Returns the selected internal validation score of the Learner for learners with property "validation". Returns NA for unsupported learners, when no validation was done, or when the selected id was not found. The id of this measure is set to the value of select if provided.
Dictionary
This Measure can be instantiated via the dictionary mlr_measures or with the associated sugar function msr():
Which of the internal validation scores to select. Which scores are available depends on the learner and its configuration. By default, the first score is chosen.
minimize: (logical(1))
Whether smaller values are better. Must be set to use for tuning.
Method clone()
The objects of this class are cloneable with this method.