This chapter gives instructions on how to extend mlr3 and its extension packages with custom objects.

The approach is always the same:

  1. determine the base class you want to inherit from,
  2. extend the class with your custom functionality,
  3. test your implementation
  4. (optionally) add new object to the respective Dictionary.

The chapter Create a new learner illustrates the steps needed to create a custom learner in mlr3.