matlab实验 用给定的多项式，y=x3-6x2+5x-3，产生一组数据(xi,yi，i=1,2,…,n),再在yi上添加随机干扰(可用rand产生(0,1)均匀分布随机数,或用rands产生N(0,1)分布随机数)，然后用xi和添加了随机干扰的yi作的3次多项式拟合，与原系数比较。

如果作2或4次多项式拟合，结果如何？

-matlab experiment with a given polynomial, y = x3-6x2+5 x-3, generated a set of data (xi, yi, i = 1,2, ..., n), then add random noise in yi (available rand generation (0,1) uniformly distributed random number, or rands generated N (0,1) random numbers), then xi and yi to add a random disturbance polynomial fitting for the three times, compared with the original coefficient . If 2 or 4 times for polynomial fitting, the result?