Objective interface where user can pass an R function that works on an data.table().

## Super class

bbotk::Objective -> ObjectiveRFunDt

## Active bindings

fun

(function)
Objective function.

## Methods

### Public methods

Inherited methods

### Method new()

Creates a new instance of this R6 class.

#### Usage

ObjectiveRFunDt$new( fun, domain, codomain = NULL, id = "function", properties = character(), constants = ParamSet$new(),
check_values = TRUE
)

#### Arguments

fun

(function)
R function that encodes objective and expects an data.table() as input whereas each point is represented by one row.

domain

Specifies domain of function. The paradox::ParamSet should describe all possible input parameters of the objective function. This includes their id, their types and the possible range.

codomain

Specifies codomain of function. Most importantly the tags of each output "Parameter" define whether it should be minimized or maximized. The default is to minimize each component.

id

(character(1)).

properties

(character()).

constants

Changeable constants or parameters that are not subject to tuning can be stored and accessed here.

check_values

(logical(1))
Should points before the evaluation and the results be checked for validity?

### Method eval_many()

Evaluates multiple input values received as a list, converted to a data.table() on the objective function.

#### Arguments

xdt

(data.table::data.table())
Set of untransformed points / points from the search space. One point per row, e.g. data.table(x1 = c(1, 3), x2 = c(2, 4)). Column names have to match ids of the search_space. However, xdt can contain additional columns.

#### Returns

data.table::data.table()] that contains one y-column for single-criteria functions and multiple y-columns for multi-criteria functions, e.g. data.table(y = 1:2) or data.table(y1 = 1:2, y2 = 3:4).

### Method clone()

The objects of this class are cloneable with this method.

#### Usage

ObjectiveRFunDt\$clone(deep = FALSE)

#### Arguments

deep

Whether to make a deep clone.