The set of hyperparameter combinations a grid search would fit, one per row.
Derived from the object, so it can be inspected before train() is called.
Value
data.frame with one row per combination and one column per searched hyperparameter, or NULL if nothing needs tuning.
Details
The grid is the cross product of the search values, reduced by two rules:
A hyperparameter that declares it applies only under certain values of another is set to
NA– meaning "left unset for this fit" – in the rows that do not meet them.reduce_basisapplies only atsmoothness_ordersof 0, so a search over both drops it from the higher-order rows.Rows that become identical once that is done are collapsed, so a combination is never fit, scored, and ranked twice.
tune_GridSearch() fits exactly these rows, so what this prints is what will
run.