apunkt/GPy
1
0
Fork 0
mirror of https://github.com/SheffieldML/GPy.git synced 2026-05-15 06:52:39 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions
GPy/GPy/testing/likelihoods_tests.py
Alan Saul 2fdb60287f Added derivatives for poisson and a couple of examples, 
need to fix for EP.
2013-10-25 15:08:53 +01:00

573 lines
23 KiB
Python
Raw Blame History

import numpy as np
import unittest
import GPy
from GPy.models import GradientChecker
import functools
import inspect
from GPy.likelihoods.noise_models import gp_transformations
from functools import partial
def dparam_partial(inst_func, *args):
"""
If we have a instance method that needs to be called but that doesn't
take the parameter we wish to change to checkgrad, then this function
will change the variable using set params.
inst_func: should be a instance function of an object that we would like
to change
param: the param that will be given to set_params
args: anything else that needs to be given to the function (for example
the f or Y that are being used in the function whilst we tweak the
param
"""
def param_func(param, inst_func, args):
inst_func.im_self._set_params(param)
return inst_func(*args)
return functools.partial(param_func, inst_func=inst_func, args=args)
def dparam_checkgrad(func, dfunc, params, args, constraints=None, randomize=False, verbose=False):
"""
checkgrad expects a f: R^N -> R^1 and df: R^N -> R^N
However if we are holding other parameters fixed and moving something else
We need to check the gradient of each of the fixed parameters
(f and y for example) seperately, whilst moving another parameter.
Otherwise f: gives back R^N and
df: gives back R^NxM where M is
The number of parameters and N is the number of data
Need to take a slice out from f and a slice out of df
"""
#print "\n{} likelihood: {} vs {}".format(func.im_self.__class__.__name__,
#func.__name__, dfunc.__name__)
partial_f = dparam_partial(func, *args)
partial_df = dparam_partial(dfunc, *args)
gradchecking = True
for param in params:
fnum = np.atleast_1d(partial_f(param)).shape[0]
dfnum = np.atleast_1d(partial_df(param)).shape[0]
for fixed_val in range(dfnum):
#dlik and dlik_dvar gives back 1 value for each
f_ind = min(fnum, fixed_val+1) - 1
print "fnum: {} dfnum: {} f_ind: {} fixed_val: {}".format(fnum, dfnum, f_ind, fixed_val)
#Make grad checker with this param moving, note that set_params is NOT being called
#The parameter is being set directly with __setattr__
grad = GradientChecker(lambda x: np.atleast_1d(partial_f(x))[f_ind],
lambda x : np.atleast_1d(partial_df(x))[fixed_val],
param, 'p')
#This is not general for more than one param...
if constraints is not None:
for constraint in constraints:
constraint('p', grad)
if randomize:
grad.randomize()
if verbose:
print grad
grad.checkgrad(verbose=1)
if not grad.checkgrad():
gradchecking = False
return gradchecking
from nose.tools import with_setup
class TestNoiseModels(object):
"""
Generic model checker
"""
def setUp(self):
self.N = 5
self.D = 3
self.X = np.random.rand(self.N, self.D)*10
self.real_std = 0.1
noise = np.random.randn(*self.X[:, 0].shape)*self.real_std
self.Y = (np.sin(self.X[:, 0]*2*np.pi) + noise)[:, None]
self.f = np.random.rand(self.N, 1)
self.binary_Y = np.asarray(np.random.rand(self.N) > 0.5, dtype=np.int)[:, None]
self.positive_Y = np.exp(self.Y.copy())
self.integer_Y = np.round(self.X[:, 0]*3-3)[:, None] + np.random.randint(0,3, self.X.shape[0])[:, None]
self.integer_Y = np.where(self.integer_Y > 0, self.integer_Y, 0)
print self.integer_Y
print self.Y
self.var = 0.2
self.var = np.random.rand(1)
#Make a bigger step as lower bound can be quite curved
self.step = 1e-3
def tearDown(self):
self.Y = None
self.f = None
self.X = None
def test_noise_models(self):
self.setUp()
####################################################
# Constraint wrappers so we can just list them off #
####################################################
def constrain_negative(regex, model):
model.constrain_negative(regex)
def constrain_positive(regex, model):
model.constrain_positive(regex)
def constrain_bounded(regex, model, lower, upper):
"""
Used like: partial(constrain_bounded, lower=0, upper=1)
"""
model.constrain_bounded(regex, lower, upper)
"""
Dictionary where we nest models we would like to check
Name: {
"model": model_instance,
"grad_params": {
"names": [names_of_params_we_want, to_grad_check],
"vals": [values_of_params, to_start_at],
"constrain": [constraint_wrappers, listed_here]
},
"laplace": boolean_of_whether_model_should_work_for_laplace,
"ep": boolean_of_whether_model_should_work_for_laplace,
"link_f_constraints": [constraint_wrappers, listed_here]
}
"""
noise_models = {"Student_t_default": {
"model": GPy.likelihoods.student_t(deg_free=5, sigma2=self.var),
"grad_params": {
"names": ["t_noise"],
"vals": [self.var],
"constraints": [constrain_positive]
},
"laplace": True
},
"Student_t_1_var": {
"model": GPy.likelihoods.student_t(deg_free=5, sigma2=self.var),
"grad_params": {
"names": ["t_noise"],
"vals": [1],
"constraints": [constrain_positive]
},
"laplace": True
},
"Student_t_small_var": {
"model": GPy.likelihoods.student_t(deg_free=5, sigma2=self.var),
"grad_params": {
"names": ["t_noise"],
"vals": [0.01],
"constraints": [constrain_positive]
},
"laplace": True
},
"Student_t_approx_gauss": {
"model": GPy.likelihoods.student_t(deg_free=1000, sigma2=self.var),
"grad_params": {
"names": ["t_noise"],
"vals": [self.var],
"constraints": [constrain_positive]
},
"laplace": True
},
"Student_t_log": {
"model": GPy.likelihoods.student_t(gp_link=gp_transformations.Log(), deg_free=5, sigma2=self.var),
"grad_params": {
"names": ["t_noise"],
"vals": [self.var],
"constraints": [constrain_positive]
},
"laplace": True
},
"Gaussian_default": {
"model": GPy.likelihoods.gaussian(variance=self.var, D=self.D, N=self.N),
"grad_params": {
"names": ["noise_model_variance"],
"vals": [self.var],
"constraints": [constrain_positive]
},
"laplace": True,
"ep": True
},
"Gaussian_log": {
"model": GPy.likelihoods.gaussian(gp_link=gp_transformations.Log(), variance=self.var, D=self.D, N=self.N),
"grad_params": {
"names": ["noise_model_variance"],
"vals": [self.var],
"constraints": [constrain_positive]
},
"laplace": True
},
"Gaussian_probit": {
"model": GPy.likelihoods.gaussian(gp_link=gp_transformations.Probit(), variance=self.var, D=self.D, N=self.N),
"grad_params": {
"names": ["noise_model_variance"],
"vals": [self.var],
"constraints": [constrain_positive]
},
"laplace": True
},
"Gaussian_log_ex": {
"model": GPy.likelihoods.gaussian(gp_link=gp_transformations.Log_ex_1(), variance=self.var, D=self.D, N=self.N),
"grad_params": {
"names": ["noise_model_variance"],
"vals": [self.var],
"constraints": [constrain_positive]
},
"laplace": True
},
"Bernoulli_default": {
"model": GPy.likelihoods.bernoulli(),
"link_f_constraints": [partial(constrain_bounded, lower=0, upper=1)],
"laplace": True,
"Y": self.binary_Y,
"ep": True
},
"Exponential_default": {
"model": GPy.likelihoods.exponential(),
"link_f_constraints": [constrain_positive],
"Y": self.positive_Y,
"laplace": True,
},
"Poisson_default": {
"model": GPy.likelihoods.poisson(),
"link_f_constraints": [constrain_positive],
"Y": self.integer_Y,
"laplace": True,
"ep": False #Should work though...
}
}
for name, attributes in noise_models.iteritems():
model = attributes["model"]
if "grad_params" in attributes:
params = attributes["grad_params"]
param_vals = params["vals"]
param_names= params["names"]
param_constraints = params["constraints"]
else:
params = []
param_vals = []
param_names = []
constrain_positive = []
if "link_f_constraints" in attributes:
link_f_constraints = attributes["link_f_constraints"]
else:
link_f_constraints = []
if "Y" in attributes:
Y = attributes["Y"].copy()
else:
Y = self.Y.copy()
if "f" in attributes:
f = attributes["f"].copy()
else:
f = self.f.copy()
if "laplace" in attributes:
laplace = attributes["laplace"]
else:
laplace = False
if "ep" in attributes:
ep = attributes["ep"]
else:
ep = False
if len(param_vals) > 1:
raise NotImplementedError("Cannot support multiple params in likelihood yet!")
#Required by all
#Normal derivatives
yield self.t_logpdf, model, Y, f
yield self.t_dlogpdf_df, model, Y, f
yield self.t_d2logpdf_df2, model, Y, f
#Link derivatives
yield self.t_dlogpdf_dlink, model, Y, f, link_f_constraints
yield self.t_d2logpdf_dlink2, model, Y, f, link_f_constraints
if laplace:
#Laplace only derivatives
yield self.t_d3logpdf_df3, model, Y, f
yield self.t_d3logpdf_dlink3, model, Y, f, link_f_constraints
#Params
yield self.t_dlogpdf_dparams, model, Y, f, param_vals, param_constraints
yield self.t_dlogpdf_df_dparams, model, Y, f, param_vals, param_constraints
yield self.t_d2logpdf2_df2_dparams, model, Y, f, param_vals, param_constraints
#Link params
yield self.t_dlogpdf_link_dparams, model, Y, f, param_vals, param_constraints
yield self.t_dlogpdf_dlink_dparams, model, Y, f, param_vals, param_constraints
yield self.t_d2logpdf2_dlink2_dparams, model, Y, f, param_vals, param_constraints
#laplace likelihood gradcheck
yield self.t_laplace_fit_rbf_white, model, self.X, Y, f, self.step, param_vals, param_names, param_constraints
if ep:
#ep likelihood gradcheck
yield self.t_ep_fit_rbf_white, model, self.X, Y, f, self.step, param_vals, param_names, param_constraints
self.tearDown()
#############
# dpdf_df's #
#############
@with_setup(setUp, tearDown)
def t_logpdf(self, model, Y, f):
print "\n{}".format(inspect.stack()[0][3])
print model
np.testing.assert_almost_equal(
np.log(model.pdf(f.copy(), Y.copy())),
model.logpdf(f.copy(), Y.copy()))
@with_setup(setUp, tearDown)
def t_dlogpdf_df(self, model, Y, f):
print "\n{}".format(inspect.stack()[0][3])
self.description = "\n{}".format(inspect.stack()[0][3])
logpdf = functools.partial(model.logpdf, y=Y)
dlogpdf_df = functools.partial(model.dlogpdf_df, y=Y)
grad = GradientChecker(logpdf, dlogpdf_df, f.copy(), 'g')
grad.randomize()
grad.checkgrad(verbose=1)
print model
assert grad.checkgrad()
@with_setup(setUp, tearDown)
def t_d2logpdf_df2(self, model, Y, f):
print "\n{}".format(inspect.stack()[0][3])
dlogpdf_df = functools.partial(model.dlogpdf_df, y=Y)
d2logpdf_df2 = functools.partial(model.d2logpdf_df2, y=Y)
grad = GradientChecker(dlogpdf_df, d2logpdf_df2, f.copy(), 'g')
grad.randomize()
grad.checkgrad(verbose=1)
print model
assert grad.checkgrad()
@with_setup(setUp, tearDown)
def t_d3logpdf_df3(self, model, Y, f):
print "\n{}".format(inspect.stack()[0][3])
d2logpdf_df2 = functools.partial(model.d2logpdf_df2, y=Y)
d3logpdf_df3 = functools.partial(model.d3logpdf_df3, y=Y)
grad = GradientChecker(d2logpdf_df2, d3logpdf_df3, f.copy(), 'g')
grad.randomize()
grad.checkgrad(verbose=1)
print model
assert grad.checkgrad()
##############
# df_dparams #
##############
@with_setup(setUp, tearDown)
def t_dlogpdf_dparams(self, model, Y, f, params, param_constraints):
print "\n{}".format(inspect.stack()[0][3])
print model
assert (
dparam_checkgrad(model.logpdf, model.dlogpdf_dtheta,
params, args=(f, Y), constraints=param_constraints,
randomize=False, verbose=True)
)
@with_setup(setUp, tearDown)
def t_dlogpdf_df_dparams(self, model, Y, f, params, param_constraints):
print "\n{}".format(inspect.stack()[0][3])
print model
assert (
dparam_checkgrad(model.dlogpdf_df, model.dlogpdf_df_dtheta,
params, args=(f, Y), constraints=param_constraints,
randomize=False, verbose=True)
)
@with_setup(setUp, tearDown)
def t_d2logpdf2_df2_dparams(self, model, Y, f, params, param_constraints):
print "\n{}".format(inspect.stack()[0][3])
print model
assert (
dparam_checkgrad(model.d2logpdf_df2, model.d2logpdf_df2_dtheta,
params, args=(f, Y), constraints=param_constraints,
randomize=False, verbose=True)
)
################
# dpdf_dlink's #
################
@with_setup(setUp, tearDown)
def t_dlogpdf_dlink(self, model, Y, f, link_f_constraints):
print "\n{}".format(inspect.stack()[0][3])
logpdf = functools.partial(model.logpdf_link, y=Y)
dlogpdf_dlink = functools.partial(model.dlogpdf_dlink, y=Y)
grad = GradientChecker(logpdf, dlogpdf_dlink, f.copy(), 'g')
#Apply constraints to link_f values
for constraint in link_f_constraints:
constraint('g', grad)
grad.randomize()
print grad
grad.checkgrad(verbose=1)
assert grad.checkgrad()
@with_setup(setUp, tearDown)
def t_d2logpdf_dlink2(self, model, Y, f, link_f_constraints):
print "\n{}".format(inspect.stack()[0][3])
dlogpdf_dlink = functools.partial(model.dlogpdf_dlink, y=Y)
d2logpdf_dlink2 = functools.partial(model.d2logpdf_dlink2, y=Y)
grad = GradientChecker(dlogpdf_dlink, d2logpdf_dlink2, f.copy(), 'g')
#Apply constraints to link_f values
for constraint in link_f_constraints:
constraint('g', grad)
grad.randomize()
grad.checkgrad(verbose=1)
print grad
assert grad.checkgrad()
@with_setup(setUp, tearDown)
def t_d3logpdf_dlink3(self, model, Y, f, link_f_constraints):
print "\n{}".format(inspect.stack()[0][3])
d2logpdf_dlink2 = functools.partial(model.d2logpdf_dlink2, y=Y)
d3logpdf_dlink3 = functools.partial(model.d3logpdf_dlink3, y=Y)
grad = GradientChecker(d2logpdf_dlink2, d3logpdf_dlink3, f.copy(), 'g')
#Apply constraints to link_f values
for constraint in link_f_constraints:
constraint('g', grad)
grad.randomize()
grad.checkgrad(verbose=1)
print grad
assert grad.checkgrad()
#################
# dlink_dparams #
#################
@with_setup(setUp, tearDown)
def t_dlogpdf_link_dparams(self, model, Y, f, params, param_constraints):
print "\n{}".format(inspect.stack()[0][3])
print model
assert (
dparam_checkgrad(model.logpdf_link, model.dlogpdf_link_dtheta,
params, args=(f, Y), constraints=param_constraints,
randomize=False, verbose=True)
)
@with_setup(setUp, tearDown)
def t_dlogpdf_dlink_dparams(self, model, Y, f, params, param_constraints):
print "\n{}".format(inspect.stack()[0][3])
print model
assert (
dparam_checkgrad(model.dlogpdf_dlink, model.dlogpdf_dlink_dtheta,
params, args=(f, Y), constraints=param_constraints,
randomize=False, verbose=True)
)
@with_setup(setUp, tearDown)
def t_d2logpdf2_dlink2_dparams(self, model, Y, f, params, param_constraints):
print "\n{}".format(inspect.stack()[0][3])
print model
assert (
dparam_checkgrad(model.d2logpdf_dlink2, model.d2logpdf_dlink2_dtheta,
params, args=(f, Y), constraints=param_constraints,
randomize=False, verbose=True)
)
################
# laplace test #
################
@with_setup(setUp, tearDown)
def t_laplace_fit_rbf_white(self, model, X, Y, f, step, param_vals, param_names, constraints):
print "\n{}".format(inspect.stack()[0][3])
#Normalize
Y = Y/Y.max()
white_var = 0.001
kernel = GPy.kern.rbf(X.shape[1]) + GPy.kern.white(X.shape[1])
laplace_likelihood = GPy.likelihoods.Laplace(Y.copy(), model)
m = GPy.models.GPRegression(X.copy(), Y.copy(), kernel, likelihood=laplace_likelihood)
m.ensure_default_constraints()
m.constrain_fixed('white', white_var)
for param_num in range(len(param_names)):
name = param_names[param_num]
m[name] = param_vals[param_num]
constraints[param_num](name, m)
m.randomize()
m.checkgrad(verbose=1, step=step)
print m
assert m.checkgrad(step=step)
###########
# EP test #
###########
@with_setup(setUp, tearDown)
def t_ep_fit_rbf_white(self, model, X, Y, f, step, param_vals, param_names, constraints):
print "\n{}".format(inspect.stack()[0][3])
#Normalize
Y = Y/Y.max()
white_var = 0.001
kernel = GPy.kern.rbf(X.shape[1]) + GPy.kern.white(X.shape[1])
ep_likelihood = GPy.likelihoods.EP(Y.copy(), model)
m = GPy.models.GPRegression(X.copy(), Y.copy(), kernel, likelihood=ep_likelihood)
m.ensure_default_constraints()
m.constrain_fixed('white', white_var)
for param_num in range(len(param_names)):
name = param_names[param_num]
m[name] = param_vals[param_num]
constraints[param_num](name, m)
m.randomize()
m.checkgrad(verbose=1, step=step)
print m
assert m.checkgrad(step=step)
class LaplaceTests(unittest.TestCase):
"""
Specific likelihood tests, not general enough for the above tests
"""
def setUp(self):
self.N = 5
self.D = 3
self.X = np.random.rand(self.N, self.D)*10
self.real_std = 0.1
noise = np.random.randn(*self.X[:, 0].shape)*self.real_std
self.Y = (np.sin(self.X[:, 0]*2*np.pi) + noise)[:, None]
self.f = np.random.rand(self.N, 1)
self.var = 0.2
self.var = np.random.rand(1)
self.stu_t = GPy.likelihoods.student_t(deg_free=5, sigma2=self.var)
self.gauss = GPy.likelihoods.gaussian(gp_transformations.Log(), variance=self.var, D=self.D, N=self.N)
#Make a bigger step as lower bound can be quite curved
self.step = 1e-6
def tearDown(self):
self.stu_t = None
self.gauss = None
self.Y = None
self.f = None
self.X = None
def test_gaussian_d2logpdf_df2_2(self):
print "\n{}".format(inspect.stack()[0][3])
self.Y = None
self.gauss = None
self.N = 2
self.D = 1
self.X = np.linspace(0, self.D, self.N)[:, None]
self.real_std = 0.2
noise = np.random.randn(*self.X.shape)*self.real_std
self.Y = np.sin(self.X*2*np.pi) + noise
self.f = np.random.rand(self.N, 1)
self.gauss = GPy.likelihoods.gaussian(variance=self.var, D=self.D, N=self.N)
dlogpdf_df = functools.partial(self.gauss.dlogpdf_df, y=self.Y)
d2logpdf_df2 = functools.partial(self.gauss.d2logpdf_df2, y=self.Y)
grad = GradientChecker(dlogpdf_df, d2logpdf_df2, self.f.copy(), 'g')
grad.randomize()
grad.checkgrad(verbose=1)
self.assertTrue(grad.checkgrad())
if __name__ == "__main__":
print "Running unit tests"
unittest.main()
Reference in a new issue View git blame Copy permalink