DeepLearnToolbox

A Matlab toolbox for Deep Learning.

Deep Learning is a new subfield of machine learning that focuses on learning deep hierarchical models of data. It is inspired by the human brain's apparent deep (layered, hierarchical) architecture. A good overview of the theory of Deep Learning theory is Learning Deep Architectures for AI

For a more informal introduction, see the following videos by Geoffrey Hinton and Andrew Ng.

• The Next Generation of Neural Networks (Hinton, 2007)
• Recent Developments in Deep Learning (Hinton, 2010)
• Unsupervised Feature Learning and Deep Learning (Ng, 2011)

If you use this toolbox in your research please cite:

Prediction as a candidate for learning deep hierarchical models of data (Palm, 2012)

Directories included in the toolbox

NN/ - A library for Feedforward Backpropagation Neural Networks

CNN/ - A library for Convolutional Neural Networks

DBN/ - A library for Deep Belief Networks

SAE/ - A library for Stacked Auto-Encoders

CAE/ - A library for Convolutional Auto-Encoders

util/ - Utility functions used by the libraries

data/ - Data used by the examples

tests/ - unit tests to verify toolbox is working

For references on each library check REFS.md

Setup

1. Download.
2. addpath(genpath('DeepLearnToolbox'));

Everything is work in progress

Example: Deep Belief Network

function test_example_DBN
load mnist_uint8;

train_x = double(train_x) / 255;
test_x  = double(test_x)  / 255;
train_y = double(train_y);
test_y  = double(test_y);

%%  ex1 train a 100 hidden unit RBM and visualize its weights
rng(0);
dbn.sizes = [100];
opts.numepochs =   1;
opts.batchsize = 100;
opts.momentum  =   0;
opts.alpha     =   1;
dbn = dbnsetup(dbn, train_x, opts);
dbn = dbntrain(dbn, train_x, opts);
figure; visualize(dbn.rbm{1}.W');   %  Visualize the RBM weights

%%  ex2 train a 100-100 hidden unit DBN and use its weights to initialize a NN
rng(0);
%train dbn
dbn.sizes = [100 100];
opts.numepochs =   1;
opts.batchsize = 100;
opts.momentum  =   0;
opts.alpha     =   1;
dbn = dbnsetup(dbn, train_x, opts);
dbn = dbntrain(dbn, train_x, opts);

%unfold dbn to nn
nn = dbnunfoldtonn(dbn, 10);

%train nn
nn.learningRate  = 1;
opts.numepochs =  1;
opts.batchsize = 100;
nn = nntrain(nn, train_x, train_y, opts);
[er, bad] = nntest(nn, test_x, test_y);

assert(er < 0.12, 'Too big error');

Example: Stacked Auto-Encoders

function test_example_SAE
load mnist_uint8;

train_x = double(train_x)/255;
test_x  = double(test_x)/255;
train_y = double(train_y);
test_y  = double(test_y);

%%  ex1 train a 100 hidden unit SDAE and use it to initialize a FFNN
%  Setup and train a stacked denoising autoencoder (SDAE)
rng(0);
sae = saesetup([784 100]);
sae.ae{1}.learningRate              = 1;
sae.ae{1}.inputZeroMaskedFraction   = 0.5;
opts.numepochs =   1;
opts.batchsize = 100;
sae = saetrain(sae, train_x, opts);
visualize(sae.ae{1}.W{1}')

% Use the SDAE to initialize a FFNN
nn = nnsetup([784 100 10]);
nn.W{1} = sae.ae{1}.W{1};
nn.b{1} = sae.ae{1}.b{1};

% Train the FFNN
nn.learningRate  = 1;
opts.numepochs =   1;
opts.batchsize = 100;
nn = nntrain(nn, train_x, train_y, opts);
[er, bad] = nntest(nn, test_x, test_y);
assert(er < 0.21, 'Too big error');

Example: Convolutional Neural Nets

function test_example_CNN
load mnist_uint8;

train_x = double(reshape(train_x',28,28,60000))/255;
test_x = double(reshape(test_x',28,28,10000))/255;
train_y = double(train_y');
test_y = double(test_y');

%% ex1 Train a 6c-2s-12c-2s Convolutional neural network 
%will run 1 epoch in about 200 second and get around 11% error. 
%With 100 epochs you'll get around 1.2% error
rng(0)
cnn.layers = {
    struct('type', 'i') %input layer
    struct('type', 'c', 'outputmaps', 6, 'kernelsize', 5) %convolution layer
    struct('type', 's', 'scale', 2) %sub sampling layer
    struct('type', 'c', 'outputmaps', 12, 'kernelsize', 5) %convolution layer
    struct('type', 's', 'scale', 2) %subsampling layer
};
cnn = cnnsetup(cnn, train_x, train_y);

opts.alpha = 1;
opts.batchsize = 50;
opts.numepochs = 1;

cnn = cnntrain(cnn, train_x, train_y, opts);

[er, bad] = cnntest(cnn, test_x, test_y);

%plot mean squared error
figure; plot(cnn.rL);

assert(er<0.12, 'Too big error');

Example: Neural Networks

function test_example_NN
load mnist_uint8;

train_x = double(train_x) / 255;
test_x  = double(test_x)  / 255;
train_y = double(train_y);
test_y  = double(test_y);

%% ex1 vanilla neural net
rng(0);
nn = nnsetup([784 100 10]);

nn.learningRate = 1;   %  Learning rate
opts.numepochs =  1;   %  Number of full sweeps through data
opts.batchsize = 100;  %  Take a mean gradient step over this many samples
opts.silent = 1;
nn = nntrain(nn, train_x, train_y, opts);

[er, bad] = nntest(nn, test_x, test_y);
assert(er < 0.1, 'Too big error');

%% ex2 neural net with L2 weight decay
rng(0);
nn = nnsetup([784 100 10]);

nn.weightPenaltyL2 = 1e-4;  %  L2 weight decay
nn.learningRate = 1;        %  Learning rate
opts.numepochs =  1;        %  Number of full sweeps through data
opts.batchsize = 100;       %  Take a mean gradient step over this many samples
opts.silent = 1;
nn = nntrain(nn, train_x, train_y, opts);

[er, bad] = nntest(nn, test_x, test_y);
assert(er < 0.1, 'Too big error');

%% ex3 neural net with dropout
rng(0);
nn = nnsetup([784 100 10]);

nn.dropoutFraction = 0.5;   %  Dropout fraction 
nn.learningRate = 1;        %  Learning rate
opts.numepochs =  1;        %  Number of full sweeps through data
opts.batchsize = 100;       %  Take a mean gradient step over this many samples
opts.silent = 1;
nn = nntrain(nn, train_x, train_y, opts);

[er, bad] = nntest(nn, test_x, test_y);
assert(er < 0.16, 'Too big error');