const struct variable *w = all_vars[j];
const union value *val_w = case_data (&c, w);
covariance_pass_two (X, *mom[i]->mean, *mom[j]->mean,
const struct variable *w = all_vars[j];
const union value *val_w = case_data (&c, w);
covariance_pass_two (X, *mom[i]->mean, *mom[j]->mean,