sxy               289 core/gps_math.c     rcb->sxy        = 0.0;
sxy               318 core/gps_math.c         rcb->sxy        -= old_x*old_y;
sxy               329 core/gps_math.c         rcb->sxy        += x*y;
sxy               356 core/gps_math.c     rcb->s = (rcb->n * rcb->sxy - rcb->sx * rcb->sy ) / det;
sxy               357 core/gps_math.c     rcb->t = (rcb->sxx*rcb->sy  - rcb->sx * rcb->sxy) / det;
sxy                65 core/gps_math.h     double sxy;