def step(x_t,y_t,h_tm1,Wx,Wh,bh,Wy,by,lr,switch):
h_t = relu(T.dot(x_t,Wx)+T.dot(h_tm1,Wh)+bh)
yo_t = relu(T.dot(h_t,Wy)+by)
updates = OrderedDict()
# Train the RNN: backprop (loss + DNI output)
loss = T.mean(T.square(yo_t-y_t))
dni_out = self.dni.output(h_t)
for param in self.params:
dlossdparam = T.grad(loss,param)
dniJ = T.Lop(h_t,param,dni_out,disconnected_inputs='ignore')
updates[param] = param-lr*T.switch(T.gt(switch,0),
dlossdparam+dniJ,
dlossdparam)
# Update the DNI (from the last step)
# re-calculate the DNI prediction from the last step
# note: can't be passed through scan or T.grad won't work
dni_out_old = self.dni.output(h_tm1)
# dni_target: current loss backprop'ed + new dni backprop'ed
dni_target = T.grad(loss,h_tm1) \
+T.Lop(h_t,h_tm1,dni_out)
dni_error = T.sum(T.square(dni_out_old-dni_target))
for param in self.dni.params:
gparam = T.grad(dni_error,param)
updates[param] = param-lr*gparam
return [h_t,loss,dni_error],updates
def test_multiple_outputs(self):
m = tensor.matrix('m')
v = tensor.vector('v')
m_ = tensor.matrix('m_')
v_ = tensor.vector('v_')
mval = self.rng.uniform(size=(3, 7)).astype(theano.config.floatX)
vval = self.rng.uniform(size=(7, )).astype(theano.config.floatX)
m_val = self.rng.uniform(size=(3, 7)).astype(theano.config.floatX)
v_val = self.rng.uniform(size=(7, )).astype(theano.config.floatX)
rop_out1 = tensor.Rop([m, v, m + v], [m, v], [m_, v_])
assert isinstance(rop_out1, list)
assert len(rop_out1) == 3
rop_out2 = tensor.Rop((m, v, m + v), [m, v], [m_, v_])
assert isinstance(rop_out2, tuple)
assert len(rop_out2) == 3
lop_out1 = tensor.Lop([m, v, m + v], (m, v), [m_, v_])
assert isinstance(lop_out1, tuple)
assert len(lop_out1) == 2
lop_out2 = tensor.Lop((m, v, m + v), [m, v], [m_, v_])
assert isinstance(lop_out2, list)
assert len(lop_out2) == 2
all_outs = []
for o in rop_out1, rop_out2, lop_out1, lop_out2:
all_outs.extend(o)
f = theano.function([m, v, m_, v_], all_outs)
f(mval, vval, m_val, v_val)
def Gv_step(*gv_args):
idx = TT.cast(gv_args[0], 'int32')
nw_inps = [x[idx * options['cbs']: \
(idx + 1) * options['cbs']] for x in
loc_inputs]
replace = dict(zip(model.inputs, nw_inps))
nw_outs = safe_clone(model.gc_outs, replace)
final_results = dict(
zip(model.params, [None] * len(model.params)))
for nw_out, out_operator in zip(nw_outs,
model.gc_outs_operator):
loc_params = [
x for x in model.params
if x in theano.gof.graph.inputs([nw_out])
]
loc_args = [
x for x, y in zip(args, model.params)
if y in theano.gof.graph.inputs([nw_out])
]
if out_operator == 'softmax':
factor = const(options['cbs']) * (nw_out + eps)
elif out_operator == 'sigmoid':
factor = const(
options['cbs']) # * nw_out * (1 - nw_out)
else:
factor = const(options['cbs'])
if out_operator != 'sigmoid':
loc_Gvs = TT.Lop(nw_out, loc_params,
TT.Rop(nw_out, loc_params, loc_args) /\
factor)
else:
tnwout = TT.nnet.sigmoid(nw_out)
loc_Gvs = TT.Lop(nw_out, loc_params,
TT.Rop(nw_out, loc_params,
loc_args) *\
tnwout * (1 - tnwout)/ factor)
for lp, lgv in zip(loc_params, loc_Gvs):
if final_results[lp] is None:
final_results[lp] = lgv
else:
final_results[lp] += lgv
Gvs = [
ogv + final_results[param]
for (ogv, param) in zip(gv_args[1:], model.params)
]
return [gv_args[0] + const(1)] + Gvs
nw_cost, nw_preactiv_out = safe_clone(
[model.train_cost, model.preactiv_out], replace)
nw_gvs = TT.Lop(
nw_preactiv_out, model.params,
TT.Rop(TT.grad(nw_cost, nw_preactiv_out), model.params,
args))
Gvs = [ogv + ngv for (ogv, ngv) in zip(gv_args[1:], nw_gvs)]
return [gv_args[0] + const(1)] + Gvs
def hypergrad(params_ele,
params_hyper,
dvalid_dtheta,
loss_ele,
loss_hyper,
loss_ele_penalty=0.):
""" Function defining the hypergradients: gradients of validation cost
with respect to various hyperparameters.
The function is separating penalty hyperparameters
(which is assumed to depend only on w) from noise and other hyperparameters,
due to otherwise dependancy errors in the Lop operator.
Inputs:
paramsT1, paramsT2 :: T1 and T2 parameters
c1, c2 :: cross-entropy on training and validation set
p1, p2 :: penalty terms on training and validation set (p2 assumed 0)
"""
# initializations
reg_penalty, reg_noise, grad_penalty, grad_noise, w, dvalid_dw = [], [], [], [], [], []
# separate different types of parameters
for regular in params_hyper:
reg_type, _ = regular.name.split('_')
if reg_type in penalty_list:
reg_penalty += [regular]
elif reg_type in noise_list:
reg_noise += [regular]
else:
print 'Hypergrad not implemented for ', reg_type
# separate weight parameters and gradients
for (param, grad) in zip(params_ele, dvalid_dtheta):
paramType, _ = param.name.split('_')
if paramType == 'W':
w += [param]
dvalid_dw += [grad]
# hyper-gradients
if reg_penalty:
dpenalty_dw = T.grad(loss_ele_penalty, w)
dpenalty_dw = [-grad for grad in dpenalty_dw]
grad_penalty = T.Lop(dpenalty_dw, reg_penalty, dvalid_dw)
if reg_noise:
dele_dtheta = T.grad(loss_ele, params_ele)
dele_dtheta = [-grad for grad in dele_dtheta]
grad_noise = T.Lop(dele_dtheta, reg_noise, dvalid_dtheta)
# outputs
params_hyper = reg_penalty + reg_noise
dvalid_dgamma = grad_penalty + grad_noise
return params_hyper, dvalid_dgamma
def hypergrad(paramsT1, paramsT2, gradC2T1, c1, c2, p1=0., p2=0.):
''' Function defining the hypergradients: gradients of validation cost
with respect to various hyperparameters.
The function is separating penalty hyperparameters
(which is assumed to depend only on W) from noise and other hyperparameters,
due to otherwise dependancy errors in the Lop operator.
Inputs:
paramsT1, paramsT2 :: T1 and T2 parameters
c1, c2 :: cross-entropy on training and validation set
p1, p2 :: penalty terms on training and validation set (p2 assumed 0)
'''
# initializations
rglrzPenal = []
rglrzNoiz = []
gradPenal = []
gradNoiz = []
W = []
gradC2W = []
# separate different types of parameters
for rglrz in paramsT2:
rglrzType, _ = rglrz.name.split('_')
if rglrzType in penalList:
rglrzPenal += [rglrz]
elif rglrzType in noizList:
rglrzNoiz += [rglrz]
else:
print 'Hypergrad not implemented for ', rglrzType
# separate weight parameters and gradients
for (param, grad) in zip(paramsT1, gradC2T1):
paramType, _ = param.name.split('_')
if paramType == 'W':
W += [param]
gradC2W += [grad]
# hyper-gradients
if rglrzPenal != []:
gradPW = T.grad(p1, W)
gradPW = [-grad for grad in gradPW]
gradPenal = T.Lop(gradPW, rglrzPenal, gradC2W)
if rglrzNoiz != []:
gradE1T1 = T.grad(c1, paramsT1)
gradE1T1 = [-grad for grad in gradE1T1]
gradNoiz = T.Lop(gradE1T1, rglrzNoiz, gradC2T1)
# outputs
paramsT2 = rglrzPenal + rglrzNoiz
gradC2T2 = gradPenal + gradNoiz
return paramsT2, gradC2T2
def Gvs(self, *args):
# Contribution of hid_sig
nw_args1 = TT.Lop(
self.hid_sig, self.params,
TT.Rop(self.hid_sig, self.params, args) /
((1 - self.hid_sig) * self.hid_sig * self.mbs))
nw_args2 = TT.Lop(
self.hid_sftmax, self.params,
TT.Rop(self.hid_sftmax, self.params, args) /
(self.hid_sftmax * self.mbs))
return [x + y for x, y in zip(nw_args1, nw_args2)]
def reinforce_no_baseline(params, policy, cost, lr, regularising_cost=None):
"""
return reinforce updates
@policy and @cost should be of shape (minibatch_size, 1)
@policy should be the probability of the sampled actions
"""
log_pol = T.log(policy)
if regularising_cost is None:
return [(i, i - lr * gi) for i, gi in zip(
params, T.Lop(f=log_pol, wrt=params, eval_points=cost))]
else:
return [(i, i - lr * (gi + gr)) for i, gi, gr in zip(
params, T.Lop(f=log_pol, wrt=params, eval_points=cost),
T.grad(regularising_cost, params))]
def compute_Gv(*args):
(hid_sig, hid_sftmax) = self.get_hiddens()
nw_args1 = TT.Lop(
hid_sig, self.params,
TT.Rop(hid_sig, self.params, args) /
((1 - hid_sig) * hid_sig * self.batchsize))
nw_args2 = TT.Lop(
hid_sftmax, self.params,
TT.Rop(hid_sftmax, self.params, args) /
(hid_sftmax * self.batchsize))
fin_vals = [x + y for x, y in zip(nw_args1, nw_args2)]
new_vals = safe_clone(fin_vals, [self.X, self.Y],
[self.loc_x, self.loc_y])
return new_vals, {}
def setup(self, bottom, top):
input = T.tensor4("input")
v = T.matrix("v")
result = T.sum(input, axis=(2, 3))
result_g = T.Lop(result, input, v)
self.f = theano.function([input], result)
self.b = theano.function([input, v], result_g)
def Gv_step(*gv_args):
idx = TT.cast(gv_args[0], 'int32')
nw_inps = [x[idx * options['cbs']: \
(idx + 1) * options['cbs']] for x in
loc_inputs]
replace = dict(zip(model.inputs, nw_inps))
nw_outs = safe_clone(model.outs, replace)
final_results = dict(zip(model.params, [None] * len(model.params)))
for nw_out, out_operator in zip(nw_outs, model.outs_operator):
loc_params = [x for x in model.params
if x in theano.gof.graph.inputs([nw_out])]
loc_args = [x for x, y in zip(cgv, model.params)
if y in theano.gof.graph.inputs([nw_out])]
if out_operator == 'softmax':
factor = const(options['cbs']) * nw_out
elif out_operator == 'sigmoid':
factor = const(options['cbs']) * nw_out * (1 - nw_out)
else:
factor = const(options['cbs'])
loc_Gvs = TT.Lop(nw_out, loc_params,
TT.Rop(nw_out, loc_params, loc_args) /\
factor)
for lp, lgv in zip(loc_params, loc_Gvs):
if final_results[lp] is None:
final_results[lp] = lgv
else:
final_results[lp] += lgv
Gvs = [ogv + final_results[param]
for (ogv, param) in zip(gv_args[1:], model.params)]
return [gv_args[0] + const(1)] + Gvs
def create_esgd_updates(updates, params, gparams, gsums, xsums, lr, eps, gamma,
momentum):
has_momentum = momentum.get_value() > 0.0
samples = [
default_mrng.normal(size=p.shape,
avg=0,
std=1,
dtype=theano.config.floatX) for p in params
]
HVs = T.Lop(gparams, params, samples)
i = theano.shared(np.float64(0.0).astype(theano.config.floatX))
i_t = i + 1.0
omg_t = 1.0 - gamma**i_t
for p, g, m, D, Hv in zip(params, gparams, gsums, xsums, HVs):
if is_subtensor_op(p):
raise Exception("ESGD subtensor update not implemented!")
else:
D_t = D * gamma + T.sqr(Hv) * (1.0 - gamma)
if has_momentum:
m_t = m * momentum + g
updates[m] = m_t
else:
m_t = g
g_t = m_t / (T.sqrt(D_t / omg_t + eps))
updates[D] = D_t
updates[p] = p - lr * g_t
updates[i] = i_t
def compute_Ax(x):
# There are three ways to compute the Fisher-vector product:
# 1. https://github.com/joschu/modular_rl/blob/master/modular_rl/trpo.py#L54
# Use theano.gradient.disconnected_grad and call theano.tensor.grad() twice.
# WARNING: In our case (with the attention mechanism) it is extremly slow.
# 2. http://deeplearning.net/software/theano/tutorial/gradients.html#hessian-times-a-vector
# Use only theano.tensor.Rop, but you will need to calculate the fixed_output outside
# of the compiled function, because disconnected_grad will not work with Rop.
# 3. https://github.com/pascanur/natgrad/blob/master/model_convMNIST_standard.py
# Rop devided by output because a metric F is based on gradient of log(output).
# Here we also split the vector of parameters. Not checked, but it may be
# faster then supply few vectors to minresQLP.
xs = []
offset = 0
for p in params:
shape = p.get_value().shape
size = np.prod(shape)
xs.append(x[offset:offset + size].reshape(shape))
offset += size
jvp = T.Rop(new_output, params, xs) / (
new_output * self.batch_size * self.history + TINY)
fvp = T.Lop(new_output, params, jvp)
fvp = T.concatenate([g.flatten() for g in fvp])
return [fvp], {}
def __init__(self, t_cost, t_traj_info, t_inputs, params, reg=1e-5):
t_new_params = [
_np2theano(p.name, p.get_value(borrow=True)) for p in params
]
t_mean = t_traj_info['act_mean']
t_mean = t_mean.reshape((-1, t_mean.shape[-1]))
t_logstd = t_traj_info['act_logstd']
t_logstd = t_logstd.reshape((-1, t_logstd.shape[-1]))
t_new_mean = t_traj_info['new_act_mean']
t_new_mean = t_new_mean.reshape((-1, t_new_mean.shape[-1]))
t_new_logstd = t_traj_info['new_act_logstd']
t_new_logstd = t_new_logstd.reshape((-1, t_new_logstd.shape[-1]))
print 'Compiling cost function ... ',
s = time()
self.cost = theano.function(inputs=t_inputs,
outputs=t_cost,
on_unused_input='ignore')
print 'finished in %f seconds' % (time() - s)
print 'Building cost grad function ... ',
s = time()
_t_cost_grad = T.grad(-t_cost, wrt=params)
print 'finished in %f seconds' % (time() - s)
print 'Compiling cost grad function ... ',
s = time()
self._cost_grad = theano.function(inputs=t_inputs,
outputs=[t_cost] + _t_cost_grad,
on_unused_input='ignore')
print 'finished in %f seconds' % (time() - s)
print 'Building Hx function ... ',
s = time()
mu = T.concatenate([t_new_mean, t_new_logstd], axis=-1)
Jx = sum([T.Rop(mu, p, x) for (p, x) in zip(params, t_new_params)])
M = T.tile(T.eye(2), (mu.shape[0], 1, 1))
Jx = Jx.reshape((Jx.shape[0], Jx.shape[1], 1))
Jx = T.tile(Jx, (1, 1, Jx.shape[1]))
MJx = Jx
JMJx = [
T.Lop(MJx, p, x, disconnected_inputs='ignore')
for (p, x) in zip(params, t_new_params)
]
Hx = [h + reg * p for (h, p) in zip(JMJx, t_new_params)]
print 'finished in %f seconds' % (time() - s)
# TODO: Use mask to handle different lengths.
print 'Compiling Hx function ...',
s = time()
self._constraint_Hx = theano.function(inputs=t_inputs + t_new_params,
outputs=Hx,
on_unused_input='ignore')
self.constraint_Hx = lambda inputs, params: self._constraint_Hx(*(
inputs + params))
print 'finished in %f seconds' % (time() - s)
def mean_weighted_grad(weights, loss):
# Lop to the rescue! Here I was calling T.jacobian and trying to
# broadcast things and elementwise-multiply through the resulting lists,
# when a function already existed to do all of that for me...
return T.Lop(loss,
params,
weights / T.cast(weights.shape[0], 'float32'),
disconnected_inputs='ignore')
def check_rop_lop(self, y, out_shape):
"""
As check_mat_rop_lop, except the input is self.x which is a
vector. The output is still a vector.
"""
# TEST ROP
vx = np.asarray(self.rng.uniform(size=self.in_shape),
theano.config.floatX)
vv = np.asarray(self.rng.uniform(size=self.in_shape),
theano.config.floatX)
yv = tensor.Rop(y, self.x, self.v)
rop_f = function([self.x, self.v], yv, on_unused_input="ignore")
J, _ = theano.scan(
lambda i, y, x: tensor.grad(y[i], x),
sequences=tensor.arange(y.shape[0]),
non_sequences=[y, self.x],
)
sy = tensor.dot(J, self.v)
scan_f = function([self.x, self.v], sy, on_unused_input="ignore")
v1 = rop_f(vx, vv)
v2 = scan_f(vx, vv)
assert np.allclose(v1, v2), "ROP mismatch: %s %s" % (v1, v2)
known_fail = False
try:
tensor.Rop(theano.clone(y, replace={self.x: break_op(self.x)}),
self.x, self.v)
except ValueError:
known_fail = True
# TEST LOP
vx = np.asarray(self.rng.uniform(size=self.in_shape),
theano.config.floatX)
vv = np.asarray(self.rng.uniform(size=out_shape), theano.config.floatX)
yv = tensor.Lop(y, self.x, self.v)
lop_f = function([self.x, self.v], yv, on_unused_input="ignore")
J, _ = theano.scan(
lambda i, y, x: tensor.grad(y[i], x),
sequences=tensor.arange(y.shape[0]),
non_sequences=[y, self.x],
)
sy = tensor.dot(self.v, J)
scan_f = function([self.x, self.v], sy)
v1 = lop_f(vx, vv)
v2 = scan_f(vx, vv)
assert np.allclose(v1, v2), "LOP mismatch: %s %s" % (v1, v2)
if known_fail:
pytest.skip("Rop does not handle non-differentiable inputs "
"correctly. Bug exposed by fixing Add.grad method.")
def setup(self, bottom, top):
import theano.tensor as T
import theano
x = T.dvector('x')
v = T.dvector('v')
y = x * 2
yg = T.Lop(y, x, v)
self.f = theano.function([x], y)
self.b = theano.function([x, v], yg, on_unused_input='warn')
def test_rop_lop():
mx = tensor.matrix('mx')
mv = tensor.matrix('mv')
v = tensor.vector('v')
y = matrix_inverse(mx).sum(axis=0)
yv = tensor.Rop(y, mx, mv)
yv2 = tensor.Rop_via_Lop(y, mx, mv)
rop_f = function([mx, mv], [yv, yv2])
sy, _ = theano.scan(lambda i, y, x, v: (tensor.grad(y[i], x) * v).sum(),
sequences=tensor.arange(y.shape[0]),
non_sequences=[y, mx, mv])
scan_f = function([mx, mv], sy)
rng = np.random.RandomState(utt.fetch_seed())
vx = np.asarray(rng.randn(4, 4), theano.config.floatX)
vv = np.asarray(rng.randn(4, 4), theano.config.floatX)
v1 = scan_f(vx, vv)
v2, v3 = rop_f(vx, vv)
assert _allclose(v2, v1), ('Rop mismatch: %s %s' % (v2, v1))
assert _allclose(v3, v1), ('Rop_via_Lop mismatch: %s %s' % (v3, v1))
raised = False
try:
tensor.Rop(theano.clone(y, replace={mx: break_op(mx)}), mx, mv)
except ValueError:
raised = True
if not raised:
raise Exception(('Op did not raised an error even though the function'
' is not differentiable'))
try:
tensor.Rop_via_Lop(theano.clone(y, replace={mx: break_op(mx)}), mx, mv)
except theano.gradient.NullTypeGradError:
raised = True
except theano.gradient.DisconnectedInputError:
raised = True
if not raised:
raise Exception((
'Rop_via_Lop for Op did not raise an error even though the function'
' is not differentiable'))
vv = np.asarray(rng.uniform(size=(4, )), theano.config.floatX)
yv = tensor.Lop(y, mx, v)
lop_f = function([mx, v], yv)
sy = tensor.grad((v * y).sum(), mx)
scan_f = function([mx, v], sy)
v1 = lop_f(vx, vv)
v2 = scan_f(vx, vv)
assert _allclose(v1, v2), ('LOP mismatch: %s %s' % (v1, v2))
def check_rop_lop(self, y, out_shape):
"""
As check_mat_rop_lop, except the input is self.x which is a
vector. The output is still a vector.
"""
# TEST ROP
vx = numpy.asarray(self.rng.uniform(size=self.in_shape),
theano.config.floatX)
vv = numpy.asarray(self.rng.uniform(size=self.in_shape),
theano.config.floatX)
yv = tensor.Rop(y, self.x, self.v)
rop_f = function([self.x, self.v], yv, on_unused_input='ignore')
J, _ = theano.scan(lambda i, y, x: tensor.grad(y[i], x),
sequences=tensor.arange(y.shape[0]),
non_sequences=[y, self.x])
sy = tensor.dot(J, self.v)
scan_f = function([self.x, self.v], sy, on_unused_input='ignore')
v1 = rop_f(vx, vv)
v2 = scan_f(vx, vv)
assert numpy.allclose(v1, v2), ('ROP mismatch: %s %s' % (v1, v2))
known_fail = False
try:
self.check_nondiff_rop(
theano.clone(y, replace={self.x: break_op(self.x)}))
except AssertionError:
known_fail = True
# TEST LOP
vx = numpy.asarray(self.rng.uniform(size=self.in_shape),
theano.config.floatX)
vv = numpy.asarray(self.rng.uniform(size=out_shape),
theano.config.floatX)
yv = tensor.Lop(y, self.x, self.v)
lop_f = function([self.x, self.v], yv, on_unused_input='ignore')
J, _ = theano.scan(lambda i, y, x: tensor.grad(y[i], x),
sequences=tensor.arange(y.shape[0]),
non_sequences=[y, self.x])
sy = tensor.dot(self.v, J)
scan_f = function([self.x, self.v], sy)
v1 = lop_f(vx, vv)
v2 = scan_f(vx, vv)
assert numpy.allclose(v1, v2), ('LOP mismatch: %s %s' % (v1, v2))
if known_fail:
raise KnownFailureTest(
"Rop doesn't handle non-differentiable "
"inputs correctly. Bug exposed by fixing Add.grad"
" method.")
def __init__(self, p, inputs, s, costs):
# useful data for reshaping
self.shapes = [i.get_value().shape for i in p]
self.sizes = map(np.prod, self.shapes)
self.positions = np.cumsum([0] + self.sizes)[:-1]
self.p = p
self.inputs = inputs
self.s = s
self.costs = costs
g = T.grad(costs[0], p)
g = map(T.as_tensor_variable, g) # for CudaNdarray
self.f_gc = theano.function(inputs, g + costs) # gradient computation
self.f_cost = theano.function(inputs, costs) # quick cost evaluation
symbolic_types = T.scalar, T.vector, T.matrix, T.tensor3, T.tensor4
coefficient = T.scalar() # this is lambda*mu
# this computes the product Gv = J'HJv (G is the Gauss-Newton matrix)
v = [symbolic_types[len(i)]() for i in self.shapes]
Jv = T.Rop(s, p, v)
HJv = T.grad(T.sum(T.grad(costs[0], s) * Jv),
s,
consider_constant=[Jv])
Gv = T.grad(T.sum(HJv * s), p, consider_constant=[HJv, Jv])
Gv = map(T.as_tensor_variable, Gv) # for CudaNdarray
self.function_Gv = theano.function(inputs + v + [coefficient],
Gv,
givens={},
on_unused_input='ignore')
# compute J'sqrt(diag(H))v for jacobi preconditioner
r = T.matrix()
sqrt_Hv = T.sqrt(T.grad(T.sum(T.grad(costs[0], s)), s)) * r
J_sqrt_Hv = T.Lop(s, p, sqrt_Hv)
J_sqrt_Hv = map(T.as_tensor_variable, J_sqrt_Hv) # for CudaNdarray
self.function_J_sqrt_Hv = theano.function(inputs + [r],
J_sqrt_Hv,
givens={},
on_unused_input='ignore')
# compute Hv
dp = T.grad(costs[0], p)
total = 0
for dp_, v_ in zip(dp, v):
total += T.sum(dp_ * v_)
Hv = T.grad(total, p)
Hv = map(T.as_tensor_variable, Hv) # for CudaNdarray
self.function_Hv = theano.function(inputs + v + [coefficient],
Hv,
on_unused_input='ignore')
def check_mat_rop_lop(self, y, out_shape):
"""
Test the Rop/Lop when input is a matrix and the output is a vector
:param y: the output variable of the op applied to self.mx
:param out_shape: Used to generate a random tensor
corresponding to the evaluation point of the Rop
(i.e. the tensor with which you multiply the
Jacobian). It should be a tuple of ints.
If the Op has more than 1 input, one of them must be mx, while
others must be shared variables / constants. We will test only
against the input self.mx, so you must call
check_mat_rop_lop/check_rop_lop for the other inputs.
We expect all inputs/outputs have dtype floatX.
If you want to test an Op with an output matrix, add a sum
after the Op you want to test.
"""
vx = np.asarray(self.rng.uniform(size=self.mat_in_shape),
theano.config.floatX)
vv = np.asarray(self.rng.uniform(size=self.mat_in_shape),
theano.config.floatX)
yv = tensor.Rop(y, self.mx, self.mv)
yv2 = tensor.Rop_via_Lop(y, self.mx, self.mv)
rop_f = function([self.mx, self.mv], [yv, yv2],
on_unused_input='ignore')
sy, _ = theano.scan(lambda i, y, x, v:
(tensor.grad(y[i], x) * v).sum(),
sequences=tensor.arange(y.shape[0]),
non_sequences=[y, self.mx, self.mv])
scan_f = function([self.mx, self.mv], sy, on_unused_input='ignore')
v1, v2 = rop_f(vx, vv)
v3 = scan_f(vx, vv)
assert np.allclose(v1, v3), ('ROP mismatch: %s %s' % (v1, v3))
assert np.allclose(v2, v3), ('ROP_VIA_LOP mismatch: %s %s' % (v2, v3))
self.check_nondiff_rop(
theano.clone(y, replace={self.mx: break_op(self.mx)}))
vv = np.asarray(self.rng.uniform(size=out_shape), theano.config.floatX)
yv = tensor.Lop(y, self.mx, self.v)
lop_f = function([self.mx, self.v], yv)
sy = tensor.grad((self.v * y).sum(), self.mx)
scan_f = function([self.mx, self.v], sy)
v1 = lop_f(vx, vv)
v2 = scan_f(vx, vv)
assert np.allclose(v1, v2), ('LOP mismatch: %s %s' % (v1, v2))
def _get_updates_for(self, param, grad):
D_tm1 = shared_like(param, 'D_ewma')
v = self.rng.normal(param.shape)
if self.hv_method == 'rop':
Hv = TT.Rop(grad, param, v)
if self.hv_method == 'lop':
Hv = TT.Lop(grad, param, v)
if self.hv_method == 'grad':
Hv = TT.grad(TT.sum(grad * v), param)
D_t = self.ewma * D_tm1 + (1 - self.ewma) * Hv * Hv
den = TT.sqrt(D_t) + self.epsilon
yield D_tm1, D_t
yield param, param - grad * self.learning_rate / den
def setup(self, bottom, top):
weights = T.matrix("weights")
weights_bc = weights.dimshuffle((0, 1, "x", "x"))
feats = T.tensor4("weights")
v = T.tensor3("v")
dot = weights_bc * feats
result = T.sum(dot, axis=1)
g_w, g_f = T.Lop(result, [weights, feats], v)
self.f = theano.function([weights, feats], result)
self.b_w = theano.function([weights, feats, v], g_w)
self.b_f = theano.function([weights, feats, v], g_f)
def setup(self, bottom, top):
small_size = bottom[0].shape[1]
small = T.matrix("small")
big = T.tensor4("big")
v = T.tensor4("v")
small_bc = small.dimshuffle(0, 1, "x", "x")
small_bc = T.addbroadcast(small_bc, 0)
result = big + small_bc
g_small, g_big = T.Lop(result, [small, big], v)
self.f = theano.function([small, big], result)
self.b_small = theano.function([v], g_small)
self.b_big = theano.function([v], g_big)
def step(x_t, y_t, h_tmT, Wx, Wh, bh, Wy, by, lr, switch):
# manually build the graph for the inner loop...
# passing correct h_tm1 is impossible in nested scans
yo_t = []
h_tm1 = h_tmT
for t in range(self.steps):
h_t = relu(T.dot(x_t[t], Wx) + T.dot(h_tm1, Wh) + bh)
yo_t.append(relu(T.dot(h_t, Wy) + by))
h_tm1 = h_t
updates = OrderedDict()
# Train the RNN: backprop (loss + DNI output)
loss = T.mean(T.square(yo_t - y_t))
dni_out = self.dni.output(h_t)
for param in self.params:
dlossdparam = T.grad(loss, param)
dniJ = T.Lop(h_t,
param,
dni_out,
disconnected_inputs='ignore')
updates[param] = param - lr * T.switch(
T.gt(switch, 0), dlossdparam + dniJ, dlossdparam)
# Update the DNI (from the last step)
# re-calculate the DNI prediction from the last step
# note: can't be passed through scan or T.grad won't work
dni_out_old = self.dni.output(h_tmT)
# dni_target: current loss backprop'ed + new dni backprop'ed
dni_target = T.grad(loss,h_tmT) \
+T.Lop(h_t,h_tmT,dni_out)
dni_error = T.sum(T.square(dni_out_old - dni_target))
for param in self.dni.params:
gparam = T.grad(dni_error, param)
updates[param] = param - lr * gparam
return [h_t, loss, dni_error], updates
def gauss_vect_mult(v):
"""
Multiply a vector by the Gauss-Newton matrix JHJ'
where J is the Jacobian between output and params and H is the Hessian between costs and output
H should be diagonal and positive.
Also add the ridge
"""
Jv = T.Rop(output, params, v)
HJv = T.Rop(T.grad(opt_cost, output), output, Jv)
JHJv = T.Lop(output, params, HJv)
if not isinstance(JHJv, list):
JHJv = [JHJv]
JHJv = [a + ridge * b for a, b in zip(JHJv, v)]
return JHJv
def setup(self, bottom, top):
attention = T.tensor4("attention")
input = T.tensor4("input")
v = T.matrix("v")
attention_bc = T.addbroadcast(attention, 1)
attended = T.mul(input, attention_bc)
result = T.sum(attended, axis=(2, 3))
result_g_attention, result_g_input = T.Lop(result, [attention, input],
v)
self.f = theano.function([attention, input], result)
self.b_attention = theano.function([attention, input, v],
result_g_attention)
self.b_input = theano.function([attention, input, v],
result_g_attention)
def parse_args(self, bottom, top):
function_str = self.pythonargs[0]
top_shape = self.pythonargs[1]
old_function_str = self.function_str
old_top_shape = self.top_shape
self.function_str = function_str
self.top_shape = top_shape
if function_str != old_function_str or len(top_shape) != len(
old_top_shape):
if old_function_str != '':
print(
'TheanoGPU function string different from cache: recompiling'
)
import theano.tensor as T
import theano
from theano.sandbox.cuda.basic_ops import gpu_from_host
x = []
for i in range(len(bottom)):
if len(bottom[i].shape) == 1:
x.append(T.vector('x%d' % i))
if len(bottom[i].shape) == 2:
x.append(T.matrix('x%d' % i))
if len(bottom[i].shape) == 3:
x.append(T.tensor3('x%d' % i))
if len(bottom[i].shape) == 4:
x.append(T.tensor4('x%d' % i))
y = eval(function_str)
self.f = theano.function(x,
gpu_from_host(y),
on_unused_input='ignore')
if len(self.top_shape) == 1:
v = T.vector('v')
elif len(self.top_shape) == 2:
v = T.matrix('v')
elif len(self.top_shape) == 3:
v = T.tensor3('v')
elif len(self.top_shape) == 4:
v = T.tensor4('v')
self.b = []
for i in range(len(bottom)):
yg = T.Lop(y, x[i], v)
self.b.append(
theano.function(x + [v],
gpu_from_host(yg),
on_unused_input='ignore'))
def check_rop_lop(self, y, out_shape):
"""
As check_mat_rop_lop, except the input is self.x witch is a
vector. The output is still a vector.
"""
# TEST ROP
vx = numpy.asarray(self.rng.uniform(size=self.in_shape),
theano.config.floatX)
vv = numpy.asarray(self.rng.uniform(size=self.in_shape),
theano.config.floatX)
yv = tensor.Rop(y, self.x, self.v)
rop_f = function([self.x, self.v], yv, on_unused_input='ignore')
J, _ = theano.scan(lambda i, y, x: tensor.grad(y[i], x),
sequences=tensor.arange(y.shape[0]),
non_sequences=[y, self.x])
sy = tensor.dot(J, self.v)
scan_f = function([self.x, self.v], sy, on_unused_input='ignore')
v1 = rop_f(vx, vv)
v2 = scan_f(vx, vv)
assert numpy.allclose(v1, v2), ('ROP mismatch: %s %s' % (v1, v2))
self.check_nondiff_rop(
theano.clone(y, replace={self.x: break_op(self.x)}))
# TEST LOP
vx = numpy.asarray(self.rng.uniform(size=self.in_shape),
theano.config.floatX)
vv = numpy.asarray(self.rng.uniform(size=out_shape),
theano.config.floatX)
yv = tensor.Lop(y, self.x, self.v)
lop_f = function([self.x, self.v], yv, on_unused_input='ignore')
J, _ = theano.scan(lambda i, y, x: tensor.grad(y[i], x),
sequences=tensor.arange(y.shape[0]),
non_sequences=[y, self.x])
sy = tensor.dot(self.v, J)
scan_f = function([self.x, self.v], sy)
v1 = lop_f(vx, vv)
v2 = scan_f(vx, vv)
assert numpy.allclose(v1, v2), ('LOP mismatch: %s %s' % (v1, v2))
def compute_Lx(energies, params, deltas):
# expectations and derivatives are commutative.
cenergies = energies - T.mean(energies)
Minv = T.cast(1. / energies.shape[0], floatX)
rhs_terms = []
for param_j, delta_j in zip(params, deltas):
rhs_term = T.Rop(cenergies, param_j, delta_j)
rhs_terms += [rhs_term]
Lx_terms = []
for param_i in params:
Lx_term = 0
for rhs in rhs_terms:
Lx_term += Minv * T.Lop(cenergies, param_i, rhs)
Lx_terms += [Lx_term]
return Lx_terms
def Gv_step(*gv_args):
idx = TT.cast(gv_args[0], 'int32')
nw_inps = [x[idx * options['cbs']: \
(idx + 1) * options['cbs']] for x in
loc_inputs]
replace = dict(zip(model.inputs, nw_inps))
nw_cost, nw_preactiv_out = safe_clone(
[model.train_cost, model.preactiv_out], replace)
nw_gvs = TT.Lop(
nw_preactiv_out, model.params,
TT.Rop(TT.grad(nw_cost, nw_preactiv_out), model.params,
cgv))
Gvs = [
ogv + ngv for (ogv, ngv) in zip(gv_args[1:], nw_gvs)
]
return [gv_args[0] + const(1)] + Gvs