Create Asynchronous Optimization Callback

Function to create a CallbackAsync.

Optimization callbacks can be called from different stages of optimization process. The stages are prefixed with on_*.

Start Optimization
     - on_optimization_begin
    Start Worker
         - on_worker_begin
           Start Optimization on Worker
             - on_optimizer_before_eval
             - on_optimizer_after_eval
           End Optimization on Worker
         - on_worker_end
    End Worker
     - on_result_begin
     - on_result_end
     - on_optimization_end
End Optimization

See also the section on parameters for more information on the stages. A optimization callback works with ContextAsync.

Usage

callback_async(
  id,
  label = NA_character_,
  man = NA_character_,
  on_optimization_begin = NULL,
  on_worker_begin = NULL,
  on_optimizer_before_eval = NULL,
  on_optimizer_after_eval = NULL,
  on_worker_end = NULL,
  on_result_begin = NULL,
  on_result_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 in the main process. Called in Optimizer$optimize(). The functions must have two arguments named callback and context.

on_worker_begin

(function())
Stage called at the beginning of the optimization on the worker. Called in the worker loop. The functions must have two arguments named callback and context.

on_optimizer_before_eval

(function())
Stage called after the optimizer proposes points. Called in OptimInstance$.eval_point(). The functions must have two arguments named callback and context. The argument of instance$.eval_point(xs) and xs_trafoed and extra are available in the context. Or xs and xs_trafoed of instance$.eval_queue() are available in the context.

on_optimizer_after_eval

(function())
Stage called after points are evaluated. Called in OptimInstance$.eval_point(). The functions must have two arguments named callback and context. The outcome y is available in the context.

on_worker_end

(function())
Stage called at the end of the optimization on the worker. Called in the worker loop. The functions must have two arguments named callback and context.

on_result_begin

(function())
Stage called before result are written. Called in OptimInstance$assign_result(). The functions must have two arguments named callback and context. The arguments of $.assign_result(xdt, y, extra) are available in the context.

on_result_end

(function())
Stage called after result are written. Called in OptimInstance$assign_result(). The functions must have two arguments named callback and context. The final result instance$result is available in the context.

on_result

(function())
Deprecated. Use on_result_end instead. Stage called after result are written. Called in OptimInstance$assign_result(). The functions must have two arguments named callback and context.

on_optimization_end

(function())
Stage called at the end of the optimization in the main process. Called in Optimizer$optimize(). The functions must have two arguments named callback and context.

Details

A callback can write data to its state ($state), e.g. settings that affect the callback itself. The ContextAsync allows to modify the instance, archive, optimizer and final result.