示例#1
0
def train(dataset='mnist', model_name='d2l', batch_size=128, epochs=50, noise_ratio=0):
    """
    Train one model with data augmentation: random padding+cropping and horizontal flip
    :param dataset: 
    :param model_name:
    :param batch_size: 
    :param epochs: 
    :param noise_ratio: 
    :return: 
    """
    print('Dataset: %s, model: %s, batch: %s, epochs: %s, noise ratio: %s%%' %
          (dataset, model_name, batch_size, epochs, noise_ratio))

    # load data
    X_train, y_train, X_test, y_test = get_data(dataset, noise_ratio, random_shuffle=True)
    # X_train, y_train, X_val, y_val = validatation_split(X_train, y_train, split=0.1)
    n_images = X_train.shape[0]
    image_shape = X_train.shape[1:]
    num_classes = y_train.shape[1]
    print("n_images", n_images, "num_classes", num_classes, "image_shape:", image_shape)

    # load model
    model = get_model(dataset, input_tensor=None, input_shape=image_shape, num_classes=num_classes)
    # model.summary()

    optimizer = SGD(lr=0.01, decay=1e-4, momentum=0.9)

    # for backward, forward loss
    # suppose the model knows noise ratio
    P = uniform_noise_model_P(num_classes, noise_ratio/100.)
    # create loss
    if model_name == 'forward':
        P = uniform_noise_model_P(num_classes, noise_ratio / 100.)
        loss = forward(P)
    elif model_name == 'backward':
        P = uniform_noise_model_P(num_classes, noise_ratio / 100.)
        loss = backward(P)
    elif model_name == 'boot_hard':
        loss = boot_hard
    elif model_name == 'boot_soft':
        loss = boot_soft
    elif model_name == 'd2l':
        loss = lid_paced_loss()
    else:
        loss = cross_entropy

    # model
    model.compile(
        loss=loss,
        optimizer=optimizer,
        metrics=['accuracy']
    )

    ## do real-time updates using callbakcs
    callbacks = []
    if model_name == 'd2l':
        init_epoch = D2L[dataset]['init_epoch']
        epoch_win = D2L[dataset]['epoch_win']
        d2l_learning = D2LCallback(model, X_train, y_train,
                                            dataset, noise_ratio,
                                            epochs=epochs,
                                            pace_type=model_name,
                                            init_epoch=init_epoch,
                                            epoch_win=epoch_win)

        callbacks.append(d2l_learning)

        cp_callback = ModelCheckpoint("model/%s_%s_%s.hdf5" % (model_name, dataset, noise_ratio),
                                      monitor='val_loss',
                                      verbose=0,
                                      save_best_only=False,
                                      save_weights_only=True,
                                      period=1)
        callbacks.append(cp_callback)

    else:
        cp_callback = ModelCheckpoint("model/%s_%s_%s.hdf5" % (model_name, dataset, noise_ratio),
                                      monitor='val_loss',
                                      verbose=0,
                                      save_best_only=False,
                                      save_weights_only=True,
                                      period=epochs)
        callbacks.append(cp_callback)

    # tensorboard callback
    callbacks.append(TensorBoard(log_dir='./log/log'))

    # learning rate scheduler if use sgd
    lr_scheduler = get_lr_scheduler(dataset)
    callbacks.append(lr_scheduler)

    # acc, loss, lid
    log_callback = LoggerCallback(model, X_train, y_train, X_test, y_test, dataset,
                                  model_name, noise_ratio, epochs)
    callbacks.append(log_callback)

    # data augmentation
    if dataset in ['mnist', 'svhn']:
        datagen = ImageDataGenerator()
    elif dataset in ['cifar-10', 'cifar-100']:
        datagen = ImageDataGenerator(
            width_shift_range=0.2,
            height_shift_range=0.2,
            horizontal_flip=True)
    else:
        datagen = ImageDataGenerator(
            width_shift_range=0.1,
            height_shift_range=0.1,
            horizontal_flip=True)
    datagen.fit(X_train)

    # train model
    model.fit_generator(datagen.flow(X_train, y_train, batch_size=batch_size),
                        steps_per_epoch=len(X_train) / batch_size, epochs=epochs,
                        validation_data=(X_test, y_test),
                        verbose=1,
                        callbacks=callbacks
                        )
                          input_tensor=None,
                          input_shape=(128, ),
                          num_classes=train_y.shape[1])
        loss = lid_paced_loss()
        model.compile(loss=loss,
                      optimizer=optimizers.Adam(0.001),
                      metrics=['accuracy'])

        callbacks = []
        init_epoch = 60
        epoch_win = 5
        d2l_learning = D2LCallback(model,
                                   train_x,
                                   train_y,
                                   DATASET,
                                   NOISE_RATIO,
                                   epochs=EPOCHS,
                                   pace_type="D2L",
                                   init_epoch=init_epoch,
                                   epoch_win=epoch_win)

        callbacks.append(d2l_learning)

        cp_callback = ModelCheckpoint("model/%s_%s_%s.hdf5" %
                                      ("D2L", DATASET, NOISE_RATIO),
                                      monitor='val_loss',
                                      verbose=0,
                                      save_best_only=False,
                                      save_weights_only=True,
                                      period=1)
        callbacks.append(cp_callback)