ValueError: Error when checking input: expected conv2d_1_input to have 4 dimensions, but got array with shape (60000, 28, 28)

• 报错

Traceback (most recent call last):
  File "D:/PyCharm 5.0.3/WorkSpace/3.Keras/3.构建各种神经网络/3.CNN.py", line 46, in <module>
    model.fit(x_train, y_train, epochs=1, batch_size=32)
  File "D:\Anaconda3\lib\site-packages\keras\engine\training.py", line 952, in fit
    batch_size=batch_size)
  File "D:\Anaconda3\lib\site-packages\keras\engine\training.py", line 751, in _standardize_user_data
    exception_prefix='input')
  File "D:\Anaconda3\lib\site-packages\keras\engine\training_utils.py", line 128, in standardize_input_data
    'with shape ' + str(data_shape))
ValueError: Error when checking input: expected conv2d_1_input to have 4 dimensions, but got array with shape (60000, 28, 28)

• 原因
  输入的格式不对
• 解决
  将数据集标准化

x_train = x_train.reshape(x_train.shape[0],1,28,28)/255
x_test = x_test.reshape(x_test.shape[0],1,28,28)/255
y_train = np_utils.to_categorical(y_train,num_classes=10)
y_test = np_utils.to_categorical(y_test,num_classes=10)