fga.m  为遗传算法的主程序   采用二进制Gray编码,采用基于轮盘赌法的非线性排名选择,  均匀交叉,变异操作,而且还引入了倒位操作!-Fga.m main program for the genetic algorithm　binary gray encoding, use based on roulette method of non-linear ranking selection, uniform crossover, mutation, and also introduced the inversion operation.