callback_async_tuning: Create Asynchronous Tuning Callback

In mlr3tuning: Hyperparameter Optimization for 'mlr3'

Create Asynchronous Tuning Callback

Description

Function to create a CallbackAsyncTuning. Predefined callbacks are stored in the dictionary mlr_callbacks and can be retrieved with clbk().

Tuning callbacks can be called from different stages of the tuning process. The stages are prefixed with ⁠on_*⁠.

Start Tuning
     - on_optimization_begin
    Start Worker
         - on_worker_begin
         Start Optimization on Worker
           - on_optimizer_before_eval
             Start Evaluation
               - on_eval_after_xs
               - on_eval_after_resample
               - on_eval_before_archive
             End Evaluation
          - on_optimizer_after_eval
         End Optimization on Worker
         - on_worker_end
    End Worker
     - on_result
     - on_optimization_end
End Tuning

See also the section on parameters for more information on the stages. A tuning callback works with ContextAsyncTuning.

Usage

callback_async_tuning(
  id,
  label = NA_character_,
  man = NA_character_,
  on_optimization_begin = NULL,
  on_worker_begin = NULL,
  on_optimizer_before_eval = NULL,
  on_eval_after_xs = NULL,
  on_eval_after_resample = NULL,
  on_eval_before_archive = NULL,
  on_optimizer_after_eval = NULL,
  on_worker_end = NULL,
  on_result = NULL,
  on_optimization_end = NULL
)

Arguments

id	(character(1)) Identifier for the new instance.
label	(character(1)) Label for the new instance.
man	(character(1)) String in the format ⁠[pkg]::[topic]⁠ pointing to a manual page for this object. The referenced help package can be opened via method ⁠$help()⁠.
on_optimization_begin	(⁠function()⁠) Stage called at the beginning of the optimization. Called in Optimizer$optimize().
on_worker_begin	(⁠function()⁠) Stage called at the beginning of the optimization on the worker. Called in the worker loop.
on_optimizer_before_eval	(⁠function()⁠) Stage called after the optimizer proposes points. Called in OptimInstance$.eval_point().
on_eval_after_xs	(⁠function()⁠) Stage called after xs is passed. Called in ObjectiveTuning$eval().
on_eval_after_resample	(⁠function()⁠) Stage called after a hyperparameter configuration is evaluated. Called in ObjectiveTuning$eval().
on_eval_before_archive	(⁠function()⁠) Stage called before performance values are written to the archive. Called in ObjectiveTuning$eval().
on_optimizer_after_eval	(⁠function()⁠) Stage called after points are evaluated. Called in OptimInstance$.eval_point().
on_worker_end	(⁠function()⁠) Stage called at the end of the optimization on the worker. Called in the worker loop.
on_result	(⁠function()⁠) Stage called after the result is written. Called in OptimInstance$assign_result().
on_optimization_end	(⁠function()⁠) Stage called at the end of the optimization. Called in Optimizer$optimize().

Details

When implementing a callback, each function must have two arguments named callback and context. A callback can write data to the state (⁠$state⁠), e.g. settings that affect the callback itself. Tuning callbacks access ContextAsyncTuning.

mlr3tuning documentation built on Oct. 27, 2024, 9:06 a.m.