def __init__(self, name = 'unnamed', filename = '%T-%N', print_to_console = False, save_result = None, show_figs = None):
"""
:param name: Base-name of the experiment
:param filename: Format of the filename (placeholders: %T is replaced by time, %N by name)
:param experiment_dir: Relative directory (relative to data dir) to save this experiment when it closes
:param print_to_console: If True, print statements still go to console - if False, they're just rerouted to file.
:param show_figs: Show figures when the experiment produces them. Can be:
'hang': Show and hang
'draw': Show but keep on going
False: Don't show figures
None: 'draw' if in test mode, else 'hang'
"""
now = datetime.now()
if save_result is None:
save_result = not is_test_mode()
if show_figs is None:
show_figs = 'draw' if is_test_mode() else 'hang'
assert show_figs in ('hang', 'draw', False)
self._experiment_identifier = format_filename(file_string = filename, base_name=name, current_time = now)
self._log_file_name = format_filename('%T-%N', base_name = name, current_time = now)
self._has_run = False
self._print_to_console = print_to_console
self._save_result = save_result
self._show_figs = show_figs
def demo_perceptron_dtp(
hidden_sizes = [240],
n_epochs = 20,
n_tests = 20,
minibatch_size=100,
lin_dtp = True,
):
dataset = get_mnist_dataset(flat = True).to_onehot()
if is_test_mode():
dataset = dataset.shorten(200)
n_epochs = 1
n_tests = 2
predictor = DifferenceTargetMLP(
layers=[PerceptronLayer.from_initializer(n_in, n_out, initial_mag=2, lin_dtp = lin_dtp)
for n_in, n_out in zip([dataset.input_size]+hidden_sizes, hidden_sizes+[dataset.target_size])],
output_cost_function = None
).compile()
result = assess_online_predictor(
predictor = predictor,
dataset = dataset,
minibatch_size=minibatch_size,
evaluation_function='percent_argmax_correct',
test_epochs = sqrtspace(0, n_epochs, n_tests),
)
plot_learning_curves(result)
def mnist_adamax_showdown(hidden_size = 300, n_epochs = 10, n_tests = 20):
dataset = get_mnist_dataset()
if is_test_mode():
dataset.shorten(200)
n_epochs = 0.1
n_tests = 3
make_mlp = lambda optimizer: GradientBasedPredictor(
function = MultiLayerPerceptron(
layer_sizes=[hidden_size, dataset.n_categories],
input_size = dataset.input_size,
hidden_activation='sig',
output_activation='lin',
w_init = normal_w_init(mag = 0.01, seed = 5)
),
cost_function = softmax_negative_log_likelihood,
optimizer = optimizer,
).compile()
return compare_predictors(
dataset=dataset,
online_predictors = {
'sgd': make_mlp(SimpleGradientDescent(eta = 0.1)),
'adamax': make_mlp(AdaMax(alpha = 1e-3)),
},
minibatch_size = 20,
test_epochs = sqrtspace(0, n_epochs, n_tests),
evaluation_function = percent_argmax_correct
)
def mnist_adamax_showdown(hidden_size = 300, n_epochs = 10, n_tests = 20):
dataset = get_mnist_dataset()
if is_test_mode():
dataset = dataset.shorten(200)
n_epochs = 0.1
n_tests = 3
make_mlp = lambda optimizer: GradientBasedPredictor(
function = MultiLayerPerceptron.from_init(
layer_sizes=[dataset.input_size, hidden_size, dataset.n_categories],
hidden_activation='sig',
output_activation='lin',
w_init = 0.01,
rng = 5
),
cost_function = softmax_negative_log_likelihood,
optimizer = optimizer,
).compile()
return compare_predictors(
dataset=dataset,
online_predictors = {
'sgd': make_mlp(SimpleGradientDescent(eta = 0.1)),
'adamax': make_mlp(AdaMax(alpha = 1e-3)),
},
minibatch_size = 20,
test_epochs = sqrtspace(0, n_epochs, n_tests),
evaluation_function = percent_argmax_correct
)
def demo_compare_dtp_methods(
predictor_constructors,
n_epochs = 10,
minibatch_size = 20,
n_tests = 20,
onehot = True,
accumulator = None
):
dataset = get_mnist_dataset(flat = True, binarize = False)
n_categories = dataset.n_categories
if onehot:
dataset = dataset.to_onehot()
if is_test_mode():
dataset = dataset.shorten(200)
n_epochs = 1
n_tests = 2
learning_curves = compare_predictors(
dataset=dataset,
online_predictors = {name: p(dataset.input_size, n_categories) for name, p in predictor_constructors.iteritems() if name in predictor_constructors},
minibatch_size = minibatch_size,
test_epochs = sqrtspace(0, n_epochs, n_tests),
evaluation_function = percent_argmax_correct,
# online_test_callbacks={'perceptron': lambda p: dbplot(p.symbolic_predictor.layers[0].w.get_value().T.reshape(-1, 28, 28))},
accumulators=accumulator
)
plot_learning_curves(learning_curves)
def demo_rbm_mnist(
vis_activation = 'bernoulli',
hid_activation = 'bernoulli',
n_hidden = 500,
plot = True,
eta = 0.01,
optimizer = 'sgd',
w_init_mag = 0.001,
minibatch_size = 9,
persistent = False,
n_epochs = 100,
plot_interval = 100,
):
"""
In this demo we train an RBM on the MNIST input data (labels are ignored). We plot the state of a markov chanin
that is being simulaniously sampled from the RBM, and the parameters of the RBM.
What you see:
A plot will appear with 6 subplots. The subplots are as follows:
hidden-neg-chain: The activity of the hidden layer for each of the persistent CD chains for draewing negative samples.
visible-neg-chain: The probabilities of the visible activations corresponding to the state of hidden-neg-chain.
w: A subset of the weight vectors, reshaped to the shape of the input.
b: The bias of the hidden units.
b_rev: The bias of the visible units.
visible-sample: The probabilities of the visible samples drawin from an independent free-sampling chain (outside the
training function).
As learning progresses, visible-neg-chain and visible-sample should increasingly resemble the data.
"""
with EnableOmniscence():
if is_test_mode():
n_epochs = 0.01
data = get_mnist_dataset(flat = True).training_set.input
rbm = simple_rbm(
visible_layer = StochasticNonlinearity(vis_activation),
bridge=FullyConnectedBridge(w = w_init_mag*np.random.randn(28*28, n_hidden).astype(theano.config.floatX), b=0, b_rev = 0),
hidden_layer = StochasticNonlinearity(hid_activation)
)
optimizer = \
SimpleGradientDescent(eta = eta) if optimizer == 'sgd' else \
AdaMax(alpha=eta) if optimizer == 'adamax' else \
bad_value(optimizer)
train_function = rbm.get_training_fcn(n_gibbs = 1, persistent = persistent, optimizer = optimizer).compile()
def plot_fcn():
lv = train_function.locals()
dbplot({
'visible-pos-chain': lv['wake_visible'].reshape((-1, 28, 28)),
'visible-neg-chain': lv['sleep_visible'].reshape((-1, 28, 28)),
})
for i, visible_data in enumerate(minibatch_iterate(data, minibatch_size=minibatch_size, n_epochs=n_epochs)):
train_function(visible_data)
if plot and i % plot_interval == 0:
plot_fcn()
def demo_lstm_novelist(
book = 'bible',
n_hidden = 400,
verse_duration = 20,
generation_duration = 200,
generate_every = 200,
max_len = None,
hidden_layer_type = 'tanh',
n_epochs = 1,
seed = None,
):
"""
An LSTM-Autoencoder learns the Bible, and can spontaniously produce biblical-ish verses.
:param n_hidden: Number of hidden/memory units in LSTM
:param verse_duration: Number of Backprop-Through-Time steps to do.
:param generation_duration: Number of characters to generate with each sample.
:param generate_every: Generate every N training iterations
:param max_len: Truncate the text to this length.
:param n_epochs: Number of passes through the bible to make.
:param seed: Random Seed
:return:
"""
if is_test_mode():
n_hidden=10
verse_duration=7
generation_duration=5
max_len = 40
rng = np.random.RandomState(seed)
text = read_book(book, max_characters=max_len)
onehot_text, decode_key = text_to_onehot(text)
n_char = onehot_text.shape[1]
the_prophet = AutoencodingLSTM(n_input=n_char, n_hidden=n_hidden,
initializer_fcn=lambda shape: 0.01*rng.randn(*shape), hidden_layer_type = hidden_layer_type)
training_fcn = the_prophet.get_training_function(optimizer=AdaMax(alpha = 0.01), update_states=True).compile()
generating_fcn = the_prophet.get_generation_function(stochastic=True).compile()
printer = TextWrappingPrinter(newline_every=100)
def prime_and_generate(n_steps, primer = ''):
onehot_primer, _ = text_to_onehot(primer, decode_key)
onehot_gen, = generating_fcn(onehot_primer, n_steps)
gen = onehot_to_text(onehot_gen, decode_key)
return '%s%s' % (primer, gen)
prime_and_generate(generation_duration, 'In the beginning, ')
for i, verse in enumerate(minibatch_iterate(onehot_text, minibatch_size=verse_duration, n_epochs=n_epochs)):
if i % generate_every == 0:
printer.write('[iter %s]%s' % (i, prime_and_generate(n_steps = generation_duration), ))
training_fcn(verse)
printer.write('[iter %s]%s' % (i, prime_and_generate(n_steps = generation_duration), ))
def demo_rbm_tutorial(
eta = 0.01,
n_hidden = 500,
n_samples = None,
minibatch_size = 10,
plot_interval = 10,
w_init_mag = 0.01,
n_epochs = 1,
persistent = False,
seed = None
):
"""
This tutorial trains a standard binary-binary RBM on MNIST, and allows you to view the weights and negative sampling
chain.
Note:
For simplicity, it uses hidden/visible samples to compute the gradient. It's actually better to use the hidden
probabilities.
"""
if is_test_mode():
n_samples=50
n_epochs=1
plot_interval=50
n_hidden = 10
data = get_mnist_dataset(flat = True).training_set.input[:n_samples]
n_visible = data.shape[1]
rng = np.random.RandomState(seed)
activation = lambda x: (1./(1+np.exp(-x)) > rng.rand(*x.shape)).astype(float)
w = w_init_mag*np.random.randn(n_visible, n_hidden)
b_hid = np.zeros(n_hidden)
b_vis = np.zeros(n_visible)
if persistent:
hid_sleep_state = np.random.rand(minibatch_size, n_hidden)
for i, vis_wake_state in enumerate(minibatch_iterate(data, n_epochs = n_epochs, minibatch_size=minibatch_size)):
hid_wake_state = activation(vis_wake_state.dot(w)+b_hid)
if not persistent:
hid_sleep_state = hid_wake_state
vis_sleep_state = activation(hid_sleep_state.dot(w.T)+b_vis)
hid_sleep_state = activation(vis_sleep_state.dot(w)+b_hid)
# Update Parameters
w_grad = (vis_wake_state.T.dot(hid_wake_state) - vis_sleep_state.T.dot(hid_sleep_state))/float(minibatch_size)
w += w_grad * eta
b_vis_grad = np.mean(vis_wake_state, axis = 0) - np.mean(vis_sleep_state, axis = 0)
b_vis += b_vis_grad * eta
b_hid_grad = np.mean(hid_wake_state, axis = 0) - np.mean(hid_sleep_state, axis = 0)
b_hid += b_hid_grad * eta
if i % plot_interval == 0:
dbplot(w.T[:100].reshape(-1, 28, 28), 'weights')
dbplot(vis_sleep_state.reshape(-1, 28, 28), 'dreams')
print 'Sample %s' % i
def plot_learning_curves(learning_curves,
xscale='sqrt',
yscale='linear',
hang=None,
title=None,
figure_name=None):
"""
Plot a set of PredictionResults. These can be obtained by running compare_predictors.
See module test_compare_predictors for an example.
:param learning_curves: An OrderedDict<str: LearningCurveData>
:param xscale: {'linear', 'log', 'symlog', 'sqrt'}
:param yscale: {'linear', 'log', 'symlog', 'sqrt'}
:param hang: True for blocking plot. False to keep executing.
:param title: Title of the plot
:return:
"""
colours = ['b', 'r', 'g', 'm', 'c', 'k']
plt.figure(figure_name)
legend = []
for (record_name, record), colour in zip(learning_curves.iteritems(),
cycle(colours)):
times, scores = record.get_results()
if len(times) == 1 and times[0] is None:
assert all(len(s) == 1 for s in scores.values())
if 'Training' in scores:
plt.axhline(scores['Training'], color=colour, linestyle='--')
if 'Test' in scores:
plt.axhline(scores['Test'], color=colour, linestyle='-')
else:
if 'Training' in scores:
plt.plot(times + (1 if xscale == 'log' else 0),
scores['Training'], '--' + colour)
if 'Test' in scores:
plt.plot(times + (1 if xscale == 'log' else 0), scores['Test'],
'-' + colour)
plt.gca().set_xscale(xscale)
plt.gca().set_yscale(yscale)
legend += ['%s-training' % record_name, '%s-test' % record_name]
plt.xlabel('Epoch')
plt.ylabel('Score')
plt.legend(legend, loc='best')
if title is not None:
plt.title(title)
if hang is True:
plt.ioff()
elif hang is False or (hang is None and is_test_mode()):
plt.ion()
plt.show()
def compare_example_predictors(
n_epochs = 5,
n_tests = 20,
minibatch_size = 10,
):
"""
This demo shows how we can compare different online predictors. The demo trains both predictors on the dataset,
returning an object that contains the results.
:param test_mode: Set this to True to just run the demo quicky (but not to completion) to see that it doesn't break.
"""
dataset = get_mnist_dataset(flat = True)
# "Flatten" the 28x28 inputs to a 784-d vector
if is_test_mode():
# Shorten the dataset so we run through it quickly in test mode.
dataset = dataset.shorten(200)
n_epochs = 1
n_tests = 3
# Here we compare three predictors on MNIST - an MLP, a Perceptron, and a Random Forest.
# - The MLP is defined using Plato's interfaces - we create a Symbolic Predictor (GradientBasedPredictor) and
# then compile it into an IPredictor object
# - The Perceptron directly implements the IPredictor interface.
# - The Random Forest implements SciKit learn's predictor interface - that is, it has a fit(x, y) and a predict(x) method.
learning_curve_data = compare_predictors(
dataset = dataset,
online_predictors = {
'Perceptron': Perceptron(
w = np.zeros((dataset.input_size, dataset.n_categories)),
alpha = 0.001
).to_categorical(n_categories = dataset.n_categories), # .to_categorical allows the perceptron to be trained on integer labels.
'MLP': GradientBasedPredictor(
function = MultiLayerPerceptron.from_init(
layer_sizes=[dataset.input_size, 500, dataset.n_categories],
hidden_activation='sig', # Sigmoidal hidden units
output_activation='softmax', # Softmax output unit, since we're doing multinomial classification
w_init = 0.01,
rng = 5
),
cost_function = negative_log_likelihood_dangerous, # "Dangerous" because it doesn't check to see that output is normalized, but we know it is because it comes from softmax.
optimizer = SimpleGradientDescent(eta = 0.1),
).compile(), # .compile() returns an IPredictor
},
offline_predictors={
'RF': RandomForestClassifier(n_estimators = 40)
},
minibatch_size = minibatch_size,
test_epochs = sqrtspace(0, n_epochs, n_tests),
evaluation_function = percent_argmax_correct # Compares one-hot
)
# Results is a LearningCurveData object
return learning_curve_data
def plot_learning_curves(learning_curves, xscale = 'sqrt', yscale = 'linear', hang = None, title = None, figure_name = None, y_title = 'Score'):
"""
Plot a set of PredictionResults. These can be obtained by running compare_predictors.
See module test_compare_predictors for an example.
:param learning_curves: An OrderedDict<str: LearningCurveData>
:param xscale: {'linear', 'log', 'symlog', 'sqrt'}
:param yscale: {'linear', 'log', 'symlog', 'sqrt'}
:param hang: True for blocking plot. False to keep executing.
:param title: Title of the plot
:return:
"""
if isinstance(learning_curves, LearningCurveData):
learning_curves = {'': learning_curves}
colours = ['b', 'r', 'g', 'm', 'c', 'k']
plt.figure(figure_name)
legend = []
for (record_name, record), colour in zip(learning_curves.iteritems(), cycle(colours)):
times, scores = record.get_results()
if np.array_equal(times.values()[0], [None]): # Offline result... make a horizontal line
assert all(len(s)==1 for s in scores.values())
if 'Training' in scores:
plt.axhline(scores['Training'], color=colour, linestyle = '--')
if 'Test' in scores:
plt.axhline(scores['Test'], color=colour, linestyle = '-')
else:
if 'Training' in scores: # Online result... make a learning curve
plt.plot(times['Training']+(1 if xscale == 'log' else 0), scores['Training'], '--'+colour)
if 'Test' in scores:
plt.plot(times['Test']+(1 if xscale == 'log' else 0), scores['Test'], '-'+colour)
plt.gca().set_xscale(xscale)
plt.gca().set_yscale(yscale)
if 'Training' in scores:
legend.append('%s-training' % record_name)
if 'Test' in scores:
legend.append('%s-test' % record_name)
plt.xlabel('Epoch')
plt.ylabel(y_title)
plt.legend(legend, loc = 'best')
if title is not None:
plt.title(title)
if hang is True:
plt.ioff()
elif hang is False or (hang is None and is_test_mode()):
plt.ion()
plt.show()
def demo_variational_autoencoder(
minibatch_size = 100,
n_epochs = 2000,
plot_interval = 100,
seed = None
):
"""
Train a Variational Autoencoder on MNIST and look at the samples it generates.
:param minibatch_size: Number of elements in the minibatch
:param n_epochs: Number of passes through dataset
:param plot_interval: Plot every x iterations
"""
data = get_mnist_dataset(flat = True).training_set.input
if is_test_mode():
n_epochs=1
minibatch_size = 10
data = data[:100]
rng = get_rng(seed)
model = VariationalAutoencoder(
pq_pair = EncoderDecoderNetworks(
x_dim=data.shape[1],
z_dim = 20,
encoder_hidden_sizes = [200],
decoder_hidden_sizes = [200],
w_init = lambda n_in, n_out: 0.01*np.random.randn(n_in, n_out),
x_distribution='bernoulli',
z_distribution='gaussian',
hidden_activation = 'softplus'
),
optimizer=AdaMax(alpha = 0.003),
rng = rng
)
training_fcn = model.train.compile()
sampling_fcn = model.sample.compile()
for i, minibatch in enumerate(minibatch_iterate(data, minibatch_size=minibatch_size, n_epochs=n_epochs)):
training_fcn(minibatch)
if i % plot_interval == 0:
print 'Epoch %s' % (i*minibatch_size/float(len(data)), )
samples = sampling_fcn(25).reshape(5, 5, 28, 28)
dbplot(samples, 'Samples from Model')
dbplot(model.pq_pair.p_net.parameters[-2].get_value()[:25].reshape(-1, 28, 28), 'dec')
dbplot(model.pq_pair.q_net.parameters[0].get_value().T[:25].reshape(-1, 28, 28), 'enc')
def demo_run_dtp_on_mnist(
hidden_sizes = [240],
n_epochs = 20,
n_tests = 20,
minibatch_size=100,
input_activation = 'sigm',
hidden_activation = 'tanh',
output_activation = 'softmax',
optimizer_constructor = lambda: RMSProp(0.001),
normalize_inputs = False,
local_cost_function = mean_squared_error,
output_cost_function = None,
noise = 1,
lin_dtp = False,
seed = 1234
):
dataset = get_mnist_dataset(flat = True).to_onehot()
if normalize_inputs:
dataset = dataset.process_with(targets_processor=multichannel(lambda x: x/np.sum(x, axis = 1, keepdims=True)))
if is_test_mode():
dataset = dataset.shorten(200)
n_epochs = 1
n_tests = 2
predictor = DifferenceTargetMLP.from_initializer(
input_size = dataset.input_size,
output_size = dataset.target_size,
hidden_sizes = hidden_sizes,
optimizer_constructor = optimizer_constructor, # Note that RMSProp/AdaMax way outperform SGD here.
# input_activation=input_activation,
hidden_activation=hidden_activation,
output_activation=output_activation,
w_init_mag=0.01,
output_cost_function=output_cost_function,
noise = noise,
cost_function = local_cost_function,
layer_constructor=DifferenceTargetLayer.from_initializer if not lin_dtp else PreActivationDifferenceTargetLayer.from_initializer,
rng = seed
).compile()
result = assess_online_predictor(
predictor = predictor,
dataset = dataset,
minibatch_size=minibatch_size,
evaluation_function='percent_argmax_correct',
test_epochs = sqrtspace(0, n_epochs, n_tests),
test_callback=lambda p: dbplot(p.symbolic_predictor.layers[0].w.get_value().T.reshape(-1, 28, 28))
)
plot_learning_curves(result)
def demo_dtp_varieties(
hidden_sizes = [240],
n_epochs = 10,
minibatch_size = 20,
n_tests = 20,
hidden_activation = 'tanh',
output_activation = 'sigm',
optimizer = 'adamax',
learning_rate = 0.01,
noise = 1,
predictors = ['MLP', 'DTP', 'PreAct-DTP', 'Linear-DTP'],
rng = 1234,
live_plot = False,
plot = False
):
"""
;
:param hidden_sizes:
:param n_epochs:
:param minibatch_size:
:param n_tests:
:return:
"""
if isinstance(predictors, str):
predictors = [predictors]
dataset = get_mnist_dataset(flat = True)
dataset = dataset.process_with(targets_processor=lambda (x, ): (OneHotEncoding(10)(x).astype(int), ))
if is_test_mode():
dataset = dataset.shorten(200)
n_epochs = 0.1
n_tests = 3
set_default_figure_size(12, 9)
predictors = OrderedDict((name, get_predictor(name, input_size = dataset.input_size, target_size=dataset.target_size,
hidden_sizes=hidden_sizes, hidden_activation=hidden_activation, output_activation = output_activation,
optimizer=optimizer, learning_rate=learning_rate, noise = noise, rng = rng)) for name in predictors)
learning_curves = compare_predictors(
dataset=dataset,
online_predictors = predictors,
minibatch_size = minibatch_size,
test_epochs = sqrtspace(0, n_epochs, n_tests),
evaluation_function = percent_argmax_correct,
)
if plot:
plot_learning_curves(learning_curves)
def __init__(self,
name='unnamed',
filename='%T-%N',
print_to_console=False,
save_result=None,
show_figs=None):
"""
:param name: Base-name of the experiment
:param filename: Format of the filename (placeholders: %T is replaced by time, %N by name)
:param experiment_dir: Relative directory (relative to data dir) to save this experiment when it closes
:param print_to_console: If True, print statements still go to console - if False, they're just rerouted to file.
:param show_figs: Show figures when the experiment produces them. Can be:
'hang': Show and hang
'draw': Show but keep on going
False: Don't show figures
None: 'draw' if in test mode, else 'hang'
"""
now = datetime.now()
if save_result is None:
save_result = not is_test_mode()
if show_figs is None:
show_figs = 'draw' if is_test_mode() else 'hang'
assert show_figs in ('hang', 'draw', False)
self._experiment_identifier = format_filename(file_string=filename,
base_name=name,
current_time=now)
self._log_file_name = format_filename('%T-%N',
base_name=name,
current_time=now)
self._has_run = False
self._print_to_console = print_to_console
self._save_result = save_result
self._show_figs = show_figs
def mlp_normalization(hidden_size = 300, n_epochs = 30, n_tests = 50, minibatch_size=20):
"""
Compare mlps with different schemes for normalizing input.
regular: Regular vanilla MLP
normalize: Mean-subtract/normalize over minibatch
normalize and scale: Mean-subtract/normalize over minibatch AND multiply by a trainable
(per-unit) scale parameter.
Conclusions: No significant benefit to scale parameter. Normalizing gives
a head start but incurs a small cost later on. But really all classifiers are quite similar.
:param hidden_size: Size of hidden layer
"""
dataset = get_mnist_dataset()
if is_test_mode():
dataset.shorten(200)
n_epochs = 0.1
n_tests = 3
make_mlp = lambda normalize, scale: GradientBasedPredictor(
function = MultiLayerPerceptron(
layer_sizes=[hidden_size, dataset.n_categories],
input_size = dataset.input_size,
hidden_activation='sig',
output_activation='lin',
normalize_minibatch=normalize,
scale_param=scale,
w_init = normal_w_init(mag = 0.01, seed = 5)
),
cost_function = softmax_negative_log_likelihood,
optimizer = SimpleGradientDescent(eta = 0.1),
).compile()
return compare_predictors(
dataset=dataset,
online_predictors = {
'regular': make_mlp(normalize = False, scale = False),
'normalize': make_mlp(normalize=True, scale = False),
'normalize and scale': make_mlp(normalize=True, scale = True),
},
minibatch_size = minibatch_size,
test_epochs = sqrtspace(0, n_epochs, n_tests),
evaluation_function = percent_argmax_correct
)
def demo_mnist_online_regression(
minibatch_size = 10,
learning_rate = 0.1,
optimizer = 'sgd',
regressor_type = 'multinomial',
n_epochs = 20,
n_test_points = 30,
max_training_samples = None,
include_biases = True,
):
"""
Train an MLP on MNIST and print the test scores as training progresses.
"""
if is_test_mode():
n_test_points = 3
minibatch_size = 5
n_epochs = 0.01
dataset = get_mnist_dataset(n_training_samples=30, n_test_samples=30, flat = True)
else:
dataset = get_mnist_dataset(n_training_samples=max_training_samples, flat = True)
assert regressor_type in ('multinomial', 'logistic', 'linear')
n_outputs = dataset.n_categories
if regressor_type in ('logistic', 'linear'):
dataset = dataset.to_onehot()
predictor = OnlineRegressor(
input_size = dataset.input_size,
output_size = n_outputs,
regressor_type = regressor_type,
optimizer=get_named_optimizer(name = optimizer, learning_rate=learning_rate),
include_biases = include_biases
).compile()
# Train and periodically report the test score.
results = assess_online_predictor(
dataset=dataset,
predictor=predictor,
evaluation_function='percent_argmax_correct',
test_epochs=sqrtspace(0, n_epochs, n_test_points),
minibatch_size=minibatch_size
)
plot_learning_curves(results)
def mlp_normalization(hidden_size = 300, n_epochs = 30, n_tests = 50, minibatch_size=20):
"""
Compare mlp with different schemes for normalizing input.
regular: Regular vanilla MLP
normalize: Mean-subtract/normalize over minibatch
normalize and scale: Mean-subtract/normalize over minibatch AND multiply by a trainable
(per-unit) scale parameter.
Conclusions: No significant benefit to scale parameter. Normalizing gives
a head start but incurs a small cost later on. But really all classifiers are quite similar.
:param hidden_size: Size of hidden layer
"""
dataset = get_mnist_dataset()
if is_test_mode():
dataset = dataset.shorten(200)
n_epochs = 0.1
n_tests = 3
make_mlp = lambda normalize, scale: GradientBasedPredictor(
function = MultiLayerPerceptron.from_init(
layer_sizes=[dataset.input_size, hidden_size, dataset.n_categories],
hidden_activation='sig',
output_activation='lin',
normalize_minibatch=normalize,
scale_param=scale,
w_init = 0.01,
rng = 5
),
cost_function = softmax_negative_log_likelihood,
optimizer = SimpleGradientDescent(eta = 0.1),
).compile()
return compare_predictors(
dataset=dataset,
online_predictors = {
'regular': make_mlp(normalize = False, scale = False),
'normalize': make_mlp(normalize=True, scale = False),
'normalize and scale': make_mlp(normalize=True, scale = True),
},
minibatch_size = minibatch_size,
test_epochs = sqrtspace(0, n_epochs, n_tests),
evaluation_function = percent_argmax_correct
)
def backprop_vs_difference_target_prop(
hidden_sizes = [240],
n_epochs = 10,
minibatch_size = 20,
n_tests = 20
):
dataset = get_mnist_dataset(flat = True)
dataset = dataset.process_with(targets_processor=lambda (x, ): (OneHotEncoding(10)(x).astype(int), ))
if is_test_mode():
dataset = dataset.shorten(200)
n_epochs = 0.1
n_tests = 3
set_default_figure_size(12, 9)
return compare_predictors(
dataset=dataset,
online_predictors = {
'backprop-mlp': GradientBasedPredictor(
function = MultiLayerPerceptron.from_init(
layer_sizes=[dataset.input_size]+hidden_sizes+[dataset.n_categories],
hidden_activation='tanh',
output_activation='sig',
w_init = 0.01,
rng = 5
),
cost_function = mean_squared_error,
optimizer = AdaMax(0.01),
).compile(),
'difference-target-prop-mlp': DifferenceTargetMLP.from_initializer(
input_size = dataset.input_size,
output_size = dataset.target_size,
hidden_sizes = hidden_sizes,
optimizer_constructor = lambda: AdaMax(0.01),
w_init=0.01,
noise = 1,
).compile()
},
minibatch_size = minibatch_size,
test_epochs = sqrtspace(0, n_epochs, n_tests),
evaluation_function = percent_argmax_correct,
)
def demo_compare_dtp_optimizers(
hidden_sizes = [240],
n_epochs = 10,
minibatch_size = 20,
n_tests = 20,
hidden_activation = 'tanh',
):
dataset = get_mnist_dataset(flat = True).to_onehot()
if is_test_mode():
dataset = dataset.shorten(200)
n_epochs = 1
n_tests = 2
def make_dtp_net(optimizer_constructor, output_fcn):
return DifferenceTargetMLP.from_initializer(
input_size = dataset.input_size,
output_size = dataset.target_size,
hidden_sizes = hidden_sizes,
optimizer_constructor = optimizer_constructor,
input_activation='sigm',
hidden_activation=hidden_activation,
output_activation=output_fcn,
w_init_mag=0.01,
noise = 1,
).compile()
learning_curves = compare_predictors(
dataset=dataset,
online_predictors = {
'SGD-0.001-softmax': make_dtp_net(lambda: SimpleGradientDescent(0.001), output_fcn = 'softmax'),
'AdaMax-0.001-softmax': make_dtp_net(lambda: AdaMax(0.001), output_fcn = 'softmax'),
'RMSProp-0.001-softmax': make_dtp_net(lambda: RMSProp(0.001), output_fcn = 'softmax'),
'SGD-0.001-sigm': make_dtp_net(lambda: SimpleGradientDescent(0.001), output_fcn = 'sigm'),
'AdaMax-0.001-sigm': make_dtp_net(lambda: AdaMax(0.001), output_fcn = 'sigm'),
'RMSProp-0.001-sigm': make_dtp_net(lambda: RMSProp(0.001), output_fcn = 'sigm'),
},
minibatch_size = minibatch_size,
test_epochs = sqrtspace(0, n_epochs, n_tests),
evaluation_function = percent_argmax_correct,
)
plot_learning_curves(learning_curves)
def demo_mnist_mlp(
minibatch_size = 10,
learning_rate = 0.1,
optimizer = 'sgd',
hidden_sizes = [300],
w_init = 0.01,
hidden_activation = 'tanh',
output_activation = 'softmax',
cost = 'nll-d',
visualize_params = False,
n_test_points = 30,
n_epochs = 10,
max_training_samples = None,
use_bias = True,
onehot = False,
rng = 1234,
plot = False,
):
"""
Train an MLP on MNIST and print the test scores as training progresses.
"""
if is_test_mode():
n_test_points = 3
minibatch_size = 5
n_epochs = 0.01
dataset = get_mnist_dataset(n_training_samples=30, n_test_samples=30)
else:
dataset = get_mnist_dataset(n_training_samples=max_training_samples)
if onehot:
dataset = dataset.to_onehot()
if minibatch_size == 'full':
minibatch_size = dataset.training_set.n_samples
optimizer = get_named_optimizer(name = optimizer, learning_rate=learning_rate)
# Setup the training and test functions
predictor = GradientBasedPredictor(
function = MultiLayerPerceptron.from_init(
layer_sizes=[dataset.input_size]+hidden_sizes+[10],
hidden_activation=hidden_activation,
output_activation=output_activation,
w_init = w_init,
use_bias=use_bias,
rng = rng,
),
cost_function=cost,
optimizer=optimizer
).compile() # .compile() turns the GradientBasedPredictor, which works with symbolic variables, into a real one that takes and returns arrays.
def vis_callback(xx):
p = predictor.symbolic_predictor._function
in_layer = {
'Layer[0].w': p.layers[0].linear_transform._w.get_value().T.reshape(-1, 28, 28),
'Layer[0].b': p.layers[0].linear_transform._b.get_value(),
}
other_layers = [{'Layer[%s].w' % (i+1): l.linear_transform._w.get_value(), 'Layer[%s].b' % (i+1): l.linear_transform._b.get_value()} for i, l in enumerate(p.layers[1:])]
dbplot(dict(in_layer.items() + sum([o.items() for o in other_layers], [])))
# Train and periodically report the test score.
results = assess_online_predictor(
dataset=dataset,
predictor=predictor,
evaluation_function='percent_argmax_correct',
test_epochs=sqrtspace(0, n_epochs, n_test_points),
minibatch_size=minibatch_size,
test_callback=vis_callback if visualize_params else None
)
if plot:
plot_learning_curves(results)
def demo_dbn_mnist(plot = True):
"""
In this demo we train an RBM on the MNIST input data (labels are ignored). We plot the state of a markov chanin
that is being simulaniously sampled from the RBM, and the parameters of the RBM.
"""
minibatch_size = 20
dataset = get_mnist_dataset().process_with(inputs_processor=lambda (x, ): (x.reshape(x.shape[0], -1), ))
w_init = lambda n_in, n_out: 0.01 * np.random.randn(n_in, n_out)
n_training_epochs_1 = 20
n_training_epochs_2 = 20
check_period = 300
with EnableOmniscence():
if is_test_mode():
n_training_epochs_1 = 0.01
n_training_epochs_2 = 0.01
check_period=100
dbn = DeepBeliefNet(
layers = {
'vis': StochasticNonlinearity('bernoulli'),
'hid': StochasticNonlinearity('bernoulli'),
'ass': StochasticNonlinearity('bernoulli'),
'lab': StochasticNonlinearity('bernoulli'),
},
bridges = {
('vis', 'hid'): FullyConnectedBridge(w = w_init(784, 500), b_rev = 0),
('hid', 'ass'): FullyConnectedBridge(w = w_init(500, 500), b_rev = 0),
('lab', 'ass'): FullyConnectedBridge(w = w_init(10, 500), b_rev = 0)
}
)
# Compile the functions you're gonna use.
train_first_layer = dbn.get_constrastive_divergence_function(visible_layers = 'vis', hidden_layers='hid', optimizer=SimpleGradientDescent(eta = 0.01), n_gibbs = 1, persistent=True).compile()
free_energy_of_first_layer = dbn.get_free_energy_function(visible_layers='vis', hidden_layers='hid').compile()
train_second_layer = dbn.get_constrastive_divergence_function(visible_layers=('hid', 'lab'), hidden_layers='ass', input_layers=('vis', 'lab'), n_gibbs=1, persistent=True).compile()
predict_label = dbn.get_inference_function(input_layers = 'vis', output_layers='lab', path = [('vis', 'hid'), ('hid', 'ass'), ('ass', 'lab')], smooth = True).compile()
encode_label = OneHotEncoding(n_classes=10)
# Step 1: Train the first layer, plotting the weights and persistent chain state.
for i, (n_samples, visible_data, label_data) in enumerate(dataset.training_set.minibatch_iterator(minibatch_size = minibatch_size, epochs = n_training_epochs_1, single_channel = True)):
train_first_layer(visible_data)
if i % check_period == 0:
print 'Free Energy of Test Data: %s' % (free_energy_of_first_layer(dataset.test_set.input).mean())
if plot:
dbplot({
'weights': dbn._bridges['vis', 'hid'].w.get_value().T.reshape((-1, 28, 28)),
'vis_sleep_state': train_first_layer.locals()['sleep_visible'][0].reshape((-1, 28, 28))
})
# Step 2: Train the second layer and simultanously compute the classification error from forward passes.
for i, (n_samples, visible_data, label_data) in enumerate(dataset.training_set.minibatch_iterator(minibatch_size = minibatch_size, epochs = n_training_epochs_2, single_channel = True)):
train_second_layer(visible_data, encode_label(label_data))
if i % check_period == 0:
out, = predict_label(dataset.test_set.input)
score = percent_argmax_correct(actual = out, target = dataset.test_set.target)
print 'Classification Score: %s' % score
if plot:
dbplot({
'w_vis_hid': dbn._bridges['vis', 'hid'].w.T.reshape((-1, 28, 28)),
'w_hid_ass': dbn._bridges['hid', 'ass'].w,
'w_lab_ass': dbn._bridges['hid', 'ass'].w,
'hidden_state': train_second_layer.locals()['sleep_visible'][0].reshape((-1, 20, 25)),
})
def demo_simple_dbn(
minibatch_size = 10,
n_training_epochs_1 = 5,
n_training_epochs_2 = 50,
n_hidden_1 = 500,
n_hidden_2 = 10,
plot_period = 100,
eta1 = 0.01,
eta2 = 0.0001,
w_init_mag_1 = 0.01,
w_init_mag_2 = 0.5,
seed = None
):
"""
Train a DBN, and create a function to project the test data into a latent space
:param minibatch_size:
:param n_training_epochs_1: Number of training epochs for the first-level RBM
:param n_training_epochs_2: Number of training epochs for the second-level RBM
:param n_hidden_1: Number of hidden units for first RBM
:param n_hidden_2:nNumber of hidden units for second RBM
:param plot_period: How often to plot
:param seed:
:return:
"""
dataset = get_mnist_dataset(flat = True)
rng = np.random.RandomState(seed)
w_init_1 = lambda shape: w_init_mag_1 * rng.randn(*shape)
w_init_2 = lambda shape: w_init_mag_2 * rng.randn(*shape)
if is_test_mode():
n_training_epochs_1 = 0.01
n_training_epochs_2 = 0.01
# Train the first RBM
dbn1 = StackedDeepBeliefNet(rbms = [BernoulliBernoulliRBM.from_initializer(n_visible = 784, n_hidden=n_hidden_1, w_init_fcn = w_init_1)])
train_first_layer = dbn1.get_training_fcn(optimizer=SimpleGradientDescent(eta = eta1), n_gibbs = 1, persistent=True).compile()
sample_first_layer = dbn1.get_sampling_fcn(initial_vis=dataset.training_set.input[:minibatch_size], n_steps = 10).compile()
for i, vis_data in enumerate(minibatch_iterate(dataset.training_set.input, minibatch_size=minibatch_size, n_epochs=n_training_epochs_1)):
if i % plot_period == plot_period-1:
dbplot(dbn1.rbms[0].w.get_value().T[:100].reshape([-1, 28, 28]), 'weights1')
dbplot(sample_first_layer()[0].reshape(-1, 28, 28), 'samples1')
train_first_layer(vis_data)
# Train the second RBM
dbn2 = dbn1.stack_another(rbm = BernoulliGaussianRBM.from_initializer(n_visible=n_hidden_1, n_hidden=n_hidden_2, w_init_fcn=w_init_2))
train_second_layer = dbn2.get_training_fcn(optimizer=SimpleGradientDescent(eta = eta2), n_gibbs = 1, persistent=True).compile()
sample_second_layer = dbn2.get_sampling_fcn(initial_vis=dataset.training_set.input[:minibatch_size], n_steps = 10).compile()
for i, vis_data in enumerate(minibatch_iterate(dataset.training_set.input, minibatch_size=minibatch_size, n_epochs=n_training_epochs_2)):
if i % plot_period == 0:
dbplot(dbn2.rbms[1].w.get_value(), 'weights2')
dbplot(sample_second_layer()[0].reshape(-1, 28, 28), 'samples2')
train_second_layer(vis_data)
# Project data to latent space.
project_to_latent = dbn2.propup.compile(fixed_args = dict(stochastic = False))
latent_test_data = project_to_latent(dataset.test_set.input)
print 'Projected the test data to a latent space. Shape: %s' % (latent_test_data.shape, )
decode = dbn2.propdown.compile(fixed_args = dict(stochastic = False))
recon_test_data = decode(latent_test_data)
print 'Reconstructed the test data. Shape: %s' % (recon_test_data.shape, )
def demo_simple_vae_on_mnist(
minibatch_size = 100,
n_epochs = 2000,
plot_interval = 100,
calculation_interval = 500,
z_dim = 2,
hidden_sizes = [400, 200],
learning_rate = 0.003,
hidden_activation = 'softplus',
binary_x = True,
w_init_mag = 0.01,
gaussian_min_var = None,
manifold_grid_size = 11,
manifold_grid_span = 2,
seed = None
):
"""
Train a Variational Autoencoder on MNIST and look at the samples it generates.
"""
dataset = get_mnist_dataset(flat = True)
training_data = dataset.training_set.input
test_data = dataset.test_set.input
if is_test_mode():
n_epochs=1
minibatch_size = 10
training_data = training_data[:100]
test_data = test_data[:100]
model = GaussianVariationalAutoencoder(
x_dim=training_data.shape[1],
z_dim = z_dim,
encoder_hidden_sizes = hidden_sizes,
decoder_hidden_sizes = hidden_sizes[::-1],
w_init_mag = w_init_mag,
binary_data=binary_x,
hidden_activation = hidden_activation,
optimizer=AdaMax(alpha = learning_rate),
gaussian_min_var = gaussian_min_var,
rng = seed
)
training_fcn = model.train.compile()
# For display, make functions to sample and represent the manifold.
sampling_fcn = model.sample.compile()
z_manifold_grid = np.array([x.flatten() for x in np.meshgrid(np.linspace(-manifold_grid_span, manifold_grid_span, manifold_grid_size),
np.linspace(-manifold_grid_span, manifold_grid_span, manifold_grid_size))]+[np.zeros(manifold_grid_size**2)]*(z_dim-2)).T
decoder_mean_fcn = model.decode.compile(fixed_args = dict(z = z_manifold_grid))
lower_bound_fcn = model.compute_lower_bound.compile()
for i, minibatch in enumerate(minibatch_iterate(training_data, minibatch_size=minibatch_size, n_epochs=n_epochs)):
training_fcn(minibatch)
if i % plot_interval == 0:
samples = sampling_fcn(25).reshape(5, 5, 28, 28)
dbplot(samples, 'Samples from Model')
if binary_x:
manifold_means = decoder_mean_fcn()
else:
manifold_means, _ = decoder_mean_fcn()
dbplot(manifold_means.reshape(manifold_grid_size, manifold_grid_size, 28, 28), 'First 2-dimensions of manifold.')
if i % calculation_interval == 0:
training_lower_bound = lower_bound_fcn(training_data)
test_lower_bound = lower_bound_fcn(test_data)
print 'Epoch: %s, Training Lower Bound: %s, Test Lower bound: %s' % \
(i*minibatch_size/float(len(training_data)), training_lower_bound, test_lower_bound)
def compare_spiking_to_nonspiking(hidden_sizes = [300, 300], eta=0.01, w_init=0.01, fractional = False, n_epochs = 20,
forward_discretize = 'rect-herding', back_discretize = 'noreset-herding', test_discretize='rect-herding', save_results = False):
mnist = get_mnist_dataset(flat=True).to_onehot()
test_epochs=[0.0, 0.05, 0.1, 0.2, 0.5]+range(1, n_epochs+1)
if is_test_mode():
mnist = mnist.shorten(500)
eta = 0.01
w_init=0.01
test_epochs = [0.0, 0.05, 0.1]
spiking_net = JavaSpikingNetWrapper.from_init(
fractional = fractional,
depth_first=False,
smooth_grads = False,
forward_discretize = forward_discretize,
back_discretize = back_discretize,
test_discretize = test_discretize,
w_init=w_init,
hold_error=True,
rng = 1234,
n_steps = 10,
eta=eta,
layer_sizes=[784]+hidden_sizes+[10],
)
relu_net = GradientBasedPredictor(
MultiLayerPerceptron.from_init(
hidden_activation = 'relu',
output_activation = 'relu',
layer_sizes=[784]+hidden_sizes+[10],
use_bias=False,
w_init=w_init,
rng=1234,
),
cost_function = 'mse',
optimizer=GradientDescent(eta)
).compile()
# Listen for spikes
forward_eavesdropper = jp.JClass('nl.uva.deepspike.eavesdroppers.SpikeCountingEavesdropper')()
backward_eavesdropper = jp.JClass('nl.uva.deepspike.eavesdroppers.SpikeCountingEavesdropper')()
for lay in spiking_net.jnet.layers:
lay.forward_herder.add_eavesdropper(forward_eavesdropper)
for lay in spiking_net.jnet.layers[1:]:
lay.backward_herder.add_eavesdropper(backward_eavesdropper)
spiking_net.jnet.error_counter.add_eavesdropper(backward_eavesdropper)
forward_counts = []
backward_counts = []
def register_counts():
forward_counts.append(forward_eavesdropper.get_count())
backward_counts.append(backward_eavesdropper.get_count())
results = compare_predictors(
dataset=mnist,
online_predictors={
'Spiking-MLP': spiking_net,
'ReLU-MLP': relu_net,
},
test_epochs=test_epochs,
online_test_callbacks=lambda p: register_counts() if p is spiking_net else None,
minibatch_size = 1,
test_on = 'training+test',
evaluation_function=percent_argmax_incorrect,
)
spiking_params = [np.array(lay.forward_weights.w.asFloat()).copy() for lay in spiking_net.jnet.layers]
relu_params = [param.get_value().astype(np.float64) for param in relu_net.parameters]
# See what the score is when we apply the final spiking weights to the
offline_trained_spiking_net = JavaSpikingNetWrapper(
ws=relu_params,
fractional = fractional,
depth_first=False,
smooth_grads = False,
forward_discretize = forward_discretize,
back_discretize = back_discretize,
test_discretize = test_discretize,
hold_error=True,
n_steps = 10,
eta=eta,
)
# for spiking_layer, p in zip(spiking_net.jnet.layers, relu_params):
# spiking_layer.w = p.astype(np.float64)
error = [
('Test', percent_argmax_incorrect(offline_trained_spiking_net.predict(mnist.test_set.input), mnist.test_set.target)),
('Training', percent_argmax_incorrect(offline_trained_spiking_net.predict(mnist.training_set.input), mnist.training_set.target))
]
results['Spiking-MLP with ReLU weights'] = LearningCurveData()
results['Spiking-MLP with ReLU weights'].add(None, error)
print 'Spiking-MLP with ReLU weights: %s' % error
# --------------------------------------------------------------------------
# See what the score is when we plug the spiking weights into the ReLU net.
for param, sval in zip(relu_net.parameters, spiking_params):
param.set_value(sval)
error = [
('Test', percent_argmax_incorrect(relu_net.predict(mnist.test_set.input), mnist.test_set.target)),
('Training', percent_argmax_incorrect(relu_net.predict(mnist.training_set.input), mnist.training_set.target))
]
results['ReLU-MLP with Spiking weights'] = LearningCurveData()
results['ReLU-MLP with Spiking weights'].add(None, error)
print 'ReLU-MLP with Spiking weights: %s' % error
# --------------------------------------------------------------------------
if save_results:
with open("mnist_relu_vs_spiking_results-%s.pkl" % datetime.now(), 'w') as f:
pickle.dump(results, f)
# Problem: this currently includes test
forward_rates = np.diff(forward_counts) / (np.diff(test_epochs)*60000)
backward_rates = np.diff(backward_counts) / (np.diff(test_epochs)*60000)
plt.figure('ReLU vs Spikes')
plt.subplot(211)
plot_learning_curves(results, title = "MNIST Learning Curves", hang=False, figure_name='ReLU vs Spikes', xscale='linear', yscale='log', y_title='Percent Error')
plt.subplot(212)
plt.plot(test_epochs[1:], forward_rates)
plt.plot(test_epochs[1:], backward_rates)
plt.xlabel('Epoch')
plt.ylabel('n_spikes')
plt.legend(['Mean Forward Spikes', 'Mean Backward Spikes'], loc='best')
plt.interactive(is_test_mode())
plt.show()
)
ExperimentLibrary.try_hyperparams = Experiment(
description="Compare the various hyperparameters to the baseline.",
function=with_jpype(lambda
fractional = False,
depth_first = False,
smooth_grads = False,
back_discretize = 'noreset-herding',
n_steps = 10,
hidden_sizes = [200, 200],
hold_error = True,
:
compare_predictors(
dataset=(get_mnist_dataset(flat=True).shorten(100) if is_test_mode() else get_mnist_dataset(flat=True)).to_onehot(),
online_predictors={'Spiking MLP': JavaSpikingNetWrapper.from_init(
fractional = fractional,
depth_first = depth_first,
smooth_grads = smooth_grads,
back_discretize = back_discretize,
w_init=0.01,
rng = 1234,
eta=0.01,
n_steps = n_steps,
hold_error=hold_error,
layer_sizes=[784]+hidden_sizes+[10],
)},
test_epochs=[0.0, 0.05] if is_test_mode() else [0.0, 0.05, 0.1, 0.2, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4],
minibatch_size = 1,
report_test_scores=True,
