这是关于TF 2.0的。
请在下面找到我的代码,它使用sklearn.model_selection.GridSearchCV
对mnist数据集执行GridSearch和交叉验证,工作得很好。
# Build Function to create model, required by KerasClassifier
def create_model(optimizer_val='RMSprop',hidden_layer_size=16,activation_fn='relu',dropout_rate=0.1,regularization_fn=tf.keras.regularizers.l1(0.001),kernel_initializer_fn=tf.keras.initializers.glorot_uniform,bias_initializer_fn=tf.keras.initializers.zeros):
model = tf.keras.models.Sequential([
tf.keras.layers.Flatten(input_shape=(28, 28)),
tf.keras.layers.Dense(units=hidden_layer_size, activation=activation_fn,kernel_regularizer=regularization_fn,kernel_initializer=kernel_initializer_fn,bias_initializer=bias_initializer_fn),
tf.keras.layers.Dropout(dropout_rate),
tf.keras.layers.Dense(units=hidden_layer_size,activation='softmax',kernel_regularizer=regularization_fn,kernel_initializer=kernel_initializer_fn,bias_initializer=bias_initializer_fn)
])
optimizer_val_final=optimizer_val
model.compile(optimizer=optimizer_val, loss='sparse_categorical_crossentropy', metrics=['accuracy'])
return model
#Create the model with the wrapper
model = tf.keras.wrappers.scikit_learn.KerasClassifier(build_fn=create_model, epochs=100, batch_size=10, verbose=2)
#Initialize the parameter grid
nn_param_grid = {
'epochs': [10],
'batch_size':[128],
'optimizer_val': ['Adam','SGD'],
'hidden_layer_size': [128],
'activation_fn': ['relu'],
'dropout_rate': [0.2],
'regularization_fn':['l1','l2','L1L2'],
'kernel_initializer_fn':['glorot_normal', 'glorot_uniform'],
'bias_initializer_fn':[tf.keras.initializers.zeros]
}
#Perform GridSearchCV
grid = GridSearchCV(estimator=model, param_grid=nn_param_grid, verbose=2, cv=3,scoring=precision_custom,return_train_score=False,n_jobs=-1)
grid_result = grid.fit(x_train, y_train)
我的想法是传递具有不同学习率的不同优化器,比如Adam的学习率为0.1,0.01和0.001。我还想尝试使用不同学习率和动量值的SGD。
在这种情况下,当我传递'optimizer_val': [tf.keras.optimizers.Adam(0.1)],
时,会得到如下所示的错误:
Cannot clone object <tensorflow.python.keras.wrappers.scikit_learn.KerasClassifier object at 0x7fe08b210e10>, as the constructor either does not set or modifies parameter optimizer_val
请告诉我如何纠正这个错误。
发布于 2020-03-03 10:33:30
这是sklearn bug。您应该降低sklearn的版本:
conda install scikit-learn==0.21.2
好了!
发布于 2020-08-23 06:55:46
您可以通过将列表更改为元组来解决此问题。如果有任何单值实例,则可以使用list。
#Initialize the parameter grid
nn_param_grid = {
'epochs': [10],
'batch_size':[128],
'optimizer_val': ('Adam','SGD'),
'hidden_layer_size': [128],
'activation_fn': ['relu'],
'dropout_rate': [0.2],
'regularization_fn':('l1','l2','L1L2'),
'kernel_initializer_fn':('glorot_normal', 'glorot_uniform'),
'bias_initializer_fn':[tf.keras.initializers.zeros]
}
https://stackoverflow.com/questions/59746974
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