Local Search — mlr_optimizers_local

Implements a simple Local Search, see local_search() for details. Currently, setting initial points is not supported.

Dictionary

This Optimizer can be instantiated via the dictionary mlr_optimizers or with the associated sugar function opt():

mlr_optimizers$get("local_search")
opt("local_search")

Parameters

The same as for local_search_control(), with the same defaults (except for minimize).

Progress Bars

$optimize() supports progress bars via the package progressr combined with a Terminator. Simply wrap the function in progressr::with_progress() to enable them. We recommend to use package progress as backend; enable with progressr::handlers("progress").

Super classes

Optimizer -> OptimizerBatch -> OptimizerBatchLocalSearch

Methods

Inherited methods

`OptimizerBatchLocalSearch$new()`

Creates a new instance of this R6 class.

Usage

OptimizerBatchLocalSearch$new()

`OptimizerBatchLocalSearch$clone()`

The objects of this class are cloneable with this method.

Usage

OptimizerBatchLocalSearch$clone(deep = FALSE)

Arguments

deep: Whether to make a deep clone.

Examples

# define the objective function
fun = function(xs) {
  list(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")
)

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

# initialize instance
instance = oi(
  objective = objective,
  terminator = trm("evals", n_evals = 20)
)

# load optimizer
optimizer = opt("local_search")

# trigger optimization
optimizer$optimize(instance)
#>          x1        x2  x_domain        y
#>       <num>     <num>    <list>    <num>
#> 1: 1.095615 -3.078378 <list[2]> 9.175946

# all evaluated configurations
instance$archive
#> 
#> ── <ArchiveBatch> - Data Table Storage ─────────────────────────────────────────
#>         x1    x2     y           timestamp batch_nr x_domain_x1 x_domain_x2
#>      <num> <num> <num>              <POSc>    <int>       <num>       <num>
#>   1:    -8  -2.5   -99 2026-09-03 12:11:12        1          -8        -2.5
#>   2:    -4  -0.3   -28 2026-09-03 12:11:12        1          -4        -0.3
#>   3:    -3   0.5   -27 2026-09-03 12:11:12        1          -3         0.5
#>   4:    -2  -2.5    -3 2026-09-03 12:11:12        1          -2        -2.5
#>   5:     2  -2.1     9 2026-09-03 12:11:12        1           2        -2.1
#>  ---                                                                       
#> 106:    -7   0.5   -84 2026-09-03 12:11:13        2          -7         0.5
#> 107:    -8   1.2   -98 2026-09-03 12:11:13        2          -8         1.2
#> 108:    -7   0.9   -86 2026-09-03 12:11:13        2          -7         0.9
#> 109:    -7   2.8  -105 2026-09-03 12:11:13        2          -7         2.8
#> 110:    -9   1.2  -125 2026-09-03 12:11:13        2          -9         1.2

# best performing configuration
instance$result
#>          x1        x2  x_domain        y
#>       <num>     <num>    <list>    <num>
#> 1: 1.095615 -3.078378 <list[2]> 9.175946