StatQuest: t-SNE, Clearly Explained

t-SNE is a popular method for making an easy to read graph from a complex dataset, but not many people know how it works. Here's the inside scoop.

Here’s how to create a t-SNE graph in R (this is copied from the help file for Rtsne)…

library("Rtsne")
iris_unique <- unique(iris) # Remove duplicates
iris_matrix <- as.matrix(iris_unique[,1:4])
set.seed(42) # Set a seed if you want reproducible results
tsne_out <- Rtsne(iris_matrix) # Run TSNE

Show the objects in the 2D tsne representation
plot(tsne_out$Y,col=iris_unique$Species)

This StatQuest is based on the original t-SNE manuscript, and it's not super hard to read (especially if you understand the general idea of how it works): https://lvdmaaten.github.io/publicati...

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0:00 Awesome song and introduction
1:19 Overview of what t-SNE does
2:24 Overview of how t-SNE works
4:12 Step 1: Determine high-dimensional similarities
9:26 Step 2: Determine low-dimensional similarities
10:33 Step 3: Move points in low-d
11:05 Why the t-distribution is used instead of the normal distribution

Corrections:
6:17 I should have said that the blue points have twice the density of the purple points.
7:08 There should be a 0.05 in the denominator, not a 0.5.

#statquest #tsne