main.m

Lagrange插值、Newton插值函数等插值函数

function c=main(n)

x=[-5:10/1000:5];
X=df(-5,5,n);
y=f(X);
y1=f(x);
y2=lx(x,X,y);
b=zeros(1,1000);
for i=500:1000
    e=abs(y1(1,i)-y2(1,i));
    e1=y1(1,i);
    
    if  e/e1<0.01
     b(1,i)=x(1,i);
     else  break;
    end 
end
c=max(b);
plot(x,y1,'r',x,y2,'b')
xlabel('x');
ylabel('f(x)=1/1+x2');
axis([-5 5 min(y2) max(y2)])