python - set_model() 缺少 1 个必需的位置参数 : 'model'

Question

我已经创建了一个 Keras 顺序模型并正在使用 Adam 优化器。我希望在每个纪元之后获得学习率。这stackoverflow question似乎回答了我的问题。但是，当我按照提到的解决方案进行操作时，出现以下错误

set_model() missing 1 required positional argument: 'model'

这是我创建模型的代码:

model = Sequential()

model.add(Conv2D(64, (5, 5), input_shape=(IMG_HEIGHT, IMG_WIDTH, 3), activation='relu'))

model.add(Conv2D(64, (5, 5), activation='relu'))
model.add(MaxPooling2D((2, 2)))
model.add(Dropout(0.2))

model.add(Conv2D(128, (5, 5), activation='relu'))
model.add(Conv2D(128, (5, 5), activation='relu'))
model.add(MaxPooling2D((2, 2)))
model.add(Dropout(0.2))

model.add(Conv2D(256, (5, 5), activation='relu'))
model.add(Conv2D(256, (5, 5), activation='relu'))
model.add(MaxPooling2D((2, 2)))
model.add(BatchNormalization(axis=3))
model.add(Dropout(0.2))

model.add(Flatten())
model.add(Dense(256, activation='relu'))

model.add(Dropout(0.5))

model.add(Dense(256, activation='relu'))

model.add(Dropout(0.5))
model.add(Dense(10, activation='softmax'))

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

learning_rate_reduction = ReduceLROnPlateau(monitor='val_acc', 
                                            patience=3, 
                                            verbose=1, 
                                            factor=0.4, 
                                            min_lr=0.0001)
csvlogger = CSVLogger("solution.csv", separator='\t')
checkpoint = ModelCheckpoint("models/best_model5.h5", monitor="val_acc", save_best_only=True, mode='max')
learning_rate_reduction = ReduceLROnPlateau(monitor='val_acc', 
                                            patience=3, 
                                            verbose=1, 
                                            factor=0.4, 
                                            min_lr=0.00001)

class MyCallback(keras.callbacks.Callback):
    def on_epoch_end(self, epoch, logs=None):
        lr = self.model.optimizer.lr
        decay = self.model.optimizer.decay
        iterations = self.model.optimizer.iterations
        lr_with_decay = lr / (1. + decay * K.cast(iterations, K.dtype(decay)))
        print(K.eval(lr_with_decay))

model.fit_generator(datagen.flow(x_train, y_train, batch_size=75), 
                           epochs=10, validation_data=(x_validation, y_test),verbose=1, 
                           steps_per_epoch=x_train.shape[0], callbacks=[csvlogger, checkpoint, MyCallback])

我如何克服这个错误“set_model() missing 1 required positional argument: 'model' “ 下面是堆栈跟踪

TypeError                                 Traceback (most recent call last)
<ipython-input-12-1826a19039cd> in <module>()
    128 model.fit_generator(datagen.flow(x_train, y_train, batch_size=75), 
    129                            epochs=10, validation_data=(x_validation, y_test),verbose=1,
--> 130                            steps_per_epoch=x_train.shape[0], callbacks=[csvlogger, checkpoint, MyCallback])
    131 model.save('trained_model5.h5')
    132 

/usr/local/lib/python3.6/dist-packages/keras/legacy/interfaces.py in wrapper(*args, **kwargs)
     89                 warnings.warn('Update your `' + object_name +
     90                               '` call to the Keras 2 API: ' + signature, stacklevel=2)
---> 91             return func(*args, **kwargs)
     92         wrapper._original_function = func
     93         return wrapper

/usr/local/lib/python3.6/dist-packages/keras/models.py in fit_generator(self, generator, steps_per_epoch, epochs, verbose, callbacks, validation_data, validation_steps, class_weight, max_queue_size, workers, use_multiprocessing, shuffle, initial_epoch)
   1274                                         use_multiprocessing=use_multiprocessing,
   1275                                         shuffle=shuffle,
-> 1276                                         initial_epoch=initial_epoch)
   1277 
   1278     @interfaces.legacy_generator_methods_support

/usr/local/lib/python3.6/dist-packages/keras/legacy/interfaces.py in wrapper(*args, **kwargs)
     89                 warnings.warn('Update your `' + object_name +
     90                               '` call to the Keras 2 API: ' + signature, stacklevel=2)
---> 91             return func(*args, **kwargs)
     92         wrapper._original_function = func
     93         return wrapper

/usr/local/lib/python3.6/dist-packages/keras/engine/training.py in fit_generator(self, generator, steps_per_epoch, epochs, verbose, callbacks, validation_data, validation_steps, class_weight, max_queue_size, workers, use_multiprocessing, shuffle, initial_epoch)
   2131         else:
   2132             callback_model = self
-> 2133         callbacks.set_model(callback_model)
   2134         callbacks.set_params({
   2135             'epochs': epochs,

/usr/local/lib/python3.6/dist-packages/keras/callbacks.py in set_model(self, model)
     50     def set_model(self, model):
     51         for callback in self.callbacks:
---> 52             callback.set_model(model)
     53 
     54     def on_epoch_begin(self, epoch, logs=None):

TypeError: set_model() missing 1 required positional argument: 'model'

另外，我的另一个问题是，上述解决方案是否正确。 This tensorflow link about Adam Optimizer建议学习率计算为:

lr_t <- learning_rate * sqrt(1 - beta2^t) / (1 - beta1^t)

这似乎与其他链接中提到的解决方案完全不同。我错过了什么吗？

Answer 1

实际上，在 model.fit_generator 方法的回调参数中，您传递的是类而不是该类的对象。

应该是

my_calback_object = MyCallback() # create an object of the MyCallback class

model.fit_generator(datagen.flow(x_train, y_train, batch_size=75), 
                    epochs=10, validation_data=(x_validation, y_test),
                    verbose=1, steps_per_epoch=x_train.shape[0],
                    callbacks=[csvlogger, checkpoint, my_callback_object])