Internal helper function that evaluates tidyselect expressions for dependent and independent variables, returning their column positions in the data frame.
evaluate_variable_selection(data, dep, indep)A list with two named elements:
dep_pos: Named integer vector of column positions for dependent variables
indep_pos: Named integer vector of column positions for independent variables
A data frame containing the variables to be selected
Quosure or tidyselect expression for dependent variables
Quosure or tidyselect expression for independent variables