使用功能性API进行Keras超参数调优
我正在尝试使用 Keras Tuner 来优化一些超参数,这是我的代码:
def criar_modelo(hp):
lstm_input = Input(shape=(x_train_lstm.shape[1], 1), name='LSTM_Input_Layer')
static_input = Input(shape=(x_train_static.shape[1], ), name='Static_Input_Layer')
# LSTM 1
lstm_layer_1 = LSTM(units=hp.Int('units_lstm_layer_1', min_value=128, max_value=256, step=64), activation='tanh', return_sequences=False, name='1_LSTM_Layer')(lstm_input)
# Static 1
static_layer_1 = Dense(units=hp.Int('units_static_layer_1', min_value=64, max_value=192, step=64), activation=hp.Choice('activation', ['relu', 'tanh']), name='1_Static_Layer')(static_input)
# Static 2 e/ou 3
for i in range(hp.Int('num_static_layers', 1, 3)):
static_layer = Dense(units=hp.Int(f'static_units_{i}', 128, 192, step=32), activation=hp.Choice('activation', ['relu', 'tanh']), name=f'{i+1}_Static_Layer')(static_layer_1)
static_layer_1 = static_layer
concatenar = Concatenate(axis=1, name='Concatenate')([lstm_layer_1, static_layer_1])
dense_1 = Dense(units=4*len(np.unique(y_train)), activation='relu', name='1_Dense_Layer')(concatenar)
dense_2 = Dense(units=2*len(np.unique(y_train)), activation='relu', name='2_Dense_Layer')(dense_1)
saida = Dense(units=len(np.unique(y_train)), activation='softmax', name='Output_Layer')(dense_2)
model = Model(inputs=[lstm_input, static_input], outputs=[saida])
model.compile(optimizer='adam', loss='sparse_categorical_crossentropy', metrics=['accuracy'])
return model
但是,我遇到了以下错误:
Traceback (most recent call last):
Cell In[11], line 27
tuner = keras_tuner.GridSearch(
File ~\miniconda3\envs\tf-gpu\lib\site-packages\keras_tuner\src\tuners\gridsearch.py:420 in __init__
super().__init__(oracle, hypermodel, **kwargs)
File ~\miniconda3\envs\tf-gpu\lib\site-packages\keras_tuner\src\engine\tuner.py:122 in __init__
super().__init__(
File ~\miniconda3\envs\tf-gpu\lib\site-packages\keras_tuner\src\engine\base_tuner.py:132 in __init__
self._populate_initial_space()
File ~\miniconda3\envs\tf-gpu\lib\site-packages\keras_tuner\src\engine\base_tuner.py:192 in _populate_initial_space
self._activate_all_conditions()
File ~\miniconda3\envs\tf-gpu\lib\site-packages\keras_tuner\src\engine\base_tuner.py:149 in _activate_all_conditions
self.hypermodel.build(hp)
Cell In[11], line 23 in criar_modelo
model = Model(inputs=[lstm_input, static_input], outputs=[saida])
File ~\miniconda3\envs\tf-gpu\lib\site-packages\tensorflow\python\training\tracking\base.py:629 in _method_wrapper
result = method(self, *args, **kwargs)
File ~\miniconda3\envs\tf-gpu\lib\site-packages\keras\engine\functional.py:146 in __init__
self._init_graph_network(inputs, outputs)
File ~\miniconda3\envs\tf-gpu\lib\site-packages\tensorflow\python\training\tracking\base.py:629 in _method_wrapper
result = method(self, *args, **kwargs)
File ~\miniconda3\envs\tf-gpu\lib\site-packages\keras\engine\functional.py:229 in _init_graph_network
nodes, nodes_by_depth, layers, _ = _map_graph_network(
File ~\miniconda3\envs\tf-gpu\lib\site-packages\keras\engine\functional.py:1049 in _map_graph_network
raise ValueError(
ValueError: The name "1_Static_Layer" is used 2 times in the model. All layer names should be unique.
我不明白为什么会出现这个错误,因为这些 i_Static_Layer
是在一个循环中定义的,循环范围是 range(1, 3)
。
如果我尝试 print('i =', i)
,它确实显示 i = 0
,但这是为什么呢?
我可以把 name=f'{i+1}_Static_Layer'
改成 name=f'{i+2}_Static_Layer'
来跳过这个错误。但我还是想搞明白到底发生了什么。
1 个回答
1
注意,
hp.Int('num_static_layers', 1, 3)
这个部分会先被计算出来,然后结果会传递给范围生成器。所以举个例子,如果 hp.Int('num_static_layers', 1, 3) 返回的是 1,那么代码就会变成:
range(1)
这时的结果是 0。