vzhou842 / neural-network-from-scratch Goto Github PK

Hi, I really enjoyed your blog post. Maybe you can make use of your Neuron class in the second example of the OurNeuralNetwork class? Seems like it was introduced earlier, then forgotten, but it does provide a good abstraction. Thanks for the great post!

Hi,
I read your article about creating a neural network, and ended up here. I am looking into modularizing my code a bit and keep stumbling across a problem. First, am I understanding this line correctly:

Is this the derivative of the cost function (MSE in this tutorial), or how does one end up here?
Does that mean, that a cost function must always exist as it's "forward" form and as it's backward(derived) from? (The later being used to initialize the starting gradient when training).

Either I am missunderstanding this, or it's hard to find the derivatives for well known cost functions (it has been a while since i have done this myself, and Math notation is a bit blurry to me).