ValueError: Error when checking input: expected conv2d_1_input to have 4 dimensions, but got array w.
在进行mnist识别时,https://www.charleychai.com/blogs/2018/ai/NN/lenet.html中,X_train=X_train.reshape(-1,28,28,1)X_test=X_test.reshape(-1,28,28,1)为什么要设置最后一维为1呢?可以查看Conv2D中对input_shape的说明,https://keras.io/layer