May i ask stupid question. Why roc curves are under diagonal in benchmark case, and above diagonal in another.
library(mlr3verse)
library(mlr3viz)
task = tsk("german_credit")
design = benchmark_grid(
tasks = task,
learners = lrns(c("classif.ranger", "classif.rpart", "classif.featureless"),
predict_type = "prob", predict_sets = c("train", "test")),
resamplings = rsmps("cv", folds = 3)
)
# Roc curve under diagonal ----------------------------
bmr = benchmark(design)
autoplot(bmr, type = "roc")
# Roc curve above diagonal ----------------------------
learner = lrn("classif.rpart", predict_type = "prob")
pred = learner$train(task)$predict(task)
autoplot(pred, type = "roc")
