下面是一个简单的MATLAB编程， 编译时出现了下面的Warning，哪位高手能看看怎么修改可以消除Warnning

主要是是对一些数据进行拟合，并画出曲线。程序如下： t=1:9;
x=[12.51,13.54,15.60,15.92,20.64,24.53,30.24,50.00,36.34];
y=[9.87,20.54,32.51,40.50,48.31,64.51,72.22,85.98,89.77];
a8=polyfit(t,x,8);
b8=polyfit(t,y,8);
ti=linspace(1,9);
xi8=polyval(a8,ti);
yi8=polyval(b8,ti);
plot(t,x,'o',ti,xi8,'k')
hold on;
plot(t,y,'*',ti,yi8,'k')

Warning: Polynomial is badly conditioned. Remove repeated data points
or try centering and scaling as described in HELP POLYFIT.
> In polyfit at 79
Warning: Polynomial is badly conditioned. Remove repeated data points
or try centering and scaling as described in HELP POLYFIT.
> In polyfit at 79

可以画出图形如上：为什么可以作图，他还出现警告了，哪位高手知道怎样修改，使它变得更加完美，没有Warning.

t=1:9;
x=[12.51,13.54,15.60,15.92,20.64,24.53,30.24,50.00,36.34];
y=[9.87,20.54,32.51,40.50,48.31,64.51,72.22,85.98,89.77];
a8=polyfit(t,x,7);
b8=polyfit(t,y,7);
ti=linspace(1,9);
xi8=polyval(a8,ti);
yi8=polyval(b8,ti);
plot(t,x,'o',ti,xi8,'k')
hold on;
plot(t,y,'*',ti,yi8,'k')

警告是告诉你，你不需要用8价函数就可以完美拟合，所以，降到7价就不报错了

在Command Window中输入>>help polyfit 试着按照他上边的提示位置看看做相应的修改吧!