GPy/GPy/likelihoods/link_functions.py
2013-06-04 16:23:04 +01:00

58 lines
1.2 KiB
Python

# Copyright (c) 2012, 2013 Ricardo Andrade
# Licensed under the BSD 3-clause license (see LICENSE.txt)
import numpy as np
from scipy import stats
import scipy as sp
import pylab as pb
from ..util.plot import gpplot
from ..util.univariate_Gaussian import std_norm_pdf,std_norm_cdf
class link_function(object):
"""
Link function class for doing non-Gaussian likelihoods approximation
:param Y: observed output (Nx1 numpy.darray)
..Note:: Y values allowed depend on the likelihood_function used
"""
def __init__(self):
pass
class identity(link_function):
def transf(self,mu):
return mu
def inv_transf(self,f):
return f
def log_inv_transf(self,f):
return np.log(f)
class log(link_function):
def transf(self,mu):
return np.log(mu)
def inv_transf(self,f):
return np.exp(f)
def log_inv_transf(self,f):
return f
class log_ex_1(link_function):
def transf(self,mu):
return np.log(np.exp(mu) - 1)
def inv_transf(self,f):
return np.log(np.exp(f)+1)
def log_inv_tranf(self,f):
return np.log(np.log(np.exp(f)+1))
class probit(link_function):
pass