This function calculate candidate splits for each selected variable.
For numerical variables splits are calculated as percentiles
(in general uniform quantiles of the length grid_points).
For all other variables splits are calculated as unique values.
calculate_variable_split(data, variables = colnames(data), grid_points = 101)validation dataset. Is used to determine distribution of observations.
names of variables for which splits shall be calculated
number of points used for response path
A named list with splits for selected variables