sxx               288 core/gps_math.c     rcb->sxx        = 0.0;
sxx               317 core/gps_math.c         rcb->sxx        -= old_x*old_x;
sxx               328 core/gps_math.c         rcb->sxx        += x*x;
sxx               351 core/gps_math.c     det = rcb->n*rcb->sxx - rcb->sx*rcb->sx;
sxx               357 core/gps_math.c     rcb->t = (rcb->sxx*rcb->sy  - rcb->sx * rcb->sxy) / det;
sxx                66 core/gps_math.h     double sxx;