# Copyright 2016 the GPflow authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import tensorflow as tf
import numpy as np
from numpy.testing import assert_array_equal, assert_array_less, assert_allclose
import gpflow
from gpflow.test_util import GPflowTestCase
class TestMethods(GPflowTestCase):
def prepare(self):
rng = np.random.RandomState(0)
X = rng.randn(100, 2)
Y = rng.randn(100, 1)
Z = rng.randn(10, 2)
lik = gpflow.likelihoods.Gaussian()
kern = gpflow.kernels.Matern32(2)
Xs = rng.randn(10, 2)
# make one of each model
ms = []
#for M in (gpflow.models.GPMC, gpflow.models.VGP):
for M in (gpflow.models.VGP, gpflow.models.GPMC):
ms.append(M(X, Y, kern, lik))
for M in (gpflow.models.SGPMC, gpflow.models.SVGP):
ms.append(M(X, Y, kern, lik, Z))
ms.append(gpflow.models.GPR(X, Y, kern))
ms.append(gpflow.models.SGPR(X, Y, kern, Z=Z))
ms.append(gpflow.models.GPRFITC(X, Y, kern, Z=Z))
return ms, Xs, rng
def test_all(self):
# test sizes.
with self.test_context():
ms, _Xs, _rng = self.prepare()
for m in ms:
self.assertEqual(m.is_built_coherence(), gpflow.Build.YES)
def test_predict_f(self):
with self.test_context():
ms, Xs, _rng = self.prepare()
for m in ms:
mf, vf = m.predict_f(Xs)
assert_array_equal(mf.shape, vf.shape)
assert_array_equal(mf.shape, (10, 1))
assert_array_less(np.full_like(vf, -1e-6), vf)
def test_predict_y(self):
with self.test_context():
ms, Xs, _rng = self.prepare()
for m in ms:
mf, vf = m.predict_y(Xs)
assert_array_equal(mf.shape, vf.shape)
assert_array_equal(mf.shape, (10, 1))
assert_array_less(np.full_like(vf, -1e-6), vf)
def test_predict_density(self):
with self.test_context():
ms, Xs, rng = self.prepare()
Ys = rng.randn(10, 1)
for m in ms:
d = m.predict_density(Xs, Ys)
assert_array_equal(d.shape, (10, 1))
class TestSVGP(GPflowTestCase):
"""
The SVGP has four modes of operation. with and without whitening, with and
without diagonals.
Here we make sure that the bound on the likelihood is the same when using
both representations (as far as possible)
"""
def setUp(self):
self.rng = np.random.RandomState(0)
self.X = self.rng.randn(20, 1)
self.Y = self.rng.randn(20, 2)**2
self.Z = self.rng.randn(3, 1)
def test_white(self):
with self.test_context() as session:
m1 = gpflow.models.SVGP(
self.X, self.Y,
kern=gpflow.kernels.RBF(1),
likelihood=gpflow.likelihoods.Exponential(),
Z=self.Z,
q_diag=True,
whiten=True)
m2 = gpflow.models.SVGP(
self.X, self.Y,
kern=gpflow.kernels.RBF(1),
likelihood=gpflow.likelihoods.Exponential(),
Z=self.Z,
q_diag=False,
whiten=True)
qsqrt, qmean = self.rng.randn(2, 3, 2)
qsqrt = (qsqrt**2) * 0.01
m1.q_sqrt = qsqrt
m1.q_mu = qmean
m2.q_sqrt = np.array([np.diag(qsqrt[:, 0]), np.diag(qsqrt[:, 1])])
m2.q_mu = qmean
obj1 = session.run(m1.objective, feed_dict=m1.feeds)
obj2 = session.run(m2.objective, feed_dict=m2.feeds)
assert_allclose(obj1, obj2)
def test_notwhite(self):
with self.test_context() as session:
m1 = gpflow.models.SVGP(
self.X,
self.Y,
kern=gpflow.kernels.RBF(1) + gpflow.kernels.White(1),
likelihood=gpflow.likelihoods.Exponential(),
Z=self.Z,
q_diag=True,
whiten=False)
m2 = gpflow.models.SVGP(
self.X,
self.Y,
kern=gpflow.kernels.RBF(1) + gpflow.kernels.White(1),
likelihood=gpflow.likelihoods.Exponential(),
Z=self.Z,
q_diag=False,
whiten=False)
qsqrt, qmean = self.rng.randn(2, 3, 2)
qsqrt = (qsqrt**2)*0.01
m1.q_sqrt = qsqrt
m1.q_mu = qmean
m2.q_sqrt = np.array([np.diag(qsqrt[:, 0]), np.diag(qsqrt[:, 1])])
m2.q_mu = qmean
obj1 = session.run(m1.objective, feed_dict=m1.feeds)
obj2 = session.run(m2.objective, feed_dict=m2.feeds)
assert_allclose(obj1, obj2)
def test_q_sqrt_fixing(self):
"""
In response to bug #46, we need to make sure that the q_sqrt matrix can be fixed
"""
with self.test_context() as session:
m1 = gpflow.models.SVGP(
self.X, self.Y,
kern=gpflow.kernels.RBF(1) + gpflow.kernels.White(1),
likelihood=gpflow.likelihoods.Exponential(),
Z=self.Z)
m1.q_sqrt.trainable = False
class TestStochasticGradients(GPflowTestCase):
"""
In response to bug #281, we need to make sure stochastic update
happens correctly in tf optimizer mode.
To do this compare stochastic updates with deterministic updates
that should be equivalent.
Data term in svgp likelihood is
\sum_{i=1^N}E_{q(i)}[\log p(y_i | f_i )
This sum is then approximated with an unbiased minibatch estimate.
In this test we substitute a deterministic analogue of the batchs
sampler for which we can predict the effects of different updates.
"""
def setUp(self):
tf.set_random_seed(0)
self.XAB = np.atleast_2d(np.array([0., 1.])).T
self.YAB = np.atleast_2d(np.array([-1., 3.])).T
self.sharedZ = np.atleast_2d(np.array([0.5]) )
self.indexA = 0
self.indexB = 1
def get_indexed_data(self, baseX, baseY, indices):
newX = baseX[indices]
newY = baseY[indices]
return newX, newY
def get_model(self, X, Y, Z, minibatch_size):
model = gpflow.models.SVGP(
X, Y, kern=gpflow.kernels.RBF(1),
likelihood=gpflow.likelihoods.Gaussian(),
Z=Z, minibatch_size=minibatch_size)
return model
def get_opt(self):
learning_rate = .001
opt = gpflow.train.GradientDescentOptimizer(learning_rate, use_locking=True)
return opt
def get_indexed_model(self, X, Y, Z, minibatch_size, indices):
Xindices, Yindices = self.get_indexed_data(X, Y, indices)
indexedModel = self.get_model(Xindices, Yindices, Z, minibatch_size)
return indexedModel
def check_models_close(self, m1, m2, tolerance=1e-2):
m1_params = {p.pathname: p for p in list(m1.trainable_parameters)}
m2_params = {p.pathname: p for p in list(m2.trainable_parameters)}
if set(m2_params.keys()) != set(m2_params.keys()):
return False
for key in m1_params:
p1 = m1_params[key]
p2 = m2_params[key]
if not np.allclose(p1.read_value(), p2.read_value(), rtol=tolerance, atol=tolerance):
return False
return True
def compare_models(self, indicesOne, indicesTwo,
batchOne, batchTwo, maxiter, checkSame=True):
m1 = self.get_indexed_model(self.XAB, self.YAB, self.sharedZ, batchOne, indicesOne)
m2 = self.get_indexed_model(self.XAB, self.YAB, self.sharedZ, batchTwo, indicesTwo)
opt1 = self.get_opt()
opt2 = self.get_opt()
opt1.minimize(m1, maxiter=maxiter)
opt2.minimize(m2, maxiter=maxiter)
if checkSame:
self.assertTrue(self.check_models_close(m1, m2))
else:
self.assertFalse(self.check_models_close(m1, m2))
# TODO(@awav):
# These three tests below can be extremly unstable on different machines
# and different settings.
def testOne(self):
with self.test_context():
self.compare_models(
[self.indexA, self.indexB],
[self.indexB, self.indexA],
batchOne=2, batchTwo=2, maxiter=3)
def testTwo(self):
with self.test_context():
self.compare_models(
[self.indexA, self.indexB],
[self.indexA, self.indexA],
batchOne=1, batchTwo=2, maxiter=1)
def testThree(self):
with self.test_context():
self.compare_models(
[self.indexA, self.indexA],
[self.indexA, self.indexB],
batchOne=1, batchTwo=1, maxiter=2)
class TestSparseMCMC(GPflowTestCase):
"""
This test makes sure that when the inducing points are the same as the data
points, the sparse mcmc is the same as full mcmc
"""
def test_likelihoods_and_gradients(self):
with self.test_context() as session:
rng = np.random.RandomState(0)
X = rng.randn(10, 1)
Y = rng.randn(10, 1)
v_vals = rng.randn(10, 1)
lik = gpflow.likelihoods.StudentT
m1 = gpflow.models.GPMC(
X=X, Y=Y,
kern=gpflow.kernels.Exponential(1),
likelihood=lik())
m2 = gpflow.models.SGPMC(
X=X, Y=Y,
kern=gpflow.kernels.Exponential(1),
likelihood=lik(), Z=X.copy())
m1.V = v_vals
m2.V = v_vals.copy()
m1.kern.lengthscale = .8
m2.kern.lengthscale = .8
m1.kern.variance = 4.2
m2.kern.variance = 4.2
f1 = session.run(m1.objective)
f2 = session.run(m2.objective)
assert_allclose(f1, f2)
# the parameters might not be in the same order, so
# sort the gradients before checking they're the same
# g1 = self.m1.objective(self.m1.get_free_state())
# g2 = self.m2.objective(self.m2.get_free_state())
# g1 = np.sort(g1)
# g2 = np.sort(g2)
# self.assertTrue(np.allclose(g1, g2, 1e-4))
if __name__ == "__main__":
tf.test.main()