two_validation_set_cv: V-fold cross-validation with two validation sets
Description
Set up V-fold cross-validation, where rather than the usual train/test split
for each fold, now there are two test datasets. In practice, this means that
each datum is in the training data V - 2 times, in the first test set once,
and in the second test set once.
Usage
two_validation_set_cv(n, V)
Arguments
n
the sample size
V
the number of folds
Value
an n by V matrix containing the train/test set 1/test set 2 data for each fold.
Details
This method is only different from V-fold cross-validation by how much data is used in the training sample,
and the fact that two validation samples are needed. Specifically, in two-validation-set V-fold CV, n/V fewer observations are used in training than in V-fold CV. These n/V observations are used in the second validation set.