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Changed default values of W and kappa for coregionalisation kernel. Changed names of keyword arguments from Nout and R to output_dim and rank.

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Neil Lawrence 2013-08-27 10:53:32 +02:00
parent b83d99cb3c
commit a61feb17a5
6 changed files with 330 additions and 235 deletions
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451
GPy/examples/regression.py
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@ -9,21 +9,224 @@ import pylab as pb
import numpy as np
import GPy
def coregionalisation_toy2(max_iters=100):
"""
A simple demonstration of coregionalisation on two sinusoidal functions.
"""
X1 = np.random.rand(50, 1) * 8
X2 = np.random.rand(30, 1) * 5
index = np.vstack((np.zeros_like(X1), np.ones_like(X2)))
X = np.hstack((np.vstack((X1, X2)), index))
Y1 = np.sin(X1) + np.random.randn(*X1.shape) * 0.05
Y2 = np.sin(X2) + np.random.randn(*X2.shape) * 0.05 + 2.
Y = np.vstack((Y1, Y2))
def toy_rbf_1d(optimizer='tnc', max_nb_eval_optim=100):
"""Run a simple demonstration of a standard Gaussian process fitting it to data sampled from an RBF covariance."""
data = GPy.util.datasets.toy_rbf_1d()
k1 = GPy.kern.rbf(1) + GPy.kern.bias(1)
k2 = GPy.kern.coregionalise(2, 1)
k = k1**k2
m = GPy.models.GPRegression(X, Y, kernel=k)
m.constrain_fixed('.*rbf_var', 1.)
# m.constrain_positive('.*kappa')
m.optimize('sim', messages=1, max_iters=max_iters)
# create simple GP Model
m = GPy.models.GPRegression(data['X'], data['Y'])
# optimize
m.optimize(optimizer, max_f_eval=max_nb_eval_optim)
# plot
m.plot()
print(m)
pb.figure()
Xtest1 = np.hstack((np.linspace(0, 9, 100)[:, None], np.zeros((100, 1))))
Xtest2 = np.hstack((np.linspace(0, 9, 100)[:, None], np.ones((100, 1))))
mean, var, low, up = m.predict(Xtest1)
GPy.util.plot.gpplot(Xtest1[:, 0], mean, low, up)
mean, var, low, up = m.predict(Xtest2)
GPy.util.plot.gpplot(Xtest2[:, 0], mean, low, up)
pb.plot(X1[:, 0], Y1[:, 0], 'rx', mew=2)
pb.plot(X2[:, 0], Y2[:, 0], 'gx', mew=2)
return m
def coregionalisation_toy(max_iters=100):
"""
A simple demonstration of coregionalisation on two sinusoidal functions.
"""
X1 = np.random.rand(50, 1) * 8
X2 = np.random.rand(30, 1) * 5
index = np.vstack((np.zeros_like(X1), np.ones_like(X2)))
X = np.hstack((np.vstack((X1, X2)), index))
Y1 = np.sin(X1) + np.random.randn(*X1.shape) * 0.05
Y2 = -np.sin(X2) + np.random.randn(*X2.shape) * 0.05
Y = np.vstack((Y1, Y2))
k1 = GPy.kern.rbf(1)
k2 = GPy.kern.coregionalise(2, 2)
k = k1**k2 #k1.prod(k2, tensor=True)
m = GPy.models.GPRegression(X, Y, kernel=k)
m.constrain_fixed('.*rbf_var', 1.)
# m.constrain_positive('kappa')
m.optimize(max_iters=max_iters)
pb.figure()
Xtest1 = np.hstack((np.linspace(0, 9, 100)[:, None], np.zeros((100, 1))))
Xtest2 = np.hstack((np.linspace(0, 9, 100)[:, None], np.ones((100, 1))))
mean, var, low, up = m.predict(Xtest1)
GPy.util.plot.gpplot(Xtest1[:, 0], mean, low, up)
mean, var, low, up = m.predict(Xtest2)
GPy.util.plot.gpplot(Xtest2[:, 0], mean, low, up)
pb.plot(X1[:, 0], Y1[:, 0], 'rx', mew=2)
pb.plot(X2[:, 0], Y2[:, 0], 'gx', mew=2)
return m
def coregionalisation_sparse(max_iters=100):
"""
A simple demonstration of coregionalisation on two sinusoidal functions using sparse approximations.
"""
X1 = np.random.rand(500, 1) * 8
X2 = np.random.rand(300, 1) * 5
index = np.vstack((np.zeros_like(X1), np.ones_like(X2)))
X = np.hstack((np.vstack((X1, X2)), index))
Y1 = np.sin(X1) + np.random.randn(*X1.shape) * 0.05
Y2 = -np.sin(X2) + np.random.randn(*X2.shape) * 0.05
Y = np.vstack((Y1, Y2))
num_inducing = 40
Z = np.hstack((np.random.rand(num_inducing, 1) * 8, np.random.randint(0, 2, num_inducing)[:, None]))
k1 = GPy.kern.rbf(1)
k2 = GPy.kern.coregionalise(2, 2)
k = k1**k2 #.prod(k2, tensor=True) # + GPy.kern.white(2,0.001)
m = GPy.models.SparseGPRegression(X, Y, kernel=k, Z=Z)
m.constrain_fixed('.*rbf_var', 1.)
m.constrain_fixed('iip')
m.constrain_bounded('noise_variance', 1e-3, 1e-1)
# m.optimize_restarts(5, robust=True, messages=1, max_iters=max_iters, optimizer='bfgs')
m.optimize(max_iters=max_iters)
# plotting:
pb.figure()
Xtest1 = np.hstack((np.linspace(0, 9, 100)[:, None], np.zeros((100, 1))))
Xtest2 = np.hstack((np.linspace(0, 9, 100)[:, None], np.ones((100, 1))))
mean, var, low, up = m.predict(Xtest1)
GPy.util.plot.gpplot(Xtest1[:, 0], mean, low, up)
mean, var, low, up = m.predict(Xtest2)
GPy.util.plot.gpplot(Xtest2[:, 0], mean, low, up)
pb.plot(X1[:, 0], Y1[:, 0], 'rx', mew=2)
pb.plot(X2[:, 0], Y2[:, 0], 'gx', mew=2)
y = pb.ylim()[0]
pb.plot(Z[:, 0][Z[:, 1] == 0], np.zeros(np.sum(Z[:, 1] == 0)) + y, 'r|', mew=2)
pb.plot(Z[:, 0][Z[:, 1] == 1], np.zeros(np.sum(Z[:, 1] == 1)) + y, 'g|', mew=2)
return m
def epomeo_gpx(max_iters=100):
"""Perform Gaussian process regression on the GPX data from the Mount Epomeo runs. Requires gpxpy to be installed on your system."""
data = GPy.util.datasets.epomeo_gpx()
num_data_list = []
for Xpart in data['X']:
num_data_list.append(Xpart.shape[0])
num_data_array = np.array(num_data_list)
num_data = num_data_array.sum()
Y = np.zeros((num_data, 3))
t = np.zeros((num_data, 2))
start = 0
for Xpart, index in zip(data['X'], range(len(data['X']))):
end = start+Xpart.shape[0]
t[start:end, :] = np.hstack((Xpart[:, 0:1],
index*np.ones((Xpart.shape[0], 1))))
Y[start:end, :] = Xpart[:, 1:4]
num_inducing = 40
Z = np.hstack((np.linspace(t[:,0].min(), t[:, 0].max(), num_inducing)[:, None],
np.random.randint(0, 4, num_inducing)[:, None]))
k1 = GPy.kern.rbf(1)
k2 = GPy.kern.coregionalise(output_dim=5, rank=5)
k = k1**k2
m = GPy.models.SparseGPRegression(t, Y, kernel=k, Z=Z)
m.constrain_fixed('.*rbf_var', 1.)
m.constrain_fixed('iip')
m.constrain_bounded('noise_variance', 1e-3, 1e-1)
# m.optimize_restarts(5, robust=True, messages=1, max_iters=max_iters, optimizer='bfgs')
# m.optimize(max_iters=max_iters)
return m
def multiple_optima(gene_number=937, resolution=80, model_restarts=10, seed=10000, max_iters=300):
"""Show an example of a multimodal error surface for Gaussian process regression. Gene 939 has bimodal behaviour where the noisy mode is higher."""
# Contour over a range of length scales and signal/noise ratios.
length_scales = np.linspace(0.1, 60., resolution)
log_SNRs = np.linspace(-3., 4., resolution)
data = GPy.util.datasets.della_gatta_TRP63_gene_expression(gene_number)
# data['Y'] = data['Y'][0::2, :]
# data['X'] = data['X'][0::2, :]
data['Y'] = data['Y'] - np.mean(data['Y'])
lls = GPy.examples.regression._contour_data(data, length_scales, log_SNRs, GPy.kern.rbf)
pb.contour(length_scales, log_SNRs, np.exp(lls), 20, cmap=pb.cm.jet)
ax = pb.gca()
pb.xlabel('length scale')
pb.ylabel('log_10 SNR')
xlim = ax.get_xlim()
ylim = ax.get_ylim()
# Now run a few optimizations
models = []
optim_point_x = np.empty(2)
optim_point_y = np.empty(2)
np.random.seed(seed=seed)
for i in range(0, model_restarts):
# kern = GPy.kern.rbf(1, variance=np.random.exponential(1.), lengthscale=np.random.exponential(50.))
kern = GPy.kern.rbf(1, variance=np.random.uniform(1e-3, 1), lengthscale=np.random.uniform(5, 50))
m = GPy.models.GPRegression(data['X'], data['Y'], kernel=kern)
m['noise_variance'] = np.random.uniform(1e-3, 1)
optim_point_x[0] = m['rbf_lengthscale']
optim_point_y[0] = np.log10(m['rbf_variance']) - np.log10(m['noise_variance']);
# optimize
m.optimize('scg', xtol=1e-6, ftol=1e-6, max_iters=max_iters)
optim_point_x[1] = m['rbf_lengthscale']
optim_point_y[1] = np.log10(m['rbf_variance']) - np.log10(m['noise_variance']);
pb.arrow(optim_point_x[0], optim_point_y[0], optim_point_x[1] - optim_point_x[0], optim_point_y[1] - optim_point_y[0], label=str(i), head_length=1, head_width=0.5, fc='k', ec='k')
models.append(m)
ax.set_xlim(xlim)
ax.set_ylim(ylim)
return m # (models, lls)
def _contour_data(data, length_scales, log_SNRs, kernel_call=GPy.kern.rbf):
"""Evaluate the GP objective function for a given data set for a range of signal to noise ratios and a range of lengthscales.
:data_set: A data set from the utils.datasets director.
:length_scales: a list of length scales to explore for the contour plot.
:log_SNRs: a list of base 10 logarithm signal to noise ratios to explore for the contour plot.
:kernel: a kernel to use for the 'signal' portion of the data."""
lls = []
total_var = np.var(data['Y'])
kernel = kernel_call(1, variance=1., lengthscale=1.)
model = GPy.models.GPRegression(data['X'], data['Y'], kernel=kernel)
for log_SNR in log_SNRs:
SNR = 10.**log_SNR
noise_var = total_var / (1. + SNR)
signal_var = total_var - noise_var
model.kern['.*variance'] = signal_var
model['noise_variance'] = noise_var
length_scale_lls = []
for length_scale in length_scales:
model['.*lengthscale'] = length_scale
length_scale_lls.append(model.log_likelihood())
lls.append(length_scale_lls)
return np.array(lls)
def olympic_100m_men(max_iters=100, kernel=None):
"""Run a standard Gaussian process regression on the Rogers and Girolami olympics data."""
data = GPy.util.datasets.olympic_100m_men()
@ -62,6 +265,20 @@ def olympic_marathon_men(max_iters=100, kernel=None):
print(m)
return m
def toy_rbf_1d(optimizer='tnc', max_nb_eval_optim=100):
"""Run a simple demonstration of a standard Gaussian process fitting it to data sampled from an RBF covariance."""
data = GPy.util.datasets.toy_rbf_1d()
# create simple GP Model
m = GPy.models.GPRegression(data['X'], data['Y'])
# optimize
m.optimize(optimizer, max_f_eval=max_nb_eval_optim)
# plot
m.plot()
print(m)
return m
def toy_rbf_1d_50(max_iters=100):
"""Run a simple demonstration of a standard Gaussian process fitting it to data sampled from an RBF covariance."""
data = GPy.util.datasets.toy_rbf_1d_50()
@ -150,203 +367,8 @@ def toy_ARD_sparse(max_iters=1000, kernel_type='linear', num_samples=300, D=4):
print(m)
return m
def silhouette(max_iters=100):
"""Predict the pose of a figure given a silhouette. This is a task from Agarwal and Triggs 2004 ICML paper."""
data = GPy.util.datasets.silhouette()
# create simple GP Model
m = GPy.models.GPRegression(data['X'], data['Y'])
# optimize
m.optimize(messages=True, max_iters=max_iters)
print(m)
return m
def coregionalisation_toy2(max_iters=100):
"""
A simple demonstration of coregionalisation on two sinusoidal functions.
"""
X1 = np.random.rand(50, 1) * 8
X2 = np.random.rand(30, 1) * 5
index = np.vstack((np.zeros_like(X1), np.ones_like(X2)))
X = np.hstack((np.vstack((X1, X2)), index))
Y1 = np.sin(X1) + np.random.randn(*X1.shape) * 0.05
Y2 = np.sin(X2) + np.random.randn(*X2.shape) * 0.05 + 2.
Y = np.vstack((Y1, Y2))
k1 = GPy.kern.rbf(1) + GPy.kern.bias(1)
k2 = GPy.kern.coregionalise(2, 1)
k = k1.prod(k2, tensor=True)
m = GPy.models.GPRegression(X, Y, kernel=k)
m.constrain_fixed('.*rbf_var', 1.)
# m.constrain_positive('.*kappa')
m.optimize('sim', messages=1, max_iters=max_iters)
pb.figure()
Xtest1 = np.hstack((np.linspace(0, 9, 100)[:, None], np.zeros((100, 1))))
Xtest2 = np.hstack((np.linspace(0, 9, 100)[:, None], np.ones((100, 1))))
mean, var, low, up = m.predict(Xtest1)
GPy.util.plot.gpplot(Xtest1[:, 0], mean, low, up)
mean, var, low, up = m.predict(Xtest2)
GPy.util.plot.gpplot(Xtest2[:, 0], mean, low, up)
pb.plot(X1[:, 0], Y1[:, 0], 'rx', mew=2)
pb.plot(X2[:, 0], Y2[:, 0], 'gx', mew=2)
return m
def coregionalisation_toy(max_iters=100):
"""
A simple demonstration of coregionalisation on two sinusoidal functions.
"""
X1 = np.random.rand(50, 1) * 8
X2 = np.random.rand(30, 1) * 5
index = np.vstack((np.zeros_like(X1), np.ones_like(X2)))
X = np.hstack((np.vstack((X1, X2)), index))
Y1 = np.sin(X1) + np.random.randn(*X1.shape) * 0.05
Y2 = -np.sin(X2) + np.random.randn(*X2.shape) * 0.05
Y = np.vstack((Y1, Y2))
k1 = GPy.kern.rbf(1)
k2 = GPy.kern.coregionalise(2, 2)
k = k1.prod(k2, tensor=True)
m = GPy.models.GPRegression(X, Y, kernel=k)
m.constrain_fixed('.*rbf_var', 1.)
# m.constrain_positive('kappa')
m.optimize(max_iters=max_iters)
pb.figure()
Xtest1 = np.hstack((np.linspace(0, 9, 100)[:, None], np.zeros((100, 1))))
Xtest2 = np.hstack((np.linspace(0, 9, 100)[:, None], np.ones((100, 1))))
mean, var, low, up = m.predict(Xtest1)
GPy.util.plot.gpplot(Xtest1[:, 0], mean, low, up)
mean, var, low, up = m.predict(Xtest2)
GPy.util.plot.gpplot(Xtest2[:, 0], mean, low, up)
pb.plot(X1[:, 0], Y1[:, 0], 'rx', mew=2)
pb.plot(X2[:, 0], Y2[:, 0], 'gx', mew=2)
return m
def coregionalisation_sparse(max_iters=100):
"""
A simple demonstration of coregionalisation on two sinusoidal functions using sparse approximations.
"""
X1 = np.random.rand(500, 1) * 8
X2 = np.random.rand(300, 1) * 5
index = np.vstack((np.zeros_like(X1), np.ones_like(X2)))
X = np.hstack((np.vstack((X1, X2)), index))
Y1 = np.sin(X1) + np.random.randn(*X1.shape) * 0.05
Y2 = -np.sin(X2) + np.random.randn(*X2.shape) * 0.05
Y = np.vstack((Y1, Y2))
num_inducing = 40
Z = np.hstack((np.random.rand(num_inducing, 1) * 8, np.random.randint(0, 2, num_inducing)[:, None]))
k1 = GPy.kern.rbf(1)
k2 = GPy.kern.coregionalise(2, 2)
k = k1.prod(k2, tensor=True) # + GPy.kern.white(2,0.001)
m = GPy.models.SparseGPRegression(X, Y, kernel=k, Z=Z)
m.constrain_fixed('.*rbf_var', 1.)
m.constrain_fixed('iip')
m.constrain_bounded('noise_variance', 1e-3, 1e-1)
# m.optimize_restarts(5, robust=True, messages=1, max_iters=max_iters, optimizer='bfgs')
m.optimize('bfgs', messages=1, max_iters=max_iters)
# plotting:
pb.figure()
Xtest1 = np.hstack((np.linspace(0, 9, 100)[:, None], np.zeros((100, 1))))
Xtest2 = np.hstack((np.linspace(0, 9, 100)[:, None], np.ones((100, 1))))
mean, var, low, up = m.predict(Xtest1)
GPy.util.plot.gpplot(Xtest1[:, 0], mean, low, up)
mean, var, low, up = m.predict(Xtest2)
GPy.util.plot.gpplot(Xtest2[:, 0], mean, low, up)
pb.plot(X1[:, 0], Y1[:, 0], 'rx', mew=2)
pb.plot(X2[:, 0], Y2[:, 0], 'gx', mew=2)
y = pb.ylim()[0]
pb.plot(Z[:, 0][Z[:, 1] == 0], np.zeros(np.sum(Z[:, 1] == 0)) + y, 'r|', mew=2)
pb.plot(Z[:, 0][Z[:, 1] == 1], np.zeros(np.sum(Z[:, 1] == 1)) + y, 'g|', mew=2)
return m
def multiple_optima(gene_number=937, resolution=80, model_restarts=10, seed=10000, max_iters=300):
"""Show an example of a multimodal error surface for Gaussian process regression. Gene 939 has bimodal behaviour where the noisey mode is higher."""
# Contour over a range of length scales and signal/noise ratios.
length_scales = np.linspace(0.1, 60., resolution)
log_SNRs = np.linspace(-3., 4., resolution)
data = GPy.util.datasets.della_gatta_TRP63_gene_expression(gene_number)
# data['Y'] = data['Y'][0::2, :]
# data['X'] = data['X'][0::2, :]
data['Y'] = data['Y'] - np.mean(data['Y'])
lls = GPy.examples.regression._contour_data(data, length_scales, log_SNRs, GPy.kern.rbf)
pb.contour(length_scales, log_SNRs, np.exp(lls), 20, cmap=pb.cm.jet)
ax = pb.gca()
pb.xlabel('length scale')
pb.ylabel('log_10 SNR')
xlim = ax.get_xlim()
ylim = ax.get_ylim()
# Now run a few optimizations
models = []
optim_point_x = np.empty(2)
optim_point_y = np.empty(2)
np.random.seed(seed=seed)
for i in range(0, model_restarts):
# kern = GPy.kern.rbf(1, variance=np.random.exponential(1.), lengthscale=np.random.exponential(50.))
kern = GPy.kern.rbf(1, variance=np.random.uniform(1e-3, 1), lengthscale=np.random.uniform(5, 50))
m = GPy.models.GPRegression(data['X'], data['Y'], kernel=kern)
m['noise_variance'] = np.random.uniform(1e-3, 1)
optim_point_x[0] = m['rbf_lengthscale']
optim_point_y[0] = np.log10(m['rbf_variance']) - np.log10(m['noise_variance']);
# optimize
m.optimize('scg', xtol=1e-6, ftol=1e-6, max_iters=max_iters)
optim_point_x[1] = m['rbf_lengthscale']
optim_point_y[1] = np.log10(m['rbf_variance']) - np.log10(m['noise_variance']);
pb.arrow(optim_point_x[0], optim_point_y[0], optim_point_x[1] - optim_point_x[0], optim_point_y[1] - optim_point_y[0], label=str(i), head_length=1, head_width=0.5, fc='k', ec='k')
models.append(m)
ax.set_xlim(xlim)
ax.set_ylim(ylim)
return m # (models, lls)
def _contour_data(data, length_scales, log_SNRs, kernel_call=GPy.kern.rbf):
"""Evaluate the GP objective function for a given data set for a range of signal to noise ratios and a range of lengthscales.
:data_set: A data set from the utils.datasets director.
:length_scales: a list of length scales to explore for the contour plot.
:log_SNRs: a list of base 10 logarithm signal to noise ratios to explore for the contour plot.
:kernel: a kernel to use for the 'signal' portion of the data."""
lls = []
total_var = np.var(data['Y'])
kernel = kernel_call(1, variance=1., lengthscale=1.)
model = GPy.models.GPRegression(data['X'], data['Y'], kernel=kernel)
for log_SNR in log_SNRs:
SNR = 10.**log_SNR
noise_var = total_var / (1. + SNR)
signal_var = total_var - noise_var
model.kern['.*variance'] = signal_var
model['noise_variance'] = noise_var
length_scale_lls = []
for length_scale in length_scales:
model['.*lengthscale'] = length_scale
length_scale_lls.append(model.log_likelihood())
lls.append(length_scale_lls)
return np.array(lls)
def robot_wireless(max_iters=100, kernel=None):
"""Predict the location of a robot given wirelss signal strengthr readings."""
"""Predict the location of a robot given wirelss signal strength readings."""
data = GPy.util.datasets.robot_wireless()
# create simple GP Model
@ -366,6 +388,21 @@ def robot_wireless(max_iters=100, kernel=None):
print('Sum of squares error on test data: ' + str(sse))
return m
def silhouette(max_iters=100):
"""Predict the pose of a figure given a silhouette. This is a task from Agarwal and Triggs 2004 ICML paper."""
data = GPy.util.datasets.silhouette()
# create simple GP Model
m = GPy.models.GPRegression(data['X'], data['Y'])
# optimize
m.optimize(messages=True, max_iters=max_iters)
print(m)
return m
def sparse_GP_regression_1D(num_samples=400, num_inducing=5, max_iters=100):
"""Run a 1D example of a sparse GP regression."""
# sample inputs and outputs