本文整理汇总了Python中bayespy.nodes.GaussianARD.initialize_from_random方法的典型用法代码示例。如果您正苦于以下问题：Python GaussianARD.initialize_from_random方法的具体用法？Python GaussianARD.initialize_from_random怎么用？Python GaussianARD.initialize_from_random使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类bayespy.nodes.GaussianARD的用法示例。
在下文中一共展示了GaussianARD.initialize_from_random方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: pca
# 需要导入模块: from bayespy.nodes import GaussianARD [as 别名]
# 或者: from bayespy.nodes.GaussianARD import initialize_from_random [as 别名]
def pca():
np.random.seed(41)
M = 10
N = 3000
D = 5
# Construct the PCA model
alpha = Gamma(1e-3, 1e-3, plates=(D,), name='alpha')
W = GaussianARD(0, alpha, plates=(M,1), shape=(D,), name='W')
X = GaussianARD(0, 1, plates=(1,N), shape=(D,), name='X')
tau = Gamma(1e-3, 1e-3, name='tau')
W.initialize_from_random()
F = SumMultiply('d,d->', W, X)
Y = GaussianARD(F, tau, name='Y')
# Observe data
data = np.sum(np.random.randn(M,1,D-1) * np.random.randn(1,N,D-1), axis=-1) + 1e-1 * np.random.randn(M,N)
Y.observe(data)
# Initialize VB engine
Q = VB(Y, X, W, alpha, tau)
# Take one update step (so phi is ok)
Q.update(repeat=1)
Q.save()
# Run VB-EM
Q.update(repeat=200)
bpplt.pyplot.plot(np.cumsum(Q.cputime), Q.L, 'k-')
# Restore the state
Q.load()
# Run Riemannian conjugate gradient
#Q.optimize(X, alpha, maxiter=100, collapsed=[W, tau])
Q.optimize(W, tau, maxiter=100, collapsed=[X, alpha])
bpplt.pyplot.plot(np.cumsum(Q.cputime), Q.L, 'r:')
bpplt.pyplot.show()示例2: test_initialization
# 需要导入模块: from bayespy.nodes import GaussianARD [as 别名]
# 或者: from bayespy.nodes.GaussianARD import initialize_from_random [as 别名]
def test_initialization(self):
"""
Test initialization methods of GaussianARD
"""
X = GaussianARD(1, 2, shape=(2,), plates=(3,))
# Prior initialization
mu = 1 * np.ones((3, 2))
alpha = 2 * np.ones((3, 2))
X.initialize_from_prior()
u = X._message_to_child()
self.assertAllClose(u[0]*np.ones((3,2)),
mu)
self.assertAllClose(u[1]*np.ones((3,2,2)),
linalg.outer(mu, mu, ndim=1) +
misc.diag(1/alpha, ndim=1))
# Parameter initialization
mu = np.random.randn(3, 2)
alpha = np.random.rand(3, 2)
X.initialize_from_parameters(mu, alpha)
u = X._message_to_child()
self.assertAllClose(u[0], mu)
self.assertAllClose(u[1], linalg.outer(mu, mu, ndim=1) +
misc.diag(1/alpha, ndim=1))
# Value initialization
x = np.random.randn(3, 2)
X.initialize_from_value(x)
u = X._message_to_child()
self.assertAllClose(u[0], x)
self.assertAllClose(u[1], linalg.outer(x, x, ndim=1))
# Random initialization
X.initialize_from_random()
pass