GPy/GPy/examples/dimensionality_reduction.py
2013-04-15 15:59:54 +01:00

268 lines
7.5 KiB
Python

# Copyright (c) 2012, GPy authors (see AUTHORS.txt).
# Licensed under the BSD 3-clause license (see LICENSE.txt)
import numpy as np
import pylab as pb
from matplotlib import pyplot as plt, pyplot
import GPy
default_seed = np.random.seed(123344)
def BGPLVM(seed=default_seed):
N = 10
M = 3
Q = 2
D = 4
# generate GPLVM-like data
X = np.random.rand(N, Q)
k = GPy.kern.rbf(Q) + GPy.kern.white(Q, 0.00001)
K = k.K(X)
Y = np.random.multivariate_normal(np.zeros(N), K, D).T
k = GPy.kern.linear(Q, ARD=True) + GPy.kern.white(Q)
# k = GPy.kern.rbf(Q) + GPy.kern.rbf(Q) + GPy.kern.white(Q)
# k = GPy.kern.rbf(Q) + GPy.kern.bias(Q) + GPy.kern.white(Q, 0.00001)
# k = GPy.kern.rbf(Q, ARD = False) + GPy.kern.white(Q, 0.00001)
m = GPy.models.Bayesian_GPLVM(Y, Q, kernel=k, M=M)
m.constrain_positive('(rbf|bias|noise|white|S)')
# m.constrain_fixed('S', 1)
# pb.figure()
# m.plot()
# pb.title('PCA initialisation')
# pb.figure()
# m.optimize(messages = 1)
# m.plot()
# pb.title('After optimisation')
m.ensure_default_constraints()
m.randomize()
m.checkgrad(verbose=1)
return m
def GPLVM_oil_100(optimize=True, M=15):
data = GPy.util.datasets.oil_100()
# create simple GP model
kernel = GPy.kern.rbf(6, ARD=True) + GPy.kern.bias(6)
m = GPy.models.GPLVM(data['X'], 6, kernel=kernel, M=M)
m.data_labels = data['Y'].argmax(axis=1)
# optimize
m.ensure_default_constraints()
if optimize:
m.optimize('scg', messages=1)
# plot
print(m)
m.plot_latent(labels=m.data_labels)
return m
def BGPLVM_oil(optimize=True, N=100, Q=10, M=15, max_f_eval=300):
data = GPy.util.datasets.oil()
# create simple GP model
kernel = GPy.kern.rbf(Q, ARD=True) + GPy.kern.bias(Q) + GPy.kern.white(Q, 0.001)
m = GPy.models.Bayesian_GPLVM(data['X'][:N], Q, kernel=kernel, M=M)
m.data_labels = data['Y'][:N].argmax(axis=1)
# optimize
if optimize:
m.constrain_fixed('noise', 0.05)
m.ensure_default_constraints()
m.optimize('scg', messages=1, max_f_eval=max(80, max_f_eval))
m.unconstrain('noise')
m.constrain_positive('noise')
m.optimize('scg', messages=1, max_f_eval=max(0, max_f_eval - 80))
else:
m.ensure_default_constraints()
# plot
print(m)
m.plot_latent(labels=m.data_labels)
pb.figure()
pb.bar(np.arange(m.kern.D), 1. / m.input_sensitivity())
return m
def oil_100():
data = GPy.util.datasets.oil_100()
m = GPy.models.GPLVM(data['X'], 2)
# optimize
m.ensure_default_constraints()
m.optimize(messages=1, max_iters=2)
# plot
print(m)
# m.plot_latent(labels=data['Y'].argmax(axis=1))
return m
def mrd_simulation(plot_sim=False):
# num = 2
# ard1 = np.array([1., 1, 0, 0], dtype=float)
# ard2 = np.array([0., 1, 1, 0], dtype=float)
# ard1[ard1 == 0] = 1E-10
# ard2[ard2 == 0] = 1E-10
# ard1i = 1. / ard1
# ard2i = 1. / ard2
# k = GPy.kern.rbf(Q, ARD=True, lengthscale=ard1i) + GPy.kern.bias(Q, 0) + GPy.kern.white(Q, 0.0001)
# Y1 = np.random.multivariate_normal(np.zeros(N), k.K(X), D1).T
# Y1 -= Y1.mean(0)
#
# k = GPy.kern.rbf(Q, ARD=True, lengthscale=ard2i) + GPy.kern.bias(Q, 0) + GPy.kern.white(Q, 0.0001)
# Y2 = np.random.multivariate_normal(np.zeros(N), k.K(X), D2).T
# Y2 -= Y2.mean(0)
# make_params = lambda ard: np.hstack([[1], ard, [1, .3]])
D1, D2, D3, N, M, Q = 6, 7, 8, 150, 18, 5
x = np.linspace(0, 2 * np.pi, N)[:, None]
s1 = np.vectorize(lambda x: np.sin(x))
s2 = np.vectorize(lambda x: np.cos(x))
s3 = np.vectorize(lambda x:-np.exp(-np.cos(2 * x)))
sS = np.vectorize(lambda x: np.sin(2 * x))
s1 = s1(x)
s2 = s2(x)
s3 = s3(x)
sS = sS(x)
s1 -= s1.mean()
s2 -= s2.mean()
s3 -= s3.mean()
sS -= sS.mean()
s1 /= np.abs(s1).max()
s2 /= np.abs(s2).max()
s3 /= np.abs(s3).max()
sS /= np.abs(sS).max()
S1 = np.hstack([s1, sS])
S2 = np.hstack([s2, sS])
S3 = np.hstack([s3, sS])
Y1 = S1.dot(np.random.randn(S1.shape[1], D1))
Y2 = S2.dot(np.random.randn(S2.shape[1], D2))
Y3 = S3.dot(np.random.randn(S3.shape[1], D3))
Y1 += .1 * np.random.randn(*Y1.shape)
Y2 += .1 * np.random.randn(*Y2.shape)
Y3 += .1 * np.random.randn(*Y3.shape)
Y1 -= Y1.mean(0)
Y2 -= Y2.mean(0)
Y3 -= Y3.mean(0)
Y1 /= Y1.std(0)
Y2 /= Y2.std(0)
Y3 /= Y3.std(0)
Slist = [s1, s2, sS]
Ylist = [Y1, Y2]
if plot_sim:
import pylab
import itertools
fig = pylab.figure("MRD Simulation", figsize=(8, 6))
fig.clf()
ax = fig.add_subplot(2, 1, 1)
labls = sorted(filter(lambda x: x.startswith("s"), locals()))
for S, lab in itertools.izip(Slist, labls):
ax.plot(x, S, label=lab)
ax.legend()
for i, Y in enumerate(Ylist):
ax = fig.add_subplot(2, len(Ylist), len(Slist) + i)
ax.imshow(Y)
ax.set_title("Y{}".format(i + 1))
pylab.draw()
pylab.tight_layout()
from GPy.models import mrd
from GPy import kern
reload(mrd); reload(kern)
k = kern.rbf(Q, ARD=True) + kern.bias(Q) + kern.white(Q)
m = mrd.MRD(*Ylist, Q=Q, M=M, kernel=k, init="single", _debug=False)
m.ensure_default_constraints()
# cstr = "noise|white|variance"
# m.unconstrain(cstr); m.constrain_bounded(cstr, 1e-10, 1.)
m.auto_scale_factor = True
# fig = pyplot.figure("expected", figsize=(8, 3))
# ax = fig.add_subplot(121)
# ax.bar(np.arange(ard1.size) + .1, ard1)
# ax = fig.add_subplot(122)
# ax.bar(np.arange(ard2.size) + .1, ard2)
return m
def mrd_silhouette():
pass
def brendan_faces():
data = GPy.util.datasets.brendan_faces()
Y = data['Y'][0:-1:10, :]
m = GPy.models.GPLVM(data['Y'], 2)
# optimize
m.ensure_default_constraints()
m.optimize(messages=1, max_f_eval=10000)
ax = m.plot_latent()
y = m.likelihood.Y[0, :]
data_show = GPy.util.visualize.image_show(y[None, :], dimensions=(20, 28), transpose=True, invert=False, scale=False)
lvm_visualizer = GPy.util.visualize.lvm(m, data_show, ax)
raw_input('Press enter to finish')
plt.close('all')
return m
def stick():
data = GPy.util.datasets.stick()
m = GPy.models.GPLVM(data['Y'], 2)
# optimize
m.ensure_default_constraints()
m.optimize(messages=1, max_f_eval=10000)
ax = m.plot_latent()
y = m.likelihood.Y[0, :]
data_show = GPy.util.visualize.stick_show(y[None, :], connect=data['connect'])
lvm_visualizer = GPy.util.visualize.lvm(m, data_show, ax)
raw_input('Press enter to finish')
plt.close('all')
return m
# def BGPLVM_oil():
# data = GPy.util.datasets.oil()
# Y, X = data['Y'], data['X']
# X -= X.mean(axis=0)
# X /= X.std(axis=0)
#
# Q = 10
# M = 30
#
# kernel = GPy.kern.rbf(Q, ARD=True) + GPy.kern.bias(Q) + GPy.kern.white(Q)
# m = GPy.models.Bayesian_GPLVM(X, Q, kernel=kernel, M=M)
# # m.scale_factor = 100.0
# m.constrain_positive('(white|noise|bias|X_variance|rbf_variance|rbf_length)')
# from sklearn import cluster
# km = cluster.KMeans(M, verbose=10)
# Z = km.fit(m.X).cluster_centers_
# # Z = GPy.util.misc.kmm_init(m.X, M)
# m.set('iip', Z)
# m.set('bias', 1e-4)
# # optimize
# # m.ensure_default_constraints()
#
# import pdb; pdb.set_trace()
# m.optimize('tnc', messages=1)
# print m
# m.plot_latent(labels=data['Y'].argmax(axis=1))
# return m