Example #1
0
def define_net():
    define_net_specific_parameters()

    io = ImageIO()

    # Read pandas csv labels
    y = util.load_labels()

    if params.SUBSET is not 0:
        y = y[:params.SUBSET]

    X = np.arange(y.shape[0])

    mean, std = io.load_mean_std(circularized=params.CIRCULARIZED_MEAN_STD)
    keys = y.index.values

    if params.AUGMENT:
        train_iterator = AugmentingParallelBatchIterator(keys,
                                                         params.BATCH_SIZE,
                                                         std,
                                                         mean,
                                                         y_all=y)
    else:
        train_iterator = ParallelBatchIterator(keys,
                                               params.BATCH_SIZE,
                                               std,
                                               mean,
                                               y_all=y)

    test_iterator = ParallelBatchIterator(keys,
                                          params.BATCH_SIZE,
                                          std,
                                          mean,
                                          y_all=y)

    if params.REGRESSION:
        y = util.float32(y)
        y = y[:, np.newaxis]

    if 'gpu' in theano.config.device:
        # Half of coma does not support cuDNN, check whether we can use it on this node
        # If not, use cuda_convnet bindings
        from theano.sandbox.cuda.dnn import dnn_available
        if dnn_available() and not params.DISABLE_CUDNN:
            from lasagne.layers import dnn
            Conv2DLayer = dnn.Conv2DDNNLayer
            MaxPool2DLayer = dnn.MaxPool2DDNNLayer
        else:
            from lasagne.layers import cuda_convnet
            Conv2DLayer = cuda_convnet.Conv2DCCLayer
            MaxPool2DLayer = cuda_convnet.MaxPool2DCCLayer
    else:
        Conv2DLayer = layers.Conv2DLayer
        MaxPool2DLayer = layers.MaxPool2DLayer

    Maxout = layers.pool.FeaturePoolLayer

    net = NeuralNet(
        layers=[
            ('input', layers.InputLayer),
            ('conv1', Conv2DLayer),
            ('pool1', MaxPool2DLayer),
            ('conv2', Conv2DLayer),
            ('pool2', MaxPool2DLayer),
            ('conv3', Conv2DLayer),
            ('pool3', MaxPool2DLayer),
            ('conv4', Conv2DLayer),
            ('pool4', MaxPool2DLayer),
            ('dropouthidden1', layers.DropoutLayer),
            ('hidden1', layers.DenseLayer),
            ('maxout1', Maxout),
            ('dropouthidden2', layers.DropoutLayer),
            ('hidden2', layers.DenseLayer),
            ('maxout2', Maxout),
            ('dropouthidden3', layers.DropoutLayer),
            ('output', layers.DenseLayer),
        ],
        input_shape=(None, params.CHANNELS, params.PIXELS, params.PIXELS),
        conv1_num_filters=32,
        conv1_filter_size=(8, 8),
        conv1_border_mode='same',
        conv1_stride=(2, 2),
        pool1_pool_size=(2, 2),
        pool1_stride=(2, 2),
        conv2_num_filters=64,
        conv2_filter_size=(5, 5),
        conv2_border_mode='same',
        pool2_pool_size=(2, 2),
        pool2_stride=(2, 2),
        conv3_num_filters=128,
        conv3_filter_size=(3, 3),
        conv3_border_mode='same',
        pool3_pool_size=(2, 2),
        pool3_stride=(2, 2),
        conv4_num_filters=256,
        conv4_filter_size=(3, 3),
        conv4_border_mode='same',
        pool4_pool_size=(2, 2),
        pool4_stride=(2, 2),
        hidden1_num_units=1024,
        hidden2_num_units=1024,
        dropouthidden1_p=0.5,
        dropouthidden2_p=0.5,
        dropouthidden3_p=0.5,
        maxout1_pool_size=2,
        maxout2_pool_size=2,
        output_num_units=1 if params.REGRESSION else 5,
        output_nonlinearity=None
        if params.REGRESSION else nonlinearities.softmax,
        conv1_nonlinearity=LeakyRectify(0.1),
        conv2_nonlinearity=LeakyRectify(0.1),
        conv3_nonlinearity=LeakyRectify(0.1),
        conv4_nonlinearity=LeakyRectify(0.1),
        hidden1_nonlinearity=LeakyRectify(0.1),
        hidden2_nonlinearity=LeakyRectify(0.1),
        update_learning_rate=theano.shared(
            util.float32(params.START_LEARNING_RATE)),
        update_momentum=theano.shared(util.float32(params.MOMENTUM)),
        custom_score=('kappa', quadratic_kappa),
        regression=params.REGRESSION,
        batch_iterator_train=train_iterator,
        batch_iterator_test=test_iterator,
        on_epoch_finished=[
            AdjustVariable('update_learning_rate',
                           start=params.START_LEARNING_RATE),
            stats.Stat(),
            ModelSaver()
        ],
        max_epochs=350,
        verbose=1,

        # Only relevant when create_validation_split = True
        eval_size=0.1,

        # Need to specify splits manually like indicated below!
        create_validation_split=params.SUBSET > 0,
    )

    # It is recommended to use the same training/validation split every model for ensembling and threshold optimization
    #
    # To set specific training/validation split:
    net.X_train = np.load(params.IMAGE_SOURCE + "/X_train.npy")
    net.X_valid = np.load(params.IMAGE_SOURCE + "/X_valid.npy")
    net.y_train = np.load(params.IMAGE_SOURCE + "/y_train.npy")
    net.y_valid = np.load(params.IMAGE_SOURCE + "/y_valid.npy")

    return net, X, y