利用遗传算法求解函数极值，　　主程序是对函数f(x,y)=x2+y2（-1<x<1,-1<y<1）求解最小值。decod.m 为子函数，实现二进制编码到十进制数的转换功能-Use of genetic algorithm for function extremum, the main program is the minimum value of the function f (x, y) = x2+ y2 (-1 <x <1,-1 <y <1) solution. decod.m Functions, binary-coded to decimal conversion function