Codomain: Codomain of Function

In bbotk: Black-Box Optimization Toolkit

Codomain of Function

Description

A paradox::ParamSet defining the codomain of a function. The parameter set must contain at least one target parameter tagged with "minimize" or "maximize". The codomain may contain extra parameters which are ignored when calling the Archive methods ⁠$best()⁠, ⁠$nds_selection()⁠ and ⁠$cols_y⁠. This class is usually constructed internally from a paradox::ParamSet when Objective is initialized.

Super class

paradox::ParamSet -> Codomain

Active bindings

is_target

(named logical())
Position is TRUE for target parameters.

target_length

(integer())
Returns number of target parameters.

target_ids

(character())
IDs of contained target parameters.

target_tags

(named list() of character())
Tags of target parameters.

maximization_to_minimization

(integer())
Returns a numeric vector with values -1 and 1. Multiply with the outcome of a maximization problem to turn it into a minimization problem.

direction

(integer())
Returns 1 for minimization and -1 for maximization. If the codomain contains multiple parameters an integer vector is returned. Multiply with the outcome of a maximization problem to turn it into a minimization problem.

Methods

Public methods

• Codomain$new()

• Codomain$clone()

Inherited methods

• paradox::ParamSet$add_dep()
• paradox::ParamSet$aggr_internal_tuned_values()
• paradox::ParamSet$assert()
• paradox::ParamSet$assert_dt()
• paradox::ParamSet$check()
• paradox::ParamSet$check_dependencies()
• paradox::ParamSet$check_dt()
• paradox::ParamSet$convert_internal_search_space()
• paradox::ParamSet$disable_internal_tuning()
• paradox::ParamSet$flatten()
• paradox::ParamSet$format()
• paradox::ParamSet$get_domain()
• paradox::ParamSet$get_values()
• paradox::ParamSet$ids()
• paradox::ParamSet$print()
• paradox::ParamSet$qunif()
• paradox::ParamSet$search_space()
• paradox::ParamSet$set_values()
• paradox::ParamSet$subset()
• paradox::ParamSet$subspaces()
• paradox::ParamSet$test()
• paradox::ParamSet$test_constraint()
• paradox::ParamSet$test_constraint_dt()
• paradox::ParamSet$test_dt()
• paradox::ParamSet$trafo()

---

Method new()

Creates a new instance of this R6 class.

Usage

Codomain$new(params)

Arguments

params

(list())
Named list with which to initialize the codomain. This argument is analogous to paradox::ParamSet's ⁠$initialize()⁠ params argument.

---

Method clone()

The objects of this class are cloneable with this method.

Usage

Codomain$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Examples

# define objective function
fun = function(xs) {
  c(y = -(xs[[1]] - 2)^2 - (xs[[2]] + 3)^2 + 10)
}

# set domain
domain = ps(
  x1 = p_dbl(-10, 10),
  x2 = p_dbl(-5, 5)
)

# set codomain
codomain = ps(
  y = p_dbl(tags = "maximize"),
  time = p_dbl()
)

# create Objective object
objective = ObjectiveRFun$new(
  fun = fun,
  domain = domain,
  codomain = codomain,
  properties = "deterministic"
)

bbotk documentation built on Nov. 5, 2025, 6:23 p.m.