Connect learner h2o from package h2o

[be-marc]

CRAN

[ck37]

Should this move to mlr3extralearners?

And would it be a single learner for all h2o algorithms, or a separate learner for each algorithm?

[sebffischer]

Great question. Maybe this should even be a own repository, e.g. mlr3h2o. I guess this should be different learners. I am not familiar with h2o but I guess they have different parameters, so this would be necessary?

I don't think we currently have the bandwidth to implement this / focus on other features, so don't expect any progress on this anytime soon. Are you familiar with these learners and interested with giving this a try? At least some of these learners are connected in mlr (mlr3's predecessor) so one could at least partially re-use this code.

[ck37]

I may write a wrapper or two - esp. for lasso since I believe h2o's makes much better use of multithreading compared to glmnet. I unfortunately don't have the capacity to maintain a separate package so I will probably propose it in mlr3extralearners, taking the recent RWeka PR as inspiration.