taken from source code for ranger package; not exported with package
parse.formula(formula, data, env = parent.frame())
Object of class formula
or character
describing the model to fit.
Training data of class data.frame
.
The environment in which the left hand side of formula
is evaluated.
Dataset including selected columns and interactions.
Parse formula and return dataset containing selected columns. Interactions are supported for numerical columns only. An interaction column is the product of all interacting columns.