Leila Etaati has an introduction to market basket analysis with R:
For instance, imagine we have below transaction items from a shopping store for last hours,
Customer 1: Salt, pepper, Blue cheese
Customer 2: Blue Cheese, Pasta, Pepper, tomato sauce
Customer 3: Salt, Blue Cheese, Pepperoni, Bacon, egg
Customer 4: water, Pepper, Egg, Salt
we want to know how many times customer purchase pepper and salt together
the support will be : from out four main transactions (4 customers), 2 of them purchased salt and pepper together. so the support will be 2 divided by 4 (all number of transaction.
Basket analysis is one way of building a recommendation engine: if you’re buying butter, cream, and eggs, do you also want to buy sugar?