A simple, clean, fast Python implementation of Deep Belief Networks based on binary Restricted Boltzmann Machines (RBM), built upon NumPy and TensorFlow libraries in order to take advantage of GPU computation:
Hinton, Geoffrey E., Simon Osindero, and Yee-Whye Teh. "A fast learning algorithm for deep belief nets." Neural computation 18.7 (2006): 1527-1554.
Fischer, Asja, and Christian Igel. "Training restricted Boltzmann machines: an introduction." Pattern Recognition 47.1 (2014): 25-39.
This implementation follows scikit-learn guidelines and in turn, can be used alongside it. Next you have a demo code for solving digits classification problem which can be found in classification_demo.py (check regression_demo.py for a regression problem and unsupervised_demo.py for an unsupervised feature learning problem).
Code can run either in GPU or CPU. To decide where the computations have to be performed is as easy as importing the classes from the correct module: if they are imported from dbn.tensorflow computations will be carried out on GPU (or CPU depending on your hardware) using TensorFlow, if imported from dbn computations will be done on CPU using NumPy. Note only pre-training step is GPU accelerated so far Both pre-training and fine-tuning steps are GPU accelarated. Look the following snippet:
import numpy as np
np.random.seed(1337) # for reproducibility
from sklearn.datasets import load_digits
from sklearn.model_selection import train_test_split
from sklearn.metrics.classification import accuracy_score
from dbn.tensorflow import SupervisedDBNClassification
# use "from dbn import SupervisedDBNClassification" for computations on CPU with numpy
# Loading dataset
digits = load_digits()
X, Y = digits.data, digits.target
# Data scaling
X = (X / 16).astype(np.float32)
# Splitting data
X_train, X_test, Y_train, Y_test = train_test_split(X, Y, test_size=0.2, random_state=0)
# Training
classifier = SupervisedDBNClassification(hidden_layers_structure=[256, 256],
learning_rate_rbm=0.05,
learning_rate=0.1,
n_epochs_rbm=10,
n_iter_backprop=100,
batch_size=32,
activation_function='relu',
dropout_p=0.2)
classifier.fit(X_train, Y_train)
# Save the model
classifier.save('model.pkl')
# Restore it
classifier = SupervisedDBNClassification.load('model.pkl')
# Test
Y_pred = classifier.predict(X_test)
print('Done.\nAccuracy: %f' % accuracy_score(Y_test, Y_pred))
I strongly recommend to use a virtualenv in order not to break anything of your current enviroment.
Open a terminal and type the following line, it will install the package using pip:
pip install git+git://github.com/albertbup/deep-belief-network.git