Container around a data.table::data.table which stores all performed function calls of the Objective.

## S3 Methods

• as.data.table(archive)
Archive -> data.table::data.table()
Returns a tabular view of all performed function calls of the Objective. The x_domain column is unnested to separate columns.

## Public fields

search_space

Search space of objective.

codomain

Codomain of objective function.

start_time

(POSIXct)
Time stamp of when the optimization started. The time is set by the Optimizer.

check_values

(logical(1))
Determines if points and results are checked for validity.

data

(data.table::data.table)
Contains all performed Objective function calls.

store_x_domain

(logical(1))
Determines if x values, should be stored in $data$x_domain as list items. The trafo will be applied if defined in search_space.

## Active bindings

n_evals

(integer(1))
Number of evaluations stored in the archive.

n_batch

(integer(1))
Number of batches stored in the archive.

cols_x

(character())
Column names of search space parameters.

cols_y

(character())
Column names of codomain parameters.

## Methods

### Method new()

Creates a new instance of this R6 class.

#### 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.

xss_trafoed

(list())
Transformed point(s) in the domain space. Not stored and needed if store_x_domain = FALSE.

ydt

(data.table::data.table())
Optimal outcome.

### Method best()

Returns the best scoring evaluation. For single-crit optimization, the solution that minimizes / maximizes the objective function. For multi-crit optimization, the Pareto set / front.

Printer.

### Method clone()

The objects of this class are cloneable with this method.

#### Usage

Archive\$clone(deep = FALSE)

#### Arguments

deep

Whether to make a deep clone.