/* Return strcmp()-type comparison of the MX->n_factors factors at _A and
_B. Sort missing values toward the end. */
static int
/* Return strcmp()-type comparison of the MX->n_factors factors at _A and
_B. Sort missing values toward the end. */
static int
struct factor_data *const *pa = a_;
struct factor_data *const *pb = b_;
const double *a = (*pa)->factors;
struct factor_data *const *pa = a_;
struct factor_data *const *pb = b_;
const double *a = (*pa)->factors;