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. See callback_tuning() for a list of stages which access ContextEval.

## Details

This context is re-created each time a new batch of hyperparameter configurations is evaluated. Changes to $objective_tuning, $design $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.

## Super class

mlr3misc::Context -> ContextEval

## Public fields

objective_tuning

## Active bindings

xss

(list())

#### Arguments

objective_tuning
id

(character(1))
Identifier for the new callback.

### Method clone()

The objects of this class are cloneable with this method.

#### Usage

ContextEval\$clone(deep = FALSE)

#### Arguments

deep

Whether to make a deep clone.