我正在尝试创建一个LSTM模型。在将数据传递到第一个LSTM层之前,我想添加一个Masking
层。我能够使用Keras中的Sequential方法来实现这一点。请参见示例。然而,当我尝试以不同的方式编写代码时,我会得到一个值错误(见下文)。有什么想法如何解决这个问题吗?
import keras
def network_structure(window_len, n_features, lstm_neurons):
masking = keras.layers.Masking(
mask_value=0.0, input_shape=(window_len, n_features)
)
lstm_h1 = keras.layers.LSTM(lstm_neurons)(masking)
lstm_h2 = keras.layers.LSTM(lstm_neurons)(lstm_h1)
cte = keras.layers.Dense(
1,
activation='linear',
name='CTE',
)(lstm_h2)
ate = keras.layers.Dense(
1,
activation='linear',
name='ATE',
)(lstm_h2)
pae = keras.layers.Dense(
1,
activation='linear',
name='PAE',
)(lstm_h2)
model = keras.models.Model(
inputs=masking,
outputs=[cte, ate, pae]
)
model.compile(loss='mean_squared_error', optimizer='adam', metrics=['mae'])
model.summary()
return model
model = network_structure(32, 44, 125)
错误信息:
Using TensorFlow backend.
Traceback (most recent call last):
File "C:\Python35\lib\site-packages\keras\engine\topology.py", line 442, in assert_input_compatibility
K.is_keras_tensor(x)
File "C:\Python35\lib\site-packages\keras\backend\tensorflow_backend.py", line 468, in is_keras_tensor
raise ValueError('Unexpectedly found an instance of type `' + str(type(x)) + '`. '
ValueError: Unexpectedly found an instance of type `<class 'keras.layers.core.Masking'>`. Expected a symbolic tensor instance.
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:/Users/Master Tk/PycharmProjects/FPL/testcompile.py", line 46, in <module>
model = network_structure(32, 44, 125)
File "C:/Users/Master Tk/PycharmProjects/FPL/testcompile.py", line 12, in network_structure
lstm_h1 = keras.layers.LSTM(lstm_neurons)(masking)
File "C:\Python35\lib\site-packages\keras\layers\recurrent.py", line 499, in __call__
return super(RNN, self).__call__(inputs, **kwargs)
File "C:\Python35\lib\site-packages\keras\engine\topology.py", line 575, in __call__
self.assert_input_compatibility(inputs)
File "C:\Python35\lib\site-packages\keras\engine\topology.py", line 448, in assert_input_compatibility
str(inputs) + '. All inputs to the layer '
ValueError: Layer lstm_1 was called with an input that isn't a symbolic tensor. Received type: <class 'keras.layers.core.Masking'>. Full input: [<keras.layers.core.Masking object at 0x000002224683A780>]. All inputs to the layer should be tensors.