def test_zero_optimal(self):
""" minimizes the kl divergence between q and p
using batch gradient descent and checks that
the result is zero"""
rng = np.random.RandomState([1,2,3])
dim = self.dim
num_trials = 3
mu = rng.randn(dim).astype(floatX)
beta = rng.uniform(.1,10.,(dim,)).astype(floatX)
self.p.mu.set_value(mu)
mu = rng.randn(dim).astype(floatX)
self.q.mu.set_value(mu)
self.p.beta.set_value(beta)
beta = rng.uniform(.1,10.,(dim,)).astype(floatX)
self.q.beta.set_value(beta)
kl = kl_divergence(self.q,self.p)
p = self.p
q = self.q
optimizer = BatchGradientDescent(
max_iter = 100,
line_search_mode = 'exhaustive',
verbose = True,
objective = kl,
conjugate = True,
params = [ p.mu, p.beta, q.mu, q.beta ],
param_constrainers = [ p.censor_updates,
q.censor_updates ])
#optimizer.verbose = True
kl = optimizer.minimize()
if kl < 0.:
if config.floatX == 'float32':
neg_tol = 4.8e-7
else:
neg_tol = 0.
if kl < - neg_tol:
raise AssertionError("KL divergence should "
"be non-negative but is "+
str(kl))
warnings.warn("KL divergence is not very numerically stable, evidently")
tol = 6e-5
if kl > tol:
print 'kl:',kl
print 'tol:',tol
assert kl <= tol
assert not (kl > tol )
def test_zero_optimal(self):
""" minimizes the kl divergence between q and p
using batch gradient descent and checks that
the result is zero"""
rng = np.random.RandomState([1,2,3])
dim = self.dim
num_trials = 3
mu = rng.randn(dim).astype(floatX)
beta = rng.uniform(.1,10.,(dim,)).astype(floatX)
self.p.mu.set_value(mu)
mu = rng.randn(dim).astype(floatX)
self.q.mu.set_value(mu)
self.p.beta.set_value(beta)
beta = rng.uniform(.1,10.,(dim,)).astype(floatX)
self.q.beta.set_value(beta)
kl = kl_divergence(self.q,self.p)
p = self.p
q = self.q
optimizer = BatchGradientDescent(
objective = kl,
params = [ p.mu, p.beta, q.mu, q.beta ],
param_constrainers = [ p.censor_updates,
q.censor_updates ])
#optimizer.verbose = True
kl = optimizer.minimize()
if kl < 0.:
raise AssertionError("KL divergence should "
"be non-negative but is "+
str(kl))
tol = 5.4e-5
assert kl <= tol
assert not (kl > tol )
def fit(self, params=None, l1=.0, l2=.0):
"""
Fit the model by minimizing the Leave One Out (LOO) loss using gradient-based optimization.
"""
loo_loss = self.loss_symbolic(self.L, self.y, self.mu, self.R, self.eta, self.eps)
if params is None:
params = [self.eta]
# Symbolic Theano variables that represent the L1 and L2 regularization terms
L1, L2 = .0, .0
for param in params:
L1 += T.sum(abs(param))
L2 += T.sum(param ** 2)
regularized_loo_loss = loo_loss + l1 * L1 + l2 * L2
minimizer = BatchGradientDescent(objective=regularized_loo_loss, params=params, inputs=[], verbose=1)
minimizer.minimize()
def createGradientFunctions(self):
#create
X = T.dmatrices("X")
mu, logSigma, u, v, f, R = T.dcols("mu", "logSigma", "u", "v", "f",
"R")
mu = sharedX(np.random.normal(10, 10, (self.dimTheta, 1)), name='mu')
logSigma = sharedX(np.random.uniform(0, 4, (self.dimTheta, 1)),
name='logSigma')
logLambd = sharedX(np.matrix(np.random.uniform(0, 10)),
name='logLambd')
logLambd = T.patternbroadcast(T.dmatrix("logLambd"), [1, 1])
negKL = 0.5 * T.sum(1 + 2 * logSigma - mu**2 - T.exp(logSigma)**2)
theta = mu + T.exp(logSigma) * v
W = theta
y = X[:, 0]
X_sim = X[:, 1:]
f = (T.dot(X_sim, W) + u).flatten()
gradvariables = [mu, logSigma, logLambd]
logLike = T.sum(-(0.5 * np.log(2 * np.pi) + logLambd) - 0.5 *
((y - f) / (T.exp(logLambd)))**2)
logp = (negKL + logLike) / self.m
optimizer = -logp
self.negKL = th.function([mu, logSigma],
negKL,
on_unused_input='ignore')
self.f = th.function(gradvariables + [X, u, v],
f,
on_unused_input='ignore')
self.logLike = th.function(gradvariables + [X, u, v],
logLike,
on_unused_input='ignore')
derivatives = T.grad(logp, gradvariables)
derivatives.append(logp)
self.gradientfunction = th.function(gradvariables + [X, u, v],
derivatives,
on_unused_input='ignore')
self.lowerboundfunction = th.function(gradvariables + [X, u, v],
logp,
on_unused_input='ignore')
self.optimizer = BatchGradientDescent(objective=optimizer,
params=gradvariables,
inputs=[X, u, v],
conjugate=True,
max_iter=1)
def fit(self, params=None, l1=.0, l2=.0):
"""
Fit the model by minimizing the Leave One Out (LOO) loss using gradient-based optimization.
"""
loo_loss = self.loss_symbolic(self.L, self.y, self.mu, self.R,
self.eta, self.eps)
if params is None:
params = [self.eta]
# Symbolic Theano variables that represent the L1 and L2 regularization terms
L1, L2 = .0, .0
for param in params:
L1 += T.sum(abs(param))
L2 += T.sum(param**2)
regularized_loo_loss = loo_loss + l1 * L1 + l2 * L2
minimizer = BatchGradientDescent(objective=regularized_loo_loss,
params=params,
inputs=[],
verbose=1)
minimizer.minimize()
#Get the objective function
nce = DNCE(noise_distribution)
J = nce(model,X,Y)
accs = []
for Y_i in Y:
pos_prob = 1./(1.+T.exp(model.free_energy(X)-model.free_energy(Y_i)))
acc = (pos_prob > .5).mean()
accs.append(acc)
acc = sum(accs) / float(len(accs))
print '\tinit accuracy ',function([],acc)()
#Minimize the objective function with batch gradient descent
minimizer = BatchGradientDescent( objective = J,
params = model.get_params(),
param_constrainers = [ model.censor_updates ])
print '\tinit obj:',minimizer.obj()
#minimizer.verbose = True
minimizer.minimize()
print '\tfinal obj:',minimizer.obj()
recovered_beta = model.beta.get_value()
recovered_mu = model.mu.get_value()
print '\trecovered beta:',recovered_beta
print '\trecovered mu:',recovered_mu
kl = kl_divergence(true, model)
kl = function([],kl)()
def test_batch_gradient_descent():
""" Verify that batch gradient descent works by checking that
it minimizes a quadratic function f(x) = x^T A x + b^T x + c
correctly for several sampled values of A, b, and c.
The ground truth minimizer is x = np.linalg.solve(A,-b)"""
n = 3
A = T.matrix(name = 'A')
b = T.vector(name = 'b')
c = T.scalar(name = 'c')
x = sharedX( np.zeros((n,)) , name = 'x')
half = np.cast[config.floatX](0.5)
obj = half * T.dot(T.dot(x,A),x)+T.dot(b,x)+c
minimizer = BatchGradientDescent(
objective = obj,
params = [ x],
inputs = [ A, b, c])
num_samples = 3
rng = np.random.RandomState([1,2,3])
for i in xrange(num_samples):
A = np.cast[config.floatX](rng.randn(1.5*n,n))
A = np.cast[config.floatX](np.dot(A.T,A))
A += np.cast[config.floatX](np.identity(n) * .02)
b = np.cast[config.floatX](rng.randn(n))
c = np.cast[config.floatX](rng.randn())
x.set_value(np.cast[config.floatX](rng.randn(n)))
analytical_x = np.linalg.solve(A,-b)
actual_obj = minimizer.minimize(A,b,c)
actual_x = x.get_value()
#Check that the value returned by the minimize method
#is the objective function value at the parameters
#chosen by the minimize method
cur_obj = minimizer.obj(A,b,c)
assert np.allclose(actual_obj, cur_obj)
x.set_value(analytical_x)
analytical_obj = minimizer.obj(A,b,c)
#make sure the objective function is accurate to first 4 digits
condition1 = not np.allclose(analytical_obj, actual_obj)
condition2 = np.abs(analytical_obj-actual_obj) >= 1e-4 * np.abs(analytical_obj)
if (config.floatX == 'float64' and condition1) \
or (config.floatX == 'float32' and condition2):
print 'objective function value came out wrong on sample ',i
print 'analytical obj', analytical_obj
print 'actual obj',actual_obj
"""
The following section of code was used to verify that numerical
error can make the objective function look non-convex
print 'Checking for numerically induced non-convex behavior'
def f(x):
return 0.5 * np.dot(x,np.dot(A,x)) + np.dot(b,x) + c
x.set_value(actual_x)
minimizer._compute_grad(A,b,c)
minimizer._normalize_grad()
d = minimizer.param_to_grad_shared[x].get_value()
x = actual_x.copy()
prev = f(x)
print prev
step_size = 1e-4
x += step_size * d
cur = f(x)
print cur
cur_sgn = np.sign(cur-prev)
flip_cnt = 0
for i in xrange(10000):
x += step_size * d
prev = cur
cur = f(x)
print cur
prev_sgn = cur_sgn
cur_sgn = np.sign(cur-prev)
if cur_sgn != prev_sgn:
print 'flip'
flip_cnt += 1
if flip_cnt > 1:
print "Non-convex!"
from matplotlib import pyplot as plt
y = []
x = actual_x.copy()
for j in xrange(10000):
y.append(f(x))
x += step_size * d
plt.plot(y)
plt.show()
assert False
print 'None found'
"""
#print 'actual x',actual_x
#print 'A:'
#print A
#print 'b:'
#print b
#print 'c:'
#print c
x.set_value(actual_x)
minimizer._compute_grad(A,b,c)
x_grad = minimizer.param_to_grad_shared[x]
actual_grad = x_grad.get_value()
correct_grad = 0.5 * np.dot(A,x.get_value())+ 0.5 * np.dot(A.T, x.get_value()) +b
if not np.allclose(actual_grad, correct_grad):
print 'gradient was wrong at convergence point'
print 'actual grad: '
print actual_grad
print 'correct grad: '
print correct_grad
print 'max difference: ',np.abs(actual_grad-correct_grad).max()
assert False
minimizer._normalize_grad()
d = minimizer.param_to_grad_shared[x].get_value()
step_len = ( np.dot(b,d) + 0.5 * np.dot(d,np.dot(A,actual_x)) \
+ 0.5 * np.dot(actual_x,np.dot(A,d)) ) / np.dot(d, np.dot(A,d))
g = np.dot(A,actual_x)+b
deriv = np.dot(g,d)
print 'directional deriv at actual', deriv
print 'optimal step_len', step_len
optimal_x = actual_x - d * step_len
g = np.dot(A,optimal_x) + b
deriv = np.dot(g,d)
print 'directional deriv at optimal: ',deriv
x.set_value(optimal_x)
print 'obj at optimal: ',minimizer.obj(A,b,c)
print 'eigenvalue range:'
val, vec = np.linalg.eig(A)
print (val.min(),val.max())
print 'condition number: ',(val.max()/val.min())
assert False
class BGD(TrainingAlgorithm):
"""Batch Gradient Descent training algorithm class"""
def __init__(self, cost, batch_size=None, batches_per_iter=None,
updates_per_batch = 10,
monitoring_batches=None, monitoring_dataset=None,
termination_criterion = None, set_batch_size = False,
reset_alpha = True, conjugate = False,
min_init_alpha = .001,
reset_conjugate = True, line_search_mode = None,
verbose_optimization=False, scale_step=1., theano_function_mode=None,
init_alpha=None, seed=None):
"""
cost: a pylearn2 Cost
batch_size: Like the SGD TrainingAlgorithm, this TrainingAlgorithm
still iterates over minibatches of data. The difference
is that this class uses partial line searches to choose
the step size along each gradient direction, and can do
repeated updates on the same batch. The assumption is
that you use big enough minibatches with this algorithm that
a large step size will generalize reasonably well to other
minibatches.
To implement true Batch Gradient Descent, set the batch_size
to the total number of examples available.
If batch_size is None, it will revert to the model's force_batch_size
attribute.
set_batch_size: If True, BGD will attempt to override the model's force_batch_size
attribute by calling set_batch_size on it.
updates_per_batch: Passed through to the optimization.BatchGradientDescent's
max_iters parameter
reset_alpha, conjugate, reset_conjugate: passed through to the
optimization.BatchGradientDescent parameters of the same names
monitoring_dataset: A Dataset or a dictionary mapping string dataset names to Datasets
"""
self.__dict__.update(locals())
del self.self
if monitoring_dataset is None:
assert monitoring_batches == None
self._set_monitoring_dataset(monitoring_dataset)
self.bSetup = False
self.termination_criterion = termination_criterion
if seed is None:
seed = [2012, 10, 16]
self.rng = np.random.RandomState(seed)
def setup(self, model, dataset):
"""
Allows the training algorithm to do some preliminary configuration
*before* we actually start training the model. The dataset is provided
in case other derived training algorithms need to modify model based on
the dataset.
Parameters
----------
model: a Python object representing the model to train loosely
implementing the interface of models.model.Model.
dataset: a pylearn2.datasets.dataset.Dataset object used to draw
training data
"""
self.model = model
if self.batch_size is None:
self.batch_size = model.force_batch_size
else:
batch_size = self.batch_size
if self.set_batch_size:
model.set_batch_size(batch_size)
elif hasattr(model, 'force_batch_size'):
if not (model.force_batch_size <= 0 or batch_size ==
model.force_batch_size):
raise ValueError("batch_size is %d but model.force_batch_size is %d" %
(batch_size, model.force_batch_size))
self.monitor = Monitor.get_monitor(model)
self.monitor.set_theano_function_mode(self.theano_function_mode)
X = self.model.get_input_space().make_theano_batch()
X.name = 'BGD_X'
self.topo = X.ndim != 2
Y = T.matrix()
Y.name = 'BGD_Y'
fixed_var_descr = self.cost.get_fixed_var_descr(model, X, Y)
self.on_load_batch = fixed_var_descr.on_load_batch
if not self.cost.supervised:
Y = None
if self.cost.supervised:
obj = self.cost(model, X, Y, ** fixed_var_descr.fixed_vars)
grads, grad_updates = self.cost.get_gradients(model, X, Y, ** fixed_var_descr.fixed_vars)
ipt = (X,Y)
else:
obj = self.cost(model, X, ** fixed_var_descr.fixed_vars)
grads, grad_updates = self.cost.get_gradients(model, X, ** fixed_var_descr.fixed_vars)
ipt = X
Y = None
assert isinstance(grads, OrderedDict)
assert isinstance(grad_updates, OrderedDict)
if obj is None:
raise ValueError("BGD is incompatible with "+str(self.cost)+" because "
" it is intractable, but BGD uses the cost function value to do "
" line searches.")
if self.monitoring_dataset is not None:
if not any([dataset.has_targets() for dataset in self.monitoring_dataset.values()]):
Y = None
channels = model.get_monitoring_channels(X,Y)
if not isinstance(channels, dict):
raise TypeError("model.get_monitoring_channels must return a "
"dictionary, but it returned " + str(channels))
channels.update(self.cost.get_monitoring_channels(model, X, Y, ** fixed_var_descr.fixed_vars))
for dataset_name in self.monitoring_dataset:
if dataset_name == '':
prefix = ''
else:
prefix = dataset_name + '_'
monitoring_dataset = self.monitoring_dataset[dataset_name]
self.monitor.add_dataset(dataset=monitoring_dataset,
mode="sequential",
batch_size=self.batch_size,
num_batches=self.monitoring_batches)
# The monitor compiles all channels for the same dataset into one function, and
# runs all prereqs before calling the function. So we only need to register the
# on_load_batch prereq once per monitoring dataset.
self.monitor.add_channel(prefix + 'objective',ipt=ipt,val=obj,
dataset = monitoring_dataset, prereqs = fixed_var_descr.on_load_batch)
for name in channels:
J = channels[name]
if isinstance(J, tuple):
assert len(J) == 2
J, prereqs = J
else:
prereqs = None
if Y is not None:
ipt = (X,Y)
else:
ipt = X
self.monitor.add_channel(name= prefix + name,
ipt=ipt,
val=J,
dataset = monitoring_dataset,
prereqs=prereqs)
if self.cost.supervised:
ipts = [X, Y]
else:
ipts = [X]
params = model.get_params()
self.optimizer = BatchGradientDescent(
objective = obj,
gradients = grads,
gradient_updates = grad_updates,
params = params,
param_constrainers = [ model.censor_updates ],
lr_scalers = model.get_lr_scalers(),
inputs = ipts,
verbose = self.verbose_optimization,
max_iter = self.updates_per_batch,
reset_alpha = self.reset_alpha,
conjugate = self.conjugate,
reset_conjugate = self.reset_conjugate,
min_init_alpha = self.min_init_alpha,
line_search_mode = self.line_search_mode,
theano_function_mode=self.theano_function_mode,
init_alpha=self.init_alpha)
if self.monitoring_dataset is not None:
self.monitor.add_channel(name='ave_step_size',
ipt=ipt, val = self.optimizer.ave_step_size, dataset=self.monitoring_dataset.values()[0])
self.monitor.add_channel(name='ave_grad_size',
ipt=ipt, val = self.optimizer.ave_grad_size, dataset=self.monitoring_dataset.values()[0])
self.monitor.add_channel(name='ave_grad_mult',
ipt=ipt, val = self.optimizer.ave_grad_mult, dataset=self.monitoring_dataset.values()[0])
self.first = True
self.bSetup = True
def train(self, dataset):
assert self.bSetup
model = self.model
batch_size = self.batch_size
if self.topo:
get_data = dataset.get_batch_topo
else:
get_data = dataset.get_batch_design
rng = self.rng
train_iteration_mode = 'shuffled_sequential'
if not is_stochastic(train_iteration_mode):
rng = None
iterator = dataset.iterator(mode=train_iteration_mode,
batch_size=self.batch_size,
targets=self.cost.supervised,
num_batches=self.batches_per_iter,
topo=self.topo,
rng = rng)
for data in iterator:
if self.cost.supervised:
args = data
X, Y = data
mode = self.theano_function_mode
if mode is not None and hasattr(mode, 'record'):
stry = str(Y).replace('\n',' ')
mode.record.handle_line('data Y '+stry+'\n')
for on_load_batch in self.on_load_batch:
on_load_batch(X, Y)
else:
args = [ data ]
X = data
for on_load_batch in self.on_load_batch:
on_load_batch(X, None)
self.before_step(model)
self.optimizer.minimize(*args)
self.after_step(model)
model.monitor.report_batch( X.shape[0] )
def continue_learning(self, model):
if self.termination_criterion is None:
return True
else:
return self.termination_criterion(self.model)
def before_step(self, model):
if self.scale_step != 1.:
self.params = list(model.get_params())
self.value = [ param.get_value() for param in self.params ]
def after_step(self, model):
if self.scale_step != 1:
for param, value in safe_zip(self.params, self.value):
value = (1.-self.scale_step) * value + self.scale_step * param.get_value()
param.set_value(value)
def setup(self, model, dataset):
"""
Allows the training algorithm to do some preliminary configuration
*before* we actually start training the model. The dataset is provided
in case other derived training algorithms need to modify model based on
the dataset.
Parameters
----------
model: a Python object representing the model to train loosely
implementing the interface of models.model.Model.
dataset: a pylearn2.datasets.dataset.Dataset object used to draw
training data
"""
self.model = model
if self.batch_size is None:
self.batch_size = model.force_batch_size
else:
batch_size = self.batch_size
if self.set_batch_size:
model.set_batch_size(batch_size)
elif hasattr(model, 'force_batch_size'):
if not (model.force_batch_size <= 0 or batch_size ==
model.force_batch_size):
raise ValueError("batch_size is %d but model.force_batch_size is %d" %
(batch_size, model.force_batch_size))
self.monitor = Monitor.get_monitor(model)
self.monitor.set_theano_function_mode(self.theano_function_mode)
X = self.model.get_input_space().make_theano_batch()
X.name = 'BGD_X'
self.topo = X.ndim != 2
Y = T.matrix()
Y.name = 'BGD_Y'
fixed_var_descr = self.cost.get_fixed_var_descr(model, X, Y)
self.on_load_batch = fixed_var_descr.on_load_batch
if not self.cost.supervised:
Y = None
if self.cost.supervised:
obj = self.cost(model, X, Y, ** fixed_var_descr.fixed_vars)
grads, grad_updates = self.cost.get_gradients(model, X, Y, ** fixed_var_descr.fixed_vars)
ipt = (X,Y)
else:
obj = self.cost(model, X, ** fixed_var_descr.fixed_vars)
grads, grad_updates = self.cost.get_gradients(model, X, ** fixed_var_descr.fixed_vars)
ipt = X
Y = None
assert isinstance(grads, OrderedDict)
assert isinstance(grad_updates, OrderedDict)
if obj is None:
raise ValueError("BGD is incompatible with "+str(self.cost)+" because "
" it is intractable, but BGD uses the cost function value to do "
" line searches.")
if self.monitoring_dataset is not None:
if not any([dataset.has_targets() for dataset in self.monitoring_dataset.values()]):
Y = None
channels = model.get_monitoring_channels(X,Y)
if not isinstance(channels, dict):
raise TypeError("model.get_monitoring_channels must return a "
"dictionary, but it returned " + str(channels))
channels.update(self.cost.get_monitoring_channels(model, X, Y, ** fixed_var_descr.fixed_vars))
for dataset_name in self.monitoring_dataset:
if dataset_name == '':
prefix = ''
else:
prefix = dataset_name + '_'
monitoring_dataset = self.monitoring_dataset[dataset_name]
self.monitor.add_dataset(dataset=monitoring_dataset,
mode="sequential",
batch_size=self.batch_size,
num_batches=self.monitoring_batches)
# The monitor compiles all channels for the same dataset into one function, and
# runs all prereqs before calling the function. So we only need to register the
# on_load_batch prereq once per monitoring dataset.
self.monitor.add_channel(prefix + 'objective',ipt=ipt,val=obj,
dataset = monitoring_dataset, prereqs = fixed_var_descr.on_load_batch)
for name in channels:
J = channels[name]
if isinstance(J, tuple):
assert len(J) == 2
J, prereqs = J
else:
prereqs = None
if Y is not None:
ipt = (X,Y)
else:
ipt = X
self.monitor.add_channel(name= prefix + name,
ipt=ipt,
val=J,
dataset = monitoring_dataset,
prereqs=prereqs)
if self.cost.supervised:
ipts = [X, Y]
else:
ipts = [X]
params = model.get_params()
self.optimizer = BatchGradientDescent(
objective = obj,
gradients = grads,
gradient_updates = grad_updates,
params = params,
param_constrainers = [ model.censor_updates ],
lr_scalers = model.get_lr_scalers(),
inputs = ipts,
verbose = self.verbose_optimization,
max_iter = self.updates_per_batch,
reset_alpha = self.reset_alpha,
conjugate = self.conjugate,
reset_conjugate = self.reset_conjugate,
min_init_alpha = self.min_init_alpha,
line_search_mode = self.line_search_mode,
theano_function_mode=self.theano_function_mode,
init_alpha=self.init_alpha)
if self.monitoring_dataset is not None:
self.monitor.add_channel(name='ave_step_size',
ipt=ipt, val = self.optimizer.ave_step_size, dataset=self.monitoring_dataset.values()[0])
self.monitor.add_channel(name='ave_grad_size',
ipt=ipt, val = self.optimizer.ave_grad_size, dataset=self.monitoring_dataset.values()[0])
self.monitor.add_channel(name='ave_grad_mult',
ipt=ipt, val = self.optimizer.ave_grad_mult, dataset=self.monitoring_dataset.values()[0])
self.first = True
self.bSetup = True
def setup_impl(self, model, dataset, algorithm):
cost = algorithm.cost
root = model.get_param_vector()
dim = root.size
rng = self.rng
points = rng.randn(self.num_points, self.num_basis_vectors)
points = points.astype(root.dtype)
points *= self.scale
if self.include_root:
points[0, :] = 0.
if not hasattr(self, 'cost_fn'):
# Cargo cult all the Pascal bullshit needed to evaluate the f*****g cost function now
# =======================================
data_specs = cost.get_data_specs(model)
mapping = DataSpecsMapping(data_specs)
space_tuple = mapping.flatten(data_specs[0], return_tuple=True)
source_tuple = mapping.flatten(data_specs[1], return_tuple=True)
# Build a flat tuple of Theano Variables, one for each space.
# We want that so that if the same space/source is specified
# more than once in data_specs, only one Theano Variable
# is generated for it, and the corresponding value is passed
# only once to the compiled Theano function.
theano_args = []
for space, source in safe_zip(space_tuple, source_tuple):
name = '%s[%s]' % (self.__class__.__name__, source)
arg = space.make_theano_batch(name=name,
batch_size=self.batch_size)
theano_args.append(arg)
theano_args = tuple(theano_args)
# Methods of `cost` need args to be passed in a format compatible
# with data_specs
nested_args = mapping.nest(theano_args)
fixed_var_descr = cost.get_fixed_var_descr(model, nested_args)
self.on_load_batch = fixed_var_descr.on_load_batch
cost_value = cost.expr(model, nested_args,
** fixed_var_descr.fixed_vars)
# End cargo culting
# ======================
print "Compiling cost function..."
cost_fn = function(theano_args, cost_value)
self.cost_fn = cost_fn
else:
cost_fn = self.cost_fn
cost_values = np.zeros(self.num_points)
data = list(dataset.get_batch_design(self.batch_size,
include_labels=True))
from pylearn2.utils.one_hot import one_hot
data[1] = one_hot(data[1])
if self.method == 'gaussian':
basis = rng.normal(dim, self.num_basis_vectors).astype(root.dtype)
elif self.method == 'element':
basis = np.zeros((dim, self.num_basis_vectors)).astype(root.dtype)
for i in xrange(self.num_basis_vectors):
basis[rng.randint(dim), i] = 1.
elif self.method == 'gradient':
if not hasattr(self, 'grad_fn'):
self.grad_fn = function(theano_args, grad(cost_value, model.get_params()))
grad_fn = self.grad_fn
basis = np.zeros((dim, self.num_basis_vectors)).astype(root.dtype)
for i in xrange(self.num_basis_vectors):
ipt = list(dataset.get_batch_design(1, include_labels=True))
label = ipt[1]
assert label.size == 1
label = label[0]
one_hot = np.zeros((1, 10,),dtype='float32')
one_hot[0, label] = 1
ipt[1] = one_hot
g = grad_fn(*ipt)
basis[:,i] = np.concatenate([e.reshape(e.size) for e in g], axis=0)
else:
assert False
basis /= np.sqrt(np.square(basis).sum(axis=0))
# Orthogonalize basis
for i in xrange(self.num_basis_vectors):
v = basis[:,i ].copy()
for j in xrange(i - 1):
u = basis[:, j].copy()
v -= np.dot(u, v) * u
norm = np.sqrt(np.square(v).sum())
assert norm > 1e-4
v /= norm
basis[:,i] = v
for i in xrange(self.num_points):
print "Evaluating cost at point ", i
point = points[i, :]
full_point = root + np.dot(basis, point)
model.set_param_vector(full_point)
cost_values[i] = cost_fn(*data)
print cost_values[i]
from pylearn2.utils import sharedX
import theano.tensor as T
print "!!!!!!!! FITTING THE QUADRATIC FUNCTION !!!!!!!!!!!!!!!!!!!"
if not hasattr(self, 'fit_quad'):
points = sharedX(points)
#from theano import config
#config.compute_test_value = 'raise'
cost_values = sharedX(cost_values)
A = sharedX(np.zeros((self.num_basis_vectors, self.num_basis_vectors)))
if self.psd:
mat = T.dot(A.T, A)
else:
mat = A
b = sharedX(np.zeros(self.num_basis_vectors))
c = sharedX(0.)
half_quad = T.dot(points, mat)
quad = (points * half_quad).sum(axis=1)
lin = T.dot(points, b)
pred = quad + lin + c
from pylearn2.optimization.batch_gradient_descent import BatchGradientDescent
mse = T.square(pred - cost_values).mean()
mae = abs(pred - cost_values).mean()
obj = locals()[self.fitting_cost]
fit_quad = BatchGradientDescent(obj, params = [A, b, c],
max_iter = self.num_basis_vectors ** 2,
verbose = 3, tol = None,
init_alpha = None, min_init_alpha = 1e-7,
reset_alpha = False, conjugate = True,
reset_conjugate = False,
line_search_mode = 'exhaustive')
self.fit_quad = fit_quad
self.A = A
self.b = b
self.c = c
self.points = points
self.cost_values = cost_values
else:
self.A.set_value(.001 * np.identity(self.A.get_value().shape[0], dtype=self.A.dtype))
self.b.set_value(self.b.get_value() * 0.)
self.c.set_value(self.c.get_value() * 0.)
self.points.set_value(points)
self.cost_values.set_value(cost_values.astype(self.cost_values.dtype))
self.fit_quad.minimize()
print "!!!!!!!!!!!!! FINDING ITS MINIMUM !!!!!!!!!!!!!!!!!!!!!!!!!!!"
if self.use_solver:
if self.psd:
Av = self.A.get_value()
mat_v = np.dot(Av.T, Av)
else:
mat_v = self.A.get_value()
bv = self.b.get_value()
# minimize for x^T A x + b^T x + c
# -> solve 2 A x + b = 0
# Ax = - b / 2
print "********** mat_v", mat_v.min(), mat_v.max()
x, ignored_residuals, ignored_rank, ignored_singular_values = np.linalg.lstsq(mat_v, - 0.5 * bv)
print "********** soln: ", x.min(), x.mean(), x.max()
print "********** SVs: ", ignored_singular_values.min(), ignored_singular_values.max()
assert x.ndim == 1, x.shape
prod = np.dot(basis, x)
norm = np.sqrt(np.square(prod).sum())
print "*************** Moving params by ",norm
vector = root + prod
model.set_param_vector(vector)
else: # use minimizer
if not hasattr(self, 'fit_params'):
self.vector = sharedX(points.get_value().mean(axis=0))
vector = self.vector
obj = T.dot(T.dot(mat, vector), vector) + T.dot(b, vector)
def constrain(d):
assert vector in d
n = d[vector]
norm = T.sqrt(T.square(n).sum())
desired_norm = T.clip(norm, 0., self.max_jump_norm)
d[vector] = n * desired_norm / norm
self.fit_params = BatchGradientDescent(obj, params=[vector],
max_iter = self.num_basis_vectors,
verbose = 3, tol=None,
param_constrainers = [constrain],
init_alpha = None, min_init_alpha = 1e-3,
reset_alpha=False, conjugate=True, reset_conjugate=False,
line_search_mode='exhaustive')
else:
self.vector.set_value(points.mean(axis=0).astype(self.vector.dtype))
self.fit_params.minimize()
model.set_param_vector(root + np.dot(basis , self.vector.get_value()))
def setup(self, model, dataset):
"""
Allows the training algorithm to do some preliminary configuration
*before* we actually start training the model. The dataset is provided
in case other derived training algorithms need to modify model based on
the dataset.
Parameters
----------
model : object
A Python object representing the model to train. Loosely
implementing the interface of models.model.Model.
dataset : pylearn2.datasets.dataset.Dataset
Dataset object used to draw training data
"""
self.model = model
if self.cost is None:
self.cost = model.get_default_cost()
try:
if self.cost.is_stochastic():
raise TypeError("BGD is not compatible with stochastic "
"costs.")
except NotImplementedError:
warnings.warn("BGD is not compatible with stochastic costs "
"and cannot determine whether the current cost is "
"stochastic.")
if self.batch_size is None:
self.batch_size = model.force_batch_size
else:
batch_size = self.batch_size
if self.set_batch_size:
model.set_batch_size(batch_size)
elif hasattr(model, 'force_batch_size'):
if not (model.force_batch_size is None or
model.force_batch_size <= 0 or
batch_size == model.force_batch_size):
raise ValueError("batch_size is %d but " +
"model.force_batch_size is %d" %
(batch_size, model.force_batch_size))
self.monitor = Monitor.get_monitor(model)
self.monitor.set_theano_function_mode(self.theano_function_mode)
data_specs = self.cost.get_data_specs(model)
mapping = DataSpecsMapping(data_specs)
space_tuple = mapping.flatten(data_specs[0], return_tuple=True)
source_tuple = mapping.flatten(data_specs[1], return_tuple=True)
# Build a flat tuple of Theano Variables, one for each space,
# named according to the sources.
theano_args = []
for space, source in safe_zip(space_tuple, source_tuple):
name = 'BGD_[%s]' % source
arg = space.make_theano_batch(name=name)
theano_args.append(arg)
theano_args = tuple(theano_args)
# Methods of `self.cost` need args to be passed in a format compatible
# with their data_specs
nested_args = mapping.nest(theano_args)
fixed_var_descr = self.cost.get_fixed_var_descr(model, nested_args)
self.on_load_batch = fixed_var_descr.on_load_batch
cost_value = self.cost.expr(model, nested_args,
** fixed_var_descr.fixed_vars)
grads, grad_updates = self.cost.get_gradients(
model, nested_args, ** fixed_var_descr.fixed_vars)
assert isinstance(grads, OrderedDict)
assert isinstance(grad_updates, OrderedDict)
if cost_value is None:
raise ValueError("BGD is incompatible with " + str(self.cost) +
" because it is intractable, but BGD uses the " +
"cost function value to do line searches.")
# obj_prereqs has to be a list of function f called with f(*data),
# where data is a data tuple coming from the iterator.
# this function enables capturing "mapping" and "f", while
# enabling the "*data" syntax
def capture(f, mapping=mapping):
new_f = lambda *args: f(mapping.flatten(args, return_tuple=True))
return new_f
obj_prereqs = [capture(f) for f in fixed_var_descr.on_load_batch]
if self.monitoring_dataset is not None:
if (self.monitoring_batch_size is None and
self.monitoring_batches is None):
self.monitoring_batch_size = self.batch_size
self.monitoring_batches = self.batches_per_iter
self.monitor.setup(
dataset=self.monitoring_dataset,
cost=self.cost,
batch_size=self.monitoring_batch_size,
num_batches=self.monitoring_batches,
obj_prereqs=obj_prereqs,
cost_monitoring_args=fixed_var_descr.fixed_vars)
params = model.get_params()
self.optimizer = BatchGradientDescent(
objective=cost_value,
gradients=grads,
gradient_updates=grad_updates,
params=params,
param_constrainers=[model.modify_updates],
lr_scalers=model.get_lr_scalers(),
inputs=theano_args,
verbose=self.verbose_optimization,
max_iter=self.updates_per_batch,
reset_alpha=self.reset_alpha,
conjugate=self.conjugate,
reset_conjugate=self.reset_conjugate,
min_init_alpha=self.min_init_alpha,
line_search_mode=self.line_search_mode,
theano_function_mode=self.theano_function_mode,
init_alpha=self.init_alpha)
# These monitoring channels keep track of shared variables,
# which do not need inputs nor data.
if self.monitoring_dataset is not None:
self.monitor.add_channel(
name='ave_step_size',
ipt=None,
val=self.optimizer.ave_step_size,
data_specs=(NullSpace(), ''),
dataset=first_value(self.monitoring_dataset))
self.monitor.add_channel(
name='ave_grad_size',
ipt=None,
val=self.optimizer.ave_grad_size,
data_specs=(NullSpace(), ''),
dataset=first_value(self.monitoring_dataset))
self.monitor.add_channel(
name='ave_grad_mult',
ipt=None,
val=self.optimizer.ave_grad_mult,
data_specs=(NullSpace(), ''),
dataset=first_value(self.monitoring_dataset))
self.first = True
self.bSetup = True
class BGD(TrainingAlgorithm):
"""Batch Gradient Descent training algorithm class"""
def __init__(self,
cost,
batch_size=None,
batches_per_iter=None,
updates_per_batch=10,
monitoring_batches=None,
monitoring_dataset=None,
termination_criterion=None,
set_batch_size=False,
reset_alpha=True,
conjugate=False,
min_init_alpha=None,
reset_conjugate=True,
line_search_mode=None):
"""
cost: a pylearn2 Cost
batch_size: Like the SGD TrainingAlgorithm, this TrainingAlgorithm
still iterates over minibatches of data. The difference
is that this class uses partial line searches to choose
the step size along each gradient direction, and can do
repeated updates on the same batch. The assumption is
that you use big enough minibatches with this algorithm that
a large step size will generalize reasonably well to other
minibatches.
To implement true Batch Gradient Descent, set the batch_size
to the total number of examples available.
If batch_size is None, it will revert to the model's force_batch_size
attribute.
set_batch_size: If True, BGD will attempt to override the model's force_batch_size
attribute by calling set_batch_size on it.
updates_per_batch: Passed through to the optimization.BatchGradientDescent's
max_iters parameter
reset_alpha, conjugate, reset_conjugate: passed through to the
optimization.BatchGradientDescent parameters of the same names
monitoring_dataset: A Dataset or a dictionary mapping string dataset names to Datasets
"""
self.__dict__.update(locals())
del self.self
if monitoring_dataset is None:
assert monitoring_batches == None
self._set_monitoring_dataset(monitoring_dataset)
self.bSetup = False
self.termination_criterion = termination_criterion
self.rng = np.random.RandomState([2012, 10, 16])
def setup(self, model, dataset):
"""
Allows the training algorithm to do some preliminary configuration
*before* we actually start training the model. The dataset is provided
in case other derived training algorithms need to modify model based on
the dataset.
Parameters
----------
model: a Python object representing the model to train loosely
implementing the interface of models.model.Model.
dataset: a pylearn2.datasets.dataset.Dataset object used to draw
training data
"""
self.model = model
if self.batch_size is None:
self.batch_size = model.force_batch_size
else:
batch_size = self.batch_size
if self.set_batch_size:
model.set_batch_size(batch_size)
elif hasattr(model, 'force_batch_size'):
if not (model.force_batch_size <= 0
or batch_size == model.force_batch_size):
raise ValueError(
"batch_size is %d but model.force_batch_size is %d" %
(batch_size, model.force_batch_size))
self.monitor = Monitor.get_monitor(model)
X = self.model.get_input_space().make_theano_batch()
self.topo = X.ndim != 2
Y = T.matrix()
if self.cost.supervised:
obj = self.cost(model, X, Y)
grads, grad_updates = self.cost.get_gradients(model, X, Y)
ipt = (X, Y)
else:
obj = self.cost(model, X)
grads, grad_updates = self.cost.get_gradients(model, X)
ipt = X
if obj is None:
raise ValueError(
"BGD is incompatible with " + str(self.cost) + " because "
" it is intractable, but BGD uses the cost function value to do "
" line searches.")
if self.monitoring_dataset is not None:
if not any([
dataset.has_targets()
for dataset in self.monitoring_dataset.values()
]):
Y = None
channels = model.get_monitoring_channels(X, Y)
if not isinstance(channels, dict):
raise TypeError("model.get_monitoring_channels must return a "
"dictionary, but it returned " + str(channels))
channels.update(self.cost.get_monitoring_channels(model, X, Y))
for dataset_name in self.monitoring_dataset:
if dataset_name == '':
prefix = ''
else:
prefix = dataset_name + '_'
monitoring_dataset = self.monitoring_dataset[dataset_name]
self.monitor.add_dataset(dataset=monitoring_dataset,
mode="sequential",
batch_size=self.batch_size,
num_batches=self.monitoring_batches)
self.monitor.add_channel(prefix + 'objective',
ipt=ipt,
val=obj,
dataset=monitoring_dataset)
for name in channels:
J = channels[name]
if isinstance(J, tuple):
assert len(J) == 2
J, prereqs = J
else:
prereqs = None
if Y is not None:
ipt = (X, Y)
else:
ipt = X
self.monitor.add_channel(name=prefix + name,
ipt=ipt,
val=J,
dataset=monitoring_dataset,
prereqs=prereqs)
if ipt is X:
ipts = [X]
else:
ipts = ipt
self.optimizer = BatchGradientDescent(
objective=obj,
gradients=grads,
gradient_updates=grad_updates,
params=model.get_params(),
param_constrainers=[model.censor_updates],
lr_scalers=model.get_lr_scalers(),
inputs=ipts,
verbose=True,
max_iter=self.updates_per_batch,
reset_alpha=self.reset_alpha,
conjugate=self.conjugate,
reset_conjugate=self.reset_conjugate,
min_init_alpha=self.min_init_alpha,
line_search_mode=self.line_search_mode)
self.first = True
self.bSetup = True
def train(self, dataset):
assert self.bSetup
model = self.model
batch_size = self.batch_size
if self.topo:
get_data = dataset.get_batch_topo
else:
get_data = dataset.get_batch_design
rng = self.rng
train_iteration_mode = 'shuffled_sequential'
if not is_stochastic(train_iteration_mode):
rng = None
iterator = dataset.iterator(mode=train_iteration_mode,
batch_size=self.batch_size,
targets=self.cost.supervised,
num_batches=self.batches_per_iter,
topo=self.topo,
rng=rng)
for data in iterator:
if self.cost.supervised:
args = data
X, Y = data
else:
args = [data]
X = data
self.optimizer.minimize(*args)
model.monitor.report_batch(X.shape[0])
def continue_learning(self, model):
if self.termination_criterion is None:
return True
else:
return self.termination_criterion(self.model)
def setup(self, model, dataset):
"""
Allows the training algorithm to do some preliminary configuration
*before* we actually start training the model. The dataset is provided
in case other derived training algorithms need to modify model based on
the dataset.
Parameters
----------
model: a Python object representing the model to train loosely
implementing the interface of models.model.Model.
dataset: a pylearn2.datasets.dataset.Dataset object used to draw
training data
"""
self.model = model
if self.set_batch_size:
model.set_batch_size(self.batch_size)
if self.batch_size is None:
self.batch_size = model.force_batch_size
model.cost = self.cost
model.mask_gen = self.mask_gen
self.monitor = Monitor.get_monitor(model)
self.monitor.set_theano_function_mode(self.theano_function_mode)
prereq = self.get_setup_batch_object()
#We want to use big batches. We need to make several theano calls on each
#batch. To avoid paying the GPU latency every time, we use a shared variable
#but the shared variable needs to stay allocated during the time that the
#monitor is working, and we don't want the monitor to increase the memory
#overhead. So we make the monitor work off of the same shared variable
space = model.get_input_space()
X = sharedX(space.get_origin_batch(model.batch_size), 'BGD_X')
self.space = space
rng = np.random.RandomState([2012, 7, 20])
test_mask = space.get_origin_batch(model.batch_size)
test_mask = rng.randint(0, 2, test_mask.shape)
if hasattr(self.mask_gen,
'sync_channels') and self.mask_gen.sync_channels:
if test_mask.ndim != 4:
raise NotImplementedError()
test_mask = test_mask[:, :, :, 0]
assert test_mask.ndim == 3
drop_mask = sharedX(np.cast[X.dtype](test_mask), name='drop_mask')
self.drop_mask = drop_mask
assert drop_mask.ndim == test_mask.ndim
Y = None
drop_mask_Y = None
if self.cost.supervised:
Y = sharedX(
model.get_output_space().get_origin_batch(model.batch_size),
'BGD_Y')
self.Y = Y
test_mask_Y = rng.randint(0, 2, (model.batch_size, ))
drop_mask_Y = sharedX(np.cast[Y.dtype](test_mask_Y),
name='drop_mask_Y')
self.drop_mask_Y = drop_mask_Y
dmx, dmy = self.mask_gen(X, Y)
updates = OrderedDict([ (drop_mask, dmx),\
(drop_mask_Y, dmy)] )
else:
updates = OrderedDict([(drop_mask, self.mask_gen(X))])
obj = self.cost(model,
X,
Y,
drop_mask=drop_mask,
drop_mask_Y=drop_mask_Y)
gradients, gradient_updates = self.cost.get_gradients(
model, X, Y, drop_mask=drop_mask, drop_mask_Y=drop_mask_Y)
if hasattr(model.inference_procedure, 'V_dropout'):
include_prob = model.inference_procedure.include_prob
theano_rng = MRG_RandomStreams(2012 + 11 + 20)
for elem in flatten([
model.inference_procedure.V_dropout,
model.inference_procedure.H_dropout
]):
updates[elem] = theano_rng.binomial(
p=include_prob, size=elem.shape, dtype=elem.dtype,
n=1) / include_prob
self.update_mask = function([], updates=updates)
if self.monitoring_dataset is not None:
if not any([
dataset.has_targets()
for dataset in self.monitoring_dataset.values()
]):
Y = None
assert X.name is not None
channels = model.get_monitoring_channels(X, Y)
if not isinstance(channels, dict):
raise TypeError("model.get_monitoring_channels must return a "
"dictionary, but it returned " + str(channels))
assert X.name is not None
wtf = self.cost.get_monitoring_channels(model,
X=X,
Y=Y,
drop_mask=drop_mask,
drop_mask_Y=drop_mask_Y)
for key in wtf:
channels[key] = wtf[key]
for dataset_name in self.monitoring_dataset:
if dataset_name == '':
prefix = ''
else:
prefix = dataset_name + '_'
monitoring_dataset = self.monitoring_dataset[dataset_name]
self.monitor.add_dataset(dataset=monitoring_dataset,
mode="sequential",
batch_size=self.batch_size,
num_batches=self.monitoring_batches)
#we only need to put the prereq in once to make sure it gets run
#adding it more times shouldn't hurt, but be careful
#each time you say "self.setup_batch" you get a new object with a
#different id, and if you install n of those the prereq will run n
#times. It won't cause any wrong results, just a big slowdown
warnings.warn(
"This is weird-- ipt=(X,Y)=tell the monitor to replace X, Y with the givens dict, "
" but you don't actually want them to be replaced.")
ipt = X
if Y is not None:
ipt = [X, Y]
self.monitor.add_channel(prefix + 'objective',
ipt=ipt,
val=obj,
dataset=monitoring_dataset,
prereqs=[prereq])
for name in channels:
J = channels[name]
if isinstance(J, tuple):
assert len(J) == 2
J, prereqs = J
else:
prereqs = []
prereqs = list(prereqs)
prereqs.append(prereq)
if Y is not None:
ipt = (X, Y)
else:
ipt = X
self.monitor.add_channel(name=prefix + name,
ipt=ipt,
val=J,
dataset=monitoring_dataset,
prereqs=prereqs)
self.accumulate = self.combine_batches > 1
if self.accumulate:
self.inputs = [
elem for elem in [X, Y, drop_mask, drop_mask_Y]
if elem is not None
]
else:
self.inputs = None
self.optimizer = BatchGradientDescent(
objective=obj,
inputs=self.inputs,
verbose=1,
gradients=gradients,
gradient_updates=gradient_updates,
params=model.get_params(),
lr_scalers=model.get_lr_scalers(),
param_constrainers=[model.censor_updates],
max_iter=self.max_iter,
tol=3e-7,
init_alpha=self.init_alpha,
reset_alpha=self.reset_alpha,
conjugate=self.conjugate,
reset_conjugate=self.reset_conjugate,
min_init_alpha=self.min_init_alpha,
line_search_mode=self.line_search_mode,
accumulate=self.accumulate,
theano_function_mode=self.theano_function_mode)
self.X = X
if self.monitoring_dataset is not None:
self.monitor.add_channel(
name='ave_step_size',
ipt=ipt,
val=self.optimizer.ave_step_size,
dataset=self.monitoring_dataset.values()[0])
self.monitor.add_channel(
name='ave_grad_size',
ipt=ipt,
val=self.optimizer.ave_grad_size,
dataset=self.monitoring_dataset.values()[0])
self.monitor.add_channel(
name='ave_grad_mult',
ipt=ipt,
val=self.optimizer.ave_grad_mult,
dataset=self.monitoring_dataset.values()[0])
self.first = True
self.bSetup = True
class DNCE_Algorithm(object):
def __init__(self, noise, batch_size=1000, batches_per_iter=10,
noise_per_clean = 30,
monitoring_batches=-1, monitoring_dataset=None):
"""
if batch_size is None, reverts to the force_batch_size field of the
model
"""
self.batch_size, self.batches_per_iter = batch_size, batches_per_iter
if monitoring_dataset is None:
assert monitoring_batches == -1
self.monitoring_dataset = monitoring_dataset
self.monitoring_batches = monitoring_batches
self.bSetup = False
self.noise = noise
self.noise_per_clean = noise_per_clean
def setup(self, model, dataset):
"""
Allows the training algorithm to do some preliminary configuration
*before* we actually start training the model. The dataset is provided
in case other derived training algorithms need to modify model based on
the dataset.
Parameters
----------
model: a Python object representing the model to train loosely
implementing the interface of models.model.Model.
dataset: a pylearn2.datasets.dataset.Dataset object used to draw
training data
"""
self.model = model
self.monitor = Monitor.get_monitor(model)
X = T.matrix()
Y = T.matrix()
dnce = DNCE( self.noise)
if self.monitoring_dataset is not None:
if not self.monitoring_dataset.has_targets():
Y = None
self.monitor.set_dataset(dataset=self.monitoring_dataset,
mode="sequential",
batch_size=self.batch_size,
num_batches=self.monitoring_batches)
X.tag.test_value = self.monitoring_dataset.get_batch_design(2)
channels = model.get_monitoring_channels(X,Y)
if not isinstance(channels, dict):
raise TypeError("model.get_monitoring_channels must return a "
"dictionary, but it returned " + str(channels))
dnce.noise_per_clean = self.noise_per_clean
obj = dnce(model,X)
dnce.noise_per_clean = None
self.monitor.add_channel('DNCE',ipt=X,val=obj)
for name in channels:
J = channels[name]
if isinstance(J, tuple):
assert len(J) == 2
J, prereqs = J
else:
prereqs = None
if Y is not None:
ipt = (X,Y)
else:
ipt = X
self.monitor.add_channel(name=name,
ipt=ipt,
val=J,
prereqs=prereqs)
X = sharedX( dataset.get_batch_design(1), 'X')
Y = []
updates = {}
for i in xrange(self.noise_per_clean):
Y_i = sharedX( X.get_value().copy() )
updates[Y_i] = self.noise.random_design_matrix(X)
Y.append(Y_i)
self.update_noise = function([], updates = updates)
obj = dnce(model,X,Y)
self.optimizer = BatchGradientDescent(
objective = obj,
params = model.get_params(),
param_constrainers = [ model.censor_updates ],
max_iter = 5)
self.X = X
self.Y = Y
self.first = True
self.bSetup = True
def train(self, dataset):
assert self.bSetup
model = self.model
if self.batch_size is None:
batch_size = model.force_batch_size
else:
batch_size = self.batch_size
if hasattr(model, 'force_batch_size'):
assert (model.force_batch_size <= 0 or batch_size ==
model.force_batch_size)
for i in xrange(self.batches_per_iter):
self.X.set_value(dataset.get_batch_design(self.batch_size))
self.update_noise()
self.optimizer.minimize()
model.monitor.report_batch( batch_size )
return True
def setup(self, model, dataset):
"""
Allows the training algorithm to do some preliminary configuration
*before* we actually start training the model. The dataset is provided
in case other derived training algorithms need to modify model based on
the dataset.
Parameters
----------
model : object
A Python object representing the model to train loosely \
implementing the interface of models.model.Model.
dataset : pylearn2.datasets.dataset.Dataset
Dataset object used to draw training data
"""
self.model = model
if self.cost is None:
self.cost = model.get_default_cost()
if self.batch_size is None:
self.batch_size = model.force_batch_size
else:
batch_size = self.batch_size
if self.set_batch_size:
model.set_batch_size(batch_size)
elif hasattr(model, 'force_batch_size'):
if not (model.force_batch_size <= 0 or batch_size ==
model.force_batch_size):
raise ValueError("batch_size is %d but " +
"model.force_batch_size is %d" %
(batch_size, model.force_batch_size))
self.monitor = Monitor.get_monitor(model)
self.monitor.set_theano_function_mode(self.theano_function_mode)
data_specs = self.cost.get_data_specs(model)
mapping = DataSpecsMapping(data_specs)
space_tuple = mapping.flatten(data_specs[0], return_tuple=True)
source_tuple = mapping.flatten(data_specs[1], return_tuple=True)
# Build a flat tuple of Theano Variables, one for each space,
# named according to the sources.
theano_args = []
for space, source in safe_zip(space_tuple, source_tuple):
name = 'BGD_[%s]' % source
arg = space.make_theano_batch(name=name)
theano_args.append(arg)
theano_args = tuple(theano_args)
# Methods of `self.cost` need args to be passed in a format compatible
# with their data_specs
nested_args = mapping.nest(theano_args)
fixed_var_descr = self.cost.get_fixed_var_descr(model, nested_args)
self.on_load_batch = fixed_var_descr.on_load_batch
cost_value = self.cost.expr(model, nested_args,
** fixed_var_descr.fixed_vars)
grads, grad_updates = self.cost.get_gradients(
model, nested_args, ** fixed_var_descr.fixed_vars)
assert isinstance(grads, OrderedDict)
assert isinstance(grad_updates, OrderedDict)
if cost_value is None:
raise ValueError("BGD is incompatible with " + str(self.cost) +
" because it is intractable, but BGD uses the " +
"cost function value to do line searches.")
# obj_prereqs has to be a list of function f called with f(*data),
# where data is a data tuple coming from the iterator.
# this function enables capturing "mapping" and "f", while
# enabling the "*data" syntax
def capture(f, mapping=mapping):
new_f = lambda *args: f(mapping.flatten(args, return_tuple=True))
return new_f
obj_prereqs = [capture(f) for f in fixed_var_descr.on_load_batch]
if self.monitoring_dataset is not None:
self.monitor.setup(
dataset=self.monitoring_dataset,
cost=self.cost,
batch_size=self.batch_size,
num_batches=self.monitoring_batches,
obj_prereqs=obj_prereqs,
cost_monitoring_args=fixed_var_descr.fixed_vars)
# TODO : Why is this commented?
'''
channels = model.get_monitoring_channels(theano_args)
if not isinstance(channels, dict):
raise TypeError("model.get_monitoring_channels must return a "
"dictionary, but it returned " + str(channels))
channels.update(self.cost.get_monitoring_channels(model, theano_args, ** fixed_var_descr.fixed_vars))
for dataset_name in self.monitoring_dataset:
if dataset_name == '':
prefix = ''
else:
prefix = dataset_name + '_'
monitoring_dataset = self.monitoring_dataset[dataset_name]
self.monitor.add_dataset(dataset=monitoring_dataset,
mode="sequential",
batch_size=self.batch_size,
num_batches=self.monitoring_batches)
# The monitor compiles all channels for the same dataset into one function, and
# runs all prereqs before calling the function. So we only need to register the
# on_load_batch prereq once per monitoring dataset.
self.monitor.add_channel(prefix + 'objective',ipt=ipt,val=cost_value,
dataset = monitoring_dataset, prereqs = fixed_var_descr.on_load_batch)
for name in channels:
J = channels[name]
if isinstance(J, tuple):
assert len(J) == 2
J, prereqs = J
else:
prereqs = None
self.monitor.add_channel(name= prefix + name,
ipt=ipt,
val=J,
data_specs=data_specs,
dataset = monitoring_dataset,
prereqs=prereqs)
'''
params = model.get_params()
self.optimizer = BatchGradientDescent(
objective = cost_value,
gradients = grads,
gradient_updates = grad_updates,
params = params,
param_constrainers = [ model.censor_updates ],
lr_scalers = model.get_lr_scalers(),
inputs = theano_args,
verbose = self.verbose_optimization,
max_iter = self.updates_per_batch,
reset_alpha = self.reset_alpha,
conjugate = self.conjugate,
reset_conjugate = self.reset_conjugate,
min_init_alpha = self.min_init_alpha,
line_search_mode = self.line_search_mode,
theano_function_mode=self.theano_function_mode,
init_alpha=self.init_alpha)
# These monitoring channels keep track of shared variables,
# which do not need inputs nor data.
if self.monitoring_dataset is not None:
self.monitor.add_channel(
name='ave_step_size',
ipt=None,
val=self.optimizer.ave_step_size,
data_specs=(NullSpace(), ''),
dataset=self.monitoring_dataset.values()[0])
self.monitor.add_channel(
name='ave_grad_size',
ipt=None,
val=self.optimizer.ave_grad_size,
data_specs=(NullSpace(), ''),
dataset=self.monitoring_dataset.values()[0])
self.monitor.add_channel(
name='ave_grad_mult',
ipt=None,
val=self.optimizer.ave_grad_mult,
data_specs=(NullSpace(), ''),
dataset=self.monitoring_dataset.values()[0])
self.first = True
self.bSetup = True
def setup(self, model, dataset):
"""
Allows the training algorithm to do some preliminary configuration
*before* we actually start training the model. The dataset is provided
in case other derived training algorithms need to modify model based on
the dataset.
Parameters
----------
model: a Python object representing the model to train loosely
implementing the interface of models.model.Model.
dataset: a pylearn2.datasets.dataset.Dataset object used to draw
training data
"""
self.model = model
if self.batch_size is None:
self.batch_size = model.force_batch_size
else:
batch_size = self.batch_size
if hasattr(model, 'force_batch_size'):
if not (model.force_batch_size <= 0 or batch_size ==
model.force_batch_size):
raise ValueError("batch_size is %d but model.force_batch_size is %d" %
(batch_size, model.force_batch_size))
self.monitor = Monitor.get_monitor(model)
X = self.model.get_input_space().make_theano_batch()
self.topo = X.ndim != 2
Y = T.matrix()
if self.monitoring_dataset is not None:
if not self.monitoring_dataset.has_targets():
Y = None
self.monitor.add_dataset(dataset=self.monitoring_dataset,
mode="sequential",
batch_size=self.batch_size,
num_batches=self.monitoring_batches)
channels = model.get_monitoring_channels(X,Y)
if not isinstance(channels, dict):
raise TypeError("model.get_monitoring_channels must return a "
"dictionary, but it returned " + str(channels))
#TODO: currently only supports unsupervised costs, support supervised too
obj = self.cost(model,X)
self.monitor.add_channel('batch_gd_objective',ipt=X,val=obj)
for name in channels:
J = channels[name]
if isinstance(J, tuple):
assert len(J) == 2
J, prereqs = J
else:
prereqs = None
if Y is not None:
ipt = (X,Y)
else:
ipt = X
self.monitor.add_channel(name=name,
ipt=ipt,
val=J,
prereqs=prereqs)
obj = self.cost(model,X)
self.optimizer = BatchGradientDescent(
objective = obj,
params = model.get_params(),
param_constrainers = [ model.censor_updates ],
lr_scalers = model.get_lr_scalers(),
inputs = [ X ],
verbose = True,
max_iter = self.updates_per_batch)
self.first = True
self.bSetup = True
_, model_path = sys.argv
from pylearn2.utils import serial
model = serial.load(model_path)
d = model.discriminator
import gc
del model
gc.collect()
from pylearn2.utils import sharedX
X = sharedX(d.get_input_space().get_origin_batch(1))
obj = -d.fprop(X).sum()
from pylearn2.optimization.batch_gradient_descent import BatchGradientDescent as BGD
import theano.tensor as T
def norm_constraint(updates):
assert X in updates
updates[X] = updates[X] / (1e-7 + T.sqrt(T.sqr(X).sum()))
opt = BGD(objective=obj, params=[X], param_constrainers=[norm_constraint], conjugate=True, reset_conjugate=False,
reset_alpha=False, line_search_mode='exhaustive', verbose=3, max_iter=20)
results = []
import numpy as np
rng = np.random.RandomState([1, 2, 3])
for i in xrange(10):
X.set_value(rng.randn(*X.get_value().shape).astype(X.dtype) / 10.)
opt.minimize()
Xv = X.dimshuffle(3, 1, 2, 0).eval()
results.append(Xv)
X = np.concatenate(results, axis=0)
from pylearn2.gui.patch_viewer import make_viewer
v = make_viewer(X)
v.show()
def setup(self, model, dataset):
"""
Allows the training algorithm to do some preliminary configuration
*before* we actually start training the model. The dataset is provided
in case other derived training algorithms need to modify model based on
the dataset.
Parameters
----------
model: a Python object representing the model to train loosely
implementing the interface of models.model.Model.
dataset: a pylearn2.datasets.dataset.Dataset object used to draw
training data
"""
self.model = model
if self.batch_size is None:
self.batch_size = model.force_batch_size
else:
batch_size = self.batch_size
if self.set_batch_size:
model.set_batch_size(batch_size)
elif hasattr(model, 'force_batch_size'):
if not (model.force_batch_size <= 0
or batch_size == model.force_batch_size):
raise ValueError(
"batch_size is %d but model.force_batch_size is %d" %
(batch_size, model.force_batch_size))
self.monitor = Monitor.get_monitor(model)
X = self.model.get_input_space().make_theano_batch()
self.topo = X.ndim != 2
Y = T.matrix()
if self.cost.supervised:
obj = self.cost(model, X, Y)
grads, grad_updates = self.cost.get_gradients(model, X, Y)
ipt = (X, Y)
else:
obj = self.cost(model, X)
grads, grad_updates = self.cost.get_gradients(model, X)
ipt = X
if obj is None:
raise ValueError(
"BGD is incompatible with " + str(self.cost) + " because "
" it is intractable, but BGD uses the cost function value to do "
" line searches.")
if self.monitoring_dataset is not None:
if not any([
dataset.has_targets()
for dataset in self.monitoring_dataset.values()
]):
Y = None
channels = model.get_monitoring_channels(X, Y)
if not isinstance(channels, dict):
raise TypeError("model.get_monitoring_channels must return a "
"dictionary, but it returned " + str(channels))
channels.update(self.cost.get_monitoring_channels(model, X, Y))
for dataset_name in self.monitoring_dataset:
if dataset_name == '':
prefix = ''
else:
prefix = dataset_name + '_'
monitoring_dataset = self.monitoring_dataset[dataset_name]
self.monitor.add_dataset(dataset=monitoring_dataset,
mode="sequential",
batch_size=self.batch_size,
num_batches=self.monitoring_batches)
self.monitor.add_channel(prefix + 'objective',
ipt=ipt,
val=obj,
dataset=monitoring_dataset)
for name in channels:
J = channels[name]
if isinstance(J, tuple):
assert len(J) == 2
J, prereqs = J
else:
prereqs = None
if Y is not None:
ipt = (X, Y)
else:
ipt = X
self.monitor.add_channel(name=prefix + name,
ipt=ipt,
val=J,
dataset=monitoring_dataset,
prereqs=prereqs)
if ipt is X:
ipts = [X]
else:
ipts = ipt
self.optimizer = BatchGradientDescent(
objective=obj,
gradients=grads,
gradient_updates=grad_updates,
params=model.get_params(),
param_constrainers=[model.censor_updates],
lr_scalers=model.get_lr_scalers(),
inputs=ipts,
verbose=True,
max_iter=self.updates_per_batch,
reset_alpha=self.reset_alpha,
conjugate=self.conjugate,
reset_conjugate=self.reset_conjugate,
min_init_alpha=self.min_init_alpha,
line_search_mode=self.line_search_mode)
self.first = True
self.bSetup = True
outputs = model.fprop(normed, return_all=True)
output = outputs[layer_idx]
neuron = output[tuple(idxs)]
from pylearn2.optimization.batch_gradient_descent import BatchGradientDescent
bgd = BatchGradientDescent(objective=-neuron,
params=[X],
inputs=None,
max_iter=100,
lr_scalers=None,
verbose=3,
tol=None,
init_alpha=None,
min_init_alpha=1e-3,
reset_alpha=True,
conjugate=True,
gradients=None,
gradient_updates=None,
accumulate=False,
theano_function_mode=None,
param_constrainers=None)
bgd.minimize()
X = normed.eval()[:,:,:,0].transpose(1,2,0)
import numpy as np
X /= np.abs(X).max()
print (X.min(), X.max())
p, h = state
p_shape = layer.get_output_space().shape
i = p_shape[0] / 2
j = p_shape[1] / 2
act = p[0,filter_idx,i,j]
obj = - act + norm_penalty * T.square(X).sum()
assert obj.ndim == 0
optimizer = BatchGradientDescent(objective = obj,
params = [X],
inputs = None,
param_constrainers = None,
max_iter = 1000,
verbose = True,
tol = None,
init_alpha = (.001, .005, .01, .05, .1))
optimizer.minimize()
img = X.get_value()[0,:,:,:]
print 'max mag: ',np.abs(img).max()
print 'norm: ',np.square(img).sum()
print 'min: ',img.min()
print 'max: ',img.max()
img /= np.abs(img).max()
class BGD(TrainingAlgorithm):
"""Batch Gradient Descent training algorithm class"""
def __init__(
self,
cost,
batch_size=None,
batches_per_iter=None,
updates_per_batch=10,
monitoring_batches=None,
monitoring_dataset=None,
termination_criterion=None,
set_batch_size=False,
reset_alpha=True,
conjugate=False,
min_init_alpha=None,
reset_conjugate=True,
line_search_mode=None,
):
"""
cost: a pylearn2 Cost
batch_size: Like the SGD TrainingAlgorithm, this TrainingAlgorithm
still iterates over minibatches of data. The difference
is that this class uses partial line searches to choose
the step size along each gradient direction, and can do
repeated updates on the same batch. The assumption is
that you use big enough minibatches with this algorithm that
a large step size will generalize reasonably well to other
minibatches.
To implement true Batch Gradient Descent, set the batch_size
to the total number of examples available.
If batch_size is None, it will revert to the model's force_batch_size
attribute.
set_batch_size: If True, BGD will attempt to override the model's force_batch_size
attribute by calling set_batch_size on it.
updates_per_batch: Passed through to the optimization.BatchGradientDescent's
max_iters parameter
reset_alpha, conjugate, reset_conjugate: passed through to the
optimization.BatchGradientDescent parameters of the same names
monitoring_dataset: A Dataset or a dictionary mapping string dataset names to Datasets
"""
self.__dict__.update(locals())
del self.self
if monitoring_dataset is None:
assert monitoring_batches == None
self._set_monitoring_dataset(monitoring_dataset)
self.bSetup = False
self.termination_criterion = termination_criterion
self.rng = np.random.RandomState([2012, 10, 16])
def setup(self, model, dataset):
"""
Allows the training algorithm to do some preliminary configuration
*before* we actually start training the model. The dataset is provided
in case other derived training algorithms need to modify model based on
the dataset.
Parameters
----------
model: a Python object representing the model to train loosely
implementing the interface of models.model.Model.
dataset: a pylearn2.datasets.dataset.Dataset object used to draw
training data
"""
self.model = model
if self.batch_size is None:
self.batch_size = model.force_batch_size
else:
batch_size = self.batch_size
if self.set_batch_size:
model.set_batch_size(batch_size)
elif hasattr(model, "force_batch_size"):
if not (model.force_batch_size <= 0 or batch_size == model.force_batch_size):
raise ValueError(
"batch_size is %d but model.force_batch_size is %d" % (batch_size, model.force_batch_size)
)
self.monitor = Monitor.get_monitor(model)
X = self.model.get_input_space().make_theano_batch()
self.topo = X.ndim != 2
Y = T.matrix()
if self.cost.supervised:
obj = self.cost(model, X, Y)
grads, grad_updates = self.cost.get_gradients(model, X, Y)
ipt = (X, Y)
else:
obj = self.cost(model, X)
grads, grad_updates = self.cost.get_gradients(model, X)
ipt = X
if obj is None:
raise ValueError(
"BGD is incompatible with " + str(self.cost) + " because "
" it is intractable, but BGD uses the cost function value to do "
" line searches."
)
if self.monitoring_dataset is not None:
if not any([dataset.has_targets() for dataset in self.monitoring_dataset.values()]):
Y = None
channels = model.get_monitoring_channels(X, Y)
if not isinstance(channels, dict):
raise TypeError(
"model.get_monitoring_channels must return a " "dictionary, but it returned " + str(channels)
)
channels.update(self.cost.get_monitoring_channels(model, X, Y))
for dataset_name in self.monitoring_dataset:
if dataset_name == "":
prefix = ""
else:
prefix = dataset_name + "_"
monitoring_dataset = self.monitoring_dataset[dataset_name]
self.monitor.add_dataset(
dataset=monitoring_dataset,
mode="sequential",
batch_size=self.batch_size,
num_batches=self.monitoring_batches,
)
self.monitor.add_channel(prefix + "objective", ipt=ipt, val=obj, dataset=monitoring_dataset)
for name in channels:
J = channels[name]
if isinstance(J, tuple):
assert len(J) == 2
J, prereqs = J
else:
prereqs = None
if Y is not None:
ipt = (X, Y)
else:
ipt = X
self.monitor.add_channel(
name=prefix + name, ipt=ipt, val=J, dataset=monitoring_dataset, prereqs=prereqs
)
if ipt is X:
ipts = [X]
else:
ipts = ipt
self.optimizer = BatchGradientDescent(
objective=obj,
gradients=grads,
gradient_updates=grad_updates,
params=model.get_params(),
param_constrainers=[model.censor_updates],
lr_scalers=model.get_lr_scalers(),
inputs=ipts,
verbose=True,
max_iter=self.updates_per_batch,
reset_alpha=self.reset_alpha,
conjugate=self.conjugate,
reset_conjugate=self.reset_conjugate,
min_init_alpha=self.min_init_alpha,
line_search_mode=self.line_search_mode,
)
self.first = True
self.bSetup = True
def train(self, dataset):
assert self.bSetup
model = self.model
batch_size = self.batch_size
if self.topo:
get_data = dataset.get_batch_topo
else:
get_data = dataset.get_batch_design
rng = self.rng
train_iteration_mode = "shuffled_sequential"
if not is_stochastic(train_iteration_mode):
rng = None
iterator = dataset.iterator(
mode=train_iteration_mode,
batch_size=self.batch_size,
targets=self.cost.supervised,
num_batches=self.batches_per_iter,
topo=self.topo,
rng=rng,
)
for data in iterator:
if self.cost.supervised:
args = data
X, Y = data
else:
args = [data]
X = data
self.optimizer.minimize(*args)
model.monitor.report_batch(X.shape[0])
def continue_learning(self, model):
if self.termination_criterion is None:
return True
else:
return self.termination_criterion(self.model)
class InpaintAlgorithm(object):
def __init__(self,
mask_gen,
cost,
batch_size=None,
batches_per_iter=None,
monitoring_batches=None,
monitoring_dataset=None,
max_iter=5,
suicide=False,
init_alpha=None,
reset_alpha=True,
conjugate=False,
reset_conjugate=True,
termination_criterion=None,
set_batch_size=False,
line_search_mode=None,
min_init_alpha=1e-3,
duplicate=1,
combine_batches=1,
scale_step=1.,
theano_function_mode=None):
assert False # deprecated
"""
if batch_size is None, reverts to the force_batch_size field of the
model
"""
if line_search_mode is None and init_alpha is None:
init_alpha = (.001, .005, .01, .05, .1)
self.__dict__.update(locals())
del self.self
if monitoring_dataset is None:
assert monitoring_batches == None
if isinstance(monitoring_dataset, Dataset):
self.monitoring_dataset = {'': monitoring_dataset}
self.bSetup = False
self.rng = np.random.RandomState([2012, 10, 17])
def setup_batch(self, X, Y=None):
assert not isinstance(X, tuple)
self.X.set_value(X)
assert self.cost.supervised == (Y is not None)
if Y is not None:
assert Y.ndim == 2
assert self.Y.ndim == 2
self.Y.set_value(Y)
self.update_mask()
def get_setup_batch_object(self):
return SetupBatch(self)
def setup(self, model, dataset):
"""
Allows the training algorithm to do some preliminary configuration
*before* we actually start training the model. The dataset is provided
in case other derived training algorithms need to modify model based on
the dataset.
Parameters
----------
model: a Python object representing the model to train loosely
implementing the interface of models.model.Model.
dataset: a pylearn2.datasets.dataset.Dataset object used to draw
training data
"""
self.model = model
if self.set_batch_size:
model.set_batch_size(self.batch_size)
if self.batch_size is None:
self.batch_size = model.force_batch_size
model.cost = self.cost
model.mask_gen = self.mask_gen
self.monitor = Monitor.get_monitor(model)
self.monitor.set_theano_function_mode(self.theano_function_mode)
prereq = self.get_setup_batch_object()
#We want to use big batches. We need to make several theano calls on each
#batch. To avoid paying the GPU latency every time, we use a shared variable
#but the shared variable needs to stay allocated during the time that the
#monitor is working, and we don't want the monitor to increase the memory
#overhead. So we make the monitor work off of the same shared variable
space = model.get_input_space()
X = sharedX(space.get_origin_batch(model.batch_size), 'BGD_X')
self.space = space
rng = np.random.RandomState([2012, 7, 20])
test_mask = space.get_origin_batch(model.batch_size)
test_mask = rng.randint(0, 2, test_mask.shape)
if hasattr(self.mask_gen,
'sync_channels') and self.mask_gen.sync_channels:
if test_mask.ndim != 4:
raise NotImplementedError()
test_mask = test_mask[:, :, :, 0]
assert test_mask.ndim == 3
drop_mask = sharedX(np.cast[X.dtype](test_mask), name='drop_mask')
self.drop_mask = drop_mask
assert drop_mask.ndim == test_mask.ndim
Y = None
drop_mask_Y = None
if self.cost.supervised:
Y = sharedX(
model.get_output_space().get_origin_batch(model.batch_size),
'BGD_Y')
self.Y = Y
test_mask_Y = rng.randint(0, 2, (model.batch_size, ))
drop_mask_Y = sharedX(np.cast[Y.dtype](test_mask_Y),
name='drop_mask_Y')
self.drop_mask_Y = drop_mask_Y
dmx, dmy = self.mask_gen(X, Y)
updates = OrderedDict([ (drop_mask, dmx),\
(drop_mask_Y, dmy)] )
else:
updates = OrderedDict([(drop_mask, self.mask_gen(X))])
obj = self.cost(model,
X,
Y,
drop_mask=drop_mask,
drop_mask_Y=drop_mask_Y)
gradients, gradient_updates = self.cost.get_gradients(
model, X, Y, drop_mask=drop_mask, drop_mask_Y=drop_mask_Y)
if hasattr(model.inference_procedure, 'V_dropout'):
include_prob = model.inference_procedure.include_prob
theano_rng = MRG_RandomStreams(2012 + 11 + 20)
for elem in flatten([
model.inference_procedure.V_dropout,
model.inference_procedure.H_dropout
]):
updates[elem] = theano_rng.binomial(
p=include_prob, size=elem.shape, dtype=elem.dtype,
n=1) / include_prob
self.update_mask = function([], updates=updates)
if self.monitoring_dataset is not None:
if not any([
dataset.has_targets()
for dataset in self.monitoring_dataset.values()
]):
Y = None
assert X.name is not None
channels = model.get_monitoring_channels(X, Y)
if not isinstance(channels, dict):
raise TypeError("model.get_monitoring_channels must return a "
"dictionary, but it returned " + str(channels))
assert X.name is not None
wtf = self.cost.get_monitoring_channels(model,
X=X,
Y=Y,
drop_mask=drop_mask,
drop_mask_Y=drop_mask_Y)
for key in wtf:
channels[key] = wtf[key]
for dataset_name in self.monitoring_dataset:
if dataset_name == '':
prefix = ''
else:
prefix = dataset_name + '_'
monitoring_dataset = self.monitoring_dataset[dataset_name]
self.monitor.add_dataset(dataset=monitoring_dataset,
mode="sequential",
batch_size=self.batch_size,
num_batches=self.monitoring_batches)
#we only need to put the prereq in once to make sure it gets run
#adding it more times shouldn't hurt, but be careful
#each time you say "self.setup_batch" you get a new object with a
#different id, and if you install n of those the prereq will run n
#times. It won't cause any wrong results, just a big slowdown
warnings.warn(
"This is weird-- ipt=(X,Y)=tell the monitor to replace X, Y with the givens dict, "
" but you don't actually want them to be replaced.")
ipt = X
if Y is not None:
ipt = [X, Y]
self.monitor.add_channel(prefix + 'objective',
ipt=ipt,
val=obj,
dataset=monitoring_dataset,
prereqs=[prereq])
for name in channels:
J = channels[name]
if isinstance(J, tuple):
assert len(J) == 2
J, prereqs = J
else:
prereqs = []
prereqs = list(prereqs)
prereqs.append(prereq)
if Y is not None:
ipt = (X, Y)
else:
ipt = X
self.monitor.add_channel(name=prefix + name,
ipt=ipt,
val=J,
dataset=monitoring_dataset,
prereqs=prereqs)
self.accumulate = self.combine_batches > 1
if self.accumulate:
self.inputs = [
elem for elem in [X, Y, drop_mask, drop_mask_Y]
if elem is not None
]
else:
self.inputs = None
self.optimizer = BatchGradientDescent(
objective=obj,
inputs=self.inputs,
verbose=1,
gradients=gradients,
gradient_updates=gradient_updates,
params=model.get_params(),
lr_scalers=model.get_lr_scalers(),
param_constrainers=[model.censor_updates],
max_iter=self.max_iter,
tol=3e-7,
init_alpha=self.init_alpha,
reset_alpha=self.reset_alpha,
conjugate=self.conjugate,
reset_conjugate=self.reset_conjugate,
min_init_alpha=self.min_init_alpha,
line_search_mode=self.line_search_mode,
accumulate=self.accumulate,
theano_function_mode=self.theano_function_mode)
self.X = X
if self.monitoring_dataset is not None:
self.monitor.add_channel(
name='ave_step_size',
ipt=ipt,
val=self.optimizer.ave_step_size,
dataset=self.monitoring_dataset.values()[0])
self.monitor.add_channel(
name='ave_grad_size',
ipt=ipt,
val=self.optimizer.ave_grad_size,
dataset=self.monitoring_dataset.values()[0])
self.monitor.add_channel(
name='ave_grad_mult',
ipt=ipt,
val=self.optimizer.ave_grad_mult,
dataset=self.monitoring_dataset.values()[0])
self.first = True
self.bSetup = True
def before_step(self, model):
if self.scale_step != 1.:
self.params = list(model.get_params())
self.value = [param.get_value() for param in self.params]
def after_step(self, model):
if self.scale_step != 1:
for param, value in safe_zip(self.params, self.value):
value = (1. - self.scale_step
) * value + self.scale_step * param.get_value()
param.set_value(value)
def train(self, dataset):
assert self.bSetup
model = self.model
if self.batch_size is None:
batch_size = model.force_batch_size
else:
batch_size = self.batch_size
if hasattr(model, 'force_batch_size'):
assert (model.force_batch_size <= 0
or batch_size == model.force_batch_size)
assert self.batch_size % self.duplicate == 0
rng = self.rng
train_iteration_mode = 'shuffled_sequential'
if not is_stochastic(train_iteration_mode):
rng = None
iterator = dataset.iterator(mode=train_iteration_mode,
batch_size=self.batch_size //
self.duplicate,
num_batches=self.batches_per_iter,
targets=self.cost.supervised,
topo=self.X.ndim != 2,
rng=rng)
accum_batches = []
if self.accumulate:
warnings.warn(
"InpaintAlg.train wastes time setting shared variables only to pull their value back out."
)
for data in iterator:
if self.cost.supervised:
X, Y = data
mode = self.theano_function_mode
if mode is not None and hasattr(mode, 'record'):
stry = str(Y).replace('\n', ' ')
mode.record.handle_line('data Y ' + stry + '\n')
if self.duplicate > 1:
Y = np.concatenate([Y] * self.duplicate, axis=0)
self.Y.set_value(Y)
else:
X = data
if self.duplicate > 1:
X = np.concatenate([X] * self.duplicate, axis=0)
self.X.set_value(X)
self.update_mask()
if self.accumulate:
accum_batches.append(
[elem.get_value() for elem in self.inputs])
if len(accum_batches) == self.combine_batches:
self.before_step(model)
self.optimizer.minimize(*accum_batches)
self.after_step(model)
actual_batch_size = sum(
[batch[0].shape[0] for batch in accum_batches])
model.monitor.report_batch(actual_batch_size)
accum_batches = []
else:
self.before_step(model)
self.optimizer.minimize()
self.after_step(model)
actual_batch_size = X.shape[0]
model.monitor.report_batch(actual_batch_size)
assert len(accum_batches) == 0
def continue_learning(self, model):
if self.termination_criterion is not None:
return self.termination_criterion(self.model)
return True
class BGD(TrainingAlgorithm):
"""Batch Gradient Descent training algorithm class"""
def __init__(self, cost=None, batch_size=None, batches_per_iter=None,
updates_per_batch=10, monitoring_batches=None,
monitoring_dataset=None, termination_criterion = None,
set_batch_size=False, reset_alpha=True, conjugate=False,
min_init_alpha=.001, reset_conjugate=True,
line_search_mode=None, verbose_optimization=False,
scale_step=1., theano_function_mode=None, init_alpha=None,
seed=None):
"""
Parameters
----------
cost : pylearn2.costs.Cost
A pylearn2 Cost, or None, in which case model.get_default_cost() \
will be used
batch_size : int
Like the SGD TrainingAlgorithm, this TrainingAlgorithm still \
iterates over minibatches of data. The difference is that this \
class uses partial line searches to choose the step size along \
each gradient direction, and can do repeated updates on the same \
batch. The assumption is that you use big enough minibatches with \
this algorithm that a large step size will generalize reasonably \
well to other minibatches. To implement true Batch Gradient \
Descent, set the batch_size to the total number of examples \
available. If batch_size is None, it will revert to the model's \
force_batch_size attribute.
batches_per_iter : int
WRITEME
updates_per_batch : int
Passed through to the optimization.BatchGradientDescent's \
`max_iters parameter`
monitoring_batches : WRITEME
monitoring_dataset: Dataset or dict
A Dataset or a dictionary mapping string dataset names to Datasets
termination_criterion : WRITEME
set_batch_size : bool
If True, BGD will attempt to override the model's \
`force_batch_size` attribute by calling set_batch_size on it.
reset_alpha : bool
Passed through to the optimization.BatchGradientDescent's \
`max_iters parameter`
conjugate : bool
Passed through to the optimization.BatchGradientDescent's \
`max_iters parameter`
min_init_alpha : float
WRITEME
reset_conjugate : bool
Passed through to the optimization.BatchGradientDescent's \
`max_iters parameter`
line_search_mode : WRITEME
verbose_optimization : bool
WRITEME
scale_step : float
WRITEME
theano_function_mode : WRITEME
init_alpha : WRITEME
seed : WRITEME
"""
self.__dict__.update(locals())
del self.self
if monitoring_dataset is None:
assert monitoring_batches == None
self._set_monitoring_dataset(monitoring_dataset)
self.bSetup = False
self.termination_criterion = termination_criterion
if seed is None:
seed = [2012, 10, 16]
self.rng = np.random.RandomState(seed)
def setup(self, model, dataset):
"""
Allows the training algorithm to do some preliminary configuration
*before* we actually start training the model. The dataset is provided
in case other derived training algorithms need to modify model based on
the dataset.
Parameters
----------
model : object
A Python object representing the model to train loosely \
implementing the interface of models.model.Model.
dataset : pylearn2.datasets.dataset.Dataset
Dataset object used to draw training data
"""
self.model = model
if self.cost is None:
self.cost = model.get_default_cost()
if self.batch_size is None:
self.batch_size = model.force_batch_size
else:
batch_size = self.batch_size
if self.set_batch_size:
model.set_batch_size(batch_size)
elif hasattr(model, 'force_batch_size'):
if not (model.force_batch_size <= 0 or batch_size ==
model.force_batch_size):
raise ValueError("batch_size is %d but " +
"model.force_batch_size is %d" %
(batch_size, model.force_batch_size))
self.monitor = Monitor.get_monitor(model)
self.monitor.set_theano_function_mode(self.theano_function_mode)
data_specs = self.cost.get_data_specs(model)
mapping = DataSpecsMapping(data_specs)
space_tuple = mapping.flatten(data_specs[0], return_tuple=True)
source_tuple = mapping.flatten(data_specs[1], return_tuple=True)
# Build a flat tuple of Theano Variables, one for each space,
# named according to the sources.
theano_args = []
for space, source in safe_zip(space_tuple, source_tuple):
name = 'BGD_[%s]' % source
arg = space.make_theano_batch(name=name)
theano_args.append(arg)
theano_args = tuple(theano_args)
# Methods of `self.cost` need args to be passed in a format compatible
# with their data_specs
nested_args = mapping.nest(theano_args)
fixed_var_descr = self.cost.get_fixed_var_descr(model, nested_args)
self.on_load_batch = fixed_var_descr.on_load_batch
cost_value = self.cost.expr(model, nested_args,
** fixed_var_descr.fixed_vars)
grads, grad_updates = self.cost.get_gradients(
model, nested_args, ** fixed_var_descr.fixed_vars)
assert isinstance(grads, OrderedDict)
assert isinstance(grad_updates, OrderedDict)
if cost_value is None:
raise ValueError("BGD is incompatible with " + str(self.cost) +
" because it is intractable, but BGD uses the " +
"cost function value to do line searches.")
# obj_prereqs has to be a list of function f called with f(*data),
# where data is a data tuple coming from the iterator.
# this function enables capturing "mapping" and "f", while
# enabling the "*data" syntax
def capture(f, mapping=mapping):
new_f = lambda *args: f(mapping.flatten(args, return_tuple=True))
return new_f
obj_prereqs = [capture(f) for f in fixed_var_descr.on_load_batch]
if self.monitoring_dataset is not None:
self.monitor.setup(
dataset=self.monitoring_dataset,
cost=self.cost,
batch_size=self.batch_size,
num_batches=self.monitoring_batches,
obj_prereqs=obj_prereqs,
cost_monitoring_args=fixed_var_descr.fixed_vars)
# TODO : Why is this commented?
'''
channels = model.get_monitoring_channels(theano_args)
if not isinstance(channels, dict):
raise TypeError("model.get_monitoring_channels must return a "
"dictionary, but it returned " + str(channels))
channels.update(self.cost.get_monitoring_channels(model, theano_args, ** fixed_var_descr.fixed_vars))
for dataset_name in self.monitoring_dataset:
if dataset_name == '':
prefix = ''
else:
prefix = dataset_name + '_'
monitoring_dataset = self.monitoring_dataset[dataset_name]
self.monitor.add_dataset(dataset=monitoring_dataset,
mode="sequential",
batch_size=self.batch_size,
num_batches=self.monitoring_batches)
# The monitor compiles all channels for the same dataset into one function, and
# runs all prereqs before calling the function. So we only need to register the
# on_load_batch prereq once per monitoring dataset.
self.monitor.add_channel(prefix + 'objective',ipt=ipt,val=cost_value,
dataset = monitoring_dataset, prereqs = fixed_var_descr.on_load_batch)
for name in channels:
J = channels[name]
if isinstance(J, tuple):
assert len(J) == 2
J, prereqs = J
else:
prereqs = None
self.monitor.add_channel(name= prefix + name,
ipt=ipt,
val=J,
data_specs=data_specs,
dataset = monitoring_dataset,
prereqs=prereqs)
'''
params = model.get_params()
self.optimizer = BatchGradientDescent(
objective = cost_value,
gradients = grads,
gradient_updates = grad_updates,
params = params,
param_constrainers = [ model.censor_updates ],
lr_scalers = model.get_lr_scalers(),
inputs = theano_args,
verbose = self.verbose_optimization,
max_iter = self.updates_per_batch,
reset_alpha = self.reset_alpha,
conjugate = self.conjugate,
reset_conjugate = self.reset_conjugate,
min_init_alpha = self.min_init_alpha,
line_search_mode = self.line_search_mode,
theano_function_mode=self.theano_function_mode,
init_alpha=self.init_alpha)
# These monitoring channels keep track of shared variables,
# which do not need inputs nor data.
if self.monitoring_dataset is not None:
self.monitor.add_channel(
name='ave_step_size',
ipt=None,
val=self.optimizer.ave_step_size,
data_specs=(NullSpace(), ''),
dataset=self.monitoring_dataset.values()[0])
self.monitor.add_channel(
name='ave_grad_size',
ipt=None,
val=self.optimizer.ave_grad_size,
data_specs=(NullSpace(), ''),
dataset=self.monitoring_dataset.values()[0])
self.monitor.add_channel(
name='ave_grad_mult',
ipt=None,
val=self.optimizer.ave_grad_mult,
data_specs=(NullSpace(), ''),
dataset=self.monitoring_dataset.values()[0])
self.first = True
self.bSetup = True
def train(self, dataset):
"""
.. todo::
WRITEME
"""
assert self.bSetup
model = self.model
rng = self.rng
train_iteration_mode = 'shuffled_sequential'
if not is_stochastic(train_iteration_mode):
rng = None
data_specs = self.cost.get_data_specs(self.model)
# The iterator should be built from flat data specs, so it returns
# flat, non-redundent tuples of data.
mapping = DataSpecsMapping(data_specs)
space_tuple = mapping.flatten(data_specs[0], return_tuple=True)
source_tuple = mapping.flatten(data_specs[1], return_tuple=True)
if len(space_tuple) == 0:
# No data will be returned by the iterator, and it is impossible
# to know the size of the actual batch.
# It is not decided yet what the right thing to do should be.
raise NotImplementedError("Unable to train with BGD, because "
"the cost does not actually use data from the data set. "
"data_specs: %s" % str(data_specs))
flat_data_specs = (CompositeSpace(space_tuple), source_tuple)
iterator = dataset.iterator(mode=train_iteration_mode,
batch_size=self.batch_size,
num_batches=self.batches_per_iter,
data_specs=flat_data_specs, return_tuple=True,
rng = rng)
mode = self.theano_function_mode
for data in iterator:
if ('targets' in source_tuple and mode is not None
and hasattr(mode, 'record')):
Y = data[source_tuple.index('targets')]
stry = str(Y).replace('\n',' ')
mode.record.handle_line('data Y '+stry+'\n')
for on_load_batch in self.on_load_batch:
on_load_batch(mapping.nest(data))
self.before_step(model)
self.optimizer.minimize(*data)
self.after_step(model)
actual_batch_size = flat_data_specs[0].np_batch_size(data)
model.monitor.report_batch(actual_batch_size)
def continue_learning(self, model):
"""
.. todo::
WRITEME
"""
if self.termination_criterion is None:
return True
else:
rval = self.termination_criterion.continue_learning(self.model)
assert rval in [True, False, 0, 1]
return rval
def before_step(self, model):
"""
.. todo::
WRITEME
"""
if self.scale_step != 1.:
self.params = list(model.get_params())
self.value = [ param.get_value() for param in self.params ]
def after_step(self, model):
"""
.. todo::
WRITEME
"""
if self.scale_step != 1:
for param, value in safe_zip(self.params, self.value):
value = (1.-self.scale_step) * value + self.scale_step * param.get_value()
param.set_value(value)
def setup(self, model, dataset):
"""
Allows the training algorithm to do some preliminary configuration
*before* we actually start training the model. The dataset is provided
in case other derived training algorithms need to modify model based on
the dataset.
Parameters
----------
model: a Python object representing the model to train loosely
implementing the interface of models.model.Model.
dataset: a pylearn2.datasets.dataset.Dataset object used to draw
training data
"""
self.model = model
if self.batch_size is None:
self.batch_size = model.force_batch_size
else:
batch_size = self.batch_size
if self.set_batch_size:
model.set_batch_size(batch_size)
elif hasattr(model, "force_batch_size"):
if not (model.force_batch_size <= 0 or batch_size == model.force_batch_size):
raise ValueError(
"batch_size is %d but model.force_batch_size is %d" % (batch_size, model.force_batch_size)
)
self.monitor = Monitor.get_monitor(model)
X = self.model.get_input_space().make_theano_batch()
self.topo = X.ndim != 2
Y = T.matrix()
if self.cost.supervised:
obj = self.cost(model, X, Y)
grads, grad_updates = self.cost.get_gradients(model, X, Y)
ipt = (X, Y)
else:
obj = self.cost(model, X)
grads, grad_updates = self.cost.get_gradients(model, X)
ipt = X
if obj is None:
raise ValueError(
"BGD is incompatible with " + str(self.cost) + " because "
" it is intractable, but BGD uses the cost function value to do "
" line searches."
)
if self.monitoring_dataset is not None:
if not any([dataset.has_targets() for dataset in self.monitoring_dataset.values()]):
Y = None
channels = model.get_monitoring_channels(X, Y)
if not isinstance(channels, dict):
raise TypeError(
"model.get_monitoring_channels must return a " "dictionary, but it returned " + str(channels)
)
channels.update(self.cost.get_monitoring_channels(model, X, Y))
for dataset_name in self.monitoring_dataset:
if dataset_name == "":
prefix = ""
else:
prefix = dataset_name + "_"
monitoring_dataset = self.monitoring_dataset[dataset_name]
self.monitor.add_dataset(
dataset=monitoring_dataset,
mode="sequential",
batch_size=self.batch_size,
num_batches=self.monitoring_batches,
)
self.monitor.add_channel(prefix + "objective", ipt=ipt, val=obj, dataset=monitoring_dataset)
for name in channels:
J = channels[name]
if isinstance(J, tuple):
assert len(J) == 2
J, prereqs = J
else:
prereqs = None
if Y is not None:
ipt = (X, Y)
else:
ipt = X
self.monitor.add_channel(
name=prefix + name, ipt=ipt, val=J, dataset=monitoring_dataset, prereqs=prereqs
)
if ipt is X:
ipts = [X]
else:
ipts = ipt
self.optimizer = BatchGradientDescent(
objective=obj,
gradients=grads,
gradient_updates=grad_updates,
params=model.get_params(),
param_constrainers=[model.censor_updates],
lr_scalers=model.get_lr_scalers(),
inputs=ipts,
verbose=True,
max_iter=self.updates_per_batch,
reset_alpha=self.reset_alpha,
conjugate=self.conjugate,
reset_conjugate=self.reset_conjugate,
min_init_alpha=self.min_init_alpha,
line_search_mode=self.line_search_mode,
)
self.first = True
self.bSetup = True