def __init__(self, initial_output='\n'):
self.theano_rng = MRG_RandomStreams(seed=random.randint(0,100000))
SoftmaxEmitter.__init__(self, initial_output=initial_output)
if not os.path.exists(outfolder):
os.makedirs(outfolder)
sample_path = os.path.join(outfolder, 'sample')
os.makedirs(sample_path)
logfile = os.path.join(outfolder, 'logfile.log')
shutil.copy(os.path.realpath(__file__), os.path.join(outfolder,
filename_script))
num_labelled = cfg['nlabeled']
ssl_para_seed = cfg['ssl_para_seed']
print('ssl_para_seed %d, num_labelled %d' % (ssl_para_seed, num_labelled))
rng = np.random.RandomState(ssl_para_seed)
theano_rng = MRG_RandomStreams(rng.randint(2**15))
lasagne.random.set_rng(np.random.RandomState(rng.randint(2**15)))
# dataset
data_dir = './data/mnist.pkl.gz'
# flags
valid_flag = False
# pre-train
pre_num_epoch = 0 if num_labelled >= 100 else 30
pre_alpha_unlabeled_entropy = .3
pre_alpha_average = .3
pre_lr = 3e-4
pre_batch_size_lc = min(100, num_labelled)
pre_batch_size_uc = 500
# C
def __init__(self, state, rng, parent):
EncoderDecoderBase.__init__(self, state, rng, parent)
self.trng = MRG_RandomStreams(self.seed)
self.init_params()
def __init__(self, seed=123):
self.rng = MRG_RandomStreams(seed)
self.y = self.rng.uniform(size=(1, ))
import theano
import theano.tensor as tensor
#global variables to use to toggle training and rng, etc
from theano.sandbox.rng_mrg import MRG_RandomStreams
layer_train_rng = MRG_RandomStreams()
layer_train_enable = tensor.bscalar()
layer_train_epoch = tensor.iscalar()
layer_train_it = theano.shared(0)
def get_rng():
global layer_train_rng
return layer_train_rng
def set_rng_seed(v):
global layer_train_rng
layer_train_rng.seed(v)
def get_train():
global layer_train_enable
return layer_train_enable
def get_epoch():
global layer_train_epoch
return layer_train_epoch
def setup_method(self):
nr.seed(self.random_seed)
self.old_tt_rng = tt_rng()
set_tt_rng(MRG_RandomStreams(self.random_seed))
def test_binomial():
#TODO: test size=None, ndim=X
#TODO: test size=X, ndim!=X.ndim
#TODO: test random seed in legal value(!=0 and other)
#TODO: test sample_size not a multiple of guessed #streams
#TODO: test size=Var, with shape that change from call to call
#we test size in a tuple of int and a tensor.shape.
#we test the param p with int.
if (mode in ['DEBUG_MODE', 'DebugMode', 'FAST_COMPILE']
or mode == 'Mode' and config.linker in ['py']):
sample_size = (10, 50)
steps = 50
rtol = 0.02
else:
sample_size = (500, 50)
steps = int(1e3)
rtol = 0.01
x = tensor.matrix()
v = tensor.vector()
for mean in [0.1, 0.5]:
for size, const_size, var_input, input in [
(sample_size, sample_size, [], []),
(x.shape, sample_size, [x],
[numpy.zeros(sample_size, dtype=config.floatX)]),
((x.shape[0], sample_size[1]), sample_size, [x],
[numpy.zeros(sample_size, dtype=config.floatX)]),
# test empty size (scalar)
((), (), [], []),
]:
#print ''
#print 'ON CPU with size=(%s) and mean(%d):' % (str(size), mean)
R = MRG_RandomStreams(234, use_cuda=False)
# Note: we specify `nstreams` to avoid a warning.
u = R.binomial(size=size,
p=mean,
nstreams=rng_mrg.guess_n_streams(size, warn=False))
f = theano.function(var_input, u, mode=mode)
#theano.printing.debugprint(f)
out = f(*input)
#print 'random?[:10]\n', out[0, 0:10]
#print 'random?[-1,-10:]\n', out[-1, -10:]
# Increase the number of steps if sizes implies only a few samples
if numpy.prod(const_size) < 10:
steps_ = steps * 100
else:
steps_ = steps
basictest(f,
steps_,
const_size,
prefix='mrg cpu',
inputs=input,
allow_01=True,
target_avg=mean,
mean_rtol=rtol)
if mode != 'FAST_COMPILE' and cuda_available:
#print ''
#print 'ON GPU with size=(%s) and mean(%d):' % (str(size), mean)
R = MRG_RandomStreams(234, use_cuda=True)
u = R.binomial(size=size,
p=mean,
dtype='float32',
nstreams=rng_mrg.guess_n_streams(size,
warn=False))
#well, it's really that this test w GPU doesn't make sense otw
assert u.dtype == 'float32'
f = theano.function(
var_input,
theano.Out(theano.sandbox.cuda.basic_ops.gpu_from_host(u),
borrow=True),
mode=mode_with_gpu)
#theano.printing.debugprint(f)
gpu_out = numpy.asarray(f(*input))
#print 'random?[:10]\n', gpu_out[0, 0:10]
#print 'random?[-1,-10:]\n', gpu_out[-1, -10:]
basictest(f,
steps_,
const_size,
prefix='mrg gpu',
inputs=input,
allow_01=True,
target_avg=mean,
mean_rtol=rtol)
numpy.testing.assert_array_almost_equal(out,
gpu_out,
decimal=6)
#print ''
#print 'ON CPU w NUMPY with size=(%s) and mean(%d):' % (str(size),
# mean)
RR = theano.tensor.shared_randomstreams.RandomStreams(234)
uu = RR.binomial(size=size, p=mean)
ff = theano.function(var_input, uu, mode=mode)
# It's not our problem if numpy generates 0 or 1
basictest(ff,
steps_,
const_size,
prefix='numpy',
allow_01=True,
inputs=input,
target_avg=mean,
mean_rtol=rtol)
def __init__(self, input_var, target_var, n_in, n_out, layers, batch_size,
n_batches):
n_hidden = layers[0]
n_in = n_in[0]
# Input to hidden layer weights
W1_mu = weight_init(n_in, n_hidden, 'W1_mu') # Weights mean
W1_log_sigma = weight_init(n_in, n_hidden,
'W1_log_sigma') # Weights log variance
# Hidden layer to output weights
W2_mu = weight_init(n_hidden, n_out, 'W2_mu') # Weights mean
W2_log_sigma = weight_init(n_hidden, n_out,
'W2_log_sigma') # Weights log variance
# Biases are not random variables (for convenience)
b1 = theano.shared(value=np.zeros((n_hidden, ),
dtype=theano.config.floatX),
name='b1',
borrow=True)
b2 = theano.shared(value=np.zeros((n_out, ),
dtype=theano.config.floatX),
name='b2',
borrow=True)
# Network parameters
params = [W1_mu, W1_log_sigma, W2_mu, W2_log_sigma, b1, b2]
# Random variables
srng = MRG_RandomStreams(seed=234)
rv_hidden = srng.normal(
(batch_size, n_in, n_hidden)) # Standard normal
rv_output = srng.normal(
(batch_size, n_hidden, n_out)) # Standard normal
# MLP
# Hidden layer
#hidden_output = T.nnet.relu(T.batched_dot(input_var, W1_mu + T.log(1.0+T.exp(W1_log_sigma))*rv_hidden) + b1)
hidden_output = T.nnet.relu(
T.batched_dot(input_var, W1_mu + T.exp(W1_log_sigma) * rv_hidden) +
b1)
# Output layer
#prediction = T.nnet.softmax(T.batched_dot(hidden_output, W2_mu + T.log(1.0+T.exp(W2_log_sigma))*rv_output) + b2)
prediction = T.nnet.softmax(
T.batched_dot(hidden_output, W2_mu +
T.exp(W2_log_sigma) * rv_output) + b2)
# KL divergence between prior and posterior
# For Gaussian prior and posterior, the formula is exact:
#DKL_hidden = (1.0 + T.log(2.0*T.log(1.0+T.exp(W1_log_sigma))) - W1_mu**2.0 - 2.0*T.log(1.0+T.exp(W1_log_sigma))).sum()/2.0
#DKL_output = (1.0 + T.log(2.0*T.log(1.0+T.exp(W2_log_sigma))) - W2_mu**2.0 - 2.0*T.log(1.0+T.exp(W2_log_sigma))).sum()/2.0
DKL_hidden = (1.0 + 2.0 * W1_log_sigma - W1_mu**2.0 -
T.exp(2.0 * W1_log_sigma)).sum() / 2.0
DKL_output = (1.0 + 2.0 * W2_log_sigma - W2_mu**2.0 -
T.exp(2.0 * W2_log_sigma)).sum() / 2.0
# Negative log likelihood
nll = T.nnet.categorical_crossentropy(prediction, target_var)
# Complete variational loss
loss = nll.mean() - (DKL_hidden + DKL_output) / float(n_batches)
#loss = nll.mean()
# ADAM training
updates = lasagne.updates.adam(loss, params)
self.train = theano.function([input_var, target_var],
loss,
updates=updates)
# Test functions
hidden_output_test = T.nnet.relu(T.dot(input_var, W1_mu) + b1)
test_prediction = T.nnet.softmax(T.dot(hidden_output_test, W2_mu) + b2)
test_acc = T.mean(T.eq(T.argmax(test_prediction, axis=1), target_var))
self.test = theano.function([input_var, target_var], [loss, test_acc])
self.pred = theano.function([input_var], test_prediction)
# Probability and entropy
self.probabilities = theano.function([input_var], prediction)
entropy = T.nnet.categorical_crossentropy(prediction, prediction)
self.entropy_bayesian = theano.function([input_var], entropy)
# Fake deterministic entropy to make the code modular (this should not be used for comparisons)
self.entropy_deterministic = theano.function([input_var],
0.0 * input_var.sum())
assert_raises(theano.gradient.NullTypeGradError, theano.grad, out, avg)
std = tensor.scalar()
out = srng.normal((), avg=0, std=std)
assert_raises(theano.gradient.NullTypeGradError, theano.grad, out, std)
out = srng.normal((), avg=avg, std=std)
assert_raises(theano.gradient.NullTypeGradError, theano.grad, out,
(avg, std))
def test_f16_nonzero(mode=None, op_to_check=rng_mrg.mrg_uniform):
srng = MRG_RandomStreams(seed=utt.fetch_seed())
m = srng.uniform(size=(1000, 1000), dtype='float16')
assert m.dtype == 'float16', m.type
f = theano.function([], m, mode=mode)
assert any(
isinstance(n.op, op_to_check) for n in f.maker.fgraph.apply_nodes)
m_val = f()
assert np.all((0 < m_val) & (m_val < 1))
if __name__ == "__main__":
rng = MRG_RandomStreams(np.random.randint(2147462579))
print(theano.__file__)
pvals = theano.tensor.fmatrix()
for i in range(10):
t0 = time.time()
multinomial = rng.multinomial(pvals=pvals)
print(time.time() - t0)
def makemodel(
name="ADGM" if ADGM else "SDGM",
nls=["rectify"] * 2,
seed=seed,
descenter=G.Adam,
K=K,
L=L,
):
#$ tensor_shapes
"""
Creates the ADGM or SDGM model.
Xl has dimension (Nl, 1, 1, 1, X)
Xu has dimension (Nu, 1, 1, 1, X)
Yl has dimension (Nl, 1, 1, 1, Y)
Yu has dimension ( 1, 1, 1, Y, Y)
EAl has dimension (Nl, K, 1, 1, A)
EAu has dimension (Nu, K, 1, 1, A)
EZl has dimension (Nl, K, L, 1, Z)
EZu has dimension (Nu, K, L, Y, Z)
Al will have dimension (Nl, K, 1, 1, A)
Au will have dimension (Nu, K, 1, 1, A)
Zl will have dimension (Nl, K, L, 1, Z)
Zu will have dimension (Nu, K, L, Y, Z)
"""
#$
Print = Log("../log/{}".format(name), "w", quiet=True)
model = Model(name=name,
shuffledata=shuffledata,
thresholddata=thresholdX,
normalizedata=normalizeX,
seed=seed,
maxvar=highvaronly)
model.Print = Print
model.loadmomentum = loadmomentum
model.descenter = descenter(gradnorm)
networks = OrderedDict()
rng = MRG_RandomStreams()
X = model.XCols
model.constants = OrderedDict([
(" ", model.name),
("shuffle data?", shuffledata),
("data seed", model.seed),
("Nu", Nu),
("Nl", Nl),
("X", X),
("Y", Y),
("Z", Z),
("A", A),
("L", L),
("K", K),
("Kt", Kt),
("aJL", aJL),
("aJU", aJU),
("aJA", aJA),
("aJW", aJW),
("gradient norm?", gradnorm),
("std. normal A?", Anormal),
("A to Z?", AtoZ),
("gaussian X?", gaussianX),
("sample X?", sampleX),
("threshold X?", thresholdX),
("normalize X?", normalizeX),
("high var only?", highvaronly),
("NSaves", NSaves),
("enable save?", enablesave),
("combolength", combolength),
("load momentum?", loadmomentum),
("juggle momentum?", jugglemomentum),
("random juggler?", randomjuggler),
("epsilon", epsilon),
])
for name, val in model.constants.items():
model.Print("{:>20s}".format(name), val)
#$ px_stack
# Create the networks for px
ins = [Y, Z] if ADGM else [A, Y, Z]
last = "linear" if gaussianX else "sigmoid"
O = [X, X] if gaussianX else [X]
fx = Stack(insizes=ins, outsizes=O, hidnls=nls, lastnl=last)
networks["fx"] = fx
#$
#$ pa_stack
# Create the networks for pa
ins = [X, Y, Z] if ADGM else [Y, Z]
fa = Stack(insizes=ins, outsizes=[A, A], hidnls=nls)
if not Anormal:
networks["fa"] = fa
#$
#$ qz_stack
# Create the networks for qz
ins = [A, X, Y] if AtoZ else [X, Y]
fz = Stack(insizes=ins, outsizes=[Z, Z], hidnls=nls)
networks["fz"] = fz
#$
#$ qax_stack
# Create the networks for qax
ins = [X]
fax = Stack(insizes=ins, outsizes=[A, A], hidnls=nls)
networks["fax"] = fax
#$
#$ qy_stack
# Create the network for qy. Outputs are
# probabilities, so last layer is always
# softmax.
ins = [A, X]
last = "softmax"
fy = Stack(insizes=ins, outsizes=[Y], hidnls=nls, lastnl=last)
networks["fy"] = fy
#$
#$ model.networks
# Collect all of the parameters together
# so we can optimize the objectives with
# respect to them.
model.networks = networks
model.params = []
for name, net in model.networks.items():
model.Print("{:>20s}".format(name), net)
model.params += net.params
#$
# For now, throw an error if Nl or Nu are
# not specified.
# Eventually, we would like to be able to
# handle only Nl, only Nu, or both Nl and Nu.
if Nl is None or Nu is None:
raise ValueError("Need to specify Nl and Nu")
#$ shared_inputs
# Xl, Ylh, and Xu are shared variables on the
# GPU. For Xu, we take random batch slices.
# We assume for now that all (Xl,Yl) are used
# in each batch.
Xl2 = model.Xl[:Nl]
Yl2 = model.Ylh[:Nl]
bidxs = rng.uniform((Nu, )) * model.Xu.shape[0]
bidxs = T.cast(bidxs, "int32")
Xu2 = model.Xu[bidxs]
#$
#$ sampleX
# If X is binary, then sample it on each
# minibatch. This idea borrowed from Maaloe's
# code. Not sure if it helps.
#
# Keep track of Xl2s, Yl2, and Xu2s so we can
# do theano variable substitution later.
if not gaussianX and sampleX:
Xl2s = rng.binomial(n=1,
p=Xl2,
size=Xl2.shape,
dtype=theano.config.floatX)
Xu2s = rng.binomial(n=1,
p=Xu2,
size=Xu2.shape,
dtype=theano.config.floatX)
else:
Xl2s = Xl2
Xu2s = Xu2
#$
#$ dimshuffled
# Reshape the labeled set matrices
# to 5th-order tensors.
Xl = Xl2s.dimshuffle([0, "x", "x", "x", 1])
Yl = Yl2.dimshuffle([0, "x", "x", "x", 1])
# Xu is known, but Yu is not known.
# Create one possible Y per class.
Xu = Xu2s.dimshuffle([0, "x", "x", "x", 1])
Yu = T.eye(Y, Y).dimshuffle(["x", "x", "x", 0, 1])
#$
#$ noises
# EZ and EA will be used to approximate
# the integrals using L samples for Z and
# K samples for A.
#
# Create shared variables for K and L so we
# can do variable substitutions later.
K = theano.shared(K, name="samplesA")
L = theano.shared(L, name="samplesZ")
EAl = rng.normal((Xl.shape[0], K, 1, 1, A))
EAu = rng.normal((Xu.shape[0], K, 1, 1, A))
EZl = rng.normal((Xl.shape[0], K, L, 1, Z))
EZu = rng.normal((Xu.shape[0], K, L, Y, Z))
#$
# Assign inputs to the model.
# We assume that all data is already on the GPU.
# Furthermore, we create functions that
# evaluate the objectives on the test data
# directly. Therefore, there are no inputs
# needed for calling the training function.
model.inputs = []
#$ al_au
# Find the latent variables.
# Note that multiplying by E effectively tiles
# all latent variables L or K times.
#
# Auxiliary A has to be found first
# because latent Z is a function of it.
muaxl, sdaxl = fax([Xl])
muaxu, sdaxu = fax([Xu])
Al = muaxl + T.exp(sdaxl) * EAl
Au = muaxu + T.exp(sdaxu) * EAu
#$
#$ zl_zu
# Compute Z.
inputl = [Al, Xl, Yl] if AtoZ else [Xl, Yl]
inputu = [Au, Xu, Yu] if AtoZ else [Xu, Yu]
muzl, sdzl = fz(inputl)
muzu, sdzu = fz(inputu)
Zl = muzl + T.exp(sdzl) * EZl
Zu = muzu + T.exp(sdzu) * EZu
#$
#$ muxl_muxu
# Find the reconstruction means and
# standard deviations.
# Note: sdxl and sdxu are used only if
# gaussian is True. The binary case
# ignores those.
# If ADGM, then X is a function of YZ.
# If SDGM, then X is a function of AYZ.
inputl = [Yl, Zl] if ADGM else [Al, Yl, Zl]
inputu = [Yu, Zu] if ADGM else [Au, Yu, Zu]
if gaussianX:
muxl, sdxl = fx(inputl)
muxu, sdxu = fx(inputu)
else:
muxl = fx(inputl)
muxu = fx(inputu)
#$
#$ mual_muau
# Find mu and sd for A in the generative
# (reconstruction) direction.
# If ADGM, then A depends on XYZ.
# If SDGM, then A depends on YZ.
inputl = [Xl, Yl, Zl] if ADGM else [Yl, Zl]
inputu = [Xu, Yu, Zu] if ADGM else [Yu, Zu]
mual, sdal = fa(inputl)
muau, sdau = fa(inputu)
#$
#$ JL_1
# Find the component probabilities and the
# labeled objective, JL.
l_pz = loggauss(Zl)
l_qz = loggauss(Zl, muzl, sdzl)
l_py = T.log(1.0 / Y)
if gaussianX:
l_px = loggauss(Xl, muxl, sdxl)
else:
l_px = logbernoulli(Xl, muxl)
#$
#$ JL_2
# In Maaloe's first revision, A is disconnected
# in the generative model, so we assume it
# to be standard normal.
#
# In the more updated version, A is fed into
# by X, Y, and Z.
# In SDGM, A is generated by Z and Y.
normal = zero if Anormal else one
l_pa = loggauss(Al, normal * mual, normal * sdal)
l_qa = loggauss(Al, muaxl, sdaxl)
#$
#$ JL_3
JL = l_qz + l_qa
JL = JL - l_px - l_py - l_pz - l_pa
JL = batchaverage(exA(exZ(JL)))
JL = aJL * JL
#$
#$ JU_1
# Find the component probabilities and the
# unlabeled objective, JU.
# The output of fy(Au, Xu) is pi.
# (Nu, K, 1, 1, Y)
# We need to relocate the last axis.
# (Nu, K, 1, Y, 1)
inputu = [Au, Xu]
pi = fy(inputu).dimshuffle([0, 1, "x", 4, "x"])
#$
#$ JU_2
u_pz = loggauss(Zu)
u_qz = loggauss(Zu, muzu, sdzu)
u_py = T.log(1.0 / Y)
u_qy = T.log(pi)
u_pa = loggauss(Au, normal * muau, normal * sdau)
u_qa = loggauss(Au, muaxu, sdaxu)
if gaussianX:
u_px = loggauss(Xu, muxu, sdxu)
else:
u_px = logbernoulli(Xu, muxu)
#$
#$ JU_3
JU = u_qz + u_qa + u_qy
JU = JU - u_px - u_py - u_pz - u_pa
JU = batchaverage(exA(classsum(exZ(JU), pi)))
JU = aJU * JU
#$
#$ JA
# Make sure that the known labels are correctly
# assigned.
# Yl has dimension (Nl, 1, 1, 1, Y)
# Al,Xl has dimension (Nl, K, 1, 1, A+X)
# fy(Al,Xl) is (Nl, K, 1, 1, Y)
#
# Yl is one-hot.
# Multiply by Yl and perform a sum over
# Y to get the one probability out, then neg
# log it, average it over K, and
# average it over N.
inputl = [Al, Xl]
JA = batchaverage(exA(-T.log(T.sum(fy(inputl) * Yl, axis=-1))))
JA = aJA * JA
#$
# Regularize the weight matrices of the
# networks so they do not stray far from zero.
# Copied from Maaloe's github code.
JW = zero
for p in model.params:
if 'W' not in str(p):
continue
JW += T.mean(p**two)
JW = aJW * JW
JCombined = JL + JU + JA + JW
# Stick the objectives into the model.
model.objective = JCombined
#$ prediction_comments
# Create a function for predictions!
# We need to evaluate a bunch of values for A,
# so Xt is an N by X dimensional matrix and
# Et is a K by A dimensional matrix.
# Reshape Xt to (N, 1, X) and
# Et to (1, K, A).
#
# Then, At = fmuax(Xt) + Et*fsdax(Xt)
# and has a dimension of (N, K, A).
#
# Class probabilities pi are fy(AXt)
# and have shape (N, K, Y). Take their
# log, average over K, then argmax over Y
# to find class predictions.
#$
#$ prediction_function
Xt2 = T.matrix("Xt")
Et2 = rng.normal((Kt, A))
Xt = Xt2.dimshuffle([0, "x", 1])
Et = Et2.dimshuffle(["x", 0, 1])
muat, sdat = fax([Xt])
At = muat + T.exp(sdat) * Et
inputt = [At, Xt]
prediction = T.argmax(T.mean(T.log(fy(inputt)), axis=1), axis=-1)
predict = theano.function(inputs=[Xt2],
outputs=prediction,
allow_input_downcast=True)
model.predict = predict
#$
#$ classification
Yt = T.ivector("Yt")
accuracyT = T.eq(Yt, prediction).mean(dtype=theano.config.floatX)
model.accuracyT = theano.function(inputs=[],
outputs=accuracyT,
givens={
Xt2: model.Xt,
Yt: model.Yt
},
allow_input_downcast=True)
#$
model.accuracyL = theano.function(inputs=[],
outputs=accuracyT,
givens={
Xt2: model.Xl,
Yt: model.Yl
},
allow_input_downcast=True)
# Create a stats function that outputs
# extra information.
model.adds = [
JL,
JU,
JA,
JW,
T.mean(l_qa),
T.mean(u_qa),
T.mean(u_qy),
T.mean(l_qz),
T.mean(u_qz),
-T.mean(l_px.max(axis=AxisY)),
-T.mean(u_px.max(axis=AxisY)),
-T.mean(l_pa),
-T.mean(u_pa),
]
model.headings = [
"J",
"JL",
"JU",
"JA",
"JW",
"l q(a)",
"u q(a)",
"u q(y)",
"l q(z)",
"u q(z)",
"l -p(x)",
"u -p(x)",
"l -p(a)",
"u -p(a)",
]
model.outputs = [model.objective] + model.adds
model.stats = theano.function(inputs=[],
outputs=model.outputs,
givens={
Xl2s: model.Xl[:1000],
Yl2: model.Ylh[:1000],
Xu2s: model.Xu[:1000],
K: 1
},
allow_input_downcast=True)
return model
def __init__(self,
glimpse_shape, glimpse_times,
dim_hidden, dim_fc, dim_out,
reward_base,
rng_std=1.0, activation=T.tanh, bptt_truncate=-1,
lmbd=0.1 # gdupdate + lmbd*rlupdate
):
if reward_base == None:
reward_base = np.zeros((glimpse_times)).astype('float32')
reward_base[-1] = 1.0
x = T.ftensor3('x') # N * W * H
y = T.ivector('y') # label
lr = T.fscalar('lr')
reward_base = theano.shared(name='reward_base', value=np.array(reward_base).astype(theano.config.floatX), borrow=True) # Time (vector)
reward_bias = T.fvector('reward_bias')
rng = MRG_RandomStreams(np.random.randint(9999999))
# rng = theano.tensor.shared_randomstreams.RandomStreams(np.random.randint(9999999))
i = InputLayer(x)
au = AttentionUnit(x, glimpse_shape, glimpse_times, dim_hidden, rng, rng_std, activation, bptt_truncate)
# All hidden states are put into decoder
# layers = [i, au, InputLayer(au.output[:,:,:].flatten(2))]
# dim_fc = [glimpse_times*dim_hidden] + dim_fc + [dim_out]
# Only the last hidden states
layers = [i, au, InputLayer(au.output[:,-1,:])]
dim_fc = [dim_hidden] + dim_fc + [dim_out]
for Idim, Odim in zip(dim_fc[:-1], dim_fc[1:]):
fc = FullConnectLayer(layers[-1].output, Idim, Odim, activation, 'FC')
layers.append(fc)
sm = SoftmaxLayer(layers[-1].output)
layers.append(sm)
output = sm.output # N * classes
hidoutput = au.output # N * dim_output
location = au.location # N * T * dim_hidden
prediction = output.argmax(1) # N
# calc
equalvec = T.eq(prediction, y) # [0, 1, 0, 0, 1 ...]
correct = T.cast(T.sum(equalvec), 'float32')
# noequalvec = T.neq(prediction, y)
# nocorrect = T.cast(T.sum(noequalvec), 'float32')
logLoss = T.log(output)[T.arange(y.shape[0]), y] #
reward_biased = T.outer(equalvec, reward_base)-reward_bias.dimshuffle('x', 0)
# N * Time
# (R_t - b_t), where b = E[R]
# gradient descent
gdobjective = logLoss.sum()/x.shape[0] # correct * dim_output (only has value on the correctly predicted sample)
gdparams = reduce(lambda x, y: x+y.params, layers, [])
gdupdates = map(lambda x: (x, x+lr*T.grad(gdobjective, x)), gdparams)
# reinforce learning
rlobjective = (reward_biased.dimshuffle(0, 1, 'x') * T.log(au.location_p)).sum() / x.shape[0]
# location_p: N * Time * 2
# location_logp: N * Time
# reward_biased: N * 2
rlparams = au.reinforceParams
rlupdates = map(lambda x: (x, x+lr*lmbd*T.grad(rlobjective, x)), rlparams)
# Hidden state keeps unchange in time
deltas = T.stack(*[((au.output[:,i,:].mean(0)-au.output[:,i+1,:].mean(0))**2).sum() for i in xrange(glimpse_times-1)])
# N * Time * dim_hidden
print 'compile step()'
self.step = theano.function([x, y, lr, reward_bias], [gdobjective, rlobjective, correct, T.outer(equalvec, reward_base)], updates=gdupdates+rlupdates)
# print 'compile gdstep()'
# self.gdstep = theano.function([x, y, lr], [gdobjective, correct, location], updates=gdupdates)
# print 'compile rlstep()'
# self.rlstep = theano.function([x, y, lr], [rlobjective], updates=rlupdates)
print 'compile predict()'
self.predict = theano.function([x], prediction)
# print 'compile forward()'
# self.forward = theano.function([x], map(lambda x: x.output, layers)) #[layers[-3].output, fc.output])
# print 'compile error()'
# self.error = theano.function([x, y], gdobjective)
print 'compile locate()'
self.locate = theano.function([x], [au.location_mean, location]) #[layers[-3].output, fc.output])
print 'compile debug()'
self.debug = theano.function([x, y, lr, reward_bias], [deltas, au.location_p], on_unused_input='warn')
# self.xxx
self.glimpse_times = glimpse_times
from theano.sandbox.rng_mrg import MRG_RandomStreams
'''
whether to use Xavier initialization, as described in
http://jmlr.org/proceedings/papers/v9/glorot10a/glorot10a.pdf
'''
USE_XAVIER_INIT = False
'''
Defaut random generators
'''
#random.seed(5817)
default_rng = np.random.RandomState(random.randint(0,9999))
#default_srng = T.shared_randomstreams.RandomStreams(default_rng.randint(9999))
default_mrng = MRG_RandomStreams(default_rng.randint(9999))
default_srng = default_mrng
'''
Activation functions
'''
ReLU = lambda x: x * (x > 0)
sigmoid = T.nnet.sigmoid
tanh = T.tanh
softmax = T.nnet.softmax
linear = lambda x: x
def get_activation_by_name(name):
if name.lower() == "relu":
return ReLU
elif name.lower() == "sigmoid":
----------
gen: generator that implements __next__ (py3) or next (py2) method
and yields np.arrays with same types
default: np.array with the same type as generator produces
Returns
-------
TensorVariable
It has 2 new methods
- var.set_gen(gen): sets new generator
- var.set_default(value): sets new default value (None erases default value)
"""
return GeneratorOp(gen, default)()
_tt_rng = MRG_RandomStreams()
def tt_rng(random_seed=None):
"""
Get the package-level random number generator or new with specified seed.
Parameters
----------
random_seed: int
If not None
returns *new* theano random generator without replacing package global one
Returns
-------
`theano.sandbox.rng_mrg.MRG_RandomStreams` instance
def test_match_grad_valid_conv():
# Tests that weightActs is the gradient of FilterActs
# with respect to the weights.
for partial_sum in [0, 1, 4]:
rng = np.random.RandomState([2012, 10, 9])
batch_size = 3
rows = 7
cols = 9
channels = 8
filter_rows = 4
filter_cols = filter_rows
num_filters = 16
images = shared(rng.uniform(
-1., 1., (channels, rows, cols, batch_size)).astype('float32'),
name='images')
filters = shared(rng.uniform(-1., 1.,
(channels, filter_rows, filter_cols,
num_filters)).astype('float32'),
name='filters')
gpu_images = gpu_from_host(images)
gpu_filters = gpu_from_host(filters)
output = FilterActs(partial_sum=partial_sum)(gpu_images, gpu_filters)
output = host_from_gpu(output)
images_bc01 = images.dimshuffle(3, 0, 1, 2)
filters_bc01 = filters.dimshuffle(3, 0, 1, 2)
filters_bc01 = filters_bc01[:, :, ::-1, ::-1]
output_conv2d = conv2d(images_bc01, filters_bc01, border_mode='valid')
output_conv2d = output_conv2d.dimshuffle(1, 2, 3, 0)
theano_rng = MRG_RandomStreams(2013 + 1 + 31)
coeffs = theano_rng.normal(avg=0.,
std=1.,
size=output_conv2d.shape,
dtype='float32')
cost_conv2d = (coeffs * output_conv2d).sum()
weights_grad_conv2d = T.grad(cost_conv2d, filters)
cost = (coeffs * output).sum()
hid_acts_grad = T.grad(cost, output)
weights_grad = host_from_gpu(
WeightActs(partial_sum=partial_sum)(gpu_images,
gpu_from_host(hid_acts_grad)))
f = function(
[], [output, output_conv2d, weights_grad, weights_grad_conv2d])
output, output_conv2d, weights_grad, weights_grad_conv2d = f()
if np.abs(output - output_conv2d).max() > 8e-6:
assert type(output) == type(output_conv2d)
assert output.dtype == output_conv2d.dtype
if output.shape != output_conv2d.shape:
print 'cuda-convnet shape: ', output.shape
print 'theano shape: ', output_conv2d.shape
assert False
err = np.abs(output - output_conv2d)
print 'absolute error range: ', (err.min(), err.max())
print 'mean absolute error: ', err.mean()
print 'cuda-convnet value range: ', (output.min(), output.max())
print 'theano value range: ', (output_conv2d.min(),
output_conv2d.max())
assert False
warnings.warn(
"""test_match_grad_valid_conv success criterion is not very strict. Can we verify that this is OK?
One possibility is that theano is numerically unstable and Alex's code is better.
Probably theano CPU 64 bit is OK but it's worth checking the others."""
)
if np.abs(weights_grad - weights_grad_conv2d).max() > 8.6e-6:
if type(weights_grad) != type(weights_grad_conv2d):
raise AssertionError("weights_grad is of type " +
str(weights_grad))
assert weights_grad.dtype == weights_grad_conv2d.dtype
if weights_grad.shape != weights_grad_conv2d.shape:
print 'cuda-convnet shape: ', weights_grad.shape
print 'theano shape: ', weights_grad_conv2d.shape
assert False
err = np.abs(weights_grad - weights_grad_conv2d)
print 'absolute error range: ', (err.min(), err.max())
print 'mean absolute error: ', err.mean()
print 'cuda-convnet value range: ', (weights_grad.min(),
weights_grad.max())
print 'theano value range: ', (weights_grad_conv2d.min(),
weights_grad_conv2d.max())
assert False
Each column corresponds to a different unit
Returns:
dW: a matrix of the derivatives of the expected gradient
of the energy
"""
return T.grad(energy(W, V, H).mean(), W, consider_constant=[V, H])
if __name__ == "__main__":
m = 2
nv = 3
nh = 4
h0 = T.alloc(1., m, nh)
rng_factory = MRG_RandomStreams(42)
W = rng_factory.normal(size=(nv, nh), dtype=h0.dtype)
pv = T.nnet.sigmoid(T.dot(h0, W.T))
v = rng_factory.binomial(p=pv, size=pv.shape, dtype=W.dtype)
ph = T.nnet.sigmoid(T.dot(v, W))
h = rng_factory.binomial(p=ph, size=ph.shape, dtype=W.dtype)
class _ElemwiseNoGradient(theano.tensor.Elemwise):
def grad(self, inputs, output_gradients):
raise TypeError("You shouldn't be differentiating through "
"the sampling process.")
return [ theano.gradient.DisconnectedType()() ]
block_gradient = _ElemwiseNoGradient(theano.scalar.identity)
v = block_gradient(v)
h = block_gradient(h)
def test_normal0():
steps = 50
std = 2.
if (config.mode in ['DEBUG_MODE', 'DebugMode', 'FAST_COMPILE']
or config.mode == 'Mode' and config.linker in ['py']):
sample_size = (25, 30)
default_rtol = .02
else:
sample_size = (999, 50)
default_rtol = .01
sample_size_odd = (sample_size[0], sample_size[1] - 1)
x = tensor.matrix()
for size, const_size, var_input, input, avg, rtol, std_tol in [
(sample_size, sample_size, [], [], -5., default_rtol, default_rtol),
(x.shape, sample_size, [x],
[np.zeros(sample_size,
dtype=config.floatX)], -5., default_rtol, default_rtol),
# test odd value
(x.shape, sample_size_odd, [x],
[np.zeros(sample_size_odd,
dtype=config.floatX)], -5., default_rtol, default_rtol),
(sample_size, sample_size, [], [],
np.arange(np.prod(sample_size), dtype='float32').reshape(sample_size),
10. * std / np.sqrt(steps), default_rtol),
# test empty size (scalar)
((), (), [], [], -5., default_rtol, 0.02),
# test with few samples at the same time
((1, ), (1, ), [], [], -5., default_rtol, 0.02),
((3, ), (3, ), [], [], -5., default_rtol, 0.02),
]:
R = MRG_RandomStreams(234)
# Note: we specify `nstreams` to avoid a warning.
n = R.normal(size=size,
avg=avg,
std=std,
nstreams=rng_mrg.guess_n_streams(size, warn=False))
f = theano.function(var_input, n)
f(*input)
# Increase the number of steps if size implies only a few samples
if np.prod(const_size) < 10:
steps_ = steps * 50
else:
steps_ = steps
basictest(f,
steps_,
const_size,
target_avg=avg,
target_std=std,
prefix='mrg ',
allow_01=True,
inputs=input,
mean_rtol=rtol,
std_tol=std_tol)
sys.stdout.flush()
RR = theano.tensor.shared_randomstreams.RandomStreams(234)
nn = RR.normal(size=size, avg=avg, std=std)
ff = theano.function(var_input, nn)
basictest(ff,
steps_,
const_size,
target_avg=avg,
target_std=std,
prefix='numpy ',
allow_01=True,
inputs=input,
mean_rtol=rtol)
def ready(self):
encoder = self.encoder
embedding_layer = self.embedding_layer
args = self.args
padding_id = embedding_layer.vocab_map["<padding>"]
dropout = self.dropout = encoder.dropout
# len*batch
x = self.x = encoder.x
z = self.z = encoder.z
n_d = args.hidden_dimension
n_e = embedding_layer.n_d
activation = get_activation_by_name(args.activation)
layers = self.layers = []
layer_type = args.layer.lower()
for i in xrange(2):
if layer_type == "rcnn":
l = RCNN(
n_in=n_e, # if i == 0 else n_d,
n_out=n_d,
activation=activation,
order=args.order)
elif layer_type == "lstm":
l = LSTM(
n_in=n_e, # if i == 0 else n_d,
n_out=n_d,
activation=activation)
layers.append(l)
# len * batch
#masks = T.cast(T.neq(x, padding_id), theano.config.floatX)
masks = T.cast(T.neq(x, padding_id), "int8").dimshuffle((0, 1, "x"))
# (len*batch)*n_e
embs = embedding_layer.forward(x.ravel())
# len*batch*n_e
embs = embs.reshape((x.shape[0], x.shape[1], n_e))
embs = apply_dropout(embs, dropout)
flipped_embs = embs[::-1]
# len*bacth*n_d
h1 = layers[0].forward_all(embs)
h2 = layers[1].forward_all(flipped_embs)
h_final = T.concatenate([h1, h2[::-1]], axis=2)
h_final = apply_dropout(h_final, dropout)
size = n_d * 2
output_layer = self.output_layer = Layer(n_in=size,
n_out=1,
activation=sigmoid)
# len*batch*1
probs = output_layer.forward(h_final)
# len*batch
probs2 = probs.reshape(x.shape)
self.MRG_rng = MRG_RandomStreams()
z_pred = self.z_pred = T.cast(
self.MRG_rng.binomial(size=probs2.shape, p=probs2), "int8")
# we are computing approximated gradient by sampling z;
# so should mark sampled z not part of the gradient propagation path
#
self.z_pred = theano.gradient.disconnected_grad(z_pred)
z2 = z.dimshuffle((0, 1, "x"))
logpz = -T.nnet.binary_crossentropy(probs, z2) * masks
logpz = self.logpz = logpz.reshape(x.shape)
probs = self.probs = probs.reshape(x.shape)
# batch
zsum = T.sum(z, axis=0, dtype=theano.config.floatX)
zdiff = T.sum(T.abs_(z[1:] - z[:-1]),
axis=0,
dtype=theano.config.floatX)
loss_mat = encoder.loss_mat
if args.aspect < 0:
loss_vec = T.mean(loss_mat, axis=1)
else:
assert args.aspect < self.nclasses
loss_vec = loss_mat[:, args.aspect]
self.loss_vec = loss_vec
coherent_factor = args.sparsity * args.coherent
loss = self.loss = T.mean(loss_vec)
sparsity_cost = self.sparsity_cost = T.mean(zsum) * args.sparsity + \
T.mean(zdiff) * coherent_factor
cost_vec = loss_vec + zsum * args.sparsity + zdiff * coherent_factor
cost_logpz = T.mean(cost_vec * T.sum(logpz, axis=0))
self.obj = T.mean(cost_vec)
params = self.params = []
for l in layers + [output_layer]:
for p in l.params:
params.append(p)
nparams = sum(len(x.get_value(borrow=True).ravel()) \
for x in params)
say("total # parameters: {}\n".format(nparams))
l2_cost = None
for p in params:
if l2_cost is None:
l2_cost = T.sum(p**2)
else:
l2_cost = l2_cost + T.sum(p**2)
l2_cost = l2_cost * args.l2_reg
cost = self.cost = cost_logpz * 10 + l2_cost
print "cost.dtype", cost.dtype
self.cost_e = loss * 10 + encoder.l2_cost
def test_undefined_grad():
srng = MRG_RandomStreams(seed=1234)
# checking uniform distribution
low = tensor.scalar()
out = srng.uniform((), low=low)
assert_raises(theano.gradient.NullTypeGradError, theano.grad, out, low)
high = tensor.scalar()
out = srng.uniform((), low=0, high=high)
assert_raises(theano.gradient.NullTypeGradError, theano.grad, out, high)
out = srng.uniform((), low=low, high=high)
assert_raises(theano.gradient.NullTypeGradError, theano.grad, out,
(low, high))
# checking binomial distribution
prob = tensor.scalar()
out = srng.binomial((), p=prob)
assert_raises(theano.gradient.NullTypeGradError, theano.grad, out, prob)
# checking multinomial distribution
prob1 = tensor.scalar()
prob2 = tensor.scalar()
p = [theano.tensor.as_tensor_variable([prob1, 0.5, 0.25])]
out = srng.multinomial(size=None, pvals=p, n=4)[0]
assert_raises(theano.gradient.NullTypeGradError, theano.grad,
theano.tensor.sum(out), prob1)
p = [theano.tensor.as_tensor_variable([prob1, prob2])]
out = srng.multinomial(size=None, pvals=p, n=4)[0]
assert_raises(theano.gradient.NullTypeGradError, theano.grad,
theano.tensor.sum(out), (prob1, prob2))
# checking choice
p = [theano.tensor.as_tensor_variable([prob1, prob2, 0.1, 0.2])]
out = srng.choice(a=None, size=1, p=p, replace=False)[0]
assert_raises(theano.gradient.NullTypeGradError, theano.grad, out[0],
(prob1, prob2))
p = [theano.tensor.as_tensor_variable([prob1, prob2])]
out = srng.choice(a=None, size=1, p=p, replace=False)[0]
assert_raises(theano.gradient.NullTypeGradError, theano.grad, out[0],
(prob1, prob2))
p = [theano.tensor.as_tensor_variable([prob1, 0.2, 0.3])]
out = srng.choice(a=None, size=1, p=p, replace=False)[0]
assert_raises(theano.gradient.NullTypeGradError, theano.grad, out[0],
prob1)
# checking normal distribution
avg = tensor.scalar()
out = srng.normal((), avg=avg)
assert_raises(theano.gradient.NullTypeGradError, theano.grad, out, avg)
std = tensor.scalar()
out = srng.normal((), avg=0, std=std)
assert_raises(theano.gradient.NullTypeGradError, theano.grad, out, std)
out = srng.normal((), avg=avg, std=std)
assert_raises(theano.gradient.NullTypeGradError, theano.grad, out,
(avg, std))
def test_uniform():
#TODO: test param low, high
#TODO: test size=None
#TODO: test ndim!=size.ndim
#TODO: test bad seed
#TODO: test size=Var, with shape that change from call to call
if (mode in ['DEBUG_MODE', 'DebugMode', 'FAST_COMPILE']
or mode == 'Mode' and config.linker in ['py']):
sample_size = (10, 100)
steps = 50
else:
sample_size = (500, 50)
steps = int(1e3)
x = tensor.matrix()
for size, const_size, var_input, input in [
(sample_size, sample_size, [], []),
(x.shape, sample_size, [x],
[numpy.zeros(sample_size, dtype=config.floatX)]),
((x.shape[0], sample_size[1]), sample_size, [x],
[numpy.zeros(sample_size, dtype=config.floatX)]),
# test empty size (scalar)
((), (), [], []),
]:
#### TEST CPU IMPLEMENTATION ####
# The python and C implementation are tested with DebugMode
#print ''
#print 'ON CPU with size=(%s):' % str(size)
x = tensor.matrix()
R = MRG_RandomStreams(234, use_cuda=False)
# Note: we specify `nstreams` to avoid a warning.
# TODO Look for all occurrences of `guess_n_streams` and `30 * 256`
# for such situations: it would be better to instead filter the
# warning using the warning module.
u = R.uniform(size=size,
nstreams=rng_mrg.guess_n_streams(size, warn=False))
f = theano.function(var_input, u, mode=mode)
assert any([
isinstance(node.op, theano.sandbox.rng_mrg.mrg_uniform)
for node in f.maker.fgraph.toposort()
])
#theano.printing.debugprint(f)
cpu_out = f(*input)
#print 'CPU: random?[:10], random?[-10:]'
#print cpu_out[0, 0:10]
#print cpu_out[-1, -10:]
# Increase the number of steps if sizes implies only a few samples
if numpy.prod(const_size) < 10:
steps_ = steps * 100
else:
steps_ = steps
basictest(f, steps_, const_size, prefix='mrg cpu', inputs=input)
if mode != 'FAST_COMPILE' and cuda_available:
#print ''
#print 'ON GPU with size=(%s):' % str(size)
R = MRG_RandomStreams(234, use_cuda=True)
u = R.uniform(size=size,
dtype='float32',
nstreams=rng_mrg.guess_n_streams(size, warn=False))
# well, it's really that this test w GPU doesn't make sense otw
assert u.dtype == 'float32'
f = theano.function(
var_input,
theano.Out(theano.sandbox.cuda.basic_ops.gpu_from_host(u),
borrow=True),
mode=mode_with_gpu)
assert any([
isinstance(node.op, theano.sandbox.rng_mrg.GPU_mrg_uniform)
for node in f.maker.fgraph.toposort()
])
#theano.printing.debugprint(f)
gpu_out = numpy.asarray(f(*input))
#print 'GPU: random?[:10], random?[-10:]'
#print gpu_out[0, 0:10]
#print gpu_out[-1, -10:]
basictest(f, steps_, const_size, prefix='mrg gpu', inputs=input)
numpy.testing.assert_array_almost_equal(cpu_out,
gpu_out,
decimal=6)
#print ''
#print 'ON CPU w Numpy with size=(%s):' % str(size)
RR = theano.tensor.shared_randomstreams.RandomStreams(234)
uu = RR.uniform(size=size)
ff = theano.function(var_input, uu, mode=mode)
# It's not our problem if numpy generates 0 or 1
basictest(ff,
steps_,
const_size,
prefix='numpy',
allow_01=True,
inputs=input)
def _pokemon_wgan_gp():
import os
os.environ["FUEL_DATA_PATH"] = os.getcwd() + "/data/"
batch_size = 20
data_train = PokemonGenYellowNormal(which_sets=['train'],
sources=['features'])
train_stream = Flatten(DataStream.default_stream(
data_train, iteration_scheme=SequentialScheme(
data_train.num_examples, batch_size)))
features_size = 56 * 56 * 1
inits = {
'weights_init': IsotropicGaussian(0.01),
'biases_init': Constant(0.)
}
# print train_stream.get_epoch_iterator(as_dict=True).next()
# raise
inputs = T.matrix('features')
inputs = ((inputs / 255.) * 2. - 1.)
rng = MRG_RandomStreams(123)
prior = Z_prior(dim=512)
gen = Generator(input_dim=512, dims=[512, 512, 512, 512,
features_size],
alpha=0.1, **inits)
dis = Discriminator(dims=[features_size, 512, 512 , 512, 512],
alpha=0.1, **inits)
gan = GAN(dis=dis, gen=gen, prior=prior)
gan.initialize()
# gradient penalty
fake_samples, _ = gan.sampling(inputs.shape[0])
e = rng.uniform(size=(inputs.shape[0], 1))
mixed_input = (e * fake_samples) + (1 - e) * inputs
output_d_mixed = gan._dis.apply(mixed_input)
grad_mixed = T.grad(T.sum(output_d_mixed), mixed_input)
norm_grad_mixed = T.sqrt(T.sum(T.square(grad_mixed), axis=1))
grad_penalty = T.mean(T.square(norm_grad_mixed -1))
y_hat1, y_hat0, z = gan.apply(inputs)
d_loss_real = y_hat1.mean()
d_loss_fake = y_hat0.mean()
d_loss = - d_loss_real + d_loss_fake + 10 * grad_penalty
g_loss = - d_loss_fake
dis_obj = d_loss
gen_obj = g_loss
model = Model([y_hat0, y_hat1])
em_loss = -d_loss_real + d_loss_fake
em_loss.name = "Earth Move loss"
dis_obj.name = 'Discriminator loss'
gen_obj.name = 'Generator loss'
cg = ComputationGraph([gen_obj, dis_obj])
gen_filter = VariableFilter(roles=[PARAMETER],
bricks=gen.linear_transformations)
dis_filter = VariableFilter(roles=[PARAMETER],
bricks=dis.linear_transformations)
gen_params = gen_filter(cg.variables)
dis_params = dis_filter(cg.variables)
# Prepare the dropout
_inputs = []
for brick_ in [gen]:
_inputs.extend(VariableFilter(roles=[INPUT],
bricks=brick_.linear_transformations)(cg.variables))
cg_dropout = apply_dropout(cg, _inputs, 0.02)
gen_obj = cg_dropout.outputs[0]
dis_obj = cg_dropout.outputs[1]
gan.dis_params = dis_params
gan.gen_params = gen_params
# gradient penalty
algo = AdverserialTraning(gen_obj=gen_obj, dis_obj=dis_obj,
model=gan, dis_iter=5, gradient_clip=None,
step_rule=RMSProp(learning_rate=1e-4),
gen_consider_constant=z)
neg_sample = gan.sampling(size=25)
from blocks.monitoring.aggregation import mean
monitor = TrainingDataMonitoring(variables=[mean(gen_obj), mean(dis_obj),
mean(em_loss)],
prefix="train", after_batch=True)
subdir = './exp/' + 'pokemon-wgan-gp' + "-" + time.strftime("%Y%m%d-%H%M%S")
check_point = Checkpoint("{}/{}".format(subdir, 'CIFAR10'),
every_n_epochs=100,
save_separately=['log', 'model'])
neg_sampling = GenerateNegtiveSample(neg_sample,
img_size=(25, 56, 56),
every_n_epochs=10)
if not os.path.exists(subdir):
os.makedirs(subdir)
main_loop = MainLoop(algorithm=algo, model=model,
data_stream=train_stream,
extensions=[Printing(), ProgressBar(), monitor,
check_point, neg_sampling])
main_loop.run()
def test_normal0():
steps = 50
std = 2.
if (mode in ['DEBUG_MODE', 'DebugMode', 'FAST_COMPILE']
or mode == 'Mode' and config.linker in ['py']):
sample_size = (25, 30)
default_rtol = .02
else:
sample_size = (999, 50)
default_rtol = .01
sample_size_odd = (sample_size[0], sample_size[1] - 1)
x = tensor.matrix()
for size, const_size, var_input, input, avg, rtol, std_tol in [
(sample_size, sample_size, [], [], -5., default_rtol, default_rtol),
(x.shape, sample_size, [x],
[numpy.zeros(sample_size,
dtype=config.floatX)], -5., default_rtol, default_rtol),
((x.shape[0], sample_size[1]), sample_size, [x],
[numpy.zeros(sample_size,
dtype=config.floatX)], -5., default_rtol, default_rtol),
#test odd value
(sample_size_odd, sample_size_odd, [], [], -5., default_rtol,
default_rtol),
#test odd value
(x.shape, sample_size_odd, [x],
[numpy.zeros(sample_size_odd,
dtype=config.floatX)], -5., default_rtol, default_rtol),
(sample_size, sample_size, [], [],
numpy.arange(numpy.prod(sample_size),
dtype='float32').reshape(sample_size),
10. * std / numpy.sqrt(steps), default_rtol),
# test empty size (scalar)
((), (), [], [], -5., default_rtol, 0.02),
# test with few samples at the same time
((1, ), (1, ), [], [], -5., default_rtol, 0.02),
((2, ), (2, ), [], [], -5., default_rtol, 0.02),
((3, ), (3, ), [], [], -5., default_rtol, 0.02),
]:
#print ''
#print 'ON CPU:'
R = MRG_RandomStreams(234, use_cuda=False)
# Note: we specify `nstreams` to avoid a warning.
n = R.normal(size=size,
avg=avg,
std=std,
nstreams=rng_mrg.guess_n_streams(size, warn=False))
f = theano.function(var_input, n, mode=mode)
#theano.printing.debugprint(f)
out = f(*input)
#print 'random?[:10]\n', out[0, 0:10]
# Increase the number of steps if size implies only a few samples
if numpy.prod(const_size) < 10:
steps_ = steps * 50
else:
steps_ = steps
basictest(f,
steps_,
const_size,
target_avg=avg,
target_std=std,
prefix='mrg ',
allow_01=True,
inputs=input,
mean_rtol=rtol,
std_tol=std_tol)
sys.stdout.flush()
if mode != 'FAST_COMPILE' and cuda_available:
#print ''
#print 'ON GPU:'
R = MRG_RandomStreams(234, use_cuda=True)
n = R.normal(size=size,
avg=avg,
std=std,
dtype='float32',
nstreams=rng_mrg.guess_n_streams(size, warn=False))
#well, it's really that this test w GPU doesn't make sense otw
assert n.dtype == 'float32'
f = theano.function(
var_input,
theano.Out(theano.sandbox.cuda.basic_ops.gpu_from_host(n),
borrow=True),
mode=mode_with_gpu)
#theano.printing.debugprint(f)
sys.stdout.flush()
gpu_out = numpy.asarray(f(*input))
#print 'random?[:10]\n', gpu_out[0, 0:10]
#print '----'
sys.stdout.flush()
basictest(f,
steps_,
const_size,
target_avg=avg,
target_std=std,
prefix='gpu mrg ',
allow_01=True,
inputs=input,
mean_rtol=rtol,
std_tol=std_tol)
# Need to allow some rounding error as their is float
# computation that are done on the gpu vs cpu
assert numpy.allclose(out, gpu_out, rtol=5e-6, atol=5e-6)
#print ''
#print 'ON CPU w NUMPY:'
RR = theano.tensor.shared_randomstreams.RandomStreams(234)
nn = RR.normal(size=size, avg=avg, std=std)
ff = theano.function(var_input, nn)
basictest(ff,
steps_,
const_size,
target_avg=avg,
target_std=std,
prefix='numpy ',
allow_01=True,
inputs=input,
mean_rtol=rtol)
def test_gaussian_vis_layer_sample_conv():
"""
Verifies that GaussianVisLayer.sample returns an expression
whose value passes check_gaussian_samples.
In this case the layer lives in a Conv2DSpace
"""
assert hasattr(np, 'exp')
n = None
num_samples = 1000
tol = .042 # tolerated variance
beta = 1 / tol # precision parameter
rows = 3
cols = 3
channels = 3
# axes for batch, rows, cols, channels, can be given in any order
axes = ['b', 0, 1, 'c']
random.shuffle(axes)
axes = tuple(axes)
print('axes:', axes)
class DummyLayer(object):
"""
A layer that we build for the test that just uses a state
as its downward message.
"""
def downward_state(self, state):
return state
def downward_message(self, state):
return state
vis = GaussianVisLayer(nvis=None,
rows=rows,
cols=cols,
channels=channels,
init_beta=beta,
axes=axes)
hid = DummyLayer()
rng = np.random.RandomState([2012, 11, 1, 259])
mean = rng.uniform(1e-6, 1. - 1e-6, (rows, cols, channels))
ofs = rng.randn(rows, cols, channels)
vis.set_biases(ofs.astype(config.floatX))
#z = inverse_sigmoid_numpy(mean) - ofs
z = mean - ofs
z_var = sharedX(np.zeros((num_samples, rows, cols, channels)) + z)
theano_rng = MRG_RandomStreams(2012 + 11 + 1)
sample = vis.sample(state_above=z_var,
layer_above=hid,
theano_rng=theano_rng)
sample = sample.eval()
check_gaussian_samples(sample, num_samples, n, rows, cols, channels, mean,
tol)
import theano
import theano.tensor as T
from theano.sandbox.rng_mrg import MRG_RandomStreams
from mozi.layers.template import Template
from mozi.weight_init import GaussianWeight
from mozi.utils.theano_utils import shared_zeros
floatX = theano.config.floatX
theano_rand = MRG_RandomStreams()
class VariationalAutoencoder(Template):
def __init__(self,
input_dim,
bottlenet_dim,
z_dim,
weight_init=GaussianWeight(mean=0, std=0.01)):
self.input_dim = input_dim
self.bottlenet_dim = bottlenet_dim
# encoder
self.W_e = weight_init((input_dim, bottlenet_dim), name='W_e')
self.b_e = shared_zeros(shape=bottlenet_dim, name='b_e')
self.W_miu = weight_init((bottlenet_dim, z_dim), name='W_miu')
self.b_miu = shared_zeros(shape=z_dim, name='b_miu')
self.W_sig = weight_init((bottlenet_dim, z_dim), name='W_sig')
self.b_sig = shared_zeros(shape=z_dim, name='b_sig')
# decoder
self.W1_d = weight_init((z_dim, bottlenet_dim), name='W1_d')
def test_bvmp_mf_sample_consistent():
# A test of the BinaryVectorMaxPool class
# Verifies that the mean field update is consistent with
# the sampling function
# Specifically, in a DBM consisting of (v, h1, h2), the
# lack of intra-layer connections means that
# P(h1|v, h2) is factorial so mf_update tells us the true
# conditional.
# We can thus use mf_update to compute the expected value
# of a sample of h1 from v and h2, and check that samples
# drawn using the layer's sample method convert to that
# value.
rng = np.random.RandomState([2012, 11, 1, 1016])
theano_rng = MRG_RandomStreams(2012 + 11 + 1 + 1036)
num_samples = 1000
tol = .042
def do_test(pool_size_1):
# Make DBM and read out its pieces
dbm = make_random_basic_binary_dbm(
rng=rng,
pool_size_1=pool_size_1,
)
v = dbm.visible_layer
h1, h2 = dbm.hidden_layers
num_p = h1.get_output_space().dim
# Choose which unit we will test
p_idx = rng.randint(num_p)
# Randomly pick a v, h1[-p_idx], and h2 to condition on
# (Random numbers are generated via dbm.rng)
layer_to_state = dbm.make_layer_to_state(1)
v_state = layer_to_state[v]
h1_state = layer_to_state[h1]
h2_state = layer_to_state[h2]
# Debugging checks
num_h = h1.detector_layer_dim
assert num_p * pool_size_1 == num_h
pv, hv = h1_state
assert pv.get_value().shape == (1, num_p)
assert hv.get_value().shape == (1, num_h)
# Infer P(h1[i] | h2, v) using mean field
expected_p, expected_h = h1.mf_update(
state_below=v.upward_state(v_state),
state_above=h2.downward_state(h2_state),
layer_above=h2)
expected_p = expected_p[0, :]
expected_h = expected_h[0, :]
expected_p, expected_h = function([], [expected_p, expected_h])()
# copy all the states out into a batch size of num_samples
cause_copy = sharedX(np.zeros((num_samples, ))).dimshuffle(0, 'x')
v_state = v_state[0, :] + cause_copy
p, h = h1_state
h1_state = (p[0, :] + cause_copy, h[0, :] + cause_copy)
p, h = h2_state
h2_state = (p[0, :] + cause_copy, h[0, :] + cause_copy)
h1_samples = h1.sample(state_below=v.upward_state(v_state),
state_above=h2.downward_state(h2_state),
layer_above=h2,
theano_rng=theano_rng)
h1_samples = function([], h1_samples)()
check_bvmp_samples(h1_samples, num_samples, num_h, pool_size,
(expected_p, expected_h), tol)
# 1 is an important corner case
# We must also run with a larger number to test the general case
for pool_size in [1, 2, 5]:
do_test(pool_size)
"""High-level modular Theano-based network components."""
from collections import OrderedDict
from functools import partial
import numpy as np
import theano
from theano import tensor as T
from theano.sandbox.rng_mrg import MRG_RandomStreams
from spinn.util import NUM_TRANSITION_TYPES
numpy_random = np.random.RandomState(1234)
theano_random = MRG_RandomStreams(numpy_random.randint(999999))
def UniformInitializer(range):
return lambda shape, **kwargs: np.random.uniform(-range, range, shape)
def HeKaimingInitializer():
def HeKaimingInit(shape, real_shape=None):
# Calculate fan-in / fan-out using real shape if given as override
fan = real_shape or shape
return np.random.normal(scale=np.sqrt(4.0/(fan[0] + fan[1])),
size=shape)
return HeKaimingInit
def NormalInitializer(std):
def test_DBN(finetune_lr, pretraining_epochs, pretrain_lr, cdk, usepersistent,
training_epochs, L1_reg, L2_reg, hidden_layers_sizes, dataset,
batch_size, output_folder, shuffle, scaling, dropout, first_layer,
dumppath):
"""
Demonstrates how to train and test a Deep Belief Network.
:type finetune_lr: float
:param finetune_lr: learning rate used in the finetune stage
:type pretraining_epochs: int
:param pretraining_epochs: number of epoch to do pretraining
:type pretrain_lr: float
:param pretrain_lr: learning rate to be used during pre-training
:type cdk: int
:param cdk: number of Gibbs steps in CD/PCD
:type training_epochs: int
:param training_epochs: maximal number of iterations ot run the optimizer
:type dataset: string
:param dataset: path the the pickled dataset
:type batch_size: int
:param batch_size: the size of a minibatch
"""
print locals()
datasets = loadmat(dataset=dataset,
shuffle=shuffle,
datasel=datasel,
scaling=scaling,
robust=robust,
h5py=1)
train_set_x, train_set_y = datasets[0]
valid_set_x, valid_set_y = datasets[1]
test_set_x, test_set_y = datasets[2]
# compute number of minibatches for training, validation and testing
n_train_batches = train_set_x.get_value(borrow=True).shape[0] / batch_size
print "%d training examples" % train_set_x.get_value(borrow=True).shape[0]
print "%d feature dimensions" % train_set_x.get_value(borrow=True).shape[1]
# numpy random generator
numpy_rng = numpy.random.RandomState(123)
print '... building the model'
# construct the Deep Belief Network
nclass = max(train_set_y.eval()) + 1
dbn = DBN(numpy_rng=numpy_rng,
n_ins=train_set_x.get_value(borrow=True).shape[1],
hidden_layers_sizes=hidden_layers_sizes,
n_outs=nclass,
L1_reg=L1_reg,
L2_reg=L2_reg,
first_layer=first_layer)
print 'n_ins:%d' % train_set_x.get_value(borrow=True).shape[1]
print 'n_outs:%d' % nclass
# SP contains an ordered list of (pos), ordered by chord class number [0,ydim-1]
SP = balanced_seg.balanced(nclass, train_set_y)
# getting pre-training and fine-tuning functions
# save images of the weights(receptive fields) in this output folder
# if not os.path.isdir(output_folder):
# os.makedirs(output_folder)
# os.chdir(output_folder)
print '... getting the pretraining functions'
pretraining_fns = dbn.pretraining_functions(train_set_x=train_set_x,
batch_size=batch_size,
cdk=cdk,
usepersistent=usepersistent)
# get the training, validation and testing function for the model
print '... getting the finetuning functions'
train_fn, train_model, validate_model, test_model = dbn.build_finetune_functions(
datasets=datasets, batch_size=batch_size, learning_rate=finetune_lr)
trng = MRG_RandomStreams(1234)
use_noise = theano.shared(numpy.asarray(0., dtype=theano.config.floatX))
if dropout:
# dbn.x = dropout_layer(use_noise, dbn.x, trng, 0.8)
for i in range(dbn.n_layers):
dbn.sigmoid_layers[i].output = dropout_layer(
use_noise, dbn.sigmoid_layers[i].output, trng, 0.5)
# start-snippet-2
#########################
# PRETRAINING THE MODEL #
#########################
print '... pre-training the model'
plotting_time = 0.
start_time = timeit.default_timer()
## Pre-train layer-wise
for i in xrange(dbn.n_layers):
# go through pretraining epochs
for epoch in xrange(pretraining_epochs):
if pretrain_dropout:
use_noise.set_value(1.) # use dropout at pre-training
# go through the training set
c = []
for batch_index in xrange(n_train_batches):
c.append(pretraining_fns[i](index=batch_index, lr=pretrain_lr))
print 'Pre-training layer %i, epoch %d, cost ' % (i, epoch),
print numpy.mean(c)
'''
for j in range(dbn.n_layers):
if j == 0:
# Plot filters after each training epoch
plotting_start = timeit.default_timer()
# Construct image from the weight matrix
this_layer = dbn.rbm_layers[j]
this_field = this_layer.W.get_value(borrow=True).T
print "field shape (%d,%d)"%this_field.shape
image = Image.fromarray(
tile_raster_images(
X=this_field[0:100], # take only the first 100 fields (100 * n_visible)
#the img_shape and tile_shape depends on n_visible and n_hidden of this_layer
# if n_visible = 144 (12,12), if n_visible = 1512 (36,42)
img_shape=(12, 12),
tile_shape=(10, 10),
tile_spacing=(1, 1)
)
)
image.save('filters_at_epoch_%i.png' % epoch)
plotting_stop = timeit.default_timer()
plotting_time += (plotting_stop - plotting_start)
'''
end_time = timeit.default_timer()
# end-snippet-2
print >> sys.stderr, ('The pretraining code for file ' +
os.path.split(__file__)[1] + ' ran for %.2fm' %
((end_time - start_time) / 60.))
########################
# FINETUNING THE MODEL #
########################
print '... finetuning the model'
# early-stopping parameters
patience = 10 * n_train_batches # look as this many examples regardless
patience_increase = 2. # wait this much longer when a new best is
# found
improvement_threshold = 0.999 # a relative improvement of this much is
# considered significant
validation_frequency = min(n_train_batches, patience / 2)
# go through this many
# minibatches before checking the network
# on the validation set; in this case we
# check every epoch
best_validation_loss = numpy.inf
test_score = 0.
start_time = timeit.default_timer()
done_looping = False
epoch = 0
# while (epoch < training_epochs) and (not done_looping):
while (epoch < training_epochs):
if earlystop and done_looping:
print 'early-stopping'
break
epoch = epoch + 1
for minibatch_index in xrange(n_train_batches):
use_noise.set_value(1.) # use dropout at training time
# FIXME: n_train_batches is a fake item
bc_idx = balanced_seg.get_bc_idx(SP, nclass)
minibatch_avg_cost = train_fn(bc_idx)
iter = (epoch - 1) * n_train_batches + minibatch_index
if (iter + 1) % validation_frequency == 0:
use_noise.set_value(0.) # stop dropout at validation/test time
validation_losses = validate_model()
training_losses = train_model()
this_validation_loss = numpy.mean(validation_losses)
this_training_loss = numpy.mean(training_losses)
# also monitor the training losses
print('epoch %i, minibatch %i/%i, training error %f %%' %
(epoch, minibatch_index + 1, n_train_batches,
this_training_loss * 100.))
print('epoch %i, minibatch %i/%i, validation error %f %%' %
(epoch, minibatch_index + 1, n_train_batches,
this_validation_loss * 100.))
# if we got the best validation score until now
if this_validation_loss < best_validation_loss:
#improve patience if loss improvement is good enough
if (this_validation_loss <
best_validation_loss * improvement_threshold):
patience = max(patience, iter * patience_increase)
with open(dumppath, "wb") as f:
cPickle.dump(dbn.params, f)
# save best validation score and iteration number
best_validation_loss = this_validation_loss
best_iter = iter
'''
# test it on the test set
test_losses = test_model()
test_score = numpy.mean(test_losses)
print((' epoch %i, minibatch %i/%i, test error of '
'best model %f %%') %
(epoch, minibatch_index + 1, n_train_batches,
test_score * 100.))
'''
if patience <= iter:
done_looping = True
if earlystop:
break
end_time = timeit.default_timer()
print(('Optimization complete with best validation score of %f %%, '
'obtained at iteration %i, '
'with test performance %f %%') %
(best_validation_loss * 100., best_iter + 1, test_score * 100.))
print >> sys.stderr, ('The fine tuning code for file ' +
os.path.split(__file__)[1] + ' ran for %.2fm' %
((end_time - start_time) / 60.))
def apply_adaptive_noise(
computation_graph,
cost,
variables,
num_examples,
parameters=None,
init_sigma=1e-6,
model_cost_coefficient=1.0,
seed=None,
gradients=None,
):
"""Add adaptive noise to parameters of a model.
Each of the given variables will be replaced by a normal
distribution with learned mean and standard deviation.
A model cost is computed based on the precision of the the distributions
associated with each variable. It is added to the given cost used to
train the model.
See: A. Graves "Practical Variational Inference for Neural Networks",
NIPS 2011
Parameters
----------
computation_graph : instance of :class:`ComputationGraph`
The computation graph.
cost : :class:`~tensor.TensorVariable`
The cost without weight noise. It should be a member of the
computation_graph.
variables : :class:`~tensor.TensorVariable`
Variables to add noise to.
num_examples : int
Number of training examples. The cost of the model is divided by
the number of training examples, please see
A. Graves "Practical Variational Inference for Neural Networks"
for justification
parameters : list of :class:`~tensor.TensorVariable`
parameters of the model, if gradients are given the list will not
be used. Otherwise, it will be used to compute the gradients
init_sigma : float,
initial standard deviation of noise variables
model_cost_coefficient : float,
the weight of the model cost
seed : int, optional
The seed with which
:class:`~theano.sandbox.rng_mrg.MRG_RandomStreams` is initialized,
is set to 1 by default.
gradients : dict, optional
Adaptive weight noise introduces new parameters for which new cost
and gradients must be computed. Unless the gradients paramter is
given, it will use theano.grad to get the gradients
Returns
-------
cost : :class:`~tensor.TensorVariable`
The new cost
computation_graph : instance of :class:`ComputationGraph`
new graph with added noise.
gradients : dict
a dictionary of gradients for all parameters: the original ones
and the adaptive noise ones
noise_brick : :class:~lvsr.graph.NoiseBrick
the brick that holds all noise parameters and whose .apply method
can be used to find variables added by adaptive noise
"""
if not seed:
seed = config.default_seed
rng = MRG_RandomStreams(seed)
try:
cost_index = computation_graph.outputs.index(cost)
except ValueError:
raise ValueError("cost is not part of the computation_graph")
if gradients is None:
if parameters is None:
raise ValueError("Either gradients or parameters must be given")
logger.info("Taking the cost gradient")
gradients = dict(equizip(parameters, tensor.grad(cost, parameters)))
else:
if parameters is not None:
logger.warn("Both gradients and parameters given, will ignore"
"parameters")
parameters = gradients.keys()
gradients = OrderedDict(gradients)
log_sigma_scale = 2048.0
P_noisy = variables # We will add noise to these
Beta = [] # will hold means, log_stdev and stdevs
P_with_noise = [] # will hold parames with added noise
# These don't change
P_clean = list(set(parameters).difference(P_noisy))
noise_brick = NoiseBrick()
for p in P_noisy:
p_u = p
p_val = p.get_value(borrow=True)
p_ls2 = theano.shared(
(numpy.zeros_like(p_val) +
numpy.log(init_sigma) * 2. / log_sigma_scale).astype(
dtype=numpy.float32))
p_ls2.name = __get_name(p_u)
noise_brick.parameters.append(p_ls2)
p_s2 = tensor.exp(p_ls2 * log_sigma_scale)
Beta.append((p_u, p_ls2, p_s2))
p_noisy = p_u + rng.normal(size=p_val.shape) * tensor.sqrt(p_s2)
p_noisy = tensor.patternbroadcast(p_noisy, p.type.broadcastable)
P_with_noise.append(p_noisy)
# compute the prior mean and variation
temp_sum = 0.0
temp_param_count = 0.0
for p_u, unused_p_ls2, unused_p_s2 in Beta:
temp_sum = temp_sum + p_u.sum()
temp_param_count = temp_param_count + p_u.shape.prod()
prior_u = tensor.cast(temp_sum / temp_param_count, 'float32')
temp_sum = 0.0
for p_u, unused_ls2, p_s2 in Beta:
temp_sum = temp_sum + (p_s2).sum() + (((p_u - prior_u)**2).sum())
prior_s2 = tensor.cast(temp_sum / temp_param_count, 'float32')
# convert everything to use the noisy parameters
full_computation_graph = ComputationGraph(computation_graph.outputs +
gradients.values())
full_computation_graph = full_computation_graph.replace(
dict(zip(P_noisy, P_with_noise)))
LC = 0.0 # model cost
for p_u, p_ls2, p_s2 in Beta:
LC = (LC + 0.5 *
((tensor.log(prior_s2) - p_ls2 * log_sigma_scale).sum()) + 1.0 /
(2.0 * prior_s2) *
(((p_u - prior_u)**2) + p_s2 - prior_s2).sum())
LC = LC / num_examples * model_cost_coefficient
train_cost = noise_brick.apply(
full_computation_graph.outputs[cost_index].copy(), LC, prior_u,
prior_s2)
gradients = OrderedDict(
zip(gradients.keys(),
full_computation_graph.outputs[-len(gradients):]))
#
# Delete the gradients form the computational graph
#
del full_computation_graph.outputs[-len(gradients):]
new_grads = {p: gradients.pop(p) for p in P_clean}
#
# Warning!!!
# This only works for batch size 1 (we want that the sum of squares
# be the square of the sum!
#
diag_hessian_estimate = {p: g**2 for p, g in gradients.iteritems()}
for p_u, p_ls2, p_s2 in Beta:
p_grad = gradients[p_u]
p_u_grad = (model_cost_coefficient * (p_u - prior_u) /
(num_examples * prior_s2) + p_grad)
p_ls2_grad = (
numpy.float32(model_cost_coefficient * 0.5 / num_examples *
log_sigma_scale) * (p_s2 / prior_s2 - 1.0) +
(0.5 * log_sigma_scale) * p_s2 * diag_hessian_estimate[p_u])
new_grads[p_u] = p_u_grad
new_grads[p_ls2] = p_ls2_grad
return train_cost, full_computation_graph, new_grads, noise_brick
def __init__(self,
numpy_rng,
theano_rng=None,
n_ins=784,
hidden_layers_sizes=[500, 500],
n_outs=10,
L1_reg=0,
L2_reg=0,
first_layer='grbm',
model=None):
"""This class is made to support a variable number of layers.
:type numpy_rng: numpy.random.RandomState
:param numpy_rng: numpy random number generator used to draw initial
weights
:type theano_rng: theano.tensor.shared_randomstreams.RandomStreams
:param theano_rng: Theano random generator; if None is given one is
generated based on a seed drawn from `rng`
:type n_ins: int
:param n_ins: dimension of the input to the DBN
:type hidden_layers_sizes: list of ints
:param hidden_layers_sizes: intermediate layers size, must contain
at least one value
:type n_outs: int
:param n_outs: dimension of the output of the network
"""
self.sigmoid_layers = []
self.rbm_layers = []
self.params = []
self.n_layers = len(hidden_layers_sizes)
self.L1 = 0
self.L2_sqr = 0
assert self.n_layers > 0
if not theano_rng:
theano_rng = MRG_RandomStreams(numpy_rng.randint(2**30))
# allocate symbolic variables for the data
self.x = T.matrix('x') # the data is presented as rasterized images
self.y = T.ivector('y') # the labels are presented as 1D vector
# of [int] labels
# end-snippet-1
# The DBN is an MLP, for which all weights of intermediate
# layers are shared with a different RBM. We will first
# construct the DBN as a deep multilayer perceptron, and when
# constructing each sigmoidal layer we also construct an RBM
# that shares weights with that layer. During pretraining we
# will train these RBMs (which will lead to chainging the
# weights of the MLP as well) During finetuning we will finish
# training the DBN by doing stochastic gradient descent on the
# MLP.
for i in xrange(self.n_layers):
# construct the sigmoidal layer
# the size of the input is either the number of hidden
# units of the layer below or the input size if we are on
# the first layer
if i == 0:
input_size = n_ins
else:
input_size = hidden_layers_sizes[i - 1]
# the input to this layer is either the activation of the
# hidden layer below or the input of the DBN if you are on
# the first layer
if i == 0:
layer_input = self.x
else:
layer_input = self.sigmoid_layers[i - 1].output
if model is None:
W = None
b = None
else:
W = model[i * 2]
b = model[i * 2 + 1]
sigmoid_layer = HiddenLayer(rng=numpy_rng,
input=layer_input,
n_in=input_size,
n_out=hidden_layers_sizes[i],
W=W,
b=b,
activation=T.nnet.sigmoid)
# add the layer to our list of layers
self.sigmoid_layers.append(sigmoid_layer)
self.L1 += (abs(sigmoid_layer.W).sum())
self.L2_sqr += ((sigmoid_layer.W**2).sum())
# its arguably a philosophical question... but we are
# going to only declare that the parameters of the
# sigmoid_layers are parameters of the DBN. The visible
# biases in the RBM are parameters of those RBMs, but not
# of the DBN.
self.params.extend(sigmoid_layer.params)
# Construct an RBM that shared weights with this layer
if i == 0: # first layer GBRBM - dealing with continous value
if first_layer == 'grbm':
rbm_layer = GRBM(numpy_rng=numpy_rng,
theano_rng=theano_rng,
input=layer_input,
n_visible=input_size,
n_hidden=hidden_layers_sizes[i],
W=sigmoid_layer.W,
hbias=sigmoid_layer.b)
if first_layer == 'rbm':
rbm_layer = RBM(numpy_rng=numpy_rng,
theano_rng=theano_rng,
input=layer_input,
n_visible=input_size,
n_hidden=hidden_layers_sizes[i],
W=sigmoid_layer.W,
hbias=sigmoid_layer.b)
# elif i == self.n_layers-1: # last layer GGRBM
# rbm_layer = GRBM(numpy_rng=numpy_rng,
# theano_rng=theano_rng,
# input=layer_input,
# n_visible=input_size,
# n_hidden=hidden_layers_sizes[i],
# W=sigmoid_layer.W,
# hbias=sigmoid_layer.b)
else: # subsequence layers BBRBM - binary RBM to cope with regularization
rbm_layer = RBM(numpy_rng=numpy_rng,
theano_rng=theano_rng,
input=layer_input,
n_visible=input_size,
n_hidden=hidden_layers_sizes[i],
W=sigmoid_layer.W,
hbias=sigmoid_layer.b)
self.rbm_layers.append(rbm_layer)
# We now need to add a logistic layer on top of the MLP
if model is None:
W = None
b = None
else:
W = model[-2]
b = model[-1]
self.logLayer = LogisticRegression(
input=self.sigmoid_layers[-1].output,
n_in=hidden_layers_sizes[-1],
W=W,
b=b,
n_out=n_outs)
self.params.extend(self.logLayer.params)
self.L1 += (abs(self.logLayer.W).sum())
self.L2_sqr += ((self.logLayer.W**2).sum())
# compute the cost for second phase of training, defined as the
# negative log likelihood of the logistic regression (output) layer
self.finetune_cost = (self.logLayer.negative_log_likelihood(self.y) +
+L1_reg * self.L1 + L2_reg * self.L2_sqr)
# compute the gradients with respect to the model parameters
# symbolic variable that points to the number of errors made on the
# minibatch given by self.x and self.y
self.errors = self.logLayer.errors(self.y)
self.predprobs = self.logLayer.p_y_given_x
self.preds = self.logLayer.y_pred
def apply_dropout(computation_graph,
variables,
drop_prob,
rng=None,
seed=None):
"""Returns a graph to variables in a computational graph.
Parameters
----------
computation_graph : instance of :class:`ComputationGraph`
The computation graph.
variables : list of :class:`~tensor.TensorVariable`
Variables to be dropped out.
drop_prob : float
Probability of dropping out. If you want to apply the dropout
with different probabilities for different layers, call it
several times.
rng : :class:`~theano.sandbox.rng_mrg.MRG_RandomStreams`
Random number generator.
seed : int
Random seed to be used if `rng` was not specified.
Notes
-----
For more information, see [DROPOUT]_.
.. [DROPOUT] Hinton et al. *Improving neural networks by preventing
co-adaptation of feature detectors*, arXiv:1207.0580.
Examples
--------
>>> import numpy
>>> from theano import tensor, function
>>> from blocks.bricks import MLP, Identity
>>> from blocks.filter import VariableFilter
>>> from blocks.initialization import Constant
>>> from blocks.roles import INPUT
>>> linear = MLP([Identity(), Identity()], [2, 10, 2],
... weights_init=Constant(1), biases_init=Constant(2))
>>> x = tensor.matrix('x')
>>> y = linear.apply(x)
>>> cg = ComputationGraph(y)
We are going to drop out all the input variables
>>> inputs = VariableFilter(roles=[INPUT])(cg.variables)
Here we apply dropout with default setting to our computation graph
>>> cg_dropout = apply_dropout(cg, inputs, 0.5)
Dropped out variables have role `DROPOUT` and are tagged with
`replacement_of` tag. Let's filter these variables and check if they
have the links to original ones.
>>> dropped_out = VariableFilter(roles=[DROPOUT])(cg_dropout.variables)
>>> inputs_referenced = [var.tag.replacement_of for var in dropped_out]
>>> set(inputs) == set(inputs_referenced)
True
Compiling theano functions to forward propagate in original and dropped
out graphs
>>> fprop = function(cg.inputs, cg.outputs[0])
>>> fprop_dropout = function(cg_dropout.inputs, cg_dropout.outputs[0])
Initialize an MLP and apply these functions
>>> linear.initialize()
>>> fprop(numpy.ones((3, 2),
... dtype=theano.config.floatX)) # doctest:+ELLIPSIS
array([[ 42., 42.],
[ 42., 42.],
[ 42., 42.]]...
>>> fprop_dropout(numpy.ones((3, 2),
... dtype=theano.config.floatX)) # doctest:+ELLIPSIS
array([[ 0., 0.],
[ 0., 0.],
[ 0., 0.]]...
And after the second run answer is different
>>> fprop_dropout(numpy.ones((3, 2),
... dtype=theano.config.floatX)) # doctest:+ELLIPSIS
array([[ 0., 52.],
[ 100., 0.],
[ 0., 0.]]...
"""
if not rng and not seed:
seed = config.default_seed
if not rng:
rng = MRG_RandomStreams(seed)
replacements = [
(var, var * rng.binomial(var.shape, p=1 - drop_prob, dtype=floatX) /
(1 - drop_prob)) for var in variables
]
for variable, replacement in replacements:
add_role(replacement, DROPOUT)
replacement.tag.replacement_of = variable
return computation_graph.replace(replacements)
def ready(self):
embedding_layer = self.embedding_layer
args = self.args
padding_id = embedding_layer.vocab_map["<padding>"]
dropout = self.dropout = theano.shared(
np.float64(args.dropout).astype(theano.config.floatX))
# len*batch
x = self.x = T.imatrix()
n_d = args.hidden_dimension
n_e = embedding_layer.n_d
activation = get_activation_by_name(args.activation)
layers = self.layers = []
layer_type = args.layer.lower()
for i in xrange(1):
l = CNN(n_in=n_e,
n_out=n_d,
activation=activation,
order=args.order)
layers.append(l)
# len * batch
masks = T.cast(T.neq(x, padding_id), "int8").dimshuffle((0, 1, 'x'))
# (len*batch)*n_e
embs = embedding_layer.forward(x.ravel())
# len*batch*n_e
embs = embs.reshape((x.shape[0], x.shape[1], n_e))
embs = apply_dropout(embs, dropout)
self.word_embs = embs
# len*bacth*n_d
h1 = layers[0].forward_all(embs)
h_final = h1
size = n_d
h_final = apply_dropout(h_final, dropout)
output_layer = self.output_layer = Layer(n_in=size,
n_out=1,
activation=sigmoid)
# len*batch*1
probs = output_layer.forward(h_final)
# len*batch
self.MRG_rng = MRG_RandomStreams()
z_pred_dim3 = self.MRG_rng.binomial(size=probs.shape,
p=probs,
dtype="int8")
z_pred = z_pred_dim3.reshape(x.shape)
# we are computing approximated gradient by sampling z;
# so should mark sampled z not part of the gradient propagation path
#
z_pred = self.z_pred = theano.gradient.disconnected_grad(z_pred)
print "z_pred", z_pred.ndim
#logpz = - T.nnet.binary_crossentropy(probs, z_pred_dim3) * masks
logpz = -T.nnet.binary_crossentropy(probs, z_pred_dim3)
logpz = self.logpz = logpz.reshape(x.shape)
probs = self.probs = probs.reshape(x.shape)
# batch
z = z_pred
self.zsum = T.sum(z, axis=0, dtype=theano.config.floatX)
self.zdiff = T.sum(T.abs_(z[1:] - z[:-1]),
axis=0,
dtype=theano.config.floatX)
params = self.params = []
for l in layers + [output_layer]:
for p in l.params:
params.append(p)
nparams = sum(len(x.get_value(borrow=True).ravel()) \
for x in params)
say("total # parameters: {}\n".format(nparams))
l2_cost = None
for p in params:
if l2_cost is None:
l2_cost = T.sum(p**2)
else:
l2_cost = l2_cost + T.sum(p**2)
l2_cost = l2_cost * args.l2_reg
self.l2_cost = l2_cost
