[jimmymacong]

确实没错啊，可以运行，而且得出结果，你试试下面的代码：
clear;clc
x=[0 1 2 3 4 5 6 7 8 9 1];
y=[0.477 1.978 3.28 6.16 7.08 7.34 7.66 9.56 9.48 9.30 11.2];
n=8;
p1=polyfit(x,y,n);
ss=poly2sym(p1);
pretty(ss)
vpa(ss)

得出的结果是：
- 0.00038518087888714822118046976484607*x^8 + 0.016239022598897725341293707401746*x^7 - 0.2821541659851403149872339781723*x^6 + 2.6007540809777962564908193598967*x^5 - 13.616809602141747959080930741038*x^4 + 40.07975689105651184718226431869*x^3 - 60.816024242565539736915525281802*x^2 + 38.117530390299357634376065107062*x + 0.47938051029589218154924878945167