def evaluate_net(*states):
activations = T.fvectors(len(weights))
idx = 0
for neurons, activator, isInput, isOutput, weightFrame in weights:
sumParts = []
for i, info in enumerate(weightFrame):
srcIdx, w = info
sumParts.append(T.dot(states[srcIdx], w.transpose()))
if len(sumParts):
sumParts = T.stack(*sumParts)
activity = T.sum(sumParts, axis=0)
if activator == TIDENTITY:
activation = activity
elif activator == TLOGISTIC:
activation = 1. / (1. + T.exp(-activity))
elif activator == THYPERBOLIC:
activation = T.tanh(activity)
elif activator == TTHRESHOLD:
activation = T.sgn(activity)
elif activator == TBIAS:
activation = T.ones_like(activity, dtype='float32')
elif activator == TRADIAL:
activation = T.exp(-activity*activity/2.0)
else:
raise Exception("Unknown activation function for layer {0}" + layer.id)
else:
activation = T.zeros_like(states[idx])#states[idx]
activations[idx] = activation
idx += 1
checklist = [T.all(T.eq(a,s)) for a,s in zip(activations, states)]
condition = T.all(T.as_tensor_variable(checklist))
return activations, {}, theano.scan_module.until(condition )
def logp(self, x):
n = self.n
p = self.p
# only defined for sum(p) == 1
return bound(
factln(n) + tt.sum(x * tt.log(p) - factln(x)), tt.all(x >= 0),
tt.all(x <= n), tt.eq(tt.sum(x), n), n >= 0)
def logp(self, x): n = self.n p = self.p s = self.s if s > 1: X = self._x_creation(x) result = self._normalizing_constant(n, p, s) + self._results_inner(n,x) return pm.dist_math.bound(result, tt.all(X <= 1), tt.all(X >= -1), self._check_pos_def(x), n > 0) else: X = x[self.tri_index] X = tt.fill_diagonal(X, 1) result = self._normalizing_constant(n, p, s) result += (n - 1.) * tt.log(tt.nlinalg.det(X)) # n-1 probably needs to become structure[0]-1 # I don't really know the likehood structure honestly return pm.dist_math.bound(result, tt.all(X <= 1), tt.all(X >= -1), matrix_pos_def(X), n > 0)
def logp(self, value):
p_ = self.p
k = self.k
# Clip values before using them for indexing
value_clip = tt.clip(value, 0, k - 1)
# We must only check that the values sum to 1 if p comes from a
# tensor variable, i.e. when p is a step_method proposal. In the other
# cases we normalize ourselves
if not isinstance(p_, (numbers.Number, np.ndarray, tt.TensorConstant,
tt.sharedvar.SharedVariable)):
sumto1 = theano.gradient.zero_grad(
tt.le(abs(tt.sum(p_, axis=-1) - 1), 1e-5))
p = p_
else:
p = p_ / tt.sum(p_, axis=-1, keepdims=True)
sumto1 = True
if p.ndim > 1:
a = tt.log(np.moveaxis(p, -1, 0)[value_clip])
else:
a = tt.log(p[value_clip])
return bound(a, value >= 0, value <= (k - 1), sumto1,
tt.all(p_ > 0, axis=-1), tt.all(p <= 1, axis=-1))
def logp(self, x):
n = self.n
p = self.p
# only defined for sum(p) == 1
return bound(
factln(n) + T.sum(x * T.log(p) - factln(x)), T.all(x >= 0), T.all(x <= n), T.eq(T.sum(x), n), n >= 0
)
def logp(self, weights):
"""
Calculate log-probability of the given set of weights.
Parameters
----------
value : 1-D array, having numeric values
Set of weights for which log-probability is calculated.
Returns
-------
TensorVariable
"""
k = self.shape
a = self.a
wts = tt.as_tensor_variable(weights)
wt = wts[:-1]
wt_sum = tt.extra_ops.cumsum(wt)
denom = 1 - wt_sum
denom_shift = tt.concatenate([[1.], denom])
betas = wts/denom_shift
Beta_ = pm.Beta.dist(1, a)
logp = Beta_.logp(betas).sum()
return bound(Beta_.logp(betas).sum(),
tt.all(betas > 0), tt.all(weights) > 0,
wt_sum < 1, wt_sum > 0,
tt.all(denom) > 0)
def logp(self, x):
n = self.n
p = self.p
# only defined for sum(p) == 1
return bound(
factln(n) + sum(x * log(p) - factln(x)), n > 0, eq(sum(x), n),
all(0 <= x), all(x <= n))
def logp(self, value):
k = self.k
a = self.a
# only defined for sum(value) == 1
return bound(
sum(logpow(value, a - 1) - gammaln(a), axis=0) + gammaln(sum(a)),
k > 1, all(a > 0), all(value >= 0), all(value <= 1))
def logp(self, value):
k = self.k
a = self.a
# only defined for sum(value) == 1
return bound(tt.sum(logpow(value, a - 1) - gammaln(a), axis=-1)
+ gammaln(tt.sum(a, axis=-1)),
tt.all(value >= 0), tt.all(value <= 1),
k > 1, tt.all(a > 0))
def logp(self, x):
n = self.n
p = self.p
return bound(
tt.sum(factln(n)) - tt.sum(factln(x)) + tt.sum(x * tt.log(p)),
tt.all(x >= 0), tt.all(tt.eq(tt.sum(x, axis=-1, keepdims=True),
n)), tt.all(p <= 1),
tt.all(tt.eq(tt.sum(p, axis=-1), 1)), tt.all(tt.ge(n, 0)))
def logp(self, x):
n = self.n
p = self.p
# only defined for sum(p) == 1
return bound(
factln(n) + sum(x * log(p) - factln(x)),
n >= 0,
eq(sum(x), n),
all(0 <= x), all(x <= n))
def logp(self, x):
n = self.n
p = self.p
X = x[self.tri_index]
X = T.fill_diagonal(X, 1)
result = self._normalizing_constant(n, p)
result += (n - 1.) * T.log(det(X))
return bound(result, T.all(X <= 1), T.all(X >= -1), n > 0)
def logp(self, value):
n = self.n
p = self.p
return bound(factln(n) - factln(value).sum() + (value * tt.log(p)).sum(),
tt.all(value >= 0),
tt.all(0 <= p), tt.all(p <= 1),
tt.isclose(p.sum(), 1),
broadcast_conditions=False
)
def logp(self, x):
n = self.n
p = self.p
X = x[self.tri_index]
X = t.fill_diagonal(X, 1)
result = self._normalizing_constant(n, p)
result += (n - 1.0) * log(det(X))
return bound(result, n > 0, all(le(X, 1)), all(ge(X, -1)))
def logp(self, x):
n = self.n
p = self.p
X = x[self.tri_index]
X = T.fill_diagonal(X, 1)
result = self._normalizing_constant(n, p)
result += (n - 1.0) * T.log(det(X))
return bound(result, T.all(X <= 1), T.all(X >= -1), n > 0)
def logp(self, x):
n = self.n
p = self.p
X = x[self.tri_index]
X = t.fill_diagonal(X, 1)
result = self._normalizing_constant(n, p)
result += (n - 1.) * log(det(X))
return bound(result, n > 0, all(le(X, 1)), all(ge(X, -1)))
def logp(self, value):
n = self.n
p = self.p
return bound(factln(n) - factln(value).sum() + (value * tt.log(p)).sum(),
tt.all(value >= 0),
tt.all(0 <= p), tt.all(p <= 1),
tt.isclose(p.sum(), 1),
broadcast_conditions=False
)
def logp(self, value):
k = self.k
a = self.a
# only defined for sum(value) == 1
return bound(tt.sum(logpow(value, a - 1) - gammaln(a), axis=-1)
+ gammaln(tt.sum(a, axis=-1)),
tt.all(value >= 0), tt.all(value <= 1),
k > 1, tt.all(a > 0),
broadcast_conditions=False)
def logp(self, x):
n = self.n
p = self.p
return bound(
tt.sum(factln(n)) - tt.sum(factln(x)) + tt.sum(x * tt.log(p)),
tt.all(x >= 0),
tt.all(tt.eq(tt.sum(x, axis=-1, keepdims=True), n)),
tt.all(p <= 1),
tt.all(tt.eq(tt.sum(p, axis=-1), 1)),
tt.all(tt.ge(n, 0)))
def logp(self, x):
n = self.n
p = self.p
X = x[self.tri_index]
X = tt.fill_diagonal(X, 1)
result = self._normalizing_constant(n, p)
result += (n - 1.) * tt.log(det(X))
return bound(result, tt.all(X <= 1), tt.all(X >= -1),
matrix_pos_def(X), n > 0)
def in_transit(self, t, r=0.0, texp=None):
"""Get a list of timestamps that are in transit
Args:
t (vector): A vector of timestamps to be evaluated.
r (Optional): The radii of the planets.
texp (Optional[float]): The exposure time.
Returns:
The indices of the timestamps that are in transit.
"""
z = tt.zeros_like(self.a)
r = tt.as_tensor_variable(r) + z
R = self.r_star + z
# Wrap the times into time since transit
hp = 0.5 * self.period
dt = tt.mod(self._warp_times(t) - self.t0 + hp, self.period) - hp
if self.ecc is None:
# Equation 14 from Winn (2010)
k = r / self.r_star
arg = tt.square(1 + k) - tt.square(self.b)
hdur = hp * tt.arcsin(self.r_star / self.a *
tt.sqrt(arg) / self.sin_incl) / np.pi
t_start = -hdur
t_end = hdur
flag = z
else:
M_contact = self.contact_points_op(
self.a, self.ecc, self.cos_omega, self.sin_omega,
self.cos_incl + z, self.sin_incl + z, R + r)
flag = M_contact[2]
t_start = (M_contact[0] - self.M0) / self.n
t_start = tt.mod(t_start + hp, self.period) - hp
t_end = (M_contact[1] - self.M0) / self.n
t_end = tt.mod(t_end + hp, self.period) - hp
if texp is not None:
t_start -= 0.5*texp
t_end += 0.5*texp
mask = tt.any(tt.and_(dt >= t_start, dt <= t_end), axis=-1)
result = ifelse(tt.and_(tt.all(tt.eq(flag, 0)),
tt.all(tt.gt(t_end, t_start))),
tt.arange(t.size)[mask],
tt.arange(t.size))
return result
def logp(self, x):
n = self.n
p = self.p
X = x[self.tri_index]
X = tt.fill_diagonal(X, 1)
result = self._normalizing_constant(n, p)
result += (n - 1.) * tt.log(det(X))
return bound(result,
tt.all(X <= 1), tt.all(X >= -1),
matrix_pos_def(X),
n > 0)
def logp(self, x):
n = self.n
p = self.p
if x.ndim == 2:
x_sum = x.sum(axis=0)
n_sum = n * x.shape[0]
else:
x_sum = x
n_sum = n
return bound(
factln(n_sum) + tt.sum(x_sum * tt.log(p) - factln(x_sum)),
tt.all(x >= 0), tt.all(x <= n), tt.eq(tt.sum(x_sum), n_sum),
tt.all(p <= 1), tt.eq(p.sum(), 1), n >= 0)
def logp(self, x): n = self.n p = self.p s = self.s #X = x[self.tri_index] # need to correct #X = tt.fill_diagonal(X, 1) # need to correct X = self._x_creation(x) result = self._normalizing_constant(n, p, s) + self._results_inner(n,x) #result += (n - 1.) * T.log(det(X)) # n-1 probably needs to become structure[0]-1 return pm.dist_math.bound(result, tt.all(X <= 1), tt.all(X >= -1), n > 0)
def logp(self, x):
n = self.n
eta = self.eta
X = x[self.tri_index]
X = tt.fill_diagonal(X, 1)
result = _lkj_normalizing_constant(eta, n)
result += (eta - 1.) * tt.log(det(X))
return bound(result,
tt.all(X <= 1), tt.all(X >= -1),
matrix_pos_def(X),
eta > 0,
broadcast_conditions=False
)
def logp(self, x):
n = self.n
eta = self.eta
X = x[self.tri_index]
X = tt.fill_diagonal(X, 1)
result = _lkj_normalizing_constant(eta, n)
result += (eta - 1.) * tt.log(det(X))
return bound(result,
tt.all(X <= 1),
tt.all(X >= -1),
matrix_pos_def(X),
eta > 0,
broadcast_conditions=False)
def compute_weights(self, energies, attended_mask):
"""Overrides ``SequenceContentAttention.compute_weights()``.
Instead of a normal softmax, it sets most of the energies to
zero, resulting in sharp attention. If ``self.nbest`` equals 1,
the thresholded attention always sets its full attention to one
single source annotation.
Args:
energies (Variable): Energies computed by the
energy_computer
attended_mask (Variable): Source sentence mask
Returns:
Variable. Thresholded alignment weights
"""
# Stabilize energies first and then exponentiate
energies = energies - energies.max(axis=0)
unnormalized_weights = tensor.exp(energies)
if attended_mask:
unnormalized_weights *= attended_mask
# Set everything to zero except the ``nbest`` best entries
best_energies = unnormalized_weights.sort(axis=0)[-self.nbest:]
min_energy = best_energies[0]
thresholded_weights = tensor.switch(unnormalized_weights >= min_energy,
unnormalized_weights, 0.0)
# If mask consists of all zeros use 1 as the normalization coefficient
normalization = (thresholded_weights.sum(axis=0) +
tensor.all(1 - attended_mask, axis=0))
return thresholded_weights / normalization
def compile(self, input_placeholder, label_placeholder, loss, optimizer):
x = input_placeholder
for k in range(self.num_layers):
x = self.layer_list[k].forward(x)
self.loss = loss.forward(x, label_placeholder)
self.updates = optimizer.get_updates(self.loss, self.params)
self.accuracy = T.mean(
T.eq(T.argmax(x, axis=-1), T.argmax(label_placeholder, axis=-1)))
self.equation_accuracy = T.all(
T.eq(T.argmax(x, axis=-1), T.argmax(label_placeholder, axis=-1)))
LOG_INFO('start compiling model...')
self.train = theano.function(
inputs=[input_placeholder, label_placeholder],
outputs=[self.loss, self.accuracy],
updates=self.updates,
allow_input_downcast=True)
self.test = theano.function(
inputs=[input_placeholder, label_placeholder],
outputs=[self.accuracy, self.equation_accuracy, self.loss],
allow_input_downcast=True)
self.predict = theano.function(inputs=[input_placeholder],
outputs=[x],
allow_input_downcast=True)
LOG_INFO('model compilation done!')
def __init__(self, a, transform=transforms.stick_breaking, *args, **kwargs):
super(Dirichlet, self).__init__(transform=transform, *args, **kwargs)
self.a = a
self.k = a.shape[0]
self.mean = a / sum(a)
self.mode = switch(all(a > 1), (a - 1) / sum(a - 1), nan)
def compute_weights(self, energies, attended_mask):
"""Compute weights from energies in softmax-like fashion.
.. todo ::
Use :class:`~blocks.bricks.Softmax`.
Parameters
----------
energies : :class:`~theano.Variable`
The energies. Must be of the same shape as the mask.
attended_mask : :class:`~theano.Variable`
The mask for the attended. The index in the sequence must be
the first dimension.
Returns
-------
weights : :class:`~theano.Variable`
Summing to 1 non-negative weights of the same shape
as `energies`.
"""
# Stabilize energies first and then exponentiate
energies = energies - energies.max(axis=0)
unnormalized_weights = tensor.exp(energies)
if attended_mask:
unnormalized_weights *= attended_mask
# If mask consists of all zeros use 1 as the normalization coefficient
normalization = (unnormalized_weights.sum(axis=0) +
tensor.all(1 - attended_mask, axis=0))
return unnormalized_weights / normalization
def dlogp(inputs, gradients):
g_logp, = gradients
cov, delta = inputs
g_logp.tag.test_value = floatX(1.)
n, k = delta.shape
chol_cov = cholesky(cov)
diag = tt.nlinalg.diag(chol_cov)
ok = tt.all(diag > 0)
chol_cov = tt.switch(ok, chol_cov, tt.fill(chol_cov, 1))
delta_trans = solve_lower(chol_cov, delta.T).T
inner = n * tt.eye(k) - tt.dot(delta_trans.T, delta_trans)
g_cov = solve_upper(chol_cov.T, inner)
g_cov = solve_upper(chol_cov.T, g_cov.T)
tau_delta = solve_upper(chol_cov.T, delta_trans.T)
g_delta = tau_delta.T
g_cov = tt.switch(ok, g_cov, -np.nan)
g_delta = tt.switch(ok, g_delta, -np.nan)
return [-0.5 * g_cov * g_logp, -g_delta * g_logp]
def theano(self, x, mu, V, ndim, ncomp):
cholesky = Cholesky(nofail=True, lower=True)
solve_lower = tt.slinalg.Solve(A_structure="lower_triangular")
if x.ndim == 1:
onedim = True
x = x[None, :]
else:
onedim = False
delta = x[:, None, :] - mu[None, ...]
logps = []
for i in range(ncomp):
_chol_cov = cholesky(V[i])
k = floatX(ndim)
diag = tt.nlinalg.diag(_chol_cov)
# Check if the covariance matrix is positive definite.
ok = tt.all(diag > 0)
# If not, replace the diagonal. We return -inf later, but
# need to prevent solve_lower from throwing an exception.
chol_cov = tt.switch(ok, _chol_cov, 1)
delta_trans = solve_lower(chol_cov, delta[:, i].T).T
_quaddist = (delta_trans**2).sum(axis=-1)
logdet = tt.sum(tt.log(diag))
if onedim:
quaddist = _quaddist[0]
else:
quaddist = _quaddist
norm = -0.5 * k * floatX(np.log(2 * np.pi))
logp = norm - 0.5 * quaddist - logdet
safe_logp = tt.switch(alltrue_elemwise([ok]), logp,
-np.inf) # safe logp (-inf for invalid)
logps.append(safe_logp)
return tt.stacklists(logps).T
def dlogp(inputs, gradients):
g_logp, = gradients
cov, delta = inputs
g_logp.tag.test_value = floatX(1.)
n, k = delta.shape
chol_cov = cholesky(cov)
diag = tt.nlinalg.diag(chol_cov)
ok = tt.all(diag > 0)
chol_cov = tt.switch(ok, chol_cov, tt.fill(chol_cov, 1))
delta_trans = solve_lower(chol_cov, delta.T).T
inner = n * tt.eye(k) - tt.dot(delta_trans.T, delta_trans)
g_cov = solve_upper(chol_cov.T, inner)
g_cov = solve_upper(chol_cov.T, g_cov.T)
tau_delta = solve_upper(chol_cov.T, delta_trans.T)
g_delta = tau_delta.T
g_cov = tt.switch(ok, g_cov, -np.nan)
g_delta = tt.switch(ok, g_delta, -np.nan)
return [-0.5 * g_cov * g_logp, -g_delta * g_logp]
def __init__(self, a, *args, **kwargs):
super(Dirichlet, self).__init__(*args, **kwargs)
self.a = a
self.k = a.shape[0]
self.mean = a / sum(a)
self.mode = switch(all(a > 1), (a - 1) / sum(a - 1), nan)
def logp(self, value):
p_ = self.p
k = self.k
# Clip values before using them for indexing
value_clip = tt.clip(value, 0, k - 1)
p = p_ / tt.sum(p_, axis=-1, keepdims=True)
if p.ndim > 1:
pattern = (p.ndim - 1,) + tuple(range(p.ndim - 1))
a = tt.log(p.dimshuffle(pattern)[value_clip])
else:
a = tt.log(p[value_clip])
return bound(a, value >= 0, value <= (k - 1),
tt.all(p_ >= 0, axis=-1), tt.all(p <= 1, axis=-1))
def adapt_step(dt, accept_prob, pos, mom, energy, energy_grad,
k_energy):
dt = tt.switch(tt.gt(accept_prob**sign, 2.**(-sign)),
(2.**sign) * dt, dt)
accept_prob = leapfrog_accept_prob(dt, pos, mom, energy,
energy_grad, k_energy)
return (dt, accept_prob), th.scan_module.until(
tt.all(tt.le(accept_prob**sign, 2.**(-sign))))
def logp(self, value):
p_ = self.p
k = self.k
# Clip values before using them for indexing
value_clip = tt.clip(value, 0, k - 1)
p = p_ / tt.sum(p_, axis=-1, keepdims=True)
if p.ndim > 1:
pattern = (p.ndim - 1, ) + tuple(range(p.ndim - 1))
a = tt.log(p.dimshuffle(pattern)[value_clip])
else:
a = tt.log(p[value_clip])
return bound(a, value >= 0, value <= (k - 1), tt.all(p_ >= 0, axis=-1),
tt.all(p <= 1, axis=-1))
def negative_log_likelihood(actual, target):
"""
:param actual: An (n_samples, n_labels) tensor where rows are normalized and actual[i,j] indicates the belief
that on sample[i] the correct target is j.
:param target: An (n_samples, ) tensor indicating the target label for each sample
:return: The average (over samples) of the negative log-likelihood.
"""
actual = tt.opt.assert_(actual, tt.all(abs(actual.sum(axis=1)-1) < 1e-7)) # Data must be normalized along axis 1.
return negative_log_likelihood_dangerous(actual, target)
def in_transit(self, t, r=0.0, texp=None):
"""Get a list of timestamps that are in transit
Args:
t (vector): A vector of timestamps to be evaluated.
r (Optional): The radii of the planets.
texp (Optional[float]): The exposure time.
Returns:
The indices of the timestamps that are in transit.
"""
z = tt.zeros_like(self.a)
r = tt.as_tensor_variable(r) + z
R = self.r_star + z
# Wrap the times into time since transit
hp = 0.5 * self.period
dt = tt.mod(self._warp_times(t) - self.t0 + hp, self.period) - hp
if self.ecc is None:
# Equation 14 from Winn (2010)
k = r / R
arg = tt.square(1 + k) - tt.square(self.b)
factor = R / (self.a * self.sin_incl)
hdur = hp * tt.arcsin(factor * tt.sqrt(arg)) / np.pi
t_start = -hdur
t_end = hdur
flag = z
else:
M_contact = self.contact_points_op(
self.a, self.ecc, self.cos_omega, self.sin_omega,
self.cos_incl + z, self.sin_incl + z, R + r)
flag = M_contact[2]
t_start = (M_contact[0] - self.M0) / self.n
t_start = tt.mod(t_start + hp, self.period) - hp
t_end = (M_contact[1] - self.M0) / self.n
t_end = tt.mod(t_end + hp, self.period) - hp
t_start = tt.switch(tt.gt(t_start, 0.0),
t_start - self.period, t_start)
t_end = tt.switch(tt.lt(t_end, 0.0),
t_end + self.period, t_end)
if texp is not None:
t_start -= 0.5*texp
t_end += 0.5*texp
mask = tt.any(tt.and_(dt >= t_start, dt <= t_end), axis=-1)
result = ifelse(tt.all(tt.eq(flag, 0)),
tt.arange(t.size)[mask],
tt.arange(t.size))
return result
def __init__(self, a, *args, **kwargs):
super(Dirichlet, self).__init__(*args, **kwargs)
self.a = a
self.k = a.shape[0]
self.mean = a / sum(a)
self.mode = switch(all(a > 1),
(a - 1) / sum(a - 1),
nan)
def logp(self, x):
n = self.n
p = self.p
if x.ndim==2:
x_sum = x.sum(axis=0)
n_sum = n * x.shape[0]
else:
x_sum = x
n_sum = n
return bound(
factln(n_sum) + tt.sum(x_sum * tt.log(p) - factln(x_sum)),
tt.all(x >= 0),
tt.all(x <= n),
tt.eq(tt.sum(x_sum), n_sum),
tt.isclose(p.sum(), 1),
n >= 0)
def __init__(self, a, transform=transforms.stick_breaking, *args, **kwargs):
shape = a.shape[0]
kwargs.setdefault("shape", shape)
super(Dirichlet, self).__init__(transform=transform, *args, **kwargs)
self.k = shape
self.a = a
self.mean = a / T.sum(a)
self.mode = T.switch(T.all(a > 1), (a - 1) / T.sum(a - 1), np.nan)
def logp(self, x): # x is assumed to be (s x n_elem) if s > 1 or n_elem n = self.n p = self.p s = self.s if s !=1: X = self._X_inner_creation(x) result = self._results_inner(n,p,s,x) return pm.dist_math.bound(result, tt.all(X <= 1), tt.all(X >= -1), n > 0) else: X = x[self.tri_index] X = tt.fill_diagonal(X, 1) result = self._normalizing_constant(n, p) result += (n - 1.) * tt.log(tt.nlinalg.det(X)) return pm.dist_math.bound(result, tt.all(X <= 1), tt.all(X >= -1), n > 0)
def test_jax_logp():
mu = tt.vector("mu")
mu.tag.test_value = np.r_[0.0, 0.0].astype(tt.config.floatX)
tau = tt.vector("tau")
tau.tag.test_value = np.r_[1.0, 1.0].astype(tt.config.floatX)
sigma = tt.vector("sigma")
sigma.tag.test_value = (1.0 / get_test_value(tau)).astype(tt.config.floatX)
value = tt.vector("value")
value.tag.test_value = np.r_[0.1, -10].astype(tt.config.floatX)
logp = (-tau * (value - mu)**2 + tt.log(tau / np.pi / 2.0)) / 2.0
conditions = [sigma > 0]
alltrue = tt.all([tt.all(1 * val) for val in conditions])
normal_logp = tt.switch(alltrue, logp, -np.inf)
fgraph = theano.gof.FunctionGraph([mu, tau, sigma, value], [normal_logp])
_ = compare_jax_and_py(fgraph, [get_test_value(i) for i in fgraph.inputs])
def __init__(self, a, transform=transforms.stick_breaking, *args, **kwargs):
self.k = shape = a.shape[0]
if "shape" not in kwargs.keys():
kwargs.update({"shape": shape})
super(Dirichlet, self).__init__(transform=transform, *args, **kwargs)
self.a = a
self.mean = a / sum(a)
self.mode = switch(all(a > 1),
(a - 1) / sum(a - 1),
nan)
def __init__(self, a, transform=transforms.stick_breaking, *args, **kwargs):
self.k = shape = a.shape[0]
if "shape" not in kwargs.keys():
kwargs.update({"shape": shape})
super(Dirichlet, self).__init__(transform=transform, *args, **kwargs)
self.a = a
self.mean = a / sum(a)
self.mode = switch(all(a > 1),
(a - 1) / sum(a - 1),
nan)
def __init__(self,
a,
transform=transforms.stick_breaking,
*args,
**kwargs):
super(Dirichlet, self).__init__(transform=transform, *args, **kwargs)
self.a = a
self.k = a.shape[0]
self.mean = a / sum(a)
self.mode = switch(all(a > 1), (a - 1) / sum(a - 1), nan)
def get_sentence_embeddings_function(hidden_states):
sentence_embedding, _ = theano.scan(fn=inner_loop,
sequences=hidden_states)
sentence_embedding = ifelse(
T.all(
T.eq(sentence_embedding[-1],
T.zeros_like(sentence_embedding[-1]))),
sentence_embedding[-2], sentence_embedding[-1])
return sentence_embedding
def logp(self, X):
n = self.n
p = self.p
V = self.V
IVI = det(V)
IXI = det(X)
return bound(
((n - p - 1) * log(IXI) - trace(matrix_inverse(V).dot(X)) -
n * p * log(2) - n * log(IVI) - 2 * multigammaln(n / 2., p)) / 2,
gt(n, (p - 1)), all(gt(eigh(X)[0], 0)), eq(X, X.T))
def logp(self, X):
n = self.n
p = self.p
V = self.V
IVI = det(V)
IXI = det(X)
return bound(
((n - p - 1) * T.log(IXI) - trace(matrix_inverse(V).dot(X)) -
n * p * T.log(2) - n * T.log(IVI) - 2 * multigammaln(n / 2., p)) /
2, T.all(eigh(X)[0] > 0), T.eq(X, X.T), n > (p - 1))
def __init__(self, a, transform=transforms.stick_breaking,
*args, **kwargs):
shape = a.shape[-1]
kwargs.setdefault("shape", shape)
super(Dirichlet, self).__init__(transform=transform, *args, **kwargs)
self.k = tt.as_tensor_variable(shape)
self.a = a = tt.as_tensor_variable(a)
self.mean = a / tt.sum(a)
self.mode = tt.switch(tt.all(a > 1),
(a - 1) / tt.sum(a - 1),
np.nan)
def _quaddist_tau(self, delta):
chol_tau = self.chol_tau
_, k = delta.shape
k = pm.floatX(k)
diag = tt.nlinalg.diag(chol_tau)
ok = tt.all(diag > 0)
chol_tau = tt.switch(ok, chol_tau, 1)
diag = tt.nlinalg.diag(chol_tau)
delta_trans = tt.dot(delta, chol_tau)
quaddist = (delta_trans ** 2).sum(axis=-1)
logdet = -tt.sum(tt.log(diag))
return quaddist, logdet, ok
def _quaddist_chol(self, delta):
chol_cov = self.chol_cov
_, k = delta.shape
k = pm.floatX(k)
diag = tt.nlinalg.diag(chol_cov)
# Check if the covariance matrix is positive definite.
ok = tt.all(diag > 0)
# If not, replace the diagonal. We return -inf later, but
# need to prevent solve_lower from throwing an exception.
chol_cov = tt.switch(ok, chol_cov, 1)
delta_trans = self.solve_lower(chol_cov, delta.T).T
quaddist = (delta_trans ** 2).sum(axis=-1)
logdet = tt.sum(tt.log(diag))
return quaddist, logdet, ok
def logp(self, X):
n = self.n
p = self.p
V = self.V
IVI = det(V)
IXI = det(X)
return bound(
((n - p - 1) * log(IXI) - trace(matrix_inverse(V).dot(X)) -
n * p * log(2) - n * log(IVI) - 2 * multigammaln(n / 2., p)) / 2,
gt(n, (p - 1)),
all(gt(eigh(X)[0], 0)),
eq(X, X.T)
)
def apply(self, source, source_mask, source_x, attention):
if source.ndim != 3 or attention.ndim != 2:
raise NotImplementedError
align_matrix = T.tanh(source_x + T.dot(attention, self.Wa)[None, :, :])
align = theano.dot(align_matrix, self.v)
align = T.exp(align - align.max(axis=0, keepdims=True))
if source_mask:
align = align * source_mask
normalization = align.sum(axis=0) + T.all(1 - source_mask, axis=0)
else:
normalization = align.sum(axis=0)
align = align/normalization
self.output = (T.shape_padright(align) * source).sum(axis=0)
return self.output
def function(inputs, outputs=None, check_valid=False, checks=(), **kwargs):
input_names = None
output_names = None
if isinstance(inputs, dict):
if inputs:
(input_names, inputs) = zip(*inputs.iteritems())
else:
(input_names, inputs) = ((), ())
if isinstance(outputs, dict):
if outputs:
(output_names, outputs) = zip(*outputs.iteritems())
else:
(output_names, outputs) = ((), ())
if check_valid or checks:
updates = kwargs.setdefault('updates', {})
asserts = [assert_(c, 'check failed: %s' % c) for c in checks]
if check_valid:
if outputs:
if not isinstance(outputs, (list, tuple)):
outputs = [outputs]
asserts += (assert_(isvalid(x),
'output invalid: %d (%s)' % (i, x.name))
for (i, x) in enumerate(outputs))
if updates:
asserts += (assert_(isvalid(xnew),
'update invalid: variable %s' % str(x))
for (x, xnew) in updates.iteritems())
checks_passed = theano.shared(np.int8(1), name='checks_passed')
updates[checks_passed] = \
T.all(T.as_tensor_variable(asserts)).astype('int8')
f = _CheckedFunction(inputs, outputs, **kwargs)
else:
f = theano.function(inputs, outputs, **kwargs)
if hasattr(f.fn, 'clear_storage'):
f.clear_storage = f.fn.clear_storage
else:
_log.warn('Function %s has no clear_storage: disabling', f.fn)
f.clear_storage = lambda: None
if input_names is not None or output_names is not None:
return NamedInputOutputFunction(input_names, output_names, f)
return f
def grad(self, inputs, gradients):
"""
Cholesky decomposition reverse-mode gradient update.
Symbolic expression for reverse-mode Cholesky gradient taken from [0]_
References
----------
.. [0] I. Murray, "Differentiation of the Cholesky decomposition",
http://arxiv.org/abs/1602.07527
"""
x = inputs[0]
dz = gradients[0]
chol_x = self(x)
ok = tt.all(tt.nlinalg.diag(chol_x) > 0)
chol_x = tt.switch(ok, chol_x, tt.fill_diagonal(chol_x, 1))
dz = tt.switch(ok, dz, floatX(1))
# deal with upper triangular by converting to lower triangular
if not self.lower:
chol_x = chol_x.T
dz = dz.T
def tril_and_halve_diagonal(mtx):
"""Extracts lower triangle of square matrix and halves diagonal."""
return tt.tril(mtx) - tt.diag(tt.diagonal(mtx) / 2.)
def conjugate_solve_triangular(outer, inner):
"""Computes L^{-T} P L^{-1} for lower-triangular L."""
solve = tt.slinalg.Solve(A_structure="upper_triangular")
return solve(outer.T, solve(outer.T, inner.T).T)
s = conjugate_solve_triangular(
chol_x, tril_and_halve_diagonal(chol_x.T.dot(dz)))
if self.lower:
grad = tt.tril(s + s.T) - tt.diag(tt.diagonal(s))
else:
grad = tt.triu(s + s.T) - tt.diag(tt.diagonal(s))
return [tt.switch(ok, grad, floatX(np.nan))]
def scan_step(pt_pre, h_pre, k_pre, w_pre, mask,
seq_str, seq_str_mask, bias):
h, a, k, p, w = self.pos_layer.step(
pt_pre, h_pre, k_pre, w_pre,
seq_str, seq_str_mask, mask=mask)
h_conc = T.concatenate([h, w], axis=-1)
pt = self.mixture.prediction(h_conc, bias)
# ending condition
last_char = T.cast(T.sum(seq_str_mask, axis=0)-1, 'int32')
last_phi = p[last_char, T.arange(last_char.shape[0])]
max_phi = T.max(p, axis=0)
condition = last_phi >= 0.95*max_phi
mask = T.switch(condition, .0, mask)
return ((pt, h, a, k, p, w, mask),
theano.scan_module.until(T.all(mask < 1.)))
