The ContextEval allows CallbackTunings to access and modify data while a batch of hyperparameter configurations is evaluated.
See section on active bindings for a list of modifiable objects.
callback_tuning() for a list of stages which access ContextEval.
This context is re-created each time a new batch of hyperparameter configurations is evaluated.
$benchmark_result are discarded after the function is finished.
Modification on the data table in
$aggregated_performance are written to the archive.
Any number of columns can be added.
The hyperparameter configurations of the latest batch. Contains the values on the learner scale i.e. transformations are applied. See
$xdtin bbotk::ContextOptimization for the untransformed values.
The benchmark design of the latest batch.
The benchmark result of the latest batch.
Aggregated performance scores and training time of the latest batch. This data table is passed to the archive. A callback can add additional columns which are also written to the archive.
Creates a new instance of this R6 class.
Identifier for the new callback.