Ejemplo n.º 1
0
def test_SdA(
    finetune_lr=0.1,
    pretraining_epochs=15,
    pretrain_lr=0.001,
    training_epochs=1000,
    dataset="../data/mnist.pkl.gz",
    batch_size=1,
):
    """
    Demonstrates how to train and test a stochastic denoising autoencoder.

    This is demonstrated on MNIST.

    :type learning_rate: float
    :param learning_rate: learning rate used in the finetune stage
    (factor for the stochastic gradient)

    :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 n_iter: int
    :param n_iter: maximal number of iterations ot run the optimizer

    :type dataset: string
    :param dataset: path the the pickled dataset

    """

    # datasets = load_data(dataset)
    datasets = load_mat("/home/ubuntu/var/train_32x32.mat", "/home/ubuntu/var/test_32x32.mat", 5000)

    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]
    n_train_batches /= batch_size

    # numpy random generator
    numpy_rng = numpy.random.RandomState(89677)
    print "... building the model"
    # construct the stacked denoising autoencoder class
    sda = SdA(
        numpy_rng=numpy_rng,
        n_ins=96 * 32,
        # hidden_layers_sizes=[1000, 1000, 1000],
        hidden_layers_sizes=[500],
        n_outs=10,
    )

    #########################
    # PRETRAINING THE MODEL #
    #########################
    print "... getting the pretraining functions"
    pretraining_fns = sda.pretraining_functions(train_set_x=train_set_x, batch_size=batch_size)

    print "... pre-training the model"
    start_time = time.clock()
    ## Pre-train layer-wise
    corruption_levels = [0.3]
    for i in xrange(sda.n_layers):
        # go through pretraining epochs
        for epoch in xrange(pretraining_epochs):
            # go through the training set
            c = []
            for batch_index in xrange(n_train_batches):
                c.append(pretraining_fns[i](index=batch_index, corruption=corruption_levels[i], lr=pretrain_lr))
            print "Pre-training layer %i, epoch %d, cost " % (i, epoch),
            print numpy.mean(c)

    end_time = time.clock()

    print >> sys.stderr, (
        "The pretraining code for file "
        + os.path.split(__file__)[1]
        + " ran for %.2fm" % ((end_time - start_time) / 60.0)
    )

    ########################
    # FINETUNING THE MODEL #
    ########################

    # get the training, validation and testing function for the model
    print "... getting the finetuning functions"
    train_fn, validate_model, test_model = sda.build_finetune_functions(
        datasets=datasets, batch_size=batch_size, learning_rate=finetune_lr
    )

    print "... finetunning the model"
    # early-stopping parameters
    patience = 10 * n_train_batches  # look as this many examples regardless
    patience_increase = 2.0  # wait this much longer when a new best is
    # found
    improvement_threshold = 0.995  # a relative improvement of this much is
    # considered significant
    validation_frequency = min(n_train_batches, patience / 2)
    # go through this many
    # minibatche before checking the network
    # on the validation set; in this case we
    # check every epoch

    best_params = None
    best_validation_loss = numpy.inf
    test_score = 0.0
    start_time = time.clock()

    done_looping = False
    epoch = 0

    while (epoch < training_epochs) and (not done_looping):
        epoch = epoch + 1
        for minibatch_index in xrange(n_train_batches):
            minibatch_avg_cost = train_fn(minibatch_index)
            iter = (epoch - 1) * n_train_batches + minibatch_index

            if (iter + 1) % validation_frequency == 0:
                validation_losses = validate_model()
                this_validation_loss = numpy.mean(validation_losses)
                print (
                    "epoch %i, minibatch %i/%i, validation error %f %%"
                    % (epoch, minibatch_index + 1, n_train_batches, this_validation_loss * 100.0)
                )

                # 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)

                    # 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 * 100.0)
                    )

            if patience <= iter:
                done_looping = True
                break

    end_time = time.clock()
    print (
        ("Optimization complete with best validation score of %f %%," "with test performance %f %%")
        % (best_validation_loss * 100.0, test_score * 100.0)
    )
    print >> sys.stderr, (
        "The training code for file " + os.path.split(__file__)[1] + " ran for %.2fm" % ((end_time - start_time) / 60.0)
    )
Ejemplo n.º 2
0
def test_dA(learning_rate=0.1, training_epochs=15,
            dataset='../data/mnist.pkl.gz',
            batch_size=20, output_folder='dA_plots'):

    """
    This demo is tested on MNIST

    :type learning_rate: float
    :param learning_rate: learning rate used for training the DeNosing
                          AutoEncoder

    :type training_epochs: int
    :param training_epochs: number of epochs used for training

    :type dataset: string
    :param dataset: path to the picked dataset

    """
    #datasets = load_data(dataset)
    #datasets = load_mat("/home/ubuntu/var/train_32x32.mat", \
    #    "/home/ubuntu/var/test_32x32.mat", 20000)
    datasets = load_mat("/home/ubuntu/var/train_32x32.mat", \
        "/home/ubuntu/var/test_32x32.mat", 5000)
    train_set_x, train_set_y = datasets[0]

    # compute number of minibatches for training, validation and testing
    n_train_batches = train_set_x.get_value(borrow=True).shape[0] / batch_size

    # allocate symbolic variables for the data
    index = T.lscalar()    # index to a [mini]batch
    x = T.matrix('x')  # the data is presented as rasterized images

    if not os.path.isdir(output_folder):
        os.makedirs(output_folder)
    os.chdir(output_folder)

    """
    ####################################
    # BUILDING THE MODEL NO CORRUPTION #
    ####################################

    rng = numpy.random.RandomState(123)
    theano_rng = RandomStreams(rng.randint(2 ** 30))

    da = dA(numpy_rng=rng, theano_rng=theano_rng, input=x,
            n_visible=96 * 32, n_hidden=500)

    cost, updates = da.get_cost_updates(corruption_level=0.,
                                        learning_rate=learning_rate)

    train_da = theano.function([index], cost, updates=updates,
         givens={x: train_set_x[index * batch_size:
                                (index + 1) * batch_size]})

    start_time = time.clock()

    ############
    # TRAINING #
    ############

    # go through training epochs
    for epoch in xrange(training_epochs):
        # go through trainng set
        c = []
        for batch_index in xrange(n_train_batches):
            c.append(train_da(batch_index))

        print 'Training epoch %d, cost ' % epoch, numpy.mean(c)

    end_time = time.clock()

    training_time = (end_time - start_time)

    print >> sys.stderr, ('The no corruption code for file ' +
                          os.path.split(__file__)[1] +
                          ' ran for %.2fm' % ((training_time) / 60.))
    image = PIL.Image.fromarray(
        tile_raster_images(X=da.W.get_value(borrow=True).T,
                           img_shape=(32, 96), tile_shape=(10, 10),
                           tile_spacing=(1, 1)))
    image.save('filters_corruption_0.png')
    """

    for rate in [0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 99]:
        print "Rate: %d" % (rate)

        #####################################
        # BUILDING THE MODEL CORRUPTION 30% #
        #####################################
        rng = numpy.random.RandomState(123)
        theano_rng = RandomStreams(rng.randint(2 ** 30))
    
        da = dA(numpy_rng=rng, theano_rng=theano_rng, input=x,
                n_visible=96 * 32, n_hidden=100)
    
        cost, updates = da.get_cost_updates(corruption_level=rate*1.0/100,
                                            learning_rate=learning_rate)
    
        train_da = theano.function([index], cost, updates=updates,
             givens={x: train_set_x[index * batch_size:
                                      (index + 1) * batch_size]})
    
        start_time = time.clock()
    
        ############
        # TRAINING #
        ############
    
        # go through training epochs
        for epoch in xrange(training_epochs):
            # go through trainng set
            c = []
            for batch_index in xrange(n_train_batches):
                c.append(train_da(batch_index))
    
            print 'Training epoch %d, cost ' % epoch, numpy.mean(c)
    
        end_time = time.clock()
    
        training_time = (end_time - start_time)
    
        print >> sys.stderr, ('The % corruption code for file ' +
                              os.path.split(__file__)[1] +
                              ' ran for %.2fm' % (training_time / 60.))
    
        bits = tile_raster_images(
            X=da.W.get_value(borrow=True).T,
            img_shape=(32, 96), tile_shape=(10, 10),
            tile_spacing=(3, 3))
        ri = PIL.Image.fromarray(numpy.array([[bits[j][i*3] for i in xrange(0,32*10+9)] for j in xrange(0,32*10+27)]))
        bi = PIL.Image.fromarray(numpy.array([[bits[j][i*3+1] for i in xrange(0,32*10+9)] for j in xrange(0,32*10+27)]))
        gi = PIL.Image.fromarray(numpy.array([[bits[j][i*3+2] for i in xrange(0,32*10+9)] for j in xrange(0,32*10+27)]))
    
        """
        image = PIL.Image.fromarray(tile_raster_images(
            X=da.W.get_value(borrow=True).T,
            img_shape=(32, 96), tile_shape=(10, 10),
            tile_spacing=(1, 1)))
        """
        image = PIL.Image.merge("RGB", (ri,gi,bi))
        image.save('filters_corruption.color.%d.png' % (rate))

    """

    #####################################
    # BUILDING THE MODEL CORRUPTION 30% #
    #####################################

    rng = numpy.random.RandomState(123)
    theano_rng = RandomStreams(rng.randint(2 ** 30))

    da = dA(numpy_rng=rng, theano_rng=theano_rng, input=x,
            n_visible=96 * 32, n_hidden=500)

    cost, updates = da.get_cost_updates(corruption_level=0.5,
                                        learning_rate=learning_rate)

    train_da = theano.function([index], cost, updates=updates,
         givens={x: train_set_x[index * batch_size:
                                  (index + 1) * batch_size]})

    start_time = time.clock()

    ############
    # TRAINING #
    ############

    # go through training epochs
    for epoch in xrange(training_epochs):
        # go through trainng set
        c = []
        for batch_index in xrange(n_train_batches):
            c.append(train_da(batch_index))

        print 'Training epoch %d, cost ' % epoch, numpy.mean(c)

    end_time = time.clock()

    training_time = (end_time - start_time)

    print >> sys.stderr, ('The 50% corruption code for file ' +
                          os.path.split(__file__)[1] +
                          ' ran for %.2fm' % (training_time / 60.))

    bits = tile_raster_images(
        X=da.W.get_value(borrow=True).T,
        img_shape=(32, 96), tile_shape=(10, 10),
        tile_spacing=(3, 3))
    ri = PIL.Image.fromarray(numpy.array([[bits[j][i*3] for i in xrange(0,32*10+9)] for j in xrange(0,32*10+27)]))
    bi = PIL.Image.fromarray(numpy.array([[bits[j][i*3+1] for i in xrange(0,32*10+9)] for j in xrange(0,32*10+27)]))
    gi = PIL.Image.fromarray(numpy.array([[bits[j][i*3+2] for i in xrange(0,32*10+9)] for j in xrange(0,32*10+27)]))
    image = PIL.Image.merge("RGB", (ri,gi,bi))
    image.save('filters_corruption_50.color.png')
    """

    os.chdir('../')
Ejemplo n.º 3
0
def test_DBN(finetune_lr=0.1, pretraining_epochs=100,
             pretrain_lr=0.01, k=1, training_epochs=1000,
             dataset='../data/mnist.pkl.gz', batch_size=10):
    """
    Demonstrates how to train and test a Deep Belief Network.

    This is demonstrated on MNIST.

    :type learning_rate: float
    :param learning_rate: 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 k: int
    :param k: 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
    """

    #datasets = load_data(dataset)
    datasets = load_mat("/home/ubuntu/var/train_32x32.mat", \
        "/home/ubuntu/var/test_32x32.mat")

    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

    # numpy random generator
    numpy_rng = numpy.random.RandomState(123)
    print '... building the model'
    # construct the Deep Belief Network
    dbn = DBN(numpy_rng=numpy_rng, n_ins=96 * 32,
              hidden_layers_sizes=[1000, 1000, 1000],
              n_outs=10)

    #########################
    # PRETRAINING THE MODEL #
    #########################
    print '... getting the pretraining functions'
    pretraining_fns = dbn.pretraining_functions(train_set_x=train_set_x,
                                                batch_size=batch_size,
                                                k=k)

    print '... pre-training the model'
    start_time = time.clock()
    ## Pre-train layer-wise
    for i in xrange(dbn.n_layers):
        # go through pretraining epochs
        for epoch in xrange(pretraining_epochs):
            # 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)

    end_time = time.clock()
    print >> sys.stderr, ('The pretraining code for file ' +
                          os.path.split(__file__)[1] +
                          ' ran for %.2fm' % ((end_time - start_time) / 60.))

    ########################
    # FINETUNING THE MODEL #
    ########################

    # get the training, validation and testing function for the model
    print '... getting the finetuning functions'
    train_fn, validate_model, test_model = dbn.build_finetune_functions(
                datasets=datasets, batch_size=batch_size,
                learning_rate=finetune_lr)

    print '... finetunning the model'
    # early-stopping parameters
    patience = 4 * n_train_batches  # look as this many examples regardless
    patience_increase = 2.    # wait this much longer when a new best is
                              # found
    improvement_threshold = 0.995  # a relative improvement of this much is
                                   # considered significant
    validation_frequency = min(n_train_batches, patience / 2)
                                  # go through this many
                                  # minibatche before checking the network
                                  # on the validation set; in this case we
                                  # check every epoch

    best_params = None
    best_validation_loss = numpy.inf
    test_score = 0.
    start_time = time.clock()

    done_looping = False
    epoch = 0

    while (epoch < training_epochs) and (not done_looping):
        epoch = epoch + 1
        for minibatch_index in xrange(n_train_batches):

            minibatch_avg_cost = train_fn(minibatch_index)
            iter = (epoch - 1) * n_train_batches + minibatch_index

            if (iter + 1) % validation_frequency == 0:

                validation_losses = validate_model()
                this_validation_loss = numpy.mean(validation_losses)
                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)

                    # 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
                break

    end_time = time.clock()
    print(('Optimization complete with best validation score of %f %%,'
           'with test performance %f %%') %
                 (best_validation_loss * 100., 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.))
Ejemplo n.º 4
0
def evaluate_lenet5(learning_rate=0.1, n_epochs=200,
                    dataset='../data/mnist.pkl.gz',
                    nkerns=[20, 50], batch_size=500):
    """ Demonstrates lenet on MNIST dataset

    :type learning_rate: float
    :param learning_rate: learning rate used (factor for the stochastic
                          gradient)

    :type n_epochs: int
    :param n_epochs: maximal number of epochs to run the optimizer

    :type dataset: string
    :param dataset: path to the dataset used for training /testing (MNIST here)

    :type nkerns: list of ints
    :param nkerns: number of kernels on each layer
    """

    rng = numpy.random.RandomState(23455)

    #datasets = load_data(dataset)
    datasets = load_mat("/home/ubuntu/var/train_32x32.mat", \
        "/home/ubuntu/var/test_32x32.mat")

    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]
    n_valid_batches = valid_set_x.get_value(borrow=True).shape[0]
    n_test_batches = test_set_x.get_value(borrow=True).shape[0]
    n_train_batches /= batch_size
    n_valid_batches /= batch_size
    n_test_batches /= batch_size

    # allocate symbolic variables for the data
    index = T.lscalar()  # index to a [mini]batch
    x = T.matrix('x')   # the data is presented as rasterized images
    y = T.ivector('y')  # the labels are presented as 1D vector of
                        # [int] labels

    ishape = (96, 32)  # this is the size of MNIST images

    ######################
    # BUILD ACTUAL MODEL #
    ######################
    print '... building the model'

    # Reshape matrix of rasterized images of shape (batch_size,28*28)
    # to a 4D tensor, compatible with our LeNetConvPoolLayer
    layer0_input = x.reshape((batch_size, 1, 96, 32))

    # Construct the first convolutional pooling layer:
    # filtering reduces the image size to (28-5+1,28-5+1)=(24,24)
    # maxpooling reduces this further to (24/2,24/2) = (12,12)
    # 4D output tensor is thus of shape (batch_size,nkerns[0],12,12)
    layer0 = LeNetConvPoolLayer(rng, input=layer0_input,
            image_shape=(batch_size, 1, 96, 32),
            filter_shape=(nkerns[0], 1, 5, 5), poolsize=(2, 2))

    # Construct the second convolutional pooling layer
    # filtering reduces the image size to (12-5+1,12-5+1)=(8,8)
    # maxpooling reduces this further to (8/2,8/2) = (4,4)
    # 4D output tensor is thus of shape (nkerns[0],nkerns[1],4,4)
    layer1 = LeNetConvPoolLayer(rng, input=layer0.output,
            image_shape=(batch_size, nkerns[0], 12, 12),
            filter_shape=(nkerns[1], nkerns[0], 5, 5), poolsize=(2, 2))

    # the TanhLayer being fully-connected, it operates on 2D matrices of
    # shape (batch_size,num_pixels) (i.e matrix of rasterized images).
    # This will generate a matrix of shape (20,32*4*4) = (20,512)
    layer2_input = layer1.output.flatten(2)

    # construct a fully-connected sigmoidal layer
    layer2 = HiddenLayer(rng, input=layer2_input, n_in=nkerns[1] * 4 * 4,
                         n_out=500, activation=T.tanh)

    # classify the values of the fully-connected sigmoidal layer
    layer3 = LogisticRegression(input=layer2.output, n_in=500, n_out=10)

    # the cost we minimize during training is the NLL of the model
    cost = layer3.negative_log_likelihood(y)

    # create a function to compute the mistakes that are made by the model
    test_model = theano.function([index], layer3.errors(y),
             givens={
                x: test_set_x[index * batch_size: (index + 1) * batch_size],
                y: test_set_y[index * batch_size: (index + 1) * batch_size]})

    validate_model = theano.function([index], layer3.errors(y),
            givens={
                x: valid_set_x[index * batch_size: (index + 1) * batch_size],
                y: valid_set_y[index * batch_size: (index + 1) * batch_size]})

    # create a list of all model parameters to be fit by gradient descent
    params = layer3.params + layer2.params + layer1.params + layer0.params

    # create a list of gradients for all model parameters
    grads = T.grad(cost, params)

    # train_model is a function that updates the model parameters by
    # SGD Since this model has many parameters, it would be tedious to
    # manually create an update rule for each model parameter. We thus
    # create the updates list by automatically looping over all
    # (params[i],grads[i]) pairs.
    updates = []
    for param_i, grad_i in zip(params, grads):
        updates.append((param_i, param_i - learning_rate * grad_i))

    train_model = theano.function([index], cost, updates=updates,
          givens={
            x: train_set_x[index * batch_size: (index + 1) * batch_size],
            y: train_set_y[index * batch_size: (index + 1) * batch_size]})

    ###############
    # TRAIN MODEL #
    ###############
    print '... training'
    # early-stopping parameters
    patience = 10000  # look as this many examples regardless
    patience_increase = 2  # wait this much longer when a new best is
                           # found
    improvement_threshold = 0.995  # a relative improvement of this much is
                                   # considered significant
    validation_frequency = min(n_train_batches, patience / 2)
                                  # go through this many
                                  # minibatche before checking the network
                                  # on the validation set; in this case we
                                  # check every epoch

    best_params = None
    best_validation_loss = numpy.inf
    best_iter = 0
    test_score = 0.
    start_time = time.clock()

    epoch = 0
    done_looping = False

    while (epoch < n_epochs) and (not done_looping):
        epoch = epoch + 1
        for minibatch_index in xrange(n_train_batches):

            iter = (epoch - 1) * n_train_batches + minibatch_index

            if iter % 100 == 0:
                print 'training @ iter = ', iter
            cost_ij = train_model(minibatch_index)

            if (iter + 1) % validation_frequency == 0:

                # compute zero-one loss on validation set
                validation_losses = [validate_model(i) for i
                                     in xrange(n_valid_batches)]
                this_validation_loss = numpy.mean(validation_losses)
                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)

                    # 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(i) for i in xrange(n_test_batches)]
                    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
                break

    end_time = time.clock()
    print('Optimization complete.')
    print('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 code for file ' +
                          os.path.split(__file__)[1] +
                          ' ran for %.2fm' % ((end_time - start_time) / 60.))