Make List of Folds for cross-validation

Generates a list of folds for a variety of cross-validation schemes.

make_folds(
  n = NULL,
  fold_fun = folds_vfold,
  cluster_ids = NULL,
  strata_ids = NULL,
  ...
)

Arguments

n: - either an integer indicating the number of observations to cross-validate over, or an object from which to guess the number of observations; can also be computed from strata_ids or cluster_ids.
fold_fun: - A function indicating the cross-validation scheme to use. See fold_funs for a list of possibilities.
cluster_ids: - a vector of cluster ids. Clusters are treated as a unit -- that is, all observations within a cluster are placed in either the training or validation set.
strata_ids: - a vector of strata ids. Strata are balanced: insofar as possible the distribution in the sample should be the same as the distribution in the training and validation sets.
...: other arguments to be passed to fold_fun.

A list of folds objects. Each fold consists of a list with a

training index vector, a validation index vector, and a

fold_index (its order in the list of folds).