def __distance_valid(self, g0, g1, p):
dist = np.sqrt((g1.x - g0.x) ** <NUM_LIT:2> +<EOL>(g1.y - g0.y) ** <NUM_LIT:2>)<EOL>return dist >= p.min_separation<EOL>
Returns true if the distance between the (x,y) locations of
two generators g0 and g1 is greater than a minimum separation.

Can be extended easily to support other criteria.