add early_stopping

Author: loveunk

Diff for: tensorflow/code/tensorflow.keras.mnist.classifier.py

@@ -117,6 +117,7 @@
                                                                verbose=1,
                                                                factor=0.5,
                                                                min_lr=0.00001)
+early_stopping = tf.keras.callbacks.EarlyStopping(monitor='val_loss', restore_best_weights=True)
 
 # 设置epochs和batch size
 epochs = 20
@@ -143,12 +144,12 @@
                               validation_data=(X_val, Y_val),
                               verbose=2,
                               steps_per_epoch=X_train.shape[0] // batch_size,
-                              callbacks=[learning_rate_reduction, tf.keras.callbacks.TensorBoard(log_dir='./log_dir')])
+                              callbacks=[learning_rate_reduction, early_stopping, tf.keras.callbacks.TensorBoard(log_dir='./log_dir')])
 
 # 画训练集和验证集的loss和accuracy曲线。可以判断是否欠拟合或过拟合
 fig, ax = plt.subplots(2, 1)
 ax[0].plot(history.history['loss'], color='b', label="Training loss")
-ax[0].plot(history.history['val_loss'], color='r', label="validation loss",axes =ax[0])
+ax[0].plot(history.history['val_loss'], color='r', label="validation loss", axes =ax[0])
 legend = ax[0].legend(loc='best', shadow=True)
 
 ax[1].plot(history.history['acc'], color='b', label="Training accuracy")