Example Dataset

Consider a dataset with $5$ users and $5$ items. The ratings are on a scale from $1$ to $5,$ with some missing values represented as NaN $.$

$\backslash$table$[[$User$/$Item$,$Item $1,$Item $2,$Item $3,$Item $4,$Item $5],[$User $1,4,3,$NaN,$5,2],[$User $2,5,$NaN,$4,4,1],[$User $3,$NaN,$4,3,3,$NaN$],[$User $4,3,$NaN,$4,5,2],[$User $5,4,3,4,$NaN,NaN$]]$

Let's calculate the similarity between User $1$ and User $2$ using Jaccard, Cosine, and Pearson correlation coefficients.