def __init__(self, dim, a=None, b=None, c=None, D=None, Q=None, name=None):
_Q = np.eye(dim) * 0.5 if Q is None else Q
super().__init__(dim=dim, Q=_Q, name=name)
self.a = Param(np.ones(self.dim) * 0.8 if a is None else a)
self.b = Param(np.ones(self.dim) * 0.2 if b is None else b)
self.c = Param(np.ones(self.dim) * 5.0 if c is None else c)
self.D = Param(np.eye(self.dim) * 2.0 if D is None else D)
def __init__(self, state_dim, state_idxs=None, W=None, t=None):
Cost.__init__(self)
self.state_dim = state_dim
if W is not None:
self.W = Param(np.reshape(W, (state_dim, state_dim)),
trainable=False)
else:
self.W = Param(np.ones((state_dim, state_dim)), trainable=False)
if t is not None:
self.t = Param(np.reshape(t, (1, state_dim)), trainable=False)
else:
self.t = Param(np.zeros((1, state_dim)), trainable=False)
if state_idxs is None:
state_idxs = np.linspace(0,
state_dim - 1,
num=state_dim,
dtype=int)
self.m_idxs = []
self.s_idxs = []
for index in state_idxs:
self.m_idxs.append([0, index])
element = []
for j in state_idxs:
element.append([index, j])
self.s_idxs.append(element)
def __init__(self, dim, input_dim=0, kern=None, Z=None, n_ind_pts=100,
mean_fn=None, Q_diag=None, Umu=None, Ucov_chol=None,
jitter=gps.numerics.jitter_level, name=None):
super().__init__(name=name)
self.OBSERVATIONS_AS_INPUT = False
self.dim = dim
self.input_dim = input_dim
self.jitter = jitter
self.Q_sqrt = Param(np.ones(self.dim) if Q_diag is None else Q_diag ** 0.5, transform=gtf.positive)
self.n_ind_pts = n_ind_pts if Z is None else (Z[0].shape[-2] if isinstance(Z, list) else Z.shape[-2])
if isinstance(Z, np.ndarray) and Z.ndim == 2:
self.Z = mf.SharedIndependentMof(gp.features.InducingPoints(Z))
else:
Z_list = [np.random.randn(self.n_ind_pts, self.dim + self.input_dim)
for _ in range(self.dim)] if Z is None else [z for z in Z]
self.Z = mf.SeparateIndependentMof([gp.features.InducingPoints(z) for z in Z_list])
if isinstance(kern, gp.kernels.Kernel):
self.kern = mk.SharedIndependentMok(kern, self.dim)
else:
kern_list = kern or [gp.kernels.Matern32(self.dim + self.input_dim, ARD=True) for _ in range(self.dim)]
self.kern = mk.SeparateIndependentMok(kern_list)
self.mean_fn = mean_fn or mean_fns.Identity(self.dim)
self.Umu = Param(np.zeros((self.dim, self.n_ind_pts)) if Umu is None else Umu) # Lm^-1(Umu - m(Z))
transform = gtf.LowerTriangular(self.n_ind_pts, num_matrices=self.dim, squeeze=False)
self.Ucov_chol = Param(np.tile(np.eye(self.n_ind_pts)[None, ...], [self.dim, 1, 1])
if Ucov_chol is None else Ucov_chol, transform=transform) # Lm^-1(Ucov_chol)
self._Kzz = None
def __init__(self, dim, input_dim=None, A=None, B=None, C=None, D=None, Q=None, name=None):
_input_dim = input_dim or dim
_Q = np.eye(dim) * np.sqrt(10.) if Q is None else Q
super().__init__(dim=dim, input_dim=_input_dim, Q=_Q, name=name)
self.A = Param(np.eye(self.dim) * 0.5 if A is None else A)
self.B = Param(np.eye(self.dim) * 25. if B is None else B)
self.C = Param(np.eye(self.dim) * 8.0 if C is None else C)
self.D = Param(np.eye(self.dim, self.input_dim) * 1.2 if D is None else D)
def __init__(self, latent_dim, input_dim, A=None, B=None, C=None, d=None, Q=None, name=None):
_Q = np.eye(latent_dim) * 0.2 if Q is None else Q
super().__init__(dim=latent_dim, input_dim=input_dim, Q=_Q, name=name)
self.OBSERVATIONS_AS_INPUT = True
self.A = Param(np.eye(self.dim) * 0.2 if A is None else A)
self.B = Param(np.eye(self.dim, self.input_dim) * (-0.2) if B is None else B)
self.C = Param(np.eye(self.dim, self.input_dim) * 0.1 if C is None else C)
self.d = Param(np.zeros(self.dim) + 0 if d is None else d)
def _build_encoder(self, layers):
Ws, bs = [], []
dims = [self.X_dim + self.Y_dim] + layers + [self.latent_dim * 2]
for dim_in, dim_out in zip(dims[:-1], dims[1:]):
init_xavier_std = (2.0 / (dim_in + dim_out)) ** 0.5
Ws.append(Param((np.random.randn(dim_in, dim_out) * init_xavier_std).astype(np.float32)))
bs.append(Param(np.zeros(dim_out).astype(np.float32)))
self.Ws, self.bs = ParamList(Ws), ParamList(bs)
def __init__(self, dim, input_dim=0, Q=None, name=None):
super().__init__(name=name)
self.OBSERVATIONS_AS_INPUT = False
self.dim = dim
self.input_dim = input_dim
if Q is None or Q.ndim == 2:
self.Qchol = Param(np.eye(self.dim) if Q is None else np.linalg.cholesky(Q),
gtf.LowerTriangular(self.dim, squeeze=True))
elif Q.ndim == 1:
self.Qchol = Param(Q ** 0.5)
def __init__(self, state_dim, W=None, t=None):
Reward.__init__(self)
self.state_dim = state_dim
if W is not None:
self.W = Param(np.reshape(W, (state_dim, state_dim)), trainable=False)
else:
self.W = Param(np.eye(state_dim), trainable=False)
if t is not None:
self.t = Param(np.reshape(t, (1, state_dim)), trainable=False)
else:
self.t = Param(np.zeros((1, state_dim)), trainable=False)
def __init__(self,
input_dim,
variance=1.0,
frequency=np.array([1.0, 1.0]),
lengthscale=1.0,
correlation=0.0,
max_freq=1.0,
active_dims=None):
assert (input_dim == 1
) # the derivations are valid only for one dimensional input
Kernel.__init__(self, input_dim=input_dim, active_dims=active_dims)
self.variance = Param(variance, transforms.positive)
self.frequency = Param(frequency, transforms.Logistic(0.0, max_freq))
self.lengthscale = Param(lengthscale, transforms.positive)
correlation = np.clip(correlation, 1e-4,
1 - 1e-4) # clip for numerical reasons
self.correlation = Param(correlation, transforms.Logistic())
def __init__(self,
input_dim,
variance=1.0,
lengthscales=None,
frequency=1.0,
active_dims=None,
ARD=False):
Stationary.__init__(self,
input_dim=input_dim,
variance=variance,
lengthscales=lengthscales,
active_dims=active_dims,
ARD=ARD)
self.frequency = Param(frequency,
transforms.positive,
dtype=float_type)
self.frequency.prior = gpflow.priors.Exponential(1.0)
self.variance.prior = gpflow.priors.LogNormal(0, 1)
def __init__(self, state_dim):
Reward.__init__(self)
self.state_dim = state_dim
self.W = Param(np.random.rand(state_dim, state_dim), trainable=False)
self.t = Param(np.random.rand(1, state_dim), trainable=False)
def __init__(self, state_dim, W):
Reward.__init__(self)
self.state_dim = state_dim
self.W = Param(np.reshape(W, (state_dim, 1)), trainable=False)
def __init__(self, state_dim):
Reward.__init__(self)
self.state_dim = state_dim
self.W = Param(np.ones((state_dim, state_dim)), trainable=False)
self.t = Param(np.zeros((1, state_dim)), trainable=False)
def to_param_list(var_list, name):
param_list = []
for idx, var in enumerate(var_list):
name_idx = '{name}_{idx}'.format(name=name, idx=idx)
param_list.append(Param(var, dtype=float_type, name=name_idx))
return ParamList(param_list)
def __init__(self,
latent_dim,
Y,
inputs=None,
emissions=None,
px1_mu=None,
px1_cov=None,
kern=None,
Z=None,
n_ind_pts=100,
mean_fn=None,
Q_diag=None,
Umu=None,
Ucov_chol=None,
qx1_mu=None,
qx1_cov=None,
As=None,
bs=None,
Ss=None,
n_samples=100,
batch_size=None,
chunking=False,
seed=None,
parallel_iterations=10,
jitter=gp.settings.numerics.jitter_level,
name=None):
super().__init__(latent_dim,
Y[0],
inputs=None if inputs is None else inputs[0],
emissions=emissions,
px1_mu=px1_mu,
px1_cov=None,
kern=kern,
Z=Z,
n_ind_pts=n_ind_pts,
mean_fn=mean_fn,
Q_diag=Q_diag,
Umu=Umu,
Ucov_chol=Ucov_chol,
qx1_mu=qx1_mu,
qx1_cov=None,
As=None,
bs=None,
Ss=False if Ss is False else None,
n_samples=n_samples,
seed=seed,
parallel_iterations=parallel_iterations,
jitter=jitter,
name=name)
self.T = [Y_s.shape[0] for Y_s in Y]
self.T_tf = tf.constant(self.T, dtype=gp.settings.int_type)
self.max_T = max(self.T)
self.sum_T = float(sum(self.T))
self.n_seq = len(self.T)
self.batch_size = batch_size
self.chunking = chunking
if self.batch_size is None:
self.Y = ParamList(Y, trainable=False)
else:
_Y = np.stack([
np.concatenate(
[Ys, np.zeros((self.max_T - len(Ys), self.obs_dim))])
for Ys in Y
])
self.Y = Param(_Y, trainable=False)
if inputs is not None:
if self.batch_size is None:
self.inputs = ParamList(inputs, trainable=False)
else:
desired_length = self.max_T if self.chunking else self.max_T - 1
_inputs = [
np.concatenate([
inputs[s],
np.zeros(
(desired_length - len(inputs[s]), self.input_dim))
]) for s in range(self.n_seq)
] # pad the inputs
self.inputs = Param(_inputs, trainable=False)
if qx1_mu is None:
self.qx1_mu = Param(np.zeros((self.n_seq, self.latent_dim)))
self.qx1_cov_chol = Param(
np.tile(np.eye(self.latent_dim)[None, ...], [self.n_seq, 1, 1])
if qx1_cov is None else np.linalg.cholesky(qx1_cov),
transform=gtf.LowerTriangular(self.latent_dim,
num_matrices=self.n_seq))
_As = [np.ones((T_s - 1, self.latent_dim))
for T_s in self.T] if As is None else As
_bs = [np.zeros((T_s - 1, self.latent_dim))
for T_s in self.T] if bs is None else bs
if Ss is not False:
_S_chols = [np.tile(self.Q_sqrt.value.copy()[None, ...], [T_s - 1, 1]) for T_s in self.T] if Ss is None \
else [np.sqrt(S) if S.ndim == 2 else np.linalg.cholesky(S) for S in Ss]
if self.batch_size is None:
self.As = ParamList(_As)
self.bs = ParamList(_bs)
if Ss is not False:
self.S_chols = ParamList([
Param(Sc,
transform=gtf.positive if Sc.ndim == 2 else
gtf.LowerTriangular(self.latent_dim,
num_matrices=Sc.shape[0]))
for Sc in _S_chols
])
else:
_As = np.stack([
np.concatenate(
[_A,
np.zeros((self.max_T - len(_A) - 1, *_A.shape[1:]))])
for _A in _As
])
_bs = np.stack([
np.concatenate([
_b,
np.zeros((self.max_T - len(_b) - 1, self.latent_dim))
]) for _b in _bs
])
self.As = Param(_As)
self.bs = Param(_bs)
if Ss is not False:
_S_chols = [
np.concatenate([
_S,
np.zeros((self.max_T - len(_S) - 1, *_S.shape[1:]))
]) for _S in _S_chols
]
_S_chols = np.stack(_S_chols)
self.S_chols = Param(_S_chols, transform=gtf.positive if _S_chols.ndim == 3 else \
gtf.LowerTriangular(self.latent_dim, num_matrices=(self.n_seq, self.max_T - 1)))
self.multi_diag_px1_cov = False
if isinstance(px1_cov, list): # different prior for each sequence
_x1_cov = np.stack(px1_cov)
_x1_cov = np.sqrt(
_x1_cov) if _x1_cov.ndim == 2 else np.linalg.cholesky(_x1_cov)
_transform = None if _x1_cov.ndim == 2 else gtf.LowerTriangular(
self.latent_dim, num_matrices=self.n_seq)
self.multi_diag_px1_cov = _x1_cov.ndim == 2
elif isinstance(px1_cov, np.ndarray): # same prior for each sequence
assert px1_cov.ndim < 3
_x1_cov = np.sqrt(
px1_cov) if px1_cov.ndim == 1 else np.linalg.cholesky(px1_cov)
_transform = None if px1_cov.ndim == 1 else gtf.LowerTriangular(
self.latent_dim, squeeze=True)
self.px1_cov_chol = None if px1_cov is None else Param(
_x1_cov, trainable=False, transform=_transform)
if self.chunking:
px1_mu_check = len(self.px1_mu.shape) == 1
px1_cov_check_1 = not self.multi_diag_px1_cov
px1_cov_check_2 = self.px1_cov_chol is None or len(
self.px1_cov_chol.shape) < 3
assert px1_mu_check and px1_cov_check_1 and px1_cov_check_2, \
'Only one prior over x1 allowed for chunking'
def __init__(self, state_dim, x_goal, Q):
Reward.__init__(self)
self.state_dim = state_dim
self.Q = Param(np.reshape(Q, (state_dim, state_dim)), trainable=False)
self.x_goal = Param(np.reshape(x_goal, (1, state_dim)),
trainable=False)
def __init__(self,
X,
Y,
kernf,
kerng,
likelihood,
Zf,
Zg,
mean_function=None,
minibatch_size=None,
name='model'):
Model.__init__(self, name)
self.mean_function = mean_function or Zero()
self.kernf = kernf
self.kerng = kerng
self.likelihood = likelihood
self.whiten = False
self.q_diag = True
# save initial attributes for future plotting purpose
Xtrain = DataHolder(X)
Ytrain = DataHolder(Y)
self.Xtrain, self.Ytrain = Xtrain, Ytrain
# sort out the X, Y into MiniBatch objects.
if minibatch_size is None:
minibatch_size = X.shape[0]
self.num_data = X.shape[0]
self.num_latent = Y.shape[1] # num_latent will be 1
self.X = MinibatchData(X, minibatch_size, np.random.RandomState(0))
self.Y = MinibatchData(Y, minibatch_size, np.random.RandomState(0))
# Add variational paramters
self.Zf = Param(Zf)
self.Zg = Param(Zg)
self.num_inducing_f = Zf.shape[0]
self.num_inducing_g = Zg.shape[0]
# init variational parameters
self.u_fm = Param(
np.random.randn(self.num_inducing_f, self.num_latent) * 0.01)
self.u_gm = Param(
np.random.randn(self.num_inducing_g, self.num_latent) * 0.01)
if self.q_diag:
self.u_fs_sqrt = Param(
np.ones((self.num_inducing_f, self.num_latent)),
transforms.positive)
self.u_gs_sqrt = Param(
np.ones((self.num_inducing_g, self.num_latent)),
transforms.positive)
else:
u_fs_sqrt = np.array([
np.eye(self.num_inducing_f) for _ in range(self.num_latent)
]).swapaxes(0, 2)
self.u_fs_sqrt = Param(
u_fs_sqrt, transforms.LowerTriangular(u_fs_sqrt.shape[2]))
u_gs_sqrt = np.array([
np.eye(self.num_inducing_g) for _ in range(self.num_latent)
]).swapaxes(0, 2)
self.u_gs_sqrt = Param(
u_gs_sqrt, transforms.LowerTriangular(u_gs_sqrt.shape[2]))
class ExponentialReward(Reward):
def __init__(self, state_dim, W=None, t=None):
Reward.__init__(self)
self.state_dim = state_dim
if W is not None:
self.W = Param(np.reshape(W, (state_dim, state_dim)), trainable=False)
else:
self.W = Param(np.eye(state_dim), trainable=False)
if t is not None:
self.t = Param(np.reshape(t, (1, state_dim)), trainable=False)
else:
self.t = Param(np.zeros((1, state_dim)), trainable=False)
def update_target(self,t):
self.t.assign(np.reshape(t, (1, self.state_dim)))
# self.t=t
def update_weights(self,w):
self.W.assign(np.reshape(w, (self.state_dim, self.state_dim)))
@params_as_tensors
def compute_reward(self, m, s):
'''
Reward function, calculating mean and variance of rewards, given
mean and variance of state distribution, along with the target State
and a weight matrix.
Input m : [1, k]
Input s : [k, k]
Output M : [1, 1]
Output S : [1, 1]
'''
# for robot arm
m=m[:,:9]
s=s[:9,:9]
SW = s @ self.W
iSpW = tf.transpose(
tf.matrix_solve( (tf.eye(self.state_dim, dtype=float_type) + SW),
tf.transpose(self.W), adjoint=True))
muR = tf.exp(-(m-self.t) @ iSpW @ tf.transpose(m-self.t)/2) / \
tf.sqrt( tf.linalg.det(tf.eye(self.state_dim, dtype=float_type) + SW) )
i2SpW = tf.transpose(
tf.matrix_solve( (tf.eye(self.state_dim, dtype=float_type) + 2*SW),
tf.transpose(self.W), adjoint=True))
r2 = tf.exp(-(m-self.t) @ i2SpW @ tf.transpose(m-self.t)) / \
tf.sqrt( tf.linalg.det(tf.eye(self.state_dim, dtype=float_type) + 2*SW) )
sR = r2 - muR @ muR
muR.set_shape([1, 1])
sR.set_shape([1, 1])
return muR, sR
# import abc
# import tensorflow as tf
# from gpflow import Parameterized, Param, params_as_tensors, settings
# import numpy as np
#
# float_type = settings.dtypes.float_type
#
#
# class Reward(Parameterized):
# def __init__(self):
# Parameterized.__init__(self)
#
# @abc.abstractmethod
# def compute_reward(self, m, s):
# raise NotImplementedError
#
#
# class ExponentialReward(Reward):
# def __init__(self, state_dim, W=None, t=None):
# Reward.__init__(self)
# self.state_dim = state_dim
# if W is not None:
# self.W = Param(np.reshape(W, (state_dim, state_dim)), trainable=False)
# else:
# self.W = Param(np.eye(state_dim), trainable=False)
# self.t=t
# # if t is not None:
# # self.t = Param(np.reshape(t, (1, state_dim)), trainable=False)
# # else:
# # self.t = Param(np.zeros((1, state_dim)), trainable=False)
#
# def update_target(self,t):
# # self.t.assign(np.reshape(t, (1, self.state_dim)))
# self.t=t
#
# @params_as_tensors
# def compute_reward(self, m, s):
# '''
# Reward function, calculating mean and variance of rewards, given
# mean and variance of state distribution, along with the target State
# and a weight matrix.
# Input m : [1, k]
# Input s : [k, k]
#
# Output M : [1, 1]
# Output S : [1, 1]
# '''
# # for robot arm
# m=m[:,:3]
# s=s[:3,:3]
#
# SW = s @ self.W
#
# iSpW = tf.transpose(
# tf.matrix_solve( (tf.eye(self.state_dim, dtype=float_type) + SW),
# tf.transpose(self.W), adjoint=True))
#
# muR = tf.exp(-(m-self.t) @ iSpW @ tf.transpose(m-self.t)/2) / \
# tf.sqrt( tf.linalg.det(tf.eye(self.state_dim, dtype=float_type) + SW) )
#
# i2SpW = tf.transpose(
# tf.matrix_solve( (tf.eye(self.state_dim, dtype=float_type) + 2*SW),
# tf.transpose(self.W), adjoint=True))
#
# r2 = tf.exp(-(m-self.t) @ i2SpW @ tf.transpose(m-self.t)) / \
# tf.sqrt( tf.linalg.det(tf.eye(self.state_dim, dtype=float_type) + 2*SW) )
#
# sR = r2 - muR @ muR
# muR.set_shape([1, 1])
# sR.set_shape([1, 1])
# return muR, sR
def __init__(self,
latent_dim,
Y,
inputs=None,
emissions=None,
px1_mu=None,
px1_cov=None,
kern=None,
Z=None,
n_ind_pts=100,
mean_fn=None,
Q_diag=None,
Umu=None,
Ucov_chol=None,
qx1_mu=None,
qx1_cov=None,
As=None,
bs=None,
Ss=None,
n_samples=100,
seed=None,
parallel_iterations=10,
jitter=gps.numerics.jitter_level,
name=None):
super().__init__(name=name)
self.latent_dim = latent_dim
self.T, self.obs_dim = Y.shape
self.Y = Param(Y, trainable=False)
self.inputs = None if inputs is None else Param(inputs,
trainable=False)
self.input_dim = 0 if self.inputs is None else self.inputs.shape[1]
self.qx1_mu = Param(
np.zeros(self.latent_dim) if qx1_mu is None else qx1_mu)
self.qx1_cov_chol = Param(
np.eye(self.latent_dim)
if qx1_cov is None else np.linalg.cholesky(qx1_cov),
transform=gtf.LowerTriangular(self.latent_dim, squeeze=True))
self.As = Param(
np.ones((self.T - 1, self.latent_dim)) if As is None else As)
self.bs = Param(
np.zeros((self.T - 1, self.latent_dim)) if bs is None else bs)
self.Q_sqrt = Param(
np.ones(self.latent_dim) if Q_diag is None else Q_diag**0.5,
transform=gtf.positive)
if Ss is False:
self._S_chols = None
else:
self.S_chols = Param(
np.tile(self.Q_sqrt.value.copy()[None, ...], [self.T - 1, 1])
if Ss is None else
(np.sqrt(Ss) if Ss.ndim == 2 else np.linalg.cholesky(Ss)),
transform=gtf.positive if
(Ss is None or Ss.ndim == 2) else gtf.LowerTriangular(
self.latent_dim, num_matrices=self.T - 1, squeeze=False))
self.emissions = emissions or GaussianEmissions(
latent_dim=self.latent_dim, obs_dim=self.obs_dim)
self.px1_mu = Param(
np.zeros(self.latent_dim) if px1_mu is None else px1_mu,
trainable=False)
self.px1_cov_chol = None if px1_cov is None else \
Param(np.sqrt(px1_cov) if px1_cov.ndim == 1 else np.linalg.cholesky(px1_cov), trainable=False,
transform=gtf.positive if px1_cov.ndim == 1 else gtf.LowerTriangular(self.latent_dim, squeeze=True))
self.n_samples = n_samples
self.seed = seed
self.parallel_iterations = parallel_iterations
self.jitter = jitter
# Inference-specific attributes (see gpssm_models.py for appropriate choices):
nans = tf.constant(np.zeros(
(self.T, self.n_samples, self.latent_dim)) * np.nan,
dtype=gps.float_type)
self.sample_fn = lambda **kwargs: (nans, None)
self.sample_kwargs = {}
self.KL_fn = lambda *fs: tf.constant(np.nan, dtype=gps.float_type)
# GP Transitions:
self.n_ind_pts = n_ind_pts if Z is None else (
Z[0].shape[-2] if isinstance(Z, list) else Z.shape[-2])
if isinstance(Z, np.ndarray) and Z.ndim == 2:
self.Z = mf.SharedIndependentMof(gp.features.InducingPoints(Z))
else:
Z_list = [
np.random.randn(self.n_ind_pts, self.latent_dim +
self.input_dim) for _ in range(self.latent_dim)
] if Z is None else [z for z in Z]
self.Z = mf.SeparateIndependentMof(
[gp.features.InducingPoints(z) for z in Z_list])
if isinstance(kern, gp.kernels.Kernel):
self.kern = mk.SharedIndependentMok(kern, self.latent_dim)
else:
kern_list = kern or [
gp.kernels.Matern32(self.latent_dim + self.input_dim, ARD=True)
for _ in range(self.latent_dim)
]
self.kern = mk.SeparateIndependentMok(kern_list)
self.mean_fn = mean_fn or mean_fns.Identity(self.latent_dim)
self.Umu = Param(
np.zeros((self.latent_dim, self.n_ind_pts))
if Umu is None else Umu) # (Lm^-1)(Umu - m(Z))
LT_transform = gtf.LowerTriangular(self.n_ind_pts,
num_matrices=self.latent_dim,
squeeze=False)
self.Ucov_chol = Param(np.tile(
np.eye(self.n_ind_pts)[None, ...], [self.latent_dim, 1, 1])
if Ucov_chol is None else Ucov_chol,
transform=LT_transform) # (Lm^-1)Lu
self._Kzz = None
def __init__(self, dims):
Parameterized.__init__(self)
self.dims = dims
for i, (dim_in, dim_out) in enumerate(zip(dims[:-1], dims[1:])):
setattr(self, 'W_{}'.format(i), Param(xavier(dim_in, dim_out)))
setattr(self, 'b_{}'.format(i), Param(np.zeros(dim_out)))
def _create_params(input_dim, output_dim):
def initializer():
limit = np.sqrt(6. / (input_dim + output_dim))
return np.random.uniform(-limit, +limit, (input_dim, output_dim))
return Param(initializer(), dtype=float_type, prior=gpflow.priors.Gaussian(0, 1)), \
Param(np.zeros(output_dim), dtype=float_type)
