Neural Networks & Deep Learning

The forward and backward pass built from nothing, then stacked until it is deep.

Module 03.1 · Intermediate
Free

10h · 12 lessons · 1 challenge

Before this: Numerical Computing & Stability, Neural Networks: the First Pass

About this module

The second pass at neural networks, and the one that takes the backward pass apart. Logistic regression is rebuilt as a one-neuron network so that the computation graph and its derivatives are visible, then vectorized across a batch, then widened into a hidden layer, then deepened.

You implement all of it in NumPy before touching a framework, because the shapes are the whole difficulty and a framework hides them.

After this module you can

12 lessons

Lesson 1
1What a neural network is, and why deep learning took off
Kind
Concept
Length
40 min
Lesson 2
2Binary classification and logistic regression as a network
Kind
Concept
Length
45 min
Lesson 3
3The computation graph, and derivatives on it
Kind
Concept
Length
50 min
Lesson 4
4Vectorizing logistic regression across a batch
Kind
Concept
Length
45 min
Lesson 5
5A shallow network: forward and backward
Kind
Concept
Length
55 min
Lesson 6
6Activation functions, and why they must be nonlinear
Kind
Concept
Length
45 min
Lesson 7
7Random initialization, and why not zeros
Kind
Concept
Length
40 min
Lesson 8
8Deep networks: forward and backward propagation
Kind
Concept
Length
55 min
Lesson 9
9Getting the matrix dimensions right
Kind
Concept
Length
45 min
Lesson 10
10Shape Sprint: annotate the network against the clock
Kind
Interactive
Length
30 min
Lesson 11
11Build a deep network in NumPy
Kind
Lab
Length
100 min
Lesson 12
12Checkpoint: trace the gradient
Kind
Checkpoint
Length
25 min

The challenge: Shape Sprint

Annotate every tensor in a deep network with its shape, against the clock. One wrong dimension ends the run.

Worth 450 XP.

Related modules

All modules
Making Deep Networks Train
9h · 12 lessons
Convolutional Networks
11h · 14 lessons