virtual bool get_list_of_nonlinear_variables(Index num_nonlin_vars,
Index* pos_nonlin_vars)
This method is called by IPOPT only if the limited-memory quasi-Newton options is used, and if the get_number_of_nonlinear_variables method returns a positive number; this number is then identical with num_nonlin_vars and the length of the array pos_nonlin_vars. In this call, you need to list the indices of all nonlinear variables in pos_nonlin_vars, where the numbering starts with 0 order 1, depending on the numbering style determined in get_nlp_info.