Create folds for multi-task and transfer learning
Examples
#--- multi-task learning ---
family <- "binomial"
y <- sim.data.multiple(family=family)$y_train
fold <- make.folds.multi(y=y,family=family)
#--- transfer learning ---
family <- "binomial"
y <- sim.data.transfer(family=family)$y_train
fold <- make.folds.trans(y,family=family)