Stiffness coefficient
From FLUX
The stiffness coefficient (in FLUX) is the ratio of the magnitude-of-sum to sum-of-magnitudes of the component forces acting on a vertex, or the average of that number across all vertices. It is a unitless number indicating the quality of the null achieved by force balance. It is unfortunately named as the stiffness is something like the reciprocal of the actual "stiffness coefficient".
A system in perfect force balance would have a stiffness coefficient of 0. Typical simulations of simple systems are relaxed to a stiffness of 10 − 3 or lower.
