Your First Neural Network in 20 Lines

Strip away the hype. A neural network is:

Matrix multiplications
A non-linear function after each one
Repeat

That's literally it. Input goes in, gets multiplied by weights, squished through an activation function, multiplied by more weights, squished again, and out comes a prediction.

Let's build one. Right now.

1 / 10

Ship it

A working classifier that predicts handwritten digits (MNIST)

Tensors Are Just Arrays (With Superpowers)

The Training Loop Explained

Rex — Your First Neural Network in 20 Lines

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PyTorch from Zero to Production/Build Your First Models/Your First Neural Network in 20 Lines

35 minLesson 3 of 14

Your First Neural Network in 20 Lines

Strip away the hype. A neural network is:

Matrix multiplications
A non-linear function after each one
Repeat

That's literally it. Input goes in, gets multiplied by weights, squished through an activation function, multiplied by more weights, squished again, and out comes a prediction.

Let's build one. Right now.

1 / 10

Ship it

A working classifier that predicts handwritten digits (MNIST)

Tensors Are Just Arrays (With Superpowers)

The Training Loop Explained