-struct covariance * covariance_create (size_t n_vars, const struct variable **vars,
- const struct variable *wv, enum mv_class excl);
+struct covariance * covariance_1pass_create (size_t n_vars, const struct variable *const *vars,
+ const struct variable *wv, enum mv_class excl);
+
+struct covariance *
+covariance_2pass_create (size_t n_vars, const struct variable *const *vars,
+ struct categoricals *cats,
+ const struct variable *wv, enum mv_class excl);