Description

Environment which stores various information to allow objects to examine and introspect their structure and properties (c.f. Reflections).

This environment be modified by third-party packages, e.g. by adding information about new task types or by extending the set of allowed feature types.

The following objects are set by mlr3:

• data_formats (character())
  Vectors of supported data formats, e.g. "data.table" or "Matrix".

• task_types (data.table())
  Table with task type ("type"), the implementing package ("pkg"), and the names of the generators of the corresponding Task ("task"), Learner ("learner"), Prediction ("prediction") and Measure ("measure").

• task_feature_types (named character())
  Vector of base R types supported as Task features, named with a 3 letter abbreviation.

• task_row_roles (character())
  Vector of supported row roles for a Task.

• task_col_roles (list of character())
  List of vectors of supported column roles for a Task, named by their task type.

• task_properties (list of character())
  List of vectors of supported Task properties, named by their task type.

• learner_properties (list of character())
  List of vectors of supported Learner properties, named by their task type.

• learner_predict_types (list of list of character())
  List of lists of supported Learner predict_types, named by their task type. The inner list translates the "predict_type" to all predict types returned, e.g. predict type "prob" for a LearnerClassif provides the probabilities as well as the predicted labels, therefore "prob" maps to c("response", "prob").

• learner_predict_types (list of list of character())
  List of lists of supported Learner predict_types, named by their task type.

• predict_sets (character())
  Vector of possible predict sets. Currently supported are "train" and "test".

• measure_properties (list of character())
  List of vectors of supported Measure properties, named by their task type.

• default_measures (list of character())
  List of keys for the default Measures, named by their task type.

• rr_names (character())
  Names of the objects stored in a ResampleResult.

• auto_converters (environment())
  Environment of converter functions used for rbind-ing data to tasks. Functions are named using the pattern "[from_type]___[to_type]". Can be extended by third-party with additional converters.

Usage

Format

environment.

Examples