Ejemplo n.º 1
0
def example_mnist_rbm(paysage_path=None, show_plot = False):
    num_hidden_units = 500
    batch_size = 50
    num_epochs = 10
    learning_rate = 0.01
    mc_steps = 1

    (_, _, shuffled_filepath) = \
            util.default_paths(paysage_path)

    # set up the reader to get minibatches
    data = batch.Batch(shuffled_filepath,
                       'train/images',
                       batch_size,
                       transform=batch.binarize_color,
                       train_fraction=0.99)

    # set up the model and initialize the parameters
    vis_layer = layers.BernoulliLayer(data.ncols)
    hid_layer = layers.BernoulliLayer(num_hidden_units)

    rbm = hidden.Model([vis_layer, hid_layer])
    rbm.initialize(data)

    # set up the optimizer and the fit method
    opt = optimizers.ADAM(rbm,
                          stepsize=learning_rate,
                          scheduler=optimizers.PowerLawDecay(0.1))

    sampler = fit.DrivenSequentialMC.from_batch(rbm, data,
                                                method='stochastic')

    cd = fit.PCD(rbm, data, opt, sampler,
                 num_epochs, mcsteps=mc_steps, skip=200,
                 metrics=[M.ReconstructionError(),
                          M.EnergyDistance(),
                          M.EnergyGap(),
                          M.EnergyZscore()])

    # fit the model
    print('training with contrastive divergence')
    cd.train()

    # evaluate the model
    # this will be the same as the final epoch results
    # it is repeated here to be consistent with the sklearn rbm example
    metrics = [M.ReconstructionError(), M.EnergyDistance(),
               M.EnergyGap(), M.EnergyZscore()]
    performance = fit.ProgressMonitor(0, data, metrics=metrics)

    util.show_metrics(rbm, performance)
    util.show_reconstructions(rbm, data.get('validate'), fit, show_plot)
    util.show_fantasy_particles(rbm, data.get('validate'), fit, show_plot)
    util.show_weights(rbm, show_plot)

    # close the HDF5 store
    data.close()
    print("Done")
Ejemplo n.º 2
0
def example_mnist_hopfield(paysage_path=None, num_epochs=10, show_plot=False):

    num_hidden_units = 500
    batch_size = 50
    learning_rate = 0.001
    mc_steps = 1

    (_, _, shuffled_filepath) = \
        util.default_paths(paysage_path)

    # set up the reader to get minibatches
    data = batch.Batch(shuffled_filepath,
                       'train/images',
                       batch_size,
                       transform=batch.binarize_color,
                       train_fraction=0.99)

    # set up the model and initialize the parameters
    vis_layer = layers.BernoulliLayer(data.ncols)
    hid_layer = layers.GaussianLayer(num_hidden_units)

    rbm = model.Model([vis_layer, hid_layer])
    rbm.initialize(data)

    metrics = [
        'ReconstructionError', 'EnergyDistance', 'EnergyGap', 'EnergyZscore'
    ]
    perf = fit.ProgressMonitor(data, metrics=metrics)

    # set up the optimizer and the fit method
    opt = optimizers.ADAM(stepsize=learning_rate,
                          scheduler=optimizers.PowerLawDecay(0.1))

    sampler = fit.DrivenSequentialMC.from_batch(rbm, data, method='stochastic')

    cd = fit.SGD(rbm,
                 data,
                 opt,
                 num_epochs,
                 method=fit.pcd,
                 sampler=sampler,
                 mcsteps=mc_steps,
                 monitor=perf)

    # fit the model
    print('training with contrastive divergence')
    cd.train()

    # evaluate the model
    util.show_metrics(rbm, perf)
    util.show_reconstructions(rbm, data.get('validate'), fit, show_plot)
    util.show_fantasy_particles(rbm, data.get('validate'), fit, show_plot)
    util.show_weights(rbm, show_plot)

    # close the HDF5 store
    data.close()
    print("Done")
Ejemplo n.º 3
0
def example_mnist_tap_machine(paysage_path=None, num_epochs = 10, show_plot=True):

    num_hidden_units = 256
    batch_size = 100
    learning_rate = 0.1

    (_, _, shuffled_filepath) = \
            util.default_paths(paysage_path)

    # set up the reader to get minibatches
    data = batch.Batch(shuffled_filepath,
                       'train/images',
                       batch_size,
                       transform=batch.binarize_color,
                       train_fraction=0.95)

    # set up the model and initialize the parameters
    vis_layer = layers.BernoulliLayer(data.ncols)
    hid_layer = layers.BernoulliLayer(num_hidden_units)

    rbm = tap_machine.TAP_rbm([vis_layer, hid_layer], num_persistent_samples=0,
                              tolerance_EMF=1e-4, max_iters_EMF=25, terms=2)
    rbm.initialize(data, 'glorot_normal')

    perf  = fit.ProgressMonitor(data,
                                metrics=['ReconstructionError',
                                         'EnergyDistance'])

    opt = optimizers.Gradient(stepsize=learning_rate,
                              scheduler=optimizers.PowerLawDecay(0.1),
                              tolerance=1e-4,
                              ascent=True)

    sgd = fit.SGD(rbm, data, opt, num_epochs, method=fit.tap, monitor=perf)

    # fit the model
    print('training with stochastic gradient ascent ')
    sgd.train()

    util.show_metrics(rbm, perf)
    util.show_reconstructions(rbm, data.get('validate'), fit, show_plot)
    util.show_fantasy_particles(rbm, data.get('validate'), fit, show_plot)
    util.show_weights(rbm, show_plot)

    # close the HDF5 store
    data.close()
    print("Done")
Ejemplo n.º 4
0
def test_tap_machine(paysage_path=None):
    num_hidden_units = 10
    batch_size = 50
    num_epochs = 1
    learning_rate = 0.01

    if not paysage_path:
        paysage_path = os.path.dirname(
            os.path.dirname(os.path.abspath(__file__)))
    filepath = os.path.join(paysage_path, 'mnist', 'mnist.h5')

    if not os.path.exists(filepath):
        raise IOError(
            "{} does not exist. run mnist/download_mnist.py to fetch from the web"
            .format(filepath))

    shuffled_filepath = os.path.join(paysage_path, 'mnist',
                                     'shuffled_mnist.h5')

    # shuffle the data
    if not os.path.exists(shuffled_filepath):
        shuffler = batch.DataShuffler(filepath, shuffled_filepath, complevel=0)
        shuffler.shuffle()

    # set a seed for the random number generator
    be.set_seed()

    # set up the reader to get minibatches
    data = batch.Batch(shuffled_filepath,
                       'train/images',
                       batch_size,
                       transform=batch.binarize_color,
                       train_fraction=0.1)

    # set up the model and initialize the parameters
    vis_layer = layers.BernoulliLayer(data.ncols)
    hid_layer = layers.BernoulliLayer(num_hidden_units)

    rbm = tap_machine.TAP_rbm([vis_layer, hid_layer],
                              tolerance_EMF=1e-2,
                              max_iters_EMF=50)
    rbm.initialize(data)

    # obtain initial estimate of the reconstruction error
    perf = fit.ProgressMonitor(data, metrics=['ReconstructionError'])
    untrained_performance = perf.check_progress(rbm)

    # set up the optimizer and the fit method
    opt = optimizers.Gradient(stepsize=learning_rate,
                              scheduler=optimizers.PowerLawDecay(0.1),
                              tolerance=1e-3,
                              ascent=True)

    solver = fit.SGD(rbm, data, opt, num_epochs, method=fit.tap, monitor=perf)

    # fit the model
    print('training with stochastic gradient ascent')
    solver.train()

    # obtain an estimate of the reconstruction error after 1 epoch
    trained_performance = perf.check_progress(rbm)

    assert (trained_performance['ReconstructionError'] <
            untrained_performance['ReconstructionError']), \
    "Reconstruction error did not decrease"

    # close the HDF5 store
    data.close()
Ejemplo n.º 5
0
def test_rbm(paysage_path=None):
    """TODO : this is just a placeholder, need to clean up & simplifiy setup. Also
    need to figure how to deal with consistent random seeding throughout the
    codebase to obtain deterministic checkable results.
    """
    num_hidden_units = 50
    batch_size = 50
    num_epochs = 1
    learning_rate = 0.01
    mc_steps = 1

    if not paysage_path:
        paysage_path = os.path.dirname(
            os.path.dirname(os.path.abspath(__file__)))
    filepath = os.path.join(paysage_path, 'mnist', 'mnist.h5')

    if not os.path.exists(filepath):
        raise IOError(
            "{} does not exist. run mnist/download_mnist.py to fetch from the web"
            .format(filepath))

    shuffled_filepath = os.path.join(paysage_path, 'mnist',
                                     'shuffled_mnist.h5')

    # shuffle the data
    if not os.path.exists(shuffled_filepath):
        shuffler = batch.DataShuffler(filepath, shuffled_filepath, complevel=0)
        shuffler.shuffle()

    # set a seed for the random number generator
    be.set_seed()

    # set up the reader to get minibatches
    data = batch.Batch(shuffled_filepath,
                       'train/images',
                       batch_size,
                       transform=batch.binarize_color,
                       train_fraction=0.99)

    # set up the model and initialize the parameters
    vis_layer = layers.BernoulliLayer(data.ncols)
    hid_layer = layers.BernoulliLayer(num_hidden_units)

    rbm = hidden.Model([vis_layer, hid_layer])
    rbm.initialize(data)

    # obtain initial estimate of the reconstruction error
    perf = fit.ProgressMonitor(0, data, metrics=[M.ReconstructionError()])
    untrained_performance = perf.check_progress(rbm, 0)

    # set up the optimizer and the fit method
    opt = optimizers.RMSProp(rbm,
                             stepsize=learning_rate,
                             scheduler=optimizers.PowerLawDecay(0.1))

    sampler = fit.DrivenSequentialMC.from_batch(rbm, data, method='stochastic')

    cd = fit.PCD(rbm,
                 data,
                 opt,
                 sampler,
                 num_epochs,
                 mcsteps=mc_steps,
                 skip=200,
                 metrics=[M.ReconstructionError()])

    # fit the model
    print('training with contrastive divergence')
    cd.train()

    # obtain an estimate of the reconstruction error after 1 epoch
    trained_performance = perf.check_progress(rbm, 0)

    assert (trained_performance['ReconstructionError'] <
            untrained_performance['ReconstructionError']), \
    "Reconstruction error did not decrease"

    # close the HDF5 store
    data.close()