python-3.x - 使用predict_generator时如何返回项目的真实标签？

Question

我正在使用 predict_generator() 函数观察神经网络的输出，但我无法看到预测项目的真实标签。如何实现一个 block 来查看输入项的真实标签？

test_datagen = ImageDataGenerator(
rescale=1./255,
rotation_range=45,
width_shift_range=0.25,
height_shift_range=0.25,
horizontal_flip=True,
)
test_generator = test_datagen.flow_from_directory(
    evaluate_path,
    target_size=(width, height),
    batch_size=batch_size,
    class_mode='categorical')

model.compile(optimizer=SGD(lr=0.0001, momentum=0.9),      loss='categorical_crossentropy', metrics=['accuracy'])
x = model.predict_generator(test_generator, val_samples=1)
print(x)

Answer 1

尝试以下功能:

from six import next

def generator_with_true_classes(model, generator):
    while True:
        x, y = next(generator)
        yield x, model.predict(x), y

它将产生原始数据，y_pred 和 y_true。按以下方式使用:

nb_of_samples = 0
nb_of_samples_to_compute = 100 # set your own value
for x, y_pred, y_true in generator_with_true_classes(model, test_generator):
    # do something with data, eg. print it.
    nb_of_samples += 1
    if nb_of_samples == nb_of_samples_to_compute:
         break