Training a Neural Network in a Spreadsheet
Channel: Kevin Lubick
Date: 2021-08-21

This is Part 1 in a series in which we create and train a neural network in a spreadsheet. This covers Gradient Descent Backpropagation for a simple (1 layer) neural network that learns the AND function.  We create and investigate a worked example of the formulas involved.

Part 2: https://youtu.be/1zwnPt73pow

Background information on Neural Nets:
https://www.youtube.com/watch?v=aircAruvnKk
http://neuralnetworksanddeeplearning.com/chap1.html

Sheets Template:
https://bit.ly/NNsheet

Geogebra plot:
https://www.geogebra.org/3d/ywg8mmax

More information on the Backpropagation Algorithm:
https://www.youtube.com/watch?v=tIeHLnjs5U8
http://neuralnetworksanddeeplearning.com/chap2.html

Narration by James K. Script and visualizations by Kaylee L.

0:00 Intro
1:23 Overview of neural networks
1:42 What we want to learn - AND function
2:18 Formulas that make up a neural network
2:49 Building the neural network
5:57 Hand-training the neural network
9:31 Examining our hand-trained solution
10:36 Line of best fit analogy
11:17 High-level explanation of gradient descent backpropagation
11:41 Formulas behind gradient descent
13:00 Implementing gradient descent in our spreadsheet
19:30 Using copy/paste to iteratively train the network
21:07 Recap

Entry in https://www.3blue1brown.com/blog/some1 #SoMe1

Full playlist of various Neural Networks in Spreadsheets: https://www.youtube.com/watch?v=fjfZZ6S1ad4&list=PLDs5gxU1J5CIt5kIiQLC3RBOAKnUAo412