A few last words about the neural network implementation
You may be wondering why we went through all of this theory just to implement a simple multilayer artificial network that can classify handwritten digits instead of using an open source Python machine learning library. In fact, we will introduce more complex NN models in the next chapters, which we will train using the open source TensorFlow library (https://www.tensorflow.org).
Although the from-scratch implementation in this chapter seems a bit tedious at first, it was a good exercise for understanding the basics behind backpropagation and NN training, and a basic understanding of algorithms is crucial for applying machine learning techniques appropriately and successfully.
Now that you have learned how feedforward NNs work, we are ready to explore more sophisticated DNNs by using TensorFlow, which allows us to construct NNs more efficiently, as we will see in Chapter 13, Parallelizing Neural Network Training with TensorFlow...