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$help()
.- on_optimization_begin
(
function()
)
Stage called at the beginning of the optimization. Called inOptimizer$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 inOptimInstance$.eval_point()
.- on_eval_after_xs
(
function()
)
Stage called after xs is passed. Called inObjectiveTuning$eval()
.- on_eval_after_resample
(
function()
)
Stage called after a hyperparameter configuration is evaluated. Called inObjectiveTuning$eval()
.- on_eval_before_archive
(
function()
)
Stage called before performance values are written to the archive. Called inObjectiveTuning$eval()
.- on_optimizer_after_eval
(
function()
)
Stage called after points are evaluated. Called inOptimInstance$.eval_point()
.- on_worker_end
(
function()
)
Stage called at the end of the optimization on the worker. Called in the worker loop.- on_result
(
function()
)
Stage called after the result is written. Called inOptimInstance$assign_result()
.- on_optimization_end
(
function()
)
Stage called at the end of the optimization. Called inOptimizer$optimize()
.
Details
When implementing a callback, each function must have two arguments named callback
and context
.
A callback can write data to the state ($state
), e.g. settings that affect the callback itself.
Tuning callbacks access ContextAsyncTuning.