data_partition(y, p = 0.5, groups = min(5, length(y)))
y
, the number of breaks in the quantiles
(see below)data_partition
creates a test/training partition.
The random sampling is done within the levels of y
when y
is a
factor in an attempt to balance the class distributions within the splits.
For numeric y
, the sample is split into groups sections based on
percentiles and sampling is done within these subgroups. The number of
percentiles is set via the groups
argument.
Also, very small class sizes (<= 3) the classes may not show up in both the training and test data
createDataPartition
function by Max Kuhn