x =[10111213141516171819202122232425];
y =[19241825202837403020152623171417];plot(x,y,'*');
hold on
y1 =polyfit(x,y,1);
f1 =poly2sym(y1);
y2 =polyfit(x,y,2);
f2 =poly2sym(y2);
y3 =polyfit(x,y,3);
f3 =poly2sym(y3);fplot(f1,'r');fplot(f2,'b');fplot(f3,'k');axis([10251045]);