如何从学习者那里获得 mlr3 重要性分数？

Question

如何获得重要性分数？我试过这个：

task = tsk("iris")
search_space = ParamSet$new(
  params = list(
  ParamDbl$new(id = "eta", lower = 0.2, upper = .4)))

at = AutoTuner$new(
  learner = lrn("classif.xgboost"),
  resampling = rsmp("holdout"),
  measure = msr("classif.ce"),
  terminator = trm("evals", n_evals = 2),
  tuner = tnr("grid_search"),
  search_space = search_space,
  store_tuning_instance = TRUE)

at$train(task)
at$importance
at$importance()

不过好像不行。

Answer 1

你需要从学习者那里得到重要性，而不是调谐器：

> at$learner$importance()
 Petal.Width Petal.Length 
   0.5028937    0.4971063

如何从学习者那里获得 mlr3 重要性分数？

How to get mlr3 importance scores from learner?

mlr3