ID variables recording NM information, from names and positions in the variable list. Presumption is that the NM cols appear at the end of the list of vars and are encased in ‘()’. If something in the code changes to make this assumption untrue, then this helper is designed to err on the side of not identifying other columns as NM cols.
identify_NM_vars(vnames)
character vector of names of NM vars, possibly of length 0
character, variable names
Hansen