some tidying in the regression examples

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James Hensman 2013-11-27 17:02:04 +00:00
parent eafcd50af5
commit c86981a110

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@ -1,7 +1,6 @@
# Copyright (c) 2012, GPy authors (see AUTHORS.txt).
# Licensed under the BSD 3-clause license (see LICENSE.txt)
"""
Gaussian Processes regression examples
"""
@ -9,88 +8,107 @@ import pylab as pb
import numpy as np
import GPy
def coregionalization_toy2(max_iters=100):
def olympic_marathon_men(optimize=True, plot=True):
"""Run a standard Gaussian process regression on the Olympic marathon data."""
data = GPy.util.datasets.olympic_marathon_men()
# create simple GP Model
m = GPy.models.GPRegression(data['X'], data['Y'])
# set the lengthscale to be something sensible (defaults to 1)
m['rbf_lengthscale'] = 10
if optimize:
m.optimize('bfgs', max_iters=200)
if plot:
m.plot(plot_limits=(1850, 2050))
return m
def coregionalization_toy2(optimize=True, plot=True):
"""
A simple demonstration of coregionalization on two sinusoidal functions.
"""
#build a design matrix with a column of integers indicating the output
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))
#build a suitable set of observed variables
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))
#build the kernel
k1 = GPy.kern.rbf(1) + GPy.kern.bias(1)
k2 = GPy.kern.coregionalize(2,1)
k = k1**k2 #k = k1.prod(k2,tensor=True)
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)
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)
if optimize:
m.optimize('bfgs', max_iters=100)
if plot:
m.plot(fixed_inputs=[(1,0)])
m.plot(fixed_inputs=[(1,1)], ax=pb.gca())
return m
def coregionalization_toy(max_iters=100):
"""
A simple demonstration of coregionalization on two sinusoidal functions.
"""
X1 = np.random.rand(50, 1) * 8
X2 = np.random.rand(30, 1) * 5
X = np.vstack((X1, X2))
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))
#FIXME: Needs recovering once likelihoods are consolidated
#def coregionalization_toy(optimize=True, plot=True):
# """
# A simple demonstration of coregionalization on two sinusoidal functions.
# """
# X1 = np.random.rand(50, 1) * 8
# X2 = np.random.rand(30, 1) * 5
# X = np.vstack((X1, X2))
# 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)
# m = GPy.models.GPMultioutputRegression(X_list=[X1,X2],Y_list=[Y1,Y2],kernel_list=[k1])
# m.constrain_fixed('.*rbf_var', 1.)
# m.optimize(max_iters=100)
#
# fig, axes = pb.subplots(2,1)
# m.plot(fixed_inputs=[(1,0)],ax=axes[0])
# m.plot(fixed_inputs=[(1,1)],ax=axes[1])
# axes[0].set_title('Output 0')
# axes[1].set_title('Output 1')
# return m
k1 = GPy.kern.rbf(1)
m = GPy.models.GPMultioutputRegression(X_list=[X1,X2],Y_list=[Y1,Y2],kernel_list=[k1])
m.constrain_fixed('.*rbf_var', 1.)
m.optimize(max_iters=max_iters)
fig, axes = pb.subplots(2,1)
m.plot(fixed_inputs=[(1,0)],ax=axes[0])
m.plot(fixed_inputs=[(1,1)],ax=axes[1])
axes[0].set_title('Output 0')
axes[1].set_title('Output 1')
return m
def coregionalization_sparse(max_iters=100):
def coregionalization_sparse(optimize=True, plot=True):
"""
A simple demonstration of coregionalization 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))
#fetch the data from the non sparse examples
m = coregionalization_toy2(optimize=False, plot=False)
X, Y = m.X, m.likelihood.Y
k1 = GPy.kern.rbf(1)
#construct a model
m = GPy.models.SparseGPRegression(X,Y)
m.constrain_fixed('iip_\d+_1') # don't optimize the inducing input indexes
m = GPy.models.SparseGPMultioutputRegression(X_list=[X1,X2],Y_list=[Y1,Y2],kernel_list=[k1],num_inducing=5)
m.constrain_fixed('.*rbf_var',1.)
#m.optimize(messages=1)
m.optimize_restarts(5, robust=True, messages=1, max_iters=max_iters, optimizer='bfgs')
if optimize:
m.optimize('bfgs', max_iters=100, messages=1)
if plot:
m.plot(fixed_inputs=[(1,0)])
m.plot(fixed_inputs=[(1,1)], ax=pb.gca())
fig, axes = pb.subplots(2,1)
m.plot_single_output(output=0,ax=axes[0],plot_limits=(-1,9))
m.plot_single_output(output=1,ax=axes[1],plot_limits=(-1,9))
axes[0].set_title('Output 0')
axes[1].set_title('Output 1')
return m
def epomeo_gpx(max_iters=100):
"""Perform Gaussian process regression on the latitude and longitude data from the Mount Epomeo runs. Requires gpxpy to be installed on your system to load in the data."""
def epomeo_gpx(optimize=True, plot=True):
"""
Perform Gaussian process regression on the latitude and longitude data
from the Mount Epomeo runs. Requires gpxpy to be installed on your system
to load in the data.
"""
data = GPy.util.datasets.epomeo_gpx()
num_data_list = []
for Xpart in data['X']:
@ -119,14 +137,17 @@ def epomeo_gpx(max_iters=100):
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,messages=True)
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."""
"""
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)
@ -175,12 +196,15 @@ def multiple_optima(gene_number=937, resolution=80, model_restarts=10, seed=1000
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.
"""
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."""
:kernel: a kernel to use for the 'signal' portion of the data.
"""
lls = []
total_var = np.var(data['Y'])
@ -203,79 +227,58 @@ def _contour_data(data, length_scales, log_SNRs, kernel_call=GPy.kern.rbf):
return np.array(lls)
def olympic_100m_men(max_iters=100, kernel=None):
def olympic_100m_men(optimize=True, plot=True):
"""Run a standard Gaussian process regression on the Rogers and Girolami olympics data."""
data = GPy.util.datasets.olympic_100m_men()
# create simple GP Model
m = GPy.models.GPRegression(data['X'], data['Y'], kernel)
m = GPy.models.GPRegression(data['X'], data['Y'])
# set the lengthscale to be something sensible (defaults to 1)
if kernel==None:
m['rbf_lengthscale'] = 10
m['rbf_lengthscale'] = 10
# optimize
m.optimize(max_iters=max_iters)
if optimize:
m.optimize('bfgs', max_iters=200)
# plot
m.plot(plot_limits=(1850, 2050))
print(m)
if plot:
m.plot(plot_limits=(1850, 2050))
return m
def olympic_marathon_men(max_iters=100, kernel=None):
"""Run a standard Gaussian process regression on the Olympic marathon data."""
data = GPy.util.datasets.olympic_marathon_men()
# create simple GP Model
m = GPy.models.GPRegression(data['X'], data['Y'], kernel)
# set the lengthscale to be something sensible (defaults to 1)
if kernel==None:
m['rbf_lengthscale'] = 10
# optimize
m.optimize(max_iters=max_iters)
# plot
m.plot(plot_limits=(1850, 2050))
print(m)
return m
def toy_rbf_1d(optimizer='tnc', max_nb_eval_optim=100):
def toy_rbf_1d(optimize=True, plot=True):
"""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)
if optimize:
m.optimize('bfgs')
if plot:
m.plot()
return m
def toy_rbf_1d_50(max_iters=100):
def toy_rbf_1d_50(optimize=True, plot=True):
"""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()
# create simple GP Model
m = GPy.models.GPRegression(data['X'], data['Y'])
# optimize
m.optimize(max_iters=max_iters)
if optimize:
m.optimize('bfgs')
if plot:
m.plot()
# plot
m.plot()
print(m)
return m
def toy_poisson_rbf_1d(optimizer='bfgs', max_nb_eval_optim=100):
def toy_poisson_rbf_1d(optimize=True, plot=True):
"""Run a simple demonstration of a standard Gaussian process fitting it to data sampled from an RBF covariance."""
x_len = 400
X = np.linspace(0, 10, x_len)[:, None]
f_true = np.random.multivariate_normal(np.zeros(x_len), GPy.kern.rbf(1).K(X))
Y = np.array([np.random.poisson(np.exp(f)) for f in f_true])[:,None]
Y = np.array([np.random.poisson(np.exp(f)) for f in f_true]).reshape(x_len,1)
noise_model = GPy.likelihoods.poisson()
likelihood = GPy.likelihoods.EP(Y,noise_model)
@ -283,14 +286,14 @@ def toy_poisson_rbf_1d(optimizer='bfgs', max_nb_eval_optim=100):
# create simple GP Model
m = GPy.models.GPRegression(X, Y, likelihood=likelihood)
# optimize
m.optimize(optimizer, max_f_eval=max_nb_eval_optim)
# plot
m.plot()
print(m)
if optimize:
m.optimize('bfgs')
if plot:
m.plot()
return m
def toy_poisson_rbf_1d_laplace(optimizer='bfgs', max_nb_eval_optim=100):
def toy_poisson_rbf_1d_laplace(optimize=True, plot=True):
"""Run a simple demonstration of a standard Gaussian process fitting it to data sampled from an RBF covariance."""
x_len = 30
X = np.linspace(0, 10, x_len)[:, None]
@ -303,13 +306,13 @@ def toy_poisson_rbf_1d_laplace(optimizer='bfgs', max_nb_eval_optim=100):
# create simple GP Model
m = GPy.models.GPRegression(X, Y, likelihood=likelihood)
# optimize
m.optimize(optimizer, max_f_eval=max_nb_eval_optim)
# plot
m.plot()
# plot the real underlying rate function
pb.plot(X, np.exp(f_true), '--k', linewidth=2)
print(m)
if optimize:
m.optimize(optimizer, max_f_eval=max_nb_eval_optim)
if plot:
m.plot()
# plot the real underlying rate function
pb.plot(X, np.exp(f_true), '--k', linewidth=2)
return m
@ -459,7 +462,7 @@ def sparse_GP_regression_2D(num_samples=400, num_inducing=50, max_iters=100):
print(m)
return m
def uncertain_inputs_sparse_regression(max_iters=100):
def uncertain_inputs_sparse_regression(optimize=True, plot=True):
"""Run a 1D example of a sparse GP regression with uncertain inputs."""
fig, axes = pb.subplots(1, 2, figsize=(12, 5))