A list containing the input data, split into testing and training
sets. If ratio
is greater than one, returns a list with ratio
entries, each with 1/ratio
of the input data in the testing set
(data.out
) and the rest in the training set (data.in
).
Otherwise, returns a list with one split of the data, with ratio
of
the input data in the testing set and the rest in the training set.