typedef double (*subplex_func)(int n, const double *x, void *func_data);
-extern int subplex(subplex_func f, double *minf, double *x, int n, void *fdata,
+extern int nlopt_subplex(subplex_func f, double *minf, double *x, int n, void *fdata,
nlopt_stopping *stop,
const double *scale);