Example #1
0
def test_mlp_parity(
    learning_rate=0.01,
    L1_reg=0.00,
    L2_reg=0.0001,
    n_epochs=100,
    batch_size=128,
    n_hidden=500,
    n_hiddenLayers=3,
    verbose=False,
    seedval=420,
    nbits=8,
    nnums=[1000, 500, 100],
    patience_p=2,
):
    # generate datasets
    numpy.random.seed(seedval)  # Gaurantees consistency across runs
    train_set = gen_parity_pair(nbits, nnums[0])
    valid_set = gen_parity_pair(nbits, nnums[1])
    test_set = gen_parity_pair(nbits, nnums[2])

    # Convert raw dataset to Theano shared variables.
    train_set_x, train_set_y = shared_dataset(train_set)
    valid_set_x, valid_set_y = shared_dataset(valid_set)
    test_set_x, test_set_y = shared_dataset(test_set)

    # Defining batch sizes
    n_train_batches = train_set_x.get_value(borrow=True).shape[0] // batch_size
    n_valid_batches = valid_set_x.get_value(borrow=True).shape[0] // batch_size
    n_test_batches = test_set_x.get_value(borrow=True).shape[0] // batch_size

    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

    rng = numpy.random.RandomState(1234)

    classifier = myMLP(rng=rng, input=x, n_in=nbits, n_hidden=n_hidden, n_hiddenLayers=n_hiddenLayers, n_out=2)

    cost = classifier.negative_log_likelihood(y) + L1_reg * classifier.L1 + L2_reg * classifier.L2_sqr

    test_model = theano.function(
        inputs=[index],
        outputs=classifier.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(
        inputs=[index],
        outputs=classifier.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],
        },
    )

    gparams = [T.grad(cost, param) for param in classifier.params]

    updates = [(param, param - learning_rate * gparam) for param, gparam in zip(classifier.params, gparams)]

    train_model = theano.function(
        inputs=[index],
        outputs=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],
        },
    )
    print("... training")

    train_nn(
        train_model, validate_model, test_model, n_train_batches, n_valid_batches, n_test_batches, n_epochs, verbose
    )

    test_losses = [test_model(i) for i in range(n_test_batches)]
    test_score = numpy.mean(test_losses)

    return test_score
def test_mlp_parity(learning_rate=0.01, L1_reg=0.00, L2_reg=0.0001, n_epochs=100,
                    batch_size=20, n_hidden=300, n_hiddenLayers=1, nbit=8, verbose=False):
    print test_mlp_parity.__name__, n_epochs, n_hidden, n_hiddenLayers, nbit

    # Generate datasets
    train_set = gen_parity_pair(nbit, 1000)
    valid_set = gen_parity_pair(nbit, 500)
    test_set  = gen_parity_pair(nbit, 100)

    # Convert raw dataset to Theano shared variablesself.
    train_set_x, train_set_y = shared_dataset(train_set)
    valid_set_x, valid_set_y = shared_dataset(valid_set)
    test_set_x, test_set_y = shared_dataset(test_set)

    # Compute number of minibatches for training, validation and testing
    n_train_batches = train_set_x.get_value(borrow=True).shape[0] // batch_size
    n_valid_batches = valid_set_x.get_value(borrow=True).shape[0] // 100
    n_test_batches = test_set_x.get_value(borrow=True).shape[0] // 100

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

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

    rng = numpy.random.RandomState(1234)

    # TODO: construct a neural network, either MLP or CNN.
    classifier = myMLP(
       rng=rng,
       input=x,
       n_in=nbit,
       n_hidden=n_hidden,
       n_out=2,
       n_hiddenLayers=n_hiddenLayers
    )

    # the cost we minimize during training is the negative log likelihood of
    # the model plus the regularization terms (L1 and L2); cost is expressed
    # here symbolically
    cost = (
        classifier.negative_log_likelihood(y)
        + L1_reg * classifier.L1
        + L2_reg * classifier.L2_sqr
    )

    # compiling a Theano function that computes the mistakes that are made
    # by the model on a minibatch
    test_model = theano.function(
        inputs=[index],
        outputs=classifier.errors(y),
        givens={
            x: test_set_x[index * 100:(index + 1) * 100],
            y: test_set_y[index * 100:(index + 1) * 100]
        }
    )

    validate_model = theano.function(
        inputs=[index],
        outputs=classifier.errors(y),
        givens={
            x: valid_set_x[index * 100:(index + 1) * 100],
            y: valid_set_y[index * 100:(index + 1) * 100]
        }
    )

    # compute the gradient of cost with respect to theta (sotred in params)
    # the resulting gradients will be stored in a list gparams
    gparams = [T.grad(cost, param) for param in classifier.params]

    # specify how to update the parameters of the model as a list of
    # (variable, update expression) pairs

    # given two lists of the same length, A = [a1, a2, a3, a4] and
    # B = [b1, b2, b3, b4], zip generates a list C of same size, where each
    # element is a pair formed from the two lists :
    #    C = [(a1, b1), (a2, b2), (a3, b3), (a4, b4)]
    updates = [
        (param, param - learning_rate * gparam)
        for param, gparam in zip(classifier.params, gparams)
    ]

    # compiling a Theano function `train_model` that returns the cost, but
    # in the same time updates the parameter of the model based on the rules
    # defined in `updates`
    train_model = theano.function(
        inputs=[index],
        outputs=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')

    train_nn(train_model, validate_model, test_model,
        n_train_batches, n_valid_batches, n_test_batches, n_epochs, verbose)
Example #3
0
def test_mlp_parity(learning_rate=0.01,
                    L1_reg=0.00,
                    L2_reg=0.0001,
                    n_epochs=100,
                    batch_size=128,
                    n_hidden=500,
                    n_hiddenLayers=3,
                    verbose=False,
                    input_bit=8):
    # generate datasets
    train_set = gen_parity_pair(input_bit, 1000)
    valid_set = gen_parity_pair(input_bit, 500)
    test_set = gen_parity_pair(input_bit, 100)

    # Convert raw dataset to Theano shared variables.
    train_set_x, train_set_y = shared_dataset(train_set)
    valid_set_x, valid_set_y = shared_dataset(valid_set)
    test_set_x, test_set_y = shared_dataset(test_set)

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

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

    # 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

    rng = numpy.random.RandomState(1234)

    # TODO: construct a neural network, either MLP or CNN.
    classifier = myMLP(rng=rng,
                       input=x,
                       n_in=input_bit,
                       n_hidden=n_hidden,
                       n_out=2,
                       n_hiddenLayers=n_hiddenLayers)

    # the cost we minimize during training is the negative log likelihood of
    # the model plus the regularization terms (L1 and L2); cost is expressed
    # here symbolically
    cost = (classifier.negative_log_likelihood(y) + L1_reg * classifier.L1 +
            L2_reg * classifier.L2_sqr)

    # compiling a Theano function that computes the mistakes that are made
    # by the model on a minibatch
    test_model = theano.function(
        inputs=[index],
        outputs=classifier.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(
        inputs=[index],
        outputs=classifier.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]
        })

    # compute the gradient of cost with respect to theta (sotred in params)
    # the resulting gradients will be stored in a list gparams
    gparams = [T.grad(cost, param) for param in classifier.params]

    # specify how to update the parameters of the model as a list of
    # (variable, update expression) pairs

    # given two lists of the same length, A = [a1, a2, a3, a4] and
    # B = [b1, b2, b3, b4], zip generates a list C of same size, where each
    # element is a pair formed from the two lists :
    #    C = [(a1, b1), (a2, b2), (a3, b3), (a4, b4)]
    updates = [(param, param - learning_rate * gparam)
               for param, gparam in zip(classifier.params, gparams)]

    # compiling a Theano function `train_model` that returns the cost, but
    # in the same time updates the parameter of the model based on the rules
    # defined in `updates`
    train_model = theano.function(
        inputs=[index],
        outputs=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')

    return train_nn(train_model, validate_model, test_model, n_train_batches,
                    n_valid_batches, n_test_batches, n_epochs, verbose)
Example #4
0
def test_mlp_parity(n_bit=8,
                    n_epochs=5000,
                    batch_size=10,
                    n_hiddenLayers=2,
                    n_hidden=[100, 100],
                    learning_rate=0.1,
                    L1_reg=0.00,
                    L2_reg=0.0001):

    # generate datasets
    train_set = gen_parity_pair(n_bit, 1000)  #1000
    valid_set = gen_parity_pair(n_bit, 500)  #500
    test_set = gen_parity_pair(n_bit, 100)  #100

    # Convert raw dataset to Theano shared variables.
    train_set_x, train_set_y = shared_dataset(train_set)
    valid_set_x, valid_set_y = shared_dataset(valid_set)
    test_set_x, test_set_y = shared_dataset(test_set)

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

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

    # 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

    rng = numpy.random.RandomState(1234)

    # construct the MLP class
    classifier = myMLP(rng=rng,
                       input=x,
                       n_in=n_bit,
                       n_hidden=n_hidden,
                       n_out=2,
                       n_hiddenLayers=n_hiddenLayers)

    # the cost we minimize during training is the negative log likelihood of
    # the model plus the regularization terms (L1 and L2); cost is expressed
    # here symbolically
    cost = (classifier.negative_log_likelihood(y) + L1_reg * classifier.L1 +
            L2_reg * classifier.L2_sqr)

    # compiling a Theano function that computes the mistakes that are made
    # by the model on a minibatch
    test_model = theano.function(
        inputs=[index],
        outputs=classifier.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(
        inputs=[index],
        outputs=classifier.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]
        })

    # compute the gradient of cost with respect to theta (sotred in params)
    # the resulting gradients will be stored in a list gparams
    gparams = [T.grad(cost, param) for param in classifier.params]

    updates = [(param, param - learning_rate * gparam)
               for param, gparam in zip(classifier.params, gparams)]

    ######################
    # TRAIN ACTUAL MODEL #
    ######################
    print('... training the model')

    # early-stopping parameters
    patience = 10000  # look as this many examples regardless
    patience_increase = 10  # wait this much longer when a new best is
    # found
    improvement_threshold = 0.9995  # 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_validation_loss = numpy.inf
    best_iter = 0
    test_score = 0.
    start_time = timeit.default_timer()

    epoch = 0
    done_looping = False
    verbose = True

    while (epoch < n_epochs) and (not done_looping):
        seed = random.randint(0, sys.maxint)
        shuffle(train_set_x, seed)

        train_model = theano.function(
            inputs=[index],
            outputs=[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]
            })

        epoch = epoch + 1
        for minibatch_index in range(n_train_batches):

            iter = (epoch - 1) * n_train_batches + minibatch_index

            if (iter % 100 == 0) and verbose:
                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 range(n_valid_batches)
                ]
                this_validation_loss = numpy.mean(validation_losses)

                if verbose:
                    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 range(n_test_batches)
                    ]
                    test_score = numpy.mean(test_losses)

                    if verbose:
                        print(('     epoch %i, minibatch %i/%i, test error of '
                               'best model %f %%') %
                              (epoch, minibatch_index + 1, n_train_batches,
                               test_score * 100.))

                    if test_score == 0:
                        done_looping = True
                        break

            if patience <= iter:
                done_looping = True
                break

    end_time = timeit.default_timer()

    # Retrieve the name of function who invokes train_nn() (caller's name)
    curframe = inspect.currentframe()
    calframe = inspect.getouterframes(curframe, 2)

    # Print out summary
    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.))
def test_mlp_parity(nbits=8,learning_rate=0.01, L1_reg=0.00, L2_reg=0.0001, n_epochs=100,
                    batch_size=20, n_hidden=200, n_hiddenLayers=3,verbose=False):
    # generate datasets
    train_set = gen_parity_pair(nbits, 1000)
    valid_set = gen_parity_pair(nbits, 500)
    test_set  = gen_parity_pair(nbits, 100)

    # Convert raw dataset to Theano shared variables.
    train_set_x, train_set_y = shared_dataset(train_set)
    valid_set_x, valid_set_y = shared_dataset(valid_set)
    test_set_x, test_set_y = shared_dataset(test_set)
    
    # compute number of minibatches for training, validation and testing
    n_train_batches = train_set_x.get_value(borrow=True).shape[0] // batch_size
    n_valid_batches = valid_set_x.get_value(borrow=True).shape[0] // batch_size
    n_test_batches = test_set_x.get_value(borrow=True).shape[0] // batch_size

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

    # 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

    rng = numpy.random.RandomState(1234)

    classifier = myMLP(rng, input=x, n_in=nbits, n_hidden=n_hidden, n_out=2, n_hiddenLayers=n_hiddenLayers)

    # the cost we minimize during training is the negative log likelihood of
    # the model plus the regularization terms (L1 and L2); cost is expressed
    # here symbolically
    cost = (
        classifier.negative_log_likelihood(y)
        + L1_reg * classifier.L1
        + L2_reg * classifier.L2_sqr
    )

    # compiling a Theano function that computes the mistakes that are made
    # by the model on a minibatch
    test_model = theano.function(
        inputs=[index],
        outputs=classifier.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(
        inputs=[index],
        outputs=classifier.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]
        }
    )

    # compute the gradient of cost with respect to theta (sotred in params)
    # the resulting gradients will be stored in a list gparams
    gparams = [T.grad(cost, param) for param in classifier.params]

    # specify how to update the parameters of the model as a list of
    # (variable, update expression) pairs

    updates = [
        (param, param - learning_rate * gparam)
        for param, gparam in zip(classifier.params, gparams)
    ]

    # compiling a Theano function `train_model` that returns the cost, but
    # in the same time updates the parameter of the model based on the rules
    # defined in `updates`
    train_model = theano.function(
        inputs=[index],
        outputs=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')

    train_nn(train_model, validate_model, test_model,
        n_train_batches, n_valid_batches, n_test_batches, n_epochs, verbose)