Create a New Learner

Helper function to generate all required files, and fill in fields, for new learners.

create_learner(
  pkg = ".",
  classname,
  algorithm,
  type,
  key = tolower(classname),
  package = tolower(classname),
  caller,
  feature_types,
  predict_types,
  properties = NULL,
  references = FALSE,
  gh_name
)

Arguments

pkg	`character(1)` Path to the mlr3extralearners package.
classname	`character(1)` Suffix for R6 class name passed to LearnerTypeclassname.
algorithm	`character(1)` Brief description of algorithm for documentation title.
type	`character(1)` See `mlr3::mlr_reflections$task_types$type`.
key	`character(1)` id for learner, if not provided defaults to the `classname` in all lower case.
package	`character(1)` Package from which the learner is implemented, defaults to the `classname` in all lower case.
caller	`character(1)` Training function called from the implemented package.
feature_types	`character()` Feature types that can be handled by the learner, see `mlr3::mlr_reflections$task_feature_types`.
predict_types	`character()` Prediction types that can be made by the learner, see `mlr3::mlr_reflections$learner_predict_types`.
properties	`character()` Properties that can be handled by the learner, see `mlr3::mlr_reflections$learner_properties`.
references	`logical(1)` Set to `TRUE` if you want to add references for the learner.
gh_name	`character(1)` Your GitHub handle, used to add you as the maintainer of the learner.

Details

This function does the following:

Creates a learner_package_type_key.R file for the implemented learner.
Creates a test_package_type_key.R file for unit testing the learner.
Creates a test_paramtest_package_type_key.R file for testing correct implementation of learner parameters.
Creates a test_package.yml file for running unit tests in GitHub actions
Automatically completes the test (2), and yaml files (4)
Automatically adds the learner package to the DESCRIPTION file
For the learner file all fields are automatically filled but methods must be manually added along with the parameter set, this is clearly marked up in the files.

To create a learner you must follow these steps:

Run this function with as many arguments as possible
Manually add .train, .predict private methods for the learner, as well as adding the param_set and possibly param_vals. If properties include "oob_error" and/or "importance" then add these public methods manually.
Check the paramtests and unit tests pass locally.
Run
1. devtools::document(roclets = c('rd', 'collate', 'namespace'))
2. styler::style_pkg(style = styler::mlr_style) (you may need to first run remotes::)
3. usethis::use_tidy_description()
4. lintr::lint_package()
Open a pull request to https://github.com/mlr-org/mlr3extralearners/pulls with the new learner template.

Arguments

Details

Examples