, Xslices=None,Z=None, M=10):
#kern defaults to rbf
if kernel is None:
kernel = kern.rbf(X.shape[1]) + kern.white(X.shape[1],1e-3)
#Z defaults to a subset of the data
if Z is None:
Z = np.random.permutation(X.copy())[:M]
else:
assert Z.shape[1]==X.shape[1]
#likelihood defaults to Gaussian
likelihood = likelihoods.Gaussian(Y,normalize=normalize_Y)
sparse_GP.__init__(self, X, likelihood, kernel, Z, normalize_X=normalize_X, Xslices=Xslices)