Asynchronous Optimization via Random Search
Source:R/OptimizerAsyncRandomSearch.R
mlr_optimizers_async_random_search.RdOptimizerAsyncRandomSearch class that implements a simple Random Search.
Source
Bergstra J, Bengio Y (2012). “Random Search for Hyper-Parameter Optimization.” Journal of Machine Learning Research, 13(10), 281–305. https://jmlr.csail.mit.edu/papers/v13/bergstra12a.html.
Dictionary
This Optimizer can be instantiated via the dictionary
mlr_optimizers or with the associated sugar function opt():
Super classes
bbotk::Optimizer -> bbotk::OptimizerAsync -> OptimizerAsyncRandomSearch
Examples
# example only runs if a Redis server is available
if (mlr3misc::require_namespaces(c("rush", "redux", "mirai"), quietly = TRUE) &&
redux::redis_available()) {
# 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$new(
fun = fun,
domain = domain,
codomain = codomain,
properties = "deterministic"
)
# start workers
rush::rush_plan(worker_type = "remote")
mirai::daemons(1)
# initialize instance
instance = oi_async(
objective = objective,
terminator = trm("evals", n_evals = 20)
)
# load optimizer
optimizer = opt("async_random_search")
# trigger optimization
optimizer$optimize(instance)
# all evaluated configurations
instance$archive
# best performing configuration
instance$archive$best()
# covert to data.table
as.data.table(instance$archive)
}
#> state x1 x2 y timestamp_xs pid
#> <char> <num> <num> <num> <POSc> <int>
#> 1: finished -8.6401429 -0.22082921 -110.93643045 2025-10-24 13:34:25 9760
#> 2: finished 2.6451261 -0.47433125 3.20480965 2025-10-24 13:34:25 9760
#> 3: finished 6.6553863 -4.98604438 -15.61699363 2025-10-24 13:34:25 9760
#> 4: finished 5.0158969 -1.16851633 -2.44996658 2025-10-24 13:34:25 9760
#> 5: finished -4.2982254 4.20337792 -81.55629675 2025-10-24 13:34:25 9760
#> 6: finished -5.3318011 3.07859096 -80.70457510 2025-10-24 13:34:25 9760
#> 7: finished -1.2947935 4.44486001 -56.28160502 2025-10-24 13:34:25 9760
#> 8: finished 4.4867714 -4.92985296 0.09163568 2025-10-24 13:34:25 9760
#> 9: finished -4.1477403 2.28072295 -55.68074611 2025-10-24 13:34:25 9760
#> 10: finished -5.6137151 4.91263287 -110.57841706 2025-10-24 13:34:25 9760
#> 11: finished 0.5407374 -0.53103894 1.77478382 2025-10-24 13:34:25 9760
#> 12: finished -5.7833451 -3.39854730 -50.73930118 2025-10-24 13:34:25 9760
#> 13: finished -8.4307422 4.47890861 -154.73445725 2025-10-24 13:34:25 9760
#> 14: finished 7.1022916 -0.75569363 -21.07029075 2025-10-24 13:34:25 9760
#> 15: finished 5.9002467 -2.48642191 -5.47568658 2025-10-24 13:34:25 9760
#> 16: finished 4.0407162 -0.43184476 -0.75994399 2025-10-24 13:34:26 9760
#> 17: finished -7.4830553 -2.92798538 -79.93352300 2025-10-24 13:34:26 9760
#> 18: finished -3.9849409 -1.06526646 -29.56271169 2025-10-24 13:34:26 9760
#> 19: finished -2.3908942 0.02101378 -18.40647620 2025-10-24 13:34:26 9760
#> 20: finished 0.8103813 4.51596998 -47.90499748 2025-10-24 13:34:26 9760
#> state x1 x2 y timestamp_xs pid
#> worker_id timestamp_ys keys
#> <char> <POSc> <char>
#> 1: papery_hog 2025-10-24 13:34:25 9b734495-fd3e-4fc6-8138-577c097d0e5d
#> 2: papery_hog 2025-10-24 13:34:25 d316281e-644d-4718-9e6a-c87407f138b6
#> 3: papery_hog 2025-10-24 13:34:25 e71ab7a0-e0bb-4bfb-8d1b-7c9d9eb15774
#> 4: papery_hog 2025-10-24 13:34:25 493feb58-84af-4a86-a5d6-b54159ce1c61
#> 5: papery_hog 2025-10-24 13:34:25 f804026b-7854-4254-9739-59748e154651
#> 6: papery_hog 2025-10-24 13:34:25 ad3da273-432d-4f52-949a-82808f8d3c56
#> 7: papery_hog 2025-10-24 13:34:25 c77d5d91-520d-4540-8509-6166011a165d
#> 8: papery_hog 2025-10-24 13:34:25 debf4a0b-8abb-49d3-b538-1aa0d478451e
#> 9: papery_hog 2025-10-24 13:34:25 4b8e75e8-3a77-4414-847e-1df935bfff7f
#> 10: papery_hog 2025-10-24 13:34:25 01bde442-c450-4af1-9314-90b57cb108c7
#> 11: papery_hog 2025-10-24 13:34:25 a8c96e17-3a66-4d58-8da1-71ad522e23fb
#> 12: papery_hog 2025-10-24 13:34:25 c98b0774-eedd-4ced-bd7b-e6570fdbb0f6
#> 13: papery_hog 2025-10-24 13:34:25 a6ce2308-2e62-48c3-b423-b3811ce711b7
#> 14: papery_hog 2025-10-24 13:34:25 ae9d9d2c-1d34-4002-8252-5549084624fa
#> 15: papery_hog 2025-10-24 13:34:25 e998dffd-98a7-48fd-952b-d5ecc5902d8d
#> 16: papery_hog 2025-10-24 13:34:26 f1a8a838-fa79-4e02-8a4c-47837dc1ad3c
#> 17: papery_hog 2025-10-24 13:34:26 42564844-b5a9-42db-a418-be21d7343917
#> 18: papery_hog 2025-10-24 13:34:26 f1308bcc-716a-4240-a50c-22de6b6243cb
#> 19: papery_hog 2025-10-24 13:34:26 1b4ba92d-3bd0-4623-bd26-f6477986956b
#> 20: papery_hog 2025-10-24 13:34:26 6386be23-49f5-4ba4-8bbd-79e8b77abeb1
#> worker_id timestamp_ys keys
#> x_domain_x1 x_domain_x2
#> <num> <num>
#> 1: -8.6401429 -0.22082921
#> 2: 2.6451261 -0.47433125
#> 3: 6.6553863 -4.98604438
#> 4: 5.0158969 -1.16851633
#> 5: -4.2982254 4.20337792
#> 6: -5.3318011 3.07859096
#> 7: -1.2947935 4.44486001
#> 8: 4.4867714 -4.92985296
#> 9: -4.1477403 2.28072295
#> 10: -5.6137151 4.91263287
#> 11: 0.5407374 -0.53103894
#> 12: -5.7833451 -3.39854730
#> 13: -8.4307422 4.47890861
#> 14: 7.1022916 -0.75569363
#> 15: 5.9002467 -2.48642191
#> 16: 4.0407162 -0.43184476
#> 17: -7.4830553 -2.92798538
#> 18: -3.9849409 -1.06526646
#> 19: -2.3908942 0.02101378
#> 20: 0.8103813 4.51596998
#> x_domain_x1 x_domain_x2