Archive-Backed Surrogate Adapter

Adapter for acquisition functions that need archive, search-space, and codomain context but do not need model predictions.

SurrogateNull inherits from mlr3mbo::Surrogate so that mlr3mbo::AcqFunction can derive its domain, codomain, and archive through the usual $surrogate active binding. Its update and reset methods are no-ops, and $predict() errors because there is no model.

Creates a new archive-backed surrogate adapter.

Prediction is intentionally unsupported.

Arguments

archive

(NULL | bbotk::Archive)
Archive carrying search-space and observed-evaluation context.

cols_x

(NULL | character())
Feature columns. Defaults to archive$cols_x.

cols_y

(NULL | character())
Target columns. Defaults to archive$cols_y.

xdt

(data.table::data.table())
New data.

Fields

print_id

(character(1)) Short printer id.

n_learner

(integer(1)) Number of represented target columns.

packages

(character()) Required packages.

feature_types

(character()) Supported feature types.

properties

(character()) Surrogate properties.

predict_type

(character(1)) Prediction type placeholder.

See also

Other Acquisition Function: AcqFunctionDist, AcqFunctionDistGSx, AcqFunctionDistIDEAL, AcqFunctionDistIGS, AcqFunctionGSy