feat: pass parameter values in design

NEWS.md

@@ -1,9 +1,11 @@
 # mlr3batchmark (development version)
 
-* feat: `reduceResultsBatchmark` gains argument `fun` which is passed on to `batchtools::reduceResultsList`, useful for deleting model data to avoid running out of memory, https://github.com/mlr-org/mlr3batchmark/issues/18 Thanks to Toby Dylan Hocking @tdhock for the PR.
-* docs: A warning is now given when the loaded mlr3 version differs from the
-mlr3 version stored in the trained learners
-* Support marshaling
+* feat: The design of `batchmark()` can now include parameter settings.
+* feat: `reduceResultsBatchmark` gains argument `fun` which is passed on to `batchtools::reduceResultsList`.
+Useful for deleting model data to avoid running out of memory.
+Thanks to Toby Dylan Hocking @tdhock for the PR (https://github.com/mlr-org/mlr3batchmark/issues/18).
+* docs: A warning is now given when the loaded mlr3 version differs from the mlr3 version stored in the trained learners
+* feat: support marshaling
 
 # mlr3batchmark 0.1.1
 

R/assertions.R

@@ -0,0 +1,12 @@
+assert_param_values = function(x, n_learners = NULL, .var.name = vname(x)) {
+  assert_list(x, len = n_learners, .var.name = .var.name)
+
+  ok = every(x, function(x) {
+    test_list(x) && every(x, test_list, names = "unique", null.ok = TRUE)
+  })
+
+  if (!ok) {
+    stopf("'%s' must be a three-time nested list and the most inner list must be named", .var.name)
+  }
+  invisible(x)
+}

R/batchmark.R

@@ -35,7 +35,7 @@
 #' reduceResultsBatchmark(reg = reg)
 batchmark = function(design, store_models = FALSE, reg = batchtools::getDefaultRegistry()) {
   design = as.data.table(assert_data_frame(design, min.rows = 1L))
-  assert_names(names(design), permutation.of = c("task", "learner", "resampling"))
+  assert_names(names(design), must.include = c("task", "learner", "resampling"))
   assert_flag(store_models)
   batchtools::assertRegistry(reg, class = "ExperimentRegistry", writeable = TRUE, sync = TRUE,
     running.ok = FALSE)
@@ -53,10 +53,22 @@ batchmark = function(design, store_models = FALSE, reg = batchtools::getDefaultR
     batchtools::addAlgorithm("run_learner", fun = run_learner, reg = reg)
   }
 
-  # group per problem to speed up addExperiments()
+  # set hashes
   set(design, j = "task_hash", value = map_chr(design$task, "hash"))
   set(design, j = "learner_hash", value = map_chr(design$learner, "hash"))
   set(design, j = "resampling_hash", value = map_chr(design$resampling, "hash"))
+
+  # expand with param values
+  if (is.null(design$param_values)) {
+    design$param_values = list()
+  } else {
+    design$param_values = list(assert_param_values(design$param_values, n_learners = length(design$learner)))
+    task = learner = resampling = NULL
+    design = design[, list(task, learner, resampling, param_values = unlist(get("param_values"), recursive = FALSE)), by = c("learner_hash", "task_hash", "resampling_hash")]
+  }
+  design[, "param_values_hash" := map(get("param_values"), calculate_hash)]
+
+  # group per problem to speed up addExperiments()
   design[, "group" := .GRP, by = c("task_hash", "resampling_hash")]
 
   groups = unique(design$group)
@@ -85,13 +97,23 @@ batchmark = function(design, store_models = FALSE, reg = batchtools::getDefaultR
       exports = c(exports, learner_hashes[i])
     }
 
+    param_values_hashes = tab$param_values_hash
+    for (i in which(param_values_hashes %nin% exports)) {
+      batchtools::batchExport(export = set_names(list(tab$param_values[[i]]), param_values_hashes[i]), reg = reg)
+      exports = c(exports, param_values_hashes[i])
+    }
+
     prob_design = data.table(
-      task_hash = task_hash, task_id = task$id,
-      resampling_hash = resampling_hash, resampling_id = resampling$id
+      task_hash = task_hash,
+      task_id = task$id,
+      resampling_hash = resampling_hash,
+      resampling_id = resampling$id
     )
 
     algo_design = data.table(
-      learner_hash = learner_hashes, learner_id = map_chr(tab$learner, "id"),
+      learner_hash = learner_hashes,
+      learner_id = map_chr(tab$learner, "id"),
+      param_values_hash = param_values_hashes,
       store_models = store_models
     )
 

R/reduceResultsBatchmark.R

@@ -1,8 +1,7 @@
 #' @title Collect Results from batchmark
 #'
 #' @description
-#' Collect the results from jobs defined via [batchmark()] and combine them into
-#' a [mlr3::BenchmarkResult].
+#' Collect the results from jobs defined via [batchmark()] and combine them into a [mlr3::BenchmarkResult].
 #'
 #' Note that `ids` defaults to finished jobs (as reported by [batchtools::findDone()]).
 #' If a job threw an error, is expired or is still running, it will be ignored with this default.

R/worker.R

@@ -1,7 +1,10 @@
-run_learner = function(job, data, learner_hash, store_models, ...) {
+run_learner = function(job, data, learner_hash, param_values_hash, store_models, ...) {
   workhorse = utils::getFromNamespace("workhorse", ns = asNamespace("mlr3"))
   resampling = get(job$prob.pars$resampling_hash, envir = .GlobalEnv)
   learner = get(learner_hash, envir = .GlobalEnv)
+  param_values = get(param_values_hash, envir = .GlobalEnv)
+
+  if (!is.null(param_values)) learner$param_set$set_values(.values = param_values)
 
   workhorse(
     iteration = job$repl,

tests/testthat/test_batchmark.R

@@ -97,3 +97,32 @@ test_that("marshaling", {
   expect_true(bmr_marshaled$resample_result(1)$learners[[1]]$marshaled)
   expect_false(bmr_unmarshaled$resample_result(1)$learners[[1]]$marshaled)
 })
+
+test_that("adding parameter values works", {
+  tasks = tsks(c("iris", "spam"))
+  resamplings = list(rsmp("cv", folds = 3)$instantiate(tasks[[1]]))
+  learners = lrns("classif.debug")
+
+  design = data.table(
+    task = tasks,
+    learner = learners,
+    resampling = resamplings,
+    param_values = list(list(list(x = 1), list(x = 0.5))))
+
+  reg = batchtools::makeExperimentRegistry(NA, make.default = FALSE)
+
+  ids = batchmark(design, reg = reg)
+  expect_data_table(ids, ncol = 1L, nrows = 12L)
+  ids = batchtools::submitJobs(reg = reg)
+  batchtools::waitForJobs(reg = reg)
+  expect_data_table(ids, nrows = 12)
+
+  logs = batchtools::getErrorMessages(reg = reg)
+  expect_data_table(logs, nrows = 0L)
+  results = reduceResultsBatchmark(reg = reg)
+  expect_is(results, "BenchmarkResult")
+  expect_benchmark_result(results)
+  expect_data_table(as.data.table(results), nrow = 12L)
+  expect_equal(results$learners$learner[[1]]$param_set$values$x, 1)
+  expect_equal(results$learners$learner[[2]]$param_set$values$x, 0.5)
+})