matlab 最小二乘法拟合函数

x=[0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1];
y=[-0.447,1.978,3.28,6.16,7.08,7.34,7.66,9.56,9.48,9.30,11.2];
a=polyfit(x,y,1);
x1=0:0.1:1;
y1=a(1)*x1+a(2); 
plot(x,y,'*',x1,y1,'r')

b=polyfit(x,y,2);
x2=0:0.1:1;
y2=b(1)*x2.^2+b(2)*x2+b(3);
plot(x,y,'*',x2,y2,'r')

 

 

c=polyfit(x,y,5);
x3=0:0.1:1;
y3=c(1)*x3.^5+c(2)*x3.^4+c(3)*x3.^3+c(4)*x3.^2+c(5)*x3+c(6);
plot(x,y,'*',x3,y3,'-r')