Hello,

I want to create CoreML Recommender model where my training data looks like that:

userID (UUID)  | itemID (UUID) | rating (Int)

user can rate from 0 to x number of items and until every user in training data rates same number of items (for example 10) everything works fine.

But when I try to create traiing model where user1 rates two items, user2 rates five items, user3 rates one item I start having this error:

Playground execution terminated: An error was thrown and was not caught:
▿ Item IDs in the recommender model must be numbered 0, 1, ..., num_items - 1.
  ▿ generic : 1 element
    - reason : "Item IDs in the recommender model must be numbered 0, 1, ..., num_items - 1."

how can I fix this?

full playground code:

let trainingData = try MLDataTable(contentsOf: URL(fileURLWithPath: "/.../test.csv"))
let model = try MLRecommender (trainingData: trainingData, userColumn: "userID", itemColumn: "itemID", ratingColumn: "rating")
let recs = try model.recommendations(fromUsers: ["050510A3-0C96-4F57-8A45-433422680464"])

and here is solution if someone will look for it

My article on MLRecommender https://www.pawelmadej.com/post/mlrecommender-in-practice/