[BUGLRN] Bugs in learner qda: Error in qda.default(x, grouping, ...) : rank deficiency in group good

[MislavSag]

Expected Behaviour

Learner works as expected.

Actual Behaviour

Training the learner retirns an error:

Error in qda.default(x, grouping, ...) : rank deficiency in group good

Reprex

task_ = tsk("german_credit")
task_$task_type
learner = lrn("classif.qda")
learner$predict_sets = c("train", "test")
learner$predict_type = "prob"
fm = learner$train(task_)

[sebffischer]

Also does not seem to be a mlr3 bug to me

[mllg]

Same problem as in #230, and same solution:

library(mlr3pipelines)
learner = as_learner(ppl("robustify") %>>% lrn("classif.qda"))
learner$param_set$values$encode.method = "treatment"
learner$train(task)
learner$predict(task)