Accessors and indexers for the different parts of a fold.

training(x = NULL, fold = NULL)

validation(x = NULL, fold = NULL)

fold_index(x = NULL, fold = NULL)



an object to be indexed by a training set, validation set, or fold index. If missing, the index itself will be returned.


Fold; the fold used to do the indexing. If missing, fold will be pulled from the calling environment, if available.


The elements of x corresponding to the indexes, or the indexes themselves if x is missing.

See also